The phenomenon of the “traveling wave,” commonly observed in various organisms, involves a wave that propagates along the body, serving as a locomotion mechanism. Particularly, in aquatic environments, organisms such as fish and cetaceans utilize traveling waves to propel themselves through water, minimizing fluid drag and maximizing movement efficiency. Inspired by nature, robotics has extensively explored replicating such locomotion strategies. This work presents a fish robot with an innovative magnetic transmission system. The mechanism transforms the unidirectional rotation of a single motor into an oscillatory, phase-shifted movement across the modules of the kinematic chain, generating a traveling wave along the body. The robot's design and functionality are detailed, highlighting advancements in bio-inspired robotics for underwater applications, such as efficient and non-invasive monitoring and exploration of marine ecosystems. The fish robot achieved a swimming speed of approximately 2 body lengths per second (BL/s) with a tail-beat frequency of 3.24 Hz and a minimum Cost of Transport (CoT) of$5.33 ~\mathrm{J} /(\text{kg} \cdot \mathrm{m})$. Biomimetic robotics can play a key role in sustainable aquafarming, biodiversity conservation, and animal-robot interaction research, offering the potential to minimize ecosystem disruption and advance marine science.

Biomimetic robotics can help support underwater exploration and monitoring while minimizing ecosystem distur-bance. It also has potential applications in sustainable aqua-farming management, biodiversity preservation, and animal-robot interaction studies. This study proposes a bio-inspired control strategy for an underactuated robotic fish, which utilizes a single DC motor to drive a mechanism that converts the motor's oscillating motion into an oscillatory motion of the robotic fishtail through a magnetic coupling and a wire-driven system. The proposed control strategy for the robotic fish is based on central pattern generators (CPGs) and incorporates proprioceptive sensory feedback. The torque exerted on the fishtail is adjusted based on its position, allowing for increased or decreased body speed and steering with different angular speeds and radii of curvature despite the underactuated design. The robotic fish can vary the swimming speed of 0.08 body lengths per second (BL/s) with a related change in the tail-beating frequency up to 2.3 Hz, and it can vary the steering angular speed in the range of 0.08 rad/s with a relative change in the curvature radius of 0.25 m. The controller can adapt to changes in tail structure, weight, or the surrounding environment based on the proprioceptive feedback. Design changes to the modular design can improve speed and steering performances, maintaining the control strategy developed.

As a traditional movement assist equipment for people with lower-limb dysfunction, the wheelchair can support and carry users to perform a long-distance movement indoor and outdoor, however, prolonged inactivity can lead to muscle atrophy and deteriorate motion functions. As a promising solution, the lower limb exoskeleton provides people the ability of standing and walking to avoid these problems. However, the exoskeleton has inevitable shortcomings in long-distance movement and balance, which do not exist in a wheelchair. To integrate the advantages of both devices, in this paper, we proposed a wheelchair-exoskeleton hybrid robot (WeHR) that can not only provide users long-time support and long-distance movement but also provide walking training and keep self-balance. Moreover, motion transitions such as sit-to-stand and stand-to-sit can also be implemented by the newly proposed device without help from caregivers. We have developed the prototype to implement the above functions. In this paper, we emphasize the strategy of motion transition including two trajectory planning methods for the Sit-To-Stand (STS) process as well as the mechanism design to implement it. Furthermore, the preliminary experiments of motion transition and walking test are also conducted and the results prove that our device can support users sitting, standing, and walking and the motion transition.

Quality control in industry involves trained operators to manipulate and inspect metallic surfaces in order to identify, and eventually correct, manufacturing defects. These tasks are manually performed, and a poor performance (e.g., missing defects) leads to an increase of the costs and prolongation of the manufacturing time cycle. In this work, we propose a multi-agent robotic platform to autonomously perform Industry 4.0 quality control processes of metallic surfaces. The platform consists of three anthropomorphic robots with custom-made end-effectors designed to manipulate, inspect, and eventually correct a metallic frame of a motorcycle. The description of a novel multi-agent platform is followed by the presentation of the developed inspection procedure, in which a linear laser scanner is used to reconstruct the three-dimensional metallic surface of a motorcycle with a resolution of ~0.1 mm. In order to validate the platform, we perform a set of experiments to assess the performance of the robotic platform in a real Industry 4.0 scenario. Results confirmed that such a system guarantees a sub-millimetric precision to identify defects on complex-shaped metallic surfaces and effectively correct them. The proposed robotic platform can be adopted for overcoming the drawbacks of a traditional procedure that relies on visual-tactile manual defects correction (e.g., low-repeatability, high-subjectivity) and is scalable to different industrial applications. The proposed approach aims to elevate the role of operators to expert supervisors of the process, limiting the interactions with potentially-dangerous tools/procedures and thus improving the working conditions in an industrial 4.0 scenario.Note to Practitioners—This work was motivated by a crucial need in industry,i.e.to automatize the manufacturing quality control, translating the commonly-used visual-based manual approach performed by operators to an objective robotic one that relies on defect detection by using a linear laser scanner. A novel multi-agent robotic platform, developed by the authors, showed its effectiveness in automatizing complex tasks, in which huge workspace and different tools are required. The aim of the paper was to develop a fully automatized application that covers the entire quality control process, while focusing on one specific phase,i.e.automatic inspection. The integrated software and the infrastructural communication protocols of the entire robotic platform were designed to be flexible in order to realize a new reference for industrial applications, where a multi-agent approach is demanded. The experimental validation focused on a specific use case (a motorcycle frame selected due to its complex structure,i.e.multiple curvatures with variable radii, and large volumes), but the proposed platform and the implemented methodology have to be intended as a general purpose approach, adaptable to any industrial process and mechanical component. The authors, starting by a laboratory development with extensive tests, applied and demonstrated the feasibility of the proposed approach in a real Industry 4.0 scenario.

This IEEE Transactions on Automation Science and Engineering (T-ASE) Special Section on New Frontiers in Smart Factories: Smart Automation and Human–Robot Interaction focuses on promising, innovative research outcomes and industrial applications of different key technologies for smart automation and human–robot interaction.

Foodservice workers perform several burdensome, tedious, and unsafe tasks that risk their health and well-being. This could be mitigated or even more avoided by using autonomously-actuated machines. Therefore, this article aims to build the foundation to support the development of a new field of robotics research dedicated to foodservice and with a human/worker-centered framework. As so, we introduce a two-level taxonomy of basic actions that compose the physical tasks of foodservice workers; it can guide future studies to design bio-inspired control models for foodservice robots. Actions are clustered in 16 categories according to their purpose and to the handled food. Furthermore, authors make a critical review of single-action equipment (SAE) and advanced equipment (AE) currently available for foodservice, which allowed us to identify opportunities for research. As a result, authors found some categories of actions rarely automated, aimed at i) separating solid-solid food parts, ii) moving food between workstations or independent appliances in the kitchen, iii) introducing food into another solid food or recipient, and iv) other specific actions, e.g. trussing food. In addition, authors discuss the applicability of collaborative robotics and human-robot collaboration to different contexts in foodservice, and show how artificial intelligence is improving the capabilities of SAE and AE and what else it could improve in this context.Note to Practitioners—This paper was motivated by a critical need in foodservice: the ability to produce consistent and high-quality meals ad-hoc, without overloading the workers or harming their health. Robotic and autonomous systems are promising technologies to solve this. However, there is not a unified framework in robotics research focused on the professional foodservice environment. This paper provides two tools for researchers and engineers in this field: (i) a taxonomy of basic actions that foodservice workers perform during their physical tasks; and (ii) a systematic review of mechatronic systems being developed or already in use in foodservice. The taxonomy can be immediately useful to divide research and development by the classes of actions. In addition, we found specific categories of actions that have been rarely automated so far and need further investigation. The results of our review can be readily applied in industry, too: presently, most equipment is a custom-built machine with limited adaptiveness; when systems include industrial robots, cobots are being preferred; the implementation of collaborative operations between humans and robots is not common yet and its applicability may be suitable only for certain contexts; finally, we identify scientific publications introducing adaptive control strategies and movement policies for some actions that can be implemented today to achieve a more robust actuation.

The study of cooking tasks, such as grilling, is hindered by several adverse conditions for sensors, such as the proximity to humidity, fat, and heat. Still, robotics research could benefit from understanding the human control of forces and torques in important contact interactions of kitchen-utensils with food. This work presents a preliminary study on the dynamics of grilling tasks (i.e. food flipping movements). A spatula and kitchen-tweezers were instrumented to measure forces and torque in multiple directions. Furthermore, we designed an experimental setup to keep sensors distant from heat/humidity and to, simultaneously, hold the effects of grilling (stickiness/slipperiness) during the tasks execution and recording. This allowed a successful data collection of 1426 movements with the spatula (flipping hamburgers, chicken, zucchini and eggplant slices) and 660 movements with the tweezers (flipping zucchini and eggplant slices), performed by chefs and ordinary home cooks. Finally, we analyzed three dynamical characteristics of the tasks for the different food: bending force and torsion torque on the impact to unstick food, and maximum pinching with tweezers. We verified that bending on impact and maximum pinching are adjusted to the food by both chefs and home cooks.

The research on rare cells makes a significant contribution to biology research and medical treatment for the application of diagnostic operation as well as prognoses treatment. Therefore, sorting them from heterogeneous mixtures is crucial and valuable. Traditional cell sorting methods featured with poor purity and recovery rate as well as limited flexibility, which are not ideal approaches for rare type. In this paper, we proposed a cell screening method based on automated microrobotic aspiration-and-placement strategy under fluorescence microscope. An innovative autofocusing visual feedback (AVF) method is proposed for precise three-dimensional (3D) locating of target cells. For depth detection, multiple depth from defocus (MDFD) method is adopted to solve symmetry problem and attain an average accuracy of 97.07%. For planar locating, Markov random field (MRF) based locating method is utilized to separate and locate the overlapped cells. The end actuator locating and real-time tracking are performed relying on normalized cross-correlation (NCC) method. Experiential results show that our system collects rare cells (100 cells ml-1) at a speed of 5 cells min-1with 90% purity and 75% recovery rate, which is valuable for biological and medical application.

Human activity recognition is an important and active field of research having a wide range of applications in numerous fields including ambient‐assisted living (AL). Although most of the researches are focused on the single user, the ability to recognise two‐person interactions is perhaps more important for its social implications. This study presents a two‐person activity recognition system that uses skeleton data extracted from a depth camera. The human actions are encoded using a set of a few basic postures obtained with an unsupervised clustering approach. Multiclass support vector machines are used to build models on the training set, whereas the X ‐means algorithm is employed to dynamically find the optimal number of clusters for each sample during the classification phase. The system is evaluated on the Institute of Systems and Robotics (ISR) ‐ University of Lincoln (UoL) and Stony Brook University (SBU) datasets, reaching overall accuracies of 0.87 and 0.88, respectively. Although the results show that the performances of the system are comparable with the state of the art, recognition improvements are obtained with the activities related to health‐care environments, showing promise for applications in the AL realm.

Daily activity recognition can help people to maintain a healthy lifestyle and robot to better interact with users. Robots could therefore use the information coming from the activities performed by users to give them some custom hints to improve lifestyle and daily routine. The pervasiveness of smart things together with advances in cloud robotics can help the robot to perceive and collect more information about the users and the environment. In particular thanks to the miniaturization and low cost of Inertial Measurement Units, in the last years, body-worn activity recognition has gained popularity. In this work, we investigated the performances with an unsupervised approach to recognize eight different gestures performed in daily living wearing a system composed of two inertial sensors placed on the hand and on the wrist. In this context our aim is to evaluate whether the system is able to recognize the gestures in more realistic applications, where is not possible to have a training set. The classification problem was analyzed using two unsupervised approaches (K-Mean and Gaussian Mixture Model), with an intra-subject and an inter-subject analysis, and two supervised approaches (Support Vector Machine and Random Forest), with a 10-fold cross validation analysis and with a Leave-One-Subject-Out analysis to compare the results. The outcomes show that even in an unsupervised context the system is able to recognize the gestures with an averaged accuracy of 0.917 in the K-Mean inter-subject approach and 0.796 in the Gaussian Mixture Model inter-subject one.

In this paper we present the design and characterization of a novel Passive Variable Stiffness Joint (pVSJ). pVSJ is the proof of concept of a passive revolute joint with controllable variable stiffness. The current design is intended to be a bench-test for future development towards applications in haptic teleoperation purposed exoskeletons. The main feature of the pVSJ is its capability of varying the stiffness with infinite range based on a simple mechanical system. Moreover, the joint can rotate freely at the zero stiffness case without any limitation. The stiffness varying mechanism consists of two torsional springs, mounted with an offset from the pVSJ rotation center and coupled with the joint shaft by an idle roller. The position of the roller between the pVSJ rotation center and the spring's center is controlled by a linear sliding actuator fitted on the chassis of the joint. The variation of the output stiffness is obtained by changing the distance from the roller-springs contact point to the joint rotation center (effective arm). If this effective arm is null, the stiffness of the joint will be zero. The stiffness increases to reach high stiffness values when the effective arm approaches its maximum value, bringing the roller close to the torsional springs' center. The experimental results matched with the physical-based modeling of the pVSJ in terms of stiffness variation curve, stiffness dependency upon the springs' elasticity, joint deflection and the spring's deflection.

This paper presents a work on mapping the use of space by humans in long periods of time. Daily geometric maps with the same coordinate frame were generated with SLAM, and in a similar manner, daily affordance density maps (places people use) were generated with the output of a human tracker running on the robot. The contribution of the paper is two-fold: an approach to detect geometric changes to cluster them in similar geometric configurations and the building of geometric and affordance composite maps on each cluster. This approach avoids the loss of long term retrieved information. Geometric similarity was computed using a normal distance approach on the maps. The analysis was performed on data collected by a mobile robot for a period of 4 months accumulating data equivalent to 70 days. Experimental results show that the system is capable of detecting geometric changes in the environment and clustering similar geometric configurations.

In this paper we present the design and technical implementation of a web based Multi-Modal User Interface (MMUI) tailored for elderly users of the robotic services developed by the EU FP7 Large-Scale Integration Project Robot-Era. The project partners are working to significantly enhance the performance and acceptability of technological services for ageing well by delivering a fully realized system based on the cooperation of multiple heterogeneous robots and with the support of an Ambient Assisted Living environment. To this end, elderly users were involved in the definition of the services and in the design of the hardware and software of the robotic platforms from the first stages of the development process and in real experimentation in two test sites. In particular, here we detail the interface software system for multi-modal elderly-robot interaction. The MMUI is designed to run on any device including touch-screen mobiles and tablets that are preferred by the elderly. This is obtained by integrating web based solutions with the Robot-Era middlewares and planner. Finally we present some preliminary results of ongoing experiments to show the successful evaluation of usability by potential users and to discuss the future directions to improve the proposed MMUI software system.

Micro-technologies based on wirelessly powered and manoeuvred submillimeter device, i.e.,microrobots, are attracting growing attention. Their application in lab-on-a-chip systems, such as micromanipulation and in vitro cell sorting, is expected to steeply increase. However, the actuation, powering and control of microrobots are challenges that still need concrete solutions. Magnetic fields generally enable wireless navigation of microrobots, but proper control architectures and magnetic navigation systems are needed, depending on the specific task and on the level of interaction required to the user. Here we present a magnetic navigation platform intended for lab-on-a-chip applications and we address its usability with different levels of human involvement by using two control architectures: teleoperated and autonomous. We perform an experimental analysis to demonstrate that both architectures, enrolling different levels of interaction by the user, lead to reliable execution of the microrobotic task. First, we validate the open-loop response of the microrobotic system, and second, we evaluate the performance of the system by testing both control architectures with a standard mobility task. The results show that users can teleoperate the microrobot with 100% success rate, in 14.4±1.9s with a normalized spatial mean error of 0.60±0.13. Moreover, results show a fast decaying learning curve for the users involved in the study. Compared to this, when the navigation task is performed by the autonomous control, 100% success rate, a time of 8.0±0.5s and a normalized spatial mean error of 0.50±0.05 are obtained. Finally, we quantitatively demonstrate how both control methodologies enable very smooth movements of the microrobot, suggesting application for any task where repeatable and dexterous movements in liquid microenvironments are key requirements.

This paper presents the full experience of designing, developing and testing ASTROMOBILE, a system composed of an enhanced robotic platform integrated in an Ambient Intelligent (AmI) infrastructure that was conceived to provide favourable independent living, improved quality of life and efficiency of care for senior citizens. The design and implementation of ASTRO robot was sustained by a multidisciplinary team in which technology developers, designers and end-user representatives collaborated using a user-centred design approach. The key point of this work is to demonstrate the general feasibility and scientific/technical effectiveness of a mobile robotic platform integrated in a smart environment and conceived to provide useful services to humans and in particular to elderly people in domestic environments. The main aspects faced in this paper are related to the design of the ASTRO's appearance and functionalities by means of a substantial analysis of users' requirements, the improvement of the ASTRO's behaviour by means of a smart sensor network able to share information with the robot (Ubiquitous Robotics) and the development of advanced human robot interfaces based on natural language.

Magnetically driven wireless capsule endoscopy (WCE) represents one of the last achievements in the research of minimally invasive tools for gastrointestinal tract (GI) diagnosis. Recently, capsule localization methodologies have been employed to enable system autonomy maintaining a magnetic link with the device and managing interaction forces with GI tissues. To achieve these objectives, the locomotion platforms exploit automatic motion in some degrees of freedom and unsupervised contact with the external patient abdomen can occur. In this paper safety issues are faced; in particular a safety system, able to monitor pressure with patient abdomen, has been designed, characterized, and integrated with a magnetically driven WCE locomotion platform. New technologies, such as smart textiles, have been employed as sensible element. The proposed system showed promising results in controlling the pressure exerted on the abdomen respecting safety limits and increasing the efficiency and range of locomotion.

This paper describes the design and development of a robot with six soft limbs, with the dual capability of pushing-based locomotion and grasping by wrapping around objects. Specifically, a central platform lodges six silicone limbs, radially distributed, with cables embedded. A new mechanism-specific gait, invariant regarding the number of limbs, has been implemented. Functionally, some limbs provide stability while others push and pull the robot to locomote in the desired direction. Once the robot is close to a target, one limb is elected to wrap around the object and, thanks to the particular limb structure and the soft material, a friction-based grasping is achieved. The robot is inspired by the octopus and implements the key principles of locomotion in this animal, without coping the full body structure. For this reason it works in water, but it is not restricted to this environment. The experiments show the effectiveness of the original solution in locomotion and grasping.

The octopus is a marine animal whose body has no rigid structures. It has eight arms mainly composed of muscles organized in a peculiar structure, named muscular hydrostat, that can change stiffness and that is used as a sort of a modifiable skeleton. Furthermore, the morphology of the arms and the mechanical characteristics of their tissues are such that the interaction with the environment, namely water, is exploited to simplify the control of movements. From these considerations, the octopus emerges as a paradigmatic example of embodied intelligence and a good model for soft robotics. In this paper the design and the development of an artificial muscular hydrostat are reported, underling the efforts in the design and development of new technologies for soft robotics, like materials, mechanisms, soft actuators. The first prototype of soft robot arm is presented, with experimental results that show its capability to perform the basic movements of the octopus arm (like elongation, shortening, and bending) and demonstrate how embodiment can be effective in the design of robots.

Exploitation of miniature robots and microrobots for endovascular therapeutics is a promising approach; besides chemical strategies (typically systemic), topical mechanical approaches exist for obstruction removal, which however produce harmful debris for blood circulation. Magnetic particles (MPs) are also studied for blood clot targeting. We investigated magnetic dragging of clots/debris by means of both electrostatic and antibody binding. We successfully produced magnetotactic blood clots in vitro and experimentally showed that they can be effectively dragged within a fluidic channel. We also exploited a magnetic force model in order to quantitatively analyze the experimental results, up to obtaining an estimate of the relative efficiency between electrostatic and antibody binding. Our study takes a first step towards more realistic in vivo investigations, in view of integration into microrobotic approaches to vascular obstructions removal.

Morphology, perception and locomotion are three key features highly inter-dependent in robotics. This paper gives an overview of an underwater modular robotic platform equipped with a bio-inspired electric sense. The platform is reconfigurable in the sense that it can split into independent rigid modules and vice-versa. Composed of 9 modules, the longer entity can swim like an eel over long distances, while once detached, each of its modules is efficient for small displacements with a high accuracy. Challenges are to mechanically ensure the morphology changes and to do it automatically. Electric sense is used to guide the modules during docking phases and to navigate in unknown scenes. Several aspects of the design of the robot are described and a particular attention is paid to the inter-module docking system. The feasibility of the design is assessed through experiments.

This paper presents a novel master-slave teleoperated robotic platform designed for Single Port Laparoscopy. The SPRINT (Single-Port lapaRoscopy bimaNual roboT) is composed of two high-dexterity 6 Degrees of Freedom (DOFs) robotic arms, a stereoscopic camera and a dedicated console for the robot control by the surgeon. Along with a short summary of the hardware features of the system, this paper describes the real-time control architecture of the SPRINT. Particular attention was given to the kinematic coupling between the master and the slave manipulators, as well as to the inverse kinematics algorithm. Tests performed to validate the performance of the robot in terms of accuracy are satisfactory, thus positioning the SPRINT as a candidate for the next generation of robots for Single Port Laparoscopy.

In this paper the development of a bio-robotic platform is described. The robot design exploits biomechanical and neuroscientific knowledge on the lamprey, an eel-like swimmer well studied and characterized thanks to the reduced complexity of its anatomy. The robot is untethered, has a compliant body, muscle-like high efficiency actuators, proprioceptive sensors to detect stretch and stereoscopic vision. Experiments on the platform are reported, including robust and autonomous goal-directed swimming. Extensive experiments have been possible thanks to very high energy efficiency (around five hour continuous operating) the platform is ready to be used as investigation tool for high level motor tasks.

This paper describes a walking stabilization control on a soft ground based on gait analysis for a humanoid robot. There are many researches on gait analysis on a hard ground, but few scientists analyze the walking ability of human beings on a soft ground. Therefore, we conducted anthropometric measurement using a motion capture system on a soft ground. By analyzing experimental data, we obtained two findings. The first finding is that although there are no significant differences in step width and step length, step height tends to increase to avoid the collision between the feet and a soft ground. The second finding is that there are no significant differences in the lateral CoM trajectories but the vertical CoM amplitude increases when walking on a soft ground. Based on these findings, we developed a walking stabilization control to stabilize the CoM motion in the lateral direction on a soft ground. Verification of the proposed control is conducted through experiments with a human-sized humanoid robot WABIAN-2R. The experimental videos are supplemented.

The results of the neuroscientific research show that humans tend to stabilize the head orientation during locomotion. In this paper we describe the implementation of inverse kinematics based head stabilization controller on the humanoid platform. The controller uses the IMU feedback and controls neck joints in order to align the head orientation with the global orientation reference. Thanks to the method, we can decouple the orientational motion of the head from the rest of the body. This way stabilized head becomes better platform for proprioceptive sensory apparatus, such as cameras or IMU. In the paper we present three experiments which prove that the method has good performance in damping both, high and low frequency motion of the head. We also prove that the proposed controller improves the stability of the tracked goal point on the image of in-built camera.

In this work we propose an adaptive model for the head stabilization based on a feedback error learning (FEL). This model is capable to overcome the delays caused by the head motor system and adapts itself to the dynamics of the head motion. It has been designed to track an arbitrary reference orientation for the head in space and reject the disturbance caused by trunk motion. For efficient error learning we use the recursive least square algorithm (RLS), a Newton-like method which guarantees very fast convergence. Moreover, we implement a neural network to compute the rotational part of the head inverse kinematics. Verification of the proposed control is conducted through experiments with Matlab SIMULINK and a humanoid robot SABIAN.

Wireless capsule endoscopy offers significant advantages compared with traditional endoscopic procedures, since it limits the invasiveness of gastrointestinal tract screening and diagnosis. Moreover, active locomotion devices would allow endoscopy to be performed in a totally controlled manner, avoiding failures in the correct visualization of pathologies. Previous works demonstrated that magnetic locomotion through a robotic-aided platform would allow us to reach this goal reliably. In this paper, the authors present a comparative evaluation of control methodologies and user interfaces for a robotic-aided magnetic platform for capsule endoscopy, controlled through human-robot cooperative and teleoperated control algorithms. A detailed statistical analysis of significant control parameters was performed: teleoperated control is the more reliable control approach, and a serial kinematic haptic device results as the most suitable control interface to perform effective robotic-aided endoscopic procedures.

-We describe the design, realization and first sea trials of a small-sized Autonomous Surface Vehicle (ASV) for environmental monitoring. The robot is being developed in the framework of the HydroNet European project [1] aiming at realizing a new multi-robot system for monitoring the quality of coastal waters, rivers and lagoons. One main innovation of the robot is the capability to measure heavy metals concentrations directly onboard using sensors ad hoc developed by the consortium. This enables the system to provide real-time measurements of heavy metals concentrations potentially changing the current water monitoring methodology in which the samples are collected by a dedicated boat and analyzed in laboratory. The robot is designed for long range missions and for lodging the onboard water analysis system. Some severe constraints imposed by the addressed scenarios are considered in the design: reduced length and limited weight for ease of transportability and deployment; low draft and protected propellers to enable the ASV to move safely in shallow waters with likely floating obstacles such as plastic bags.

We report on the design and the experimental results of DustCart, a wheeled autonomous robot for door-to-door garbage collection. DustCart is able to navigate in urban environments avoiding static and dynamic obstacles and to interact with human users. The robot is managed by an Ambient Intelligence system (AmI) through a wireless connection: it navigates to collect garbage bags to the houses of users and then moves to discharge the collected waste to a dedicated area. The architecture, navigation and localization systems are described along with the results achieved in different urban sites. In particular, a localization approach based on optical beacons was used and guaranteed position errors sufficient for a safe robot navigation. We report also the first results of a long-term experimentation of the DustCart robot in Peccioli, a small town of Tuscany (Italy). This can be considered as a first step in using robotics in the everyday life of a real town for providing a real service.

A novel approach for the design of magnetically-propelled microrobots is proposed as an effective solution for swimming in a liquid medium. While intrinsic neutral buoyancy of a microrobot per se simplifies propulsion in the liquid environments, softness makes it compliant with delicate environments, such as the human body, thus guaranteeing a safe interaction with soft structures. With this aim, two groups of soft microrobots with paramagnetic and ferromagnetic behaviors were designed, fabricated and their features were experimentally analyzed. In agreement with the theoretical predictions, in the performed trials the ferromagnetic microrobots showed orientation capabilities in response to the magnetic field that could not be achieved by the paramagnetic one. Moreover, it was observed that the ferromagnetic microrobot could reach higher speed values (maximum value of 0.73 body length/s) than the paramagnetic prototype.

A wired miniature surgical camera robot with a novel Magnetic Levitation System (MLS) was modeled, designed and fabricated. A simple analysis and a theoretical model were developed in order to describe and predict basic behavior for different structural parameters of the system. The robot is composed of two main parts (head and tail) linked by a thin elastic flexible joint. The tail module embeds two magnets for anchoring and manual rough translation. The head module incorporates two motorized donut-shaped magnets and a miniaturized vision system at the tip. The MLS can exploit the external magnetic field to induce a smooth bending of the robotic head, guaranteeing a high span tilt motion of the point of view (0°-80°). The device is 100 mm long and 12.7 mm in diameter. Use of such a robot in single port or standard multiport laparoscopy could enable reduction of number/size of ancillary trocars, and/or increase the number of working devices that can be deployed, thus paving the way for multiple point of view laparoscopy.

The maintenance of a stable and coherent representation of the surrounding environment is an essential capability in cognitive robotic systems. Most systems employ some form of 3D perception to create internal representations of space (maps) to support tasks such as navigation, manipulation and interaction. The creation and update of such representations may represent a significant effort in the overall computation performed by the robot. In this paper we propose an architecture based on the concept of Expected Perception that allows lightweight map updates whenever the course of action happens according to the robot's expectations. It is only when the robot's predictions and the real world outcomes differ, that corrections must be done at its full extent. We performed experiments and show results in a real robotic platform with stereo (3D) perception where map corrections are proposed by simple image level (2D) comparisons.

A novel mechanism for actuating a miniature swimming robot is described, modeled, and experimentally validated. Underwater propulsion is obtained through the interaction of mobile internal permanent magnets that move a number of polymeric flaps arranged around the body of the robot. Due to the flexibility of the proposed swimming mechanism, a different range of performances can be obtained by varying the design features. A simple multiphysics dynamic model was developed in order to predict basic behavior in fluids for different structural parameters of the robot. In order to experimentally verify the proposed mechanism and to validate the model, a prototype of the swimming robot was fabricated. The device is 35 mm in length and 18 mm in width and thickness, and the forward motion is provided by four flaps with an active length of 20 mm. The model was able to correctly predict flap dynamics, thrust, and energy expenditure for magnetic dragging within a spindle-frequency range going from 2 to 5 Hz. Additionally, the model was used to infer robot-thrust variation related to different spindle frequencies and a 25% increase in flap active length. Concerning swimming performance, the proposed technical implementation of the concept was able to achieve 37 mm/s with 4.9% magnetic mechanism efficiency.

Water, recognized as one of the most important and endangered resources to mankind, is very difficult to monitor in real time using conventional methods. Thanks to recent advancements in technology, the use of robots, able to fulfill missions such as sampling from aquatic environments, becomes feasible and can increase dramatically the quality of water monitoring. Due to the complications for the robot's movement in some aquatic scenarios, for instance, shallow waters or dry banks of rivers and lakes, amphibian locomotion appears to be necessary to guarantee a satisfying coverage of the monitoring activities in such areas. In this paper, we focus on developing a practical amphibian solution by introducing a pair of screw rotors, which rotate in opposite directions to generate locomotion on the ground. The primitive idea of this novel design is to enhance the versatility of a marine robot with a terrestrial locomotion without undermining its performance during the movements in the water. In particular, we elaborate the principle of this novel design and present some test results of a prototype on selected terrain types, which are similar to the target aquatic environment. We conclude the paper with some preliminary conclusions based on the analysis of the test results about effectiveness and efficiency issues.

Polymeric ultra-thin films, also called nanosheets, show peculiar properties in terms of thickness, flexibility and chemical structure. For these reasons, they were proposed as nanoplasters for localized drug release or as a new solution for closing endoluminal surgical wounds. This paper presents the fabrication and characterization of free-standing nanosheets loaded with iron oxide nanoparticles, which can be manipulated in liquid environment by means of magnetic fields. A theoretical model of magnetic manipulation of the nanosheet is proposed and validated by dragging the film with a permanent magnet mounted on an industrial robotic arm. Controlling the magnetic sheet in liquid environment represents a first step towards the application of these nanostructures as free-standing carriers to be released and magnetically controlled in endoluminal surgery or as plasters with nanometric thickness to be delivered in situ on surgical incisions. Furthermore, these magnetic nanofilms can be adapted and used as micro and nanocomponents for the design of a novel generation of magnetic actuated polymeric microrobots.

In this work, we propose a new concept for locomotion of a miniature jellyfish-like robot based on the interaction of mobile permanent magnets. The robot is 35 mm in length and 15 mm in width, and it incorporates a rotary actuator, a magnetic rotor, several elastic magnetic tails and a polymeric body embedding a wireless microcontroller and power supply. The novel magnetic mechanism is very versatile for numerous applications and can be tailored and adapted on the basis of different specifications. An analytical model of the magnetic mechanism allows to shape the robot design based on the specific application. The working principle of the robot together with the design, prototyping and testing phases are illustrated in this paper.

This work deals with a new technique for the estimation of the parameters and number of components in a finite mixture model. The learning procedure is performed by means of a expectation maximization (EM) methodology. The key feature of our approach is related to a top-down hierarchical search for the number of components, together with the integration of the model selection criterion within a modified EM procedure, used for the learning the mixture parameters. We start with a single component covering the whole data set. Then new components are added and optimized to best cover the data. The process is recursive and builds a binary tree like structure that effectively explores the search space. We show that our approach is faster that state-of-the- art alternatives, is insensitive to initialization, and has better data fits in average. We elucidate this through a series of experiments, both with synthetic and real data.

In this paper we propose a new algorithm for the least square fitting of ellipses from scattered data. Originally based on the one proposed by Fitzgibbon et Al in 1999, our procedure is able to overcome the numerical instability of that algorithm. We test our approach versus the latter and another approach with different ellipses. Then, we present and discuss our results.

In the domain of psychology and medical science, many experiments have been conducted referring to research on animal behaviors, to study the mechanism of mental disorders and to develop psychotropic drugs to treat them. Rodents such as rats are often chosen as experimental subjects in these experiments. However, according to some researchers, the experiments on social interactions using animals are poorly- reproducible. Therefore, we consider that the reproducibility of these experiments can be improved by using a robotic agent that interacts with an animal subject. We have developed a novel quadruped rat-inspired robot, the WR-2 (Waseda Rat No.2), based on the dimension and body structure of a mature rat. It is capable of reproducing the behaviors such as walking, mounting, rearing and grooming of the rat.

The usage of Gaussian mixture models for video segmentation has been widely adopted. However, the main difficulty arises in choosing the best model complexity. High complex models can describe the scene accurately, but they come with a high computational requirements, too. Low complex models promote segmentation speed, with the drawback of a less exhaustive description. In this paper we propose an algorithm that first learns a description mixture for the first video frames, and then it uses these results as a starting point for the analysis of the further frames. Then, we apply it to a video sequence and show its effectiveness for real-time tracking multiple moving objects. Moreover, we integrated this procedure into a foreground/background subtraction statistical framework. We compare our procedure against the state-of-the-art alternatives, and we show both its initialization efficacy and its improved segmentation performance.

The purpose of this work is to investigate the applicability of a visual tracking model on humanoid robots in order to achieve a human-like predictive behavior. In humans, in case of moving targets the oculomotor system uses a combination of the smooth pursuit eye movement and saccadic movements, namely “catch up” saccades to fixate the object of interest. This work aims to validate the "catch up" saccade model in order to obtain a human-like tracking system able to correctly switch from a zero-lag predictive smooth pursuit to a fast orienting saccade for the position error compensation. Experimental results on the iCub simulator show several correspondences with the human behavior.

This paper describes and discusses the preliminary results of a behavioural study on robot social acceptability, which was carried out during a public demonstration in South Korea. Data was collected by means of direct observation of people behaviour during interaction with robots. The most interesting result to emerge is that of young people: they tended to react to the robots presence with extreme curiosity and, quite often, to treat them aggressively. In this paper, the word bullying is used to describe any kind of improper and violent behaviour, intended to cause damages or impede the robot operation. It is the authors' opinion that if not tackled appropriately, abuses towards robots may become a serious hindrance to their future deployment, and safety. Hence, the necessity to tackle this issue with dedicated solutions during the early phases of design.

The possibility of controlling dexterous hand prostheses by using a direct connection with the nervous system is particularly interesting for the significant improvement of the quality of life of patients, which can derive from this achievement. Among the various approaches, peripheral nerve based intrafascicular electrodes are excellent neural interface candidates, representing an excellent compromise between high selectivity and relatively low invasiveness. Moreover, this approach has undergone preliminary testing in human volunteers and has shown promise. In this paper, we investigate whether the use of intrafascicular electrodes can be used to decode multiple sensory and motor information channels with the aim to develop a finite state algorithm that may be employed to control neuroprostheses and neurocontrolled hand prostheses. The results achieved both in animal and human experiments show that the combination of multiple sites recordings and advanced signal processing techniques (such as wavelet denoising and spike sorting algorithms) can be used to identify both sensory stimuli (in animal models) and motor commands (in a human volunteer). These findings have interesting implications, which should be investigated in future experiments.

In this paper, a reconfigurable modular robotic system is proposed to augment the dexterity of endoluminal interventions in the gastrointestinal tract. In the proposed system, miniaturized robotic modules are ingested and assembled in the stomach cavity. The assembled robot can change its configuration according to the target location, thus enabling complicated surgical tasks. The robotic assembly, the robotic configuration and the surgical tasks are controlled via wireless bidirectional communication. Based on this concept, early prototypes of the robotic modules were designed and fabricated. The developed module has 2DOF (±90° of bending and 360° of rotation), measures 15.4 mm in diameter and 36.5 mm in length. It weighs 5.6 g and contains a Li-Po battery, two brushless DC motors, and a custom-made control board capable of wireless communication. The performance of the bending and rotational motion was evaluated and the future work has been discussed.

An automated design generation algorithm for a serial kinematic chain is presented for the reconfigurable robot used in a novel endoluminal surgical procedure (European Union project ARES). The algorithm produces the possible topologies, given the design constraints, desired performance, and available modules, such that all constraints are satisfied for every point in the desired workspace. This is achieved through the use of interval analysis methods and branch-and-bound loop that searches through the end-effector pose and the design parameter spaces. The resulting algorithm is demonstrated through an example of a serial chain manipulator made of the reconfigurable modules of the surgical robot for the application. The results are presented and discussed.

This paper describes a rapid prototyping method to add robotic functionality to microfluidic devices using existing equipment, materials, and methods already employed in photolithography. Details on the fabrication as well as basic design and analyses methods are given. These techniques are then employed to fabricate an example structure that is subsequently integrated with a microfluidic channel. The eventual purpose of this example structure would be to serve as an interface between a microfluidic device and its environment, using a brush-like structure to sweep cells into the channel, which could then be delivered to another microfluidic system for analyses of the cells. The resulting brush-like structure fits within a 6 mm times 4 mm times 2 mm volume and can be further miniaturized. The alteration of compressed air and vacuum modulated by pneumatic solenoid valves is used to push and pull a plunger/rod system that actuates the device. The delivery of the pressurized air and vacuum is accomplished through flexible 500 mum-diameter tubing to the plunger/rod system but future work would involve completely containing the actuation on a chip-size device.

As medical robotics gathers increasing attention, the ergonomics of the surgical-console design becomes an important issue. Motivated by the need of augmenting the surgeon mastery, we explore the capabilities of a near infrared brain-computer interface as a complementary input modality to enhance the human-robot interaction at the robotic console. A multistage analysis framework is proposed and evaluated by an exploratory off-line synchronous study. The three stages of the data processing flow, namely dimensionality reduction, solution to binary problems and aggregation into multi-class decision are examined to address key challenges during the pattern recognition step. Early experimental results endorse near infrared based brain-computer interface as a suitable additional communication modality between the surgeon and the robotic console.

We present design and experimental performance results for a novel mechanism for robotic legged locomotion at the mesoscale (from hundreds of microns to tens of centimeters). The new mechanism is compact and strikes a balance between conflicting design objectives, exhibiting high foot forces and low power consumption. It enables a small robot to traverse a compliant, slippery, tubular environment, even while climbing against gravity. This mechanism is useful for many mesoscale locomotion tasks, including endoscopic capsule robot locomotion in the gastrointestinal tract. It has enabled fabrication of the first legged endoscopic capsule robot whose mechanical components match the dimensions of commercial pill cameras (11 mm diameter by 25 mm long). A novel slot-follower mechanism driven via lead screw enables the mechanical components of the capsule robot to be as small while simultaneously generating 0.63 N average propulsive force at each leg tip. In this paper, we describe kinematic and static analyses of the lead screw and slot-follower mechanisms, optimization of design parameters, and experimental design and tuning of a gait suitable for locomotion. A series ofex vivoexperiments demonstrate capsule performance and ability to traverse the intestine in a manner suitable for inspection of the colon in a time period equivalent to standard colonoscopy.

The focus of this special issue is to show how the main achievements on different technical topics relevant to the development of bioinspired and bioapplied mechatronic devices and robotic systems. The 19 articles in this special issue are summarized here.

Due to the limited resolution of both cameras and displays, acuity of artificial vision systems is currently well below the human eye. Visual acuity, in cameras as well as in animal eyes, can be increased by making smaller receptors or bigger eyes. In some applications, the size of the camera is constrained, so alternative solutions must be sought. This paper presents a robotic dual-camera vision system whose design is inspired by the visual system of jumping spiders (Salticidaefamily). The system is composed of a telephoto camera whose field of view (FOV) can be moved within the larger FOV of a wide-angle camera and allows to form a high-resolution image, i.e., an image with the FOV of the wide-angle camera, yet having the same resolution as the telephoto camera. We describe the design of the robotic system, the direct and inverse kinematics, and the image processing algorithms that allow to build the high-resolution image. Images from experiments are presented, together with a discussion on sources of errors and possible solutions. The system is particularly useful for fixed-camera monitoring or teleoperation applications, such as remote surveillance and minimally invasive surgery. The system achieves seven times higher resolution than typical commercial endoscopes.

Hand movement data acquisition is used in many engineering applications ranging from the analysis of gestures to the biomedical sciences. Glove-based systems represent one of the most important efforts aimed at acquiring hand movement data. While they have been around for over three decades, they keep attracting the interest of researchers from increasingly diverse fields. This paper surveys such glove systems and their applications. It also analyzes the characteristics of the devices, provides a road map of the evolution of the technology, and discusses limitations of current technology and trends at the frontiers of research. A foremost goal of this paper is to provide readers who are new to the area with a basis for understanding glove systems technology and how it can be applied, while offering specialists an updated picture of the breadth of applications in several engineering and biomedical sciences areas.

This paper presents the design of a novel sensor for slip detection. It consists of an easily fabricated miniaturized thermal probe that senses the additional convective heat transfer associated with the occurrence of mechanical slip. The fabrication procedures and the operating principle for the device are described in detail. A simple experimental setup was used to test the effectiveness of the proposed device. Tests were performed with varying velocities on four materials of differing thermal properties and surface roughnesses. The results show that slip can be effectively detected by the proposed sensor with a response times which can be as low as 6.3 ms. The performance of the device can be further improved when used in conjunction with a separate pressure sensor and by using more accurate methods of electrical resistance measurement.

Neuro-developmental engineering is a new interdisciplinary research area at the intersection of developmental neuroscience and bioengineering. Applications can be found in early detection of neuro-developmental disorders via a new generation of mechatronic toys for assessing the regular development of perceptual and motor skills in infants, in particular coordination of mobile and multiple frames of reference during manipulation. This paper focuses on the design of a novel mechatronic toy, shaped as a 5 cm (diameter) ball, i.e. small enough to be grasped with a single hand by a 1 year old child. The sensorized ball is designed to embed a kinematics sensing unit, able to sense both the orientation in 3D space and linear accelerations, as well as a force sensing unit, to detect grasping patterns during manipulation. Dimensioning of batteries able to operate for 1 hour during experimental sessions as well as a wireless communication unit are also included in the design.

Some phases of laparoscopic interventions, such as suturing, require precise and dexterous movements that are difficult to perform by means of rigid instruments. Multi-DOF hand-held instruments and teleoperated systems have been developed to increase movement dexterity. In this paper, we present the design of a novel hand-held robotic instrument that can be operated by the surgeon with one hand only, while standing at the operating table and acting on a traditional laparoscopic instrument with the other hand. Its main advantages are the low weight, achieved by dislocating the motors and using a flexible transmission, and the possibility to switch end-effector, changing the instrument type according to the phase of the intervention. The instrument can be used easily and rapidly, since it does not require long or complex set-up procedures. We describe the instrument design, the development of the first prototype and compare it to rigid instruments in the ability to approach sutures at various angles.

In this paper a polymer sensorised microgripping tool for micromanipulation is presented. The gripper structure is made by moulding of polyurethane in silicon moulds by the technique of shape deposition manufacturing (SDM), in which the force sensing elements and part of the actuator (in this case, microstrain gauges and SMA (shape memory alloy) wire, respectively) are embedded into the microgripper in one process step. The actuation principle for the microgripper is an SMA wire. The advantages of the fabrication process are low cost and manufacture cycle time. This paper details the technique for fabrication of the microgripper to produce prototypes. These prototypes were then tested and characterised in terms of force output, hysteresis and repeatability. A further miniaturised unsensorised microgripper based on the same actuation principle and fabrication process (but less than half the size) was fabricated to demonstrate the possibility of further downscaling.

Great amounts of raw data acquired with the use of an innovative mechatronic platform during an extensive clinical trial in a neuro-rehabilitation setting needs an analysis and interpretation. The platform records data from eight 6 DOF force-torque sensors during an isometric functional assessment of post-stroke patients. The identification of preprocessing parameters and onset detection methods, developed thanks to the close collaboration between biomedical engineers and clinicians, is presented in the paper. The present work presents also the implementation and testing of the software for the data pre-processing.

Many compelling future surgical applications will be enabled by a new kind of surgical tool, capable of entering the human body through natural orifices or very small incisions and then reconfiguring into complex kinematic structures at the site of intervention. We describe a first step toward this goal - the development of a microactuator designed for use in surgical robots that are composed of large quantities of reconfigurable micro-robotic modules. The miniaturizable design proposed harnesses the Bourdon effect to convert electrolytic pressure into mechanical motion obtaining more than 400% displacement variation while consuming less than 0.5 W at less than 5 V. We describe the design, construction, and experimental results with our prototype microactuator.

In this paper we present the design of a swallowable (11mm diameter by 25mm long), 12-legged endoscopic capsule for locomotion in the lower gastro intestinal tract (large bowel). A novel slot-follower mechanism driven via lead-screw allows the capsule to be as small as current commercial pill-cameras, while simultaneously generating 2/3 N of force at each leg tip. Kinematic and static analyses of the lead screw and slot-follower mechanisms allow optimization of design parameters so that the capsule satisfies experimental and clinical design requirements for legged locomotion in the GI tract.

This paper describes the design of a fast long-jumping robot conceived to move in unstructured environments through simple feed-forward control laws. Despite the apparent similarities with hopping, jumping dynamics is peculiar and involve non-trivial issues on actuation powering, energy saving and stability. The "Grillo" robot described here is a quadruped, 50-mm robot that weights about 15 grams and is suited for a long-jumping gait. Inspired by frog locomotion, a tiny motor load the springs connected to the hind limbs. At take-off, an escapement mechanism releases the loaded springs. This provides a peak power output that can exceed several times the maximum motor power. In this way, the actuation and energy systems can be significantly reduced in weight and size. On the other hand, passive dynamics is exploited by compliant forelegs, that let to partially recover the impact energy in their elastic recoil. Equipped with a 0.2W DC motor, the robot is dimensioned to achieve a forward speed of 1.5 m/s, which corresponds to about 30 body length per second.

Remote manipulation tasks in the small scale can often not be performed autonomously, due to the unstructured nature of the environments and the limited capabilities of sensor and localization technologies. For these tasks, teleoperated systems are used, in which the human operator is integral part of the control. In time-delayed teleoperation, the operator gradually adopts discrete control strategies, such as 'move-and-wait'. In this paper, we present and compare three different control strategies for driving a nanomanipulation system with direct vision feedback. Two strategies are based on a fixed step size to move the manipulator, while the third uses a variable step size. The strategies are compared on a 2D fine positioning task. Experimental results are in agreement with Fitts' law and show that the third strategy, besides allowing movements of size ranging across several orders of magnitude, also allows to complete the fine positioning task in less time. The control strategies can be used in general to control vision-guided teleoperation systems affected by time delay.

This paper addresses the problem of autonomous localization of multiple gas or odor sources in an indoor environment with no strong airflow. In our approach, a robot iteratively builds an occupancy grid map from successive measurements of odor concentration. The resulting map shows the probability of each discrete cell in the map containing an active plume source. Our method is based on a recent adaptation of Bayesian occupancy grid mapping (OGM) to the chemical plume source localization problem. We present experimental results that demonstrate the utility of the approach.

This paper presents the development of new transmission components and position controller of the NEURARM hydraulic actuation unit as critical components of a novel robotic arm specifically designed to perform joint experiments between neuroscience and robotics. NEURARM replicates the main functions and characteristics of the human arm during the execution of planar movements like reaching and catching, and it was used to investigate human motion control theories, to develop and evaluate models of control, of learning and of sensory-motor interaction.

Minimally invasive surgery (MIS) has become very common in recent years, thanks to the many advantages it provides for patients. Since it is difficult for surgeons to learn and master this technique, several training methods and metrics have been proposed, both to improve the surgeon's abilities and also to assess his/her skills. This paper presents the use of the WB-1R (Waseda bioinstrumentation system no.1 refined), which was developed at Waseda University, Tokyo, to investigate and analyze a surgeon's movements and performance. Specifically, the system can measure the movements of the head, the arms, and the hands, as well as several physiological parameters. In this paper we present our experiment to evaluate a surgeon's ability to handle surgical instruments and his/her depth perception using a laparoscopic view. Our preliminary analysis of a subset of the acquired data (i.e. comfort of the subjects; the amount of time it took o complete each exercise; and respiration) clearly shows that the expert surgeon and the group of medical students perform very differently. Therefore, WB-1R (or, better, a newer version tailored specifically for use in the operating room) could provide important additional information to help assess the experience and performance of surgeons, thus leading to the development of a global performance index for surgeons during MIS. These analyses and modeling, moreover, are an important step towards the automatization and the robotic assistance of the surgical gesture.

A biological paradigm of versatile locomotion and effective motion control is provided by the polychaete annelid worms, whose motion adapts to a large variety of unstructured environmental conditions (sand, mud, sediment, water, etc.), and could thus be of interest to replicate by robotic analogs. Their locomotion is characterized by the combination of a unique form of tail-to-head body undulations (opposite to snakes and eels), with the rowing-like action of numerous lateral appendages distributed along their long segmented body. Focusing on the former aspect of polychaete locomotion, computational models of crawling and swimming by such tail-to-head body undulations have been developed in this paper. These are based on the Lagrangian dynamics of the system and on resistive models of its interaction with the environment, and are used for simulation studies demonstrating the generation of undulatory gaits. Several biomimetic robotic prototypes have been developed, whose undulatory actuation achieves propulsion on sand and other granular unstructured environments. Extensive experimental studies demonstrate the feasibility of robot propulsion by tail-to-head body undulations in such environments, as well as the agreement of its qualitative and quantitative characteristics to the predictions of the corresponding computational models.

The biomedical application this paper refers to is the neuroendoscopy of the sub-arachnoid spinal space. Such a kind of endoscopy is strongly challenging due to the tiny space to be explored and to the delicate anatomical structures which lie into it. In order to enhance the degree of safety of the endoscopic intervention, a robotic system for neuroendoscopy has been developed, so as to obtain a robot-assisted exploration which aims to lower the risks for the patient and to ease the catheter maneuvering task. This paper explains how robot sensory feedbacks can be exploited to provide the surgeon with useful information for the navigation and to implement automatic control strategies. It is described how sensory feedbacks processing can improve the safety of the operation by implementing a human-robot cooperation for the understanding of the anatomical environment and the monitoring of physiological parameters. The focus of the paper is on vision and pressure sensory feedbacks. Experimental results prove the reliability and the effectiveness of the proposed algorithms and their suitability to be employed in real time operation

The paper presents a controller for a multi-fingered underactuated prosthetic hand based on tendon transmission. The control architecture is implemented in two subsequent and different phases. The first one is the pre-shaping of the hand, based on the grasp type is implemented by stand-alone motion controllers using PID position control algorithms. The desired force closure value is calculated according to the pre-shape measured tendons tension and to the grasping force. In the second phase, the involved fingers rapidly close around the object to perform a balanced distribution of the forces within the hand, as it happens in the human hand. The controller is thus able to perform successfully many stable grasps. An overview of the hardware architecture and the results in terms of grasping capabilities based on Cutkosky grasp taxonomy are also presented

In this paper, two methods of marking microgrippers are described, which can be used for vision recognition in micromanipulation tasks. The two techniques are shape-based FIB (focused ion beam) triangle machining and colour-based polymer ink marking; these have been applied to several microgrippers that were manufactured from stainless steel using micro-EDM (electro discharge machining). A method for detecting the colour-based markers was developed and the results presented

This paper presents a bioinspired concept of locomotion for small autonomous robots. Scale effects in locomotion highly influence gait efficiency and in lightweight micro-robots jumping can be more energetically efficient than just walking or climbing. In addition, a jump can make the robot overcome obstacles and uneven terrains. Inspired by nature, the actuation of the proposed robot is entrusted to loaded springs. During the flight phase, energy from an electric micro-motor is collected in springs, while it is released by a click mechanism during take-off. In this way instant power delivered by rear legs (about 5 W) is much higher than the one provided by the motor (0.3 W). Passive compliant legs and low-power actuation result in light, efficient micro-robot, designed to have long autonomy for environment exploration and monitoring. In order to verify these assumptions, a quadruped prototype was developed, with two active rear limbs and passive elastic forelegs. Robot Grillo is 50 mm long and weighs about 10 grams. In conservative simulations the microrobot reaches a forward speed of 1.5 m/s, which corresponds to about 30 body length s-1

This paper presents a self-organizing neural network model for visuo-motor coordination of a redundant humanoid robot arm in reaching tasks. The proposed approach is based on a biologically-inspired model which replicates some characteristics of human control: learning occurs through an action-perception cycle and does not requires explicit knowledge of the geometry of the manipulator. The transformation learned is a mapping from spatial movement direction to joint rotation. During learning, the system creates relations between the motor data associated to endogenous movements performed by the robotic arm and the sensory consequences of such motor actions, i.e. the final position and orientation of the end effector. The learnt relations are stored in the neural map structure and are then used, after learning, for generating motor commands aimed at reaching a given point in 3D space. The work is an extension of (E. Guglielmelli, et al.) including the end-effector orientation control. Experimental trials confirmed the system capability to control the end effector position and orientation and also to manage the redundancy of the robotic manipulator in reaching the 3D target point even with additional constraints, such as one or more clamped joints without additional learning phases

Personal robots, which are expected to become popular in the future, are required to be active in joint work and community life with humans. Such robots must have no bad physical or psychical effect on humans. The psychical effect of a robot on humans has been subjectively measured using questionnaires. However, it has not been objectively measured yet. Human emotion and the consciousness direction can be measured by physiological parameters and body motion, respectively. Therefore, the bioinstrumentation system WB-1 was developed in order to objectively measure the psychical effect of a robot on a human. It can measure physiological parameters such as respiration, heart rate, perspiration and pulse wave, and arm motion. Analyzing human stress in the interaction with a robot from electrocardiogram, the robot could generate a motion for decreasing the stress

This paper focus on developing a flexible biomimetic sensor, which is embedded in a soft earthworm-like crawling mini-robot and mimics exteroceptive and proprioceptive functions of invertebrates, such as its biological counterpart-earthworm. A polyvinylidene fluoride (PVDF) film is selected as the sensing element because it is flexible, highly sensitive and easy to be integrated in different shapes. Thin and narrow PVDF strips are embedded with an innovative molding-embedding-remolding fabrication procedure in a segmented compliant silicone shell which serves as skin and passive actuation of a crawling earthworm-like mini-robot with the ability to elongate and contract. Several experiments were performed by using a purposely developed test-bench in order to test sensor behaviour. The results show that the biomimetic flexible PVDF-based sensor can detect both the external contact and the internal actions, thus imitating the exteroceptive and proprioceptive sensing capabilities of real earthworms. The developed biomimetic sensors are promising in order to achieve an useful sensor feedback for the earthworm-like minirobot motion control

This paper introduces the main objectives of the neurobotics project aimed at designing and developing innovative hybrid bionic systems (HBSs) by fusing neuroscience and robotics. Eight different HBSs have been jointly designed and are being developed. This paper presents in detail the telepresence platform. The neurobotics artificial lamprey model has been designed to validate a number of neuroscience models and to investigate new telepresence strategies

In recent years, thanks to the advancement of robotics and mechatronics, new and more effective devices for the restoration and replacement of sensory-motor function in disabled people have been developed. In all these systems, user acceptability is strictly connected to several issues such as the residual abilities of the subject, the mechatronic characteristics of the robot, and also the interface chosen to link them. It is possible to figure out different "human-interface-device" combinations [also defined as "hybrid bionic systems" (HBSs)] characterized by different properties in terms of level of hybridness, connection, and augmentation. In particular, in HBSs the interface has to be customized according to the characteristics of the robotic artefact to be controlled and to the desires and needs of the final users. In this paper, our attention has been focused on the problem of the replacement of hand function after amputation. Three HBSs characterized by different levels of complexity, dexterity, and sensorization are presented in order to show the possibility of developing acceptable and effective systems by choosing different levels of connection and hybridness (i.e., different interfaces) for different devices and applications. The following case studies are presented: 1) the use of invasive interfaces to the peripheral nervous system to control a dexterous and highly sensorized hand prosthesis; 2) the use of electromyographic signals recorded using surface electrodes to control a compliant adaptive prosthesis; and 3) the use of a foot interface to control a two-degrees-of-freedom prosthesis. The preliminary results achieved so far seem to confirm the idea that the correct choice of the proper interface while developing an HBS can increase effectiveness and usability

This paper presents a new biphasic electrofluidic rotary actuator relying on electrochemical mechanisms. Gas (H2and O2) is generated at two platinum (Pt) electrodes, immersed in an electrolytic solution, when a low voltage, V, is applied to them. The generated gas pressurizes a closed elastomeric chamber, that deforms under the action of the applied pressure. The chamber is shaped so that no structural failure occurs and the desired output motion is produced, without any need for additional mechanical means such as motion converters. Simple thermodynamic considerations allow estimating the electromechanical coupling factors for the most common external loads.

This paper presents the application of a neural approach in the control of a 7-DOF robotic head. The inverse kinematics problem is addressed, for the control of the gaze fixation point of two cameras mounted on the robotic head. The proposed approach is based on a biologically-inspired model, which replicates the human brain capability of creating associations between motor and sensory data, by learning. The model is implemented here by self organizing neural maps. During learning, the system creates relations between the motor data associated to endogenous movements performed by the robotic head and the sensory consequences of such motor actions, i.e. the final position of the gaze fixation point. The learnt relations are stored in the neural map structure and are then used, after learning, for generating motor commands aimed at reaching a given fixation point. The approach proposed here allows to solve the inverse kinematics and joint redundancy problems for the ARTS robotic head, with good accuracy and robustness. Experimental trials confirmed the system capability to control the gaze direction and fixation point and also to manage the redundancy of the robotic head in reaching the target fixation point even with additional constraints, such as a clamped joint or two symmetric joint angles (e.g. eye joints).

This paper presents recent results aimed at developing a functional prosthetic hand characterized by an EMG-control and by a simple and low cost fabrication technology. In order to overcome some limitations of current prosthetic hands mainly related to the poor functionality and controllability, the prosthetic hand has been designed following a biomechatronic approach based on biologically-inspired design solutions. The core of the project described in this paper is the fabrication of a compliant under-actuated prosthetic hand: the structure of the hand (both palm and fingers) is moulded as a soft polymeric single part with compliant joints and embedded tendon driven underactuated mechanism for providing adaptive grasp. In order to make user trials, the hand is equipped with simple but functional EMG-based control of the single motor incorporated in the hand, and is integrated with a prosthesis socket. The paper presents the biomechatronics design, the fabrication process, the integration of the prosthetic device and first experimental results.

This paper describes the development of an active clamping mechanism to be integrated into a swallowable pill for the diagnosis of the gastrointestinal (GI) tract. The clamping system allows to stop the pill in desired sites of the GI tract for long monitoring purposes. After discussing the major technical constraints, the design of the clamping system, based on FEA (Finite Element Analysis), is illustrated as well as its fabrication process. The clamping unit is actuated exploiting Shape Memory Alloys (SMA), in wires and spring configuration, and it is driven by a dedicated electrical interface. A fine tuning has been performed in order to limit the power consumption. Then a working prototype is fabricated and preliminarily tested, pointing out a capability of the grasping system over 40 g.

Polychaete annelid worms provide a biological paradigm of versatile locomotion and effective motion control, adaptable to a large variety of unstructured environmental conditions (water, sand, mud, sediment, etc.). The undulatory locomotion of their segmented body is characterized by the combination of a unique form of tail-to-head body undulations, with the rowing-like action of numerous lateral appendages distributed along their body. Computational models of polychaete-like crawling and swimming have been developed, based on the Lagrangian dynamics of the system and on resistive models of its interaction with the environment, and used for simulation studies demonstrating the generation of undulatory gaits. Several lightweight robotic prototypes have been developed, whose undulatory actuation achieves propulsion on sand. Extensive experiments demonstrate that the propulsion of these robots is characterized by essential features of polychaete locomotion, in agreement with the corresponding simulations.

In recent years, advances and improvements in engineering and robotics have been strengthening interactions between biological science and robotics in the goal of mimicking the complexity of biological systems. In this paper, motor control paradigms inspired by human mechanisms of sensory-motor coordination are applied to a biologically-inspired, purpose-designed robotic platform. The goal was to define and implement a multi-network architecture and to demonstrate that progressive learning of object grasping and manipulation can greatly increase performance of a robotic system in terms of adaptability, flexibility, growing competences and generalization, while preserving the robustness of traditional control. The paper presents the neural approach to sensory-motor coordination and shows preliminary results of the integration with the robotic system by means of simulation tests and experimental trials.

Personal robots, which are expected to become popular in the future, are required to be active in joint work and community life with humans. Therefore, we have been developing new mechanisms and functions for a humanoid robot that has the ability to express emotions and to communicate with humans in a human-like manner. In 2004, we introduced the "Behavior Model" and "Consciousness Model" to the robot mental model so that the robot generated various kinds of behavior and an object of the robot's behavior became clear. We implemented the mental model in the emotion expression humanoid robot WE-4RII (Waseda Eye No.4 Refined II). Also, we have been studying a system of multiple harmonic oscillators (neurons) interacting via chaotic force since 2002. Each harmonic oscillator is driven by chaotic force whose bifurcation parameter is modulated by the position of the harmonic oscillator. In this paper, we propose an associative memory model using mutually coupled chaotic neural networks for generating an optimum behavior to a stimulus. We implemented this model in the emotional expression humanoid robot WE-4RII (Waseda Eye No.4 Refined II).

Movement and behavior analysis is a key research area in the domain of biomedical engineering and in many other medical research domains aiming at the understanding of physiological motor and cognitive basic mechanisms. The systematic application of robotic and mechatronic technologies to realize new tools and measurement methods for quantitatively assessing motor and cognitive functions in humans as well as in animal models is gaining an increasing popularity. This work represents a first step towards the development of a sensorised environment for behavioral phenotyping of animal models. In particular, this paper focuses on tremor analysis in reeler mice, an emerging potential animal model for anatomical and behavioral traits observed in autism. Ground reaction force (GRF) sensing is indeed the most direct means of measuring tremor. Although force platforms have extensively been used for large size animals, only few attempts have been made to measure GRF at a single paw for animals as small as mice or rats. Under the hypothesis that in-plane GRF components are directly connected to tremor, a small size, low-cost, 2-axis force sensor for measuring the in-plane components of GRF was designed and developed. Special care was paid to design a structure that would allow self-aligned assembly, for repeatability, and modularity for combining multiple platforms for a sensorised floor. Preliminarily testing was performed with both reeler and wildtype mice. Fourier analysis was deployed to extract information due to tremor, validating the hypothesis of a direct connection between tremor and in-plane GRFs.

In this paper, some recent results about the experimental trials we are performing on a functional prosthetic hand characterized by an EMG-control and by a simple and low cost fabrication technology are shown. The innovation described in this paper is the fabrication of a compliant under-actuated prosthetic hand. The structure of the hand (both palm and fingers) is moulded as a soft polymeric single part with compliant joints and embedded tendon driven under-actuated mechanism for providing adaptive grasp. The prosthetic hand has been designed following a biomechatronic approach based on biologically-inspired design solutions. We describe the second release of this prosthesis. The evaluating tests are related to the maximum force exerted during grasping and to the fatigue problems occurring with cables and joint.

This paper presents an experimental investigation on a novel interface for high level control of robotic hands, based on selected foot movements. A prototype has been developed that integrates 4 sensitive areas, battery, and electronics for data acquisition and wireless transmission into a wearable insole. The prototype foot interface has been experimentally validated in the control of a robotic hand prosthesis. Comparative experimental trials were conducted with 10 able-bodied subjects, with both the foot interface and an EMG-based control, which represents the most advanced interface currently available in clinical implants for amputees. The results confirmed the effectiveness of the foot interface in the control of the hand prosthesis and showed a significant decrease in required adaptation and learning from the user's side.

This work presents an adaptive segmentation algorithm for endoscopic images. It is part of a complete system for robot-assisted endoscopy of the human sub-arachnoid spinal space. The role of the vision system is to provide a feedback for assisting the navigation of the endoscope and helping avoid damages to delicate tissues. Due to the presence of small blood vessels, nerves, and possible fibrosis, a multi-step approach has been followed for segmentation of the lumen (corresponding to free space for navigation) and the other tissues. Histogram analysis, together with blob analysis and a modified implementation of the convex hull algorithm bring to the isolation of the lumen; by means of adaptive thresholding nerves are isolated; thresholding on the hue and saturation helps in recognizing the vessels. A special condition of dirty lumen helps in managing doubtful situations. Experimental trials have been conducted on video streams from endoscopic explorations of animal (pig) spinal cord in-vivo. Experimental results show that membranes, vessels, nerves, and lumen are recognized in a reliable way, so as to contribute to robot-assisted endoscopy. The speed of the processing resulted compatible with an envisaged use in real tune support of endoscopic navigation.

This paper presents the design and development of a microrobot which aims to replicate the locomotion principle of earthworms. The undulatory locomotion of living earthworms has been investigated deeply from the biological point of view, but attempts at replication of earthworm models in real size are limited. The authors have designed an artificial earthworm with four modules which can be driven independently according to defined undulatory patterns with a typical frequency of 0.5 Hz. Each module is actuated by one or more SMA springs whose configuration has been designed in order to limit wiring problems and optimize working frequency. The robot is covered by a shaped silicone material which can be used as a platform to insert tiny legs for obtaining differential friction conditions. Preliminary tests demonstrate that the earthworm prototypes can move with a speed of 0.22 mm/s, thus approximating the behavior of biological earthworms.

This paper describes an experimental work conducted in order to estimate the conditions of applicability of expected perception (EP) based on a scheme for robot sensorimotor coordination. The starting hypothesis is that predictions of incoming sensory data can improve sensorymotor coordination respect to pure feedback loops. This implies that the environment presents a level of predictability, as in realistic environments. An implementation of the EP-based scheme has been realized on a platform composed by the Dexter 8-d.o.f. robotic arm and a color camera, for executing a pushing task in a real-world environment. Its performance, where defined as a combination of the error in the trajectory following and the computational effort, has been compared with that of a feedback-based system executing the same task in the same environmental conditions. The results have been put in relation with the degree of environmental predictability, which was controlled in the experimental trials. The experimental results give support and useful insights for analyzing the applicability of the EP-based scheme.

This paper illustrates the analysis of locomotion in the gastrointestinal tract obtainable by a legged capsule for diagnostic and therapeutic purposes. A preliminary simulation of the legged locomotion onto slippery and deformable substrates has been performed and -simultaneously - mechanisms for on board actuation of the legs have been developed and tested. Moreover, an engineering translation of medical needs in endoscopy is presented, with some ad hoc solutions for improving diagnostic capabilities.

In this paper a wearable biomechatronic system (named MEKA) for the analysis of knee movements in two degrees of freedom is presented. The system has been designed in order to be used not only in laboratory environment (as many other commercial systems) but also in real-life conditions (e.g. for experiments on sport biomechanics). The performance of the MEKA device and of two commercial systems (an electrogoniometer and a camera-based motion analyzer) has been compared. The results showed that the MEKA system is able to obtain similar or even better performance during movements. After this preliminary assessment phase, the MEKA system has been used to analyse the modifications of motor performance of elderly and young people during gait using a "dual-task" approach. The results show that elderly people seems to be more affected by the increase cognitive efforts. In conclusion, the MEKA system seems to be able to provide interesting information for experiments on biomechanics and motor control.

The authors have been developing humanoid robots in order to develop new mechanisms and functions for a humanoid robot that has the ability to communicate naturally with a human by expressing human-like emotion. We considered that human hands play an important role in communication because human hands have grasping, sensing and emotional expression abilities. Then, we developed the emotion expression humanoid robot WE-4RII (Waseda Eye No.4 Refined II) by integrating the new humanoid robot hands RCH-1 (RoboCasa Hand No.1) into the emotion expression humanoid robot WE-4R. Furthermore, we confirmed that RCH-1 and WE-4RII had effective emotional expression ability because the correct recognition rate of WE-4RII's emotional expressions was higher than the WE-4R's one. In this paper, we describe the mechanical features of WE-4RII.

This paper presents the design and development of a 3-axial artificial vestibular system to be integrated on robotic heads, in order to provide a sense of head position and motion. In accordance with the role of the vestibular system in humans, this artificial vestibular system is specifically devoted to regulate and stabilize gaze during head motion, by means of the vestibulo-ocular reflex (VOR) mechanism. Future applications explore the possibility of using the artificial vestibular system on human heads, as an indirect interface between humans and robots, for 'tele-control'.

Among social infrastructure technologies, robot technology (RT) is expected to play an important role in solving the problems of both decrease of birth rate and increase of elderly people in the 21st century, specially but not only in Japan. In order to achieve this objective, the new generation of personal robots should be capable of a natural communication with humans by expressing human-like emotion. In this sense, human hands play a fundamental role in communication, because they have grasping, sensing and emotional expression ability. This paper presents the recent results of the collaboration between the Takanishi Lab of Waseda University, Tokyo, Japan, and the Arts Lab of Scuola Superiore Sant'Anna, Pisa, Italy, and ROBOCASA. In this paper, the development of a novel anthropomorphic hand for humanoid robotics RCH-1 (ROBOCASA Hand No.1) and its integration into a humanoid robotic platform, named WE-4RII (Waseda Eye No.4 Refined II) is presented.

This paper describes a microcontroller-based multichannel telemetry system, suitable for in vivo monitoring of physiological parameters. The device can digitalize and transmit up to three analog signals coming from different sensors. The telemetry transmission is obtained by using a carrier frequency of 433.92 MHz and an amplitude-shift keying modulation. The signal data rate is 13 kb/s per channel. The digital microcontroller provides good flexibility and interesting performance, such as the threshold monitoring, the transmission error detection, and a low power consumption, thanks to the implementation of a sleep mode. The small overall size (less than 1 cm3), the power density compatible with current regulations for the design of implantable devices, and the dedicated packaging make the system suitable for in vivo monitoring in humans. The design, fabrication, operation, packaging, and performance of the system are described in this paper. An in vivo pressure monitoring case study is described as well.

This paper presents the design, development and preliminary test of a new active microendoscope for neuroendoscopy and therapy of the spinal cord. Endoscopy of the spinal sub-arachnoid space is useful for some pathologies, but it is a very challenging task for several reasons: the navigation space is very narrow, there are many blood vessels and delicate structures which could be damaged by maneuvers and large forces and, finally, the CerebroSpinal Fluid (CSF) is a peculiar environment which must be preserved. An innovative method for active safe navigation in the sub-arachnoid space has been devised, based on hydrojets sustentation of the endoscope. The hydrojets, if appropriately tuned and oriented, allow the tip of the endoscope to avoid the delicate structures of the spinal cord and could also assist propulsion. A MATLAB simulation of the hydrojets is illustrated and a digital controller for the regulation of the hydrojets is demonstrated. The pressure ripple is about 5%, as tested experimentally on a 2D simulator. A prototype of steerable microendoscope whose tip is equipped with hydrojets has been fabricated and tested in an artificial path simulating the sub-arachnoid space. Performance are quite interesting.

This paper presents an underactuated artificial hand intended for functional replacement of the natural hand in upper limb amputees. The natural hand has three basic functionalities: grasping, manipulation and exploration. To accomplish the goal of restoring these capabilities by implanting an artificial hand, two fundamental steps are necessary: to develop an artificial hand equipped with artificial proprioceptive and exteroceptive sensors and to fabricate an appropriate interface able to exchange sensory-motor signals with the amputee's body and the central nervous system. In order to address these objectives, we have studied an underactuated hand according to a biomimetic approach, and we have exploited robotic and microengineering technologies to design and fabricate its building blocks. The architecture of the hand comprises the following modules: an actuator system embedded in the underactuated mechanical structure (artificial musculoskeletal system), a proprioceptive sensory system (position and force sensors), an exteroceptive sensory system (3D force sensors distributed on the cosmetic glove), an embedded control unit, and a human/machine interface. The first prototype of the artificial hand has been designed and fabricated. The hand is underactuated, and is equipped with opposable thumb and a proprioceptive sensory system. This paper presents the fabrication and experimental characterization of the hand, focusing on the mechanical structure, the actuator system and the proprioceptive sensory system.

For more than two decades, researchers have proposed and developed methods of providing propulsion at the tip of the colonoscope so that it can pull itself through the gastrointestinal (GI) tract. Most of these methods simulate the way animals move, e.g. earthworm, snake, etc. Other means such as mechanically and through natural peristalsis were also proposed for propelling endoscope. This paper reviews the various locomotion techniques associated with robotic colonoscopy.

Colonoscopy is an important medical procedure for the diagnosis of various diseases, such as cancers in the colon and rectum. However, it requires a lot of time for a doctor to acquire dexterous skills necessary to perform successful colonoscopy. Moreover, for many patients, conventional colonoscopy simply takes long time. Therefore, some studies on the development of autonomous and more convenient colonoscopes are carried out. In this paper, we propose a functional colonoscope robot system that has a locomotive function with a hollow body, a steering system, and other basic functions of typical conventional colonoscope systems. The concept and each component of the functional colonoscope system are described in this paper. In order to evaluate the functional performance of the colonoscope robot, we carried out in-vitro and in-vivo tests.

The application of robots in contact with humans, in services or assistance, implies the realization of effective and acceptable human-robot interaction. In humans, vision plays a significant role in social interaction, like for example in the recognition of faces and expressions, as well as in gesture understanding. Visuo-motor coordination of eye and neck movements in humans presents high performances in terms of accuracy, speed, effectiveness. This is due to the mechanical, cinematic, and dynamic features of the head muscular-skeletal apparatus and to the peculiar processing of visual data, detected with a space variant resolution. The work presented in this paper aims at employing retina-like cameras in human-like robotic head, reproducing similar degrees of freedom, ranges of motion, speeds, and accelerations of human neck and eye movements, in order to improve visuo-motor coordination. The use of retina-like cameras allows a faster human-like processing of visual information, better suited for the control of head movements. On the other hand, retina-like cameras provide high resolution information only in a small area of the image and thus need to be dynamically focused on the points of interest. Experimental trials were focused on the capability of identifying and tracking human faces, as a first step of human-robot interaction. Preliminary experimental results show the feasibility of a smooth face tracking, by a closed control loop for the head movements, based on retina-like vision.

The aim of this paper was to analyse the feasibility of using a sensor-based glove as a tool for the assessment of hand function in persons with orthopedic disorders such as rhizoarthrosis. A glove embedding 20 Hall-effect sensors was used for this purpose. Its performance in terms of repeatability were preliminary investigated in order to define an effective strategy for the use of the glove in these applications. After this preliminary phase, focused clinical experiments were carried out in order to verify the existence of differences usable for performance assessment in the postures of the hand of able-bodied and subjects affected by rhizoarthrosis during grasping. The data were processed by using the principal component analysis (PCA) technique. The preliminary results of these experiments showed that the use of the first and second principal components can allow to discriminate between able-bodied and disabled persons and also between disabled persons before and after the surgical intervention. For this reason, this approach could represent an effective tool for the surgeon during the rehabilitation process in this particular situation. Further experiments will be carried out in the future in order to confirm these preliminary results. Moreover, a new calibration procedure of the sensor-based glove will be developed in order to improve the performance of the glove.

This paper presents a new miniature gripper design, suitable for endoscopic surgery and similar applications. The gripper is based on a mechanism fabricated in-situ via a rapid prototyping process that permits multiple materials and the addition of embedded components. The gripper is actuated using a tuned vibrating mass and impact mechanism. The mechanism relies on close tolerances and clearances, obtained by depositing and subsequently removing thin films of sacrificial material. The gripper design and fabrication process are scalable, and future versions of the gripper can be made at a fraction of the size of the first 15 mm prototype without incurring manufacturing difficulty. Tests on the first prototype reveal the importance of controlling friction and preload at the sliding interface.

Neurophysiological studies show that humans possess the capability of generating appropriate motor behaviors to different uncertain environmental conditions by combining a forward action, produced by the internal forward dynamic model, and a feedback control, realising the transformation from sensory information to motor commands. To this regard, a control system based on the combination of a feedforward and a feedback control loop has been developed in order to provide a robot arm with human-like adaptation capabilities. The work analyses the role of biological coactivation in the mechanism of adjustable visco-elastic arm properties and proposes a function for the evaluation of the robot arm coactivation based on the measure of the position error and the interaction force. The coactivation function is used to update the proportional and derivative parameters of the feedback controller and, consequently, the arm visco-elasticity in unpredictable environmental conditions. Finally, experimental results on the evolution of the coactivation in the adaptation and de-adaptation phases are provided in the last section of the paper.

The objective of the project described in this paper is the development of a cybernetic prosthesis, replicating as much as possible the sensory-motor capabilities of the natural hand. The human hand is not only an effective tool but also an ideal instrument to acquire information from the external environment. The development of a truly human-like artificial hand is probably the most widely known paradigm of "bionics". The Cyberhand Project aims to obtain a cybernetic prosthetic hand interfaced to the peripheral nervous system. In particular this paper is focused on the hand mechanisms design and it presents preliminary results in developing the three fingered anthropomorphic hand prototype and its sensory system.

The paper proposes an anticipation mechanism to improve the perception-action loop of robots interacting with real-world environments. According to recent neuroscientific findings, sensory anticipation can increase the effectiveness of perception-action loops and reduce the delays in obtaining the sensory information, especially in case of complex sensory modalities like vision, that affect pure feed-back structures. In the proposed scheme, perception crucially involves comparison processes between incoming stimuli and expected perceptions (EPs), built from previous perceptions, current motor commands, and internal models of the robot and the environment. Background knowledge plays here a helpful role, as it reduces the computational burden of perception and motor coordination tasks in partially structured environments. In the work presented here, an EP mechanism has been applied in the visuo-motor coordination of an anthropomorphic 8 d.o.f. robotic manipulator equipped with a vision system, in order to evaluate the conditions of applicability of the proposed strategy, and to validate the viability and effectiveness of the initial hypothesis.

This paper is focused on a portable sensorized micro end-effector purposely designed for operating in biomedical test-benches. The gripper, previously designed and fabricated in various materials exploiting different technologies, has been devised to perform tasks of micromanipulation and characterization of biological tissues once integrated into the workstation developed in the authors' lab. The last model of the gripper prototype has been integrated in a "smart" mounting, with on board electronics for signal processing, and further improvements are planned in order to enhance the portability of the tool. Actually, for the development of novel tools and methodologies in the fields of biomedical engineering and computer assisted surgery (CAS), ever-growing importance have both in vitro and in vivo tests, aimed at validating methods and at optimizing innovative tools. The selected gripper, fabricated in stainless steel by laser machining, is equipped with commercial semiconductor strain gauges as force sensors.

In this survey paper, the authors analyze the general structure of robotic systems for computer-assisted surgery, present a classification of such systems based on the degree of "intelligence" of the tools, and discuss some examples of different classes of devices. Computer-assisted surgery accelerated progress is related, on the one hand, to the improvement of medical imaging techniques and, on the other hand, to the evolution of surgical instrumentation. The integration of these two factors has determined an extraordinary progress that is not just a "linear" temporal development, but it is a "discontinuity" as regards traditional surgical procedures. Specifically, the authors consider the following classes of robotic-derived surgical devices/systems: a) handheld tools augmenting the capabilities of the surgeon; b) teleoperated surgical tools; and c) autonomous surgical robots. The paper will focus essentially on the analysis of systems and components of robots and tools designed for minimally invasive surgery. Although different classification methods exist on the basis of the clinical needs and/or on the design approach, the devices which will be illustrated in this paper are classified on the basis of their scale, degrees of freedom, autonomy, embedded intelligence, and features of the interface between the surgeon and the patient.

In the development of humanoid personal robots, accompanying the life of humans in their everyday activities, vision is no doubt an extremely important sensory capability to provide the robots with. We propose the application of robot vision to the identification of hand posture, as a first step in gesture detection, for two main classes of reasons: 1) the recognition of human hand posture can help human-robot interaction, especially in relation to 'teaching by demonstration'; 2) the recognition of the robot hand can allow visual servoing, especially helpful in environments and tasks with a high level of uncertainty. The paper presents the development of a vision system for hand posture recognition, by describing the basic algorithmic implementation, based on symbolic representations, and reporting the experimental results obtained in the recognition of a three-fingered robotic hand.

Current prosthetic hands are basically simple grippers with one or two degrees of freedom, which barely restore the capability of the thumb-index pinch. Although most amputees consider this performance as acceptable for usual tasks, there is ample room for improvement by exploiting recent progresses in mechatronic design and technology. This paper focus on an innovative approach for the design and development of prosthetic hands based on underactuated mechanisms. Furthermore, it describes the development and a preliminary analysis of a first prototype of an underactuated prosthetic hand.

This paper illustrates a mechanism specifically designed for locomotion in the wet, collapsible and tortuous human gastrointestinal (GI) tract (the colon in particular). Previous works performed in the authors' laboratory were devoted to the fabrication of semi-autonomous inchworm locomotion devices for navigation in the colon; in this paper a further analysis of limitations and problems of these devices has been performed. The main limitation consists of the poor efficiency of these devices to negotiate acute bends (due to what the authors termed as the "accordion effect") and, in general, to advance in the scarcely supported colon tissue. Thus a different approach to locomotion has been developed based on "sliding clampers". This locomotion principle has been implemented in a minirobot system and has demonstrated (both theoretically and experimentally) to be effective in reducing the "accordion effect".

The development of humanoid robots and their application as personal robots introduce problems related to the interaction of robots with humans and with environments specifically designed for human beings. In tasks where human-robot cooperation is required, compliance of the robot arm can provide a helpful solution, not only to ensure safety, but especially to increase the robot functionality and usability. The concept of functional compliance is illustrated and an experimental validation is reported, where the functionality of an anthropomorphic robot arm is comparatively assessed with and without compliant control. The paper describes the implementation of a compliant control scheme on an anthropomorphic robotic manipulator, illustrates in detail the methodology adopted for the experimental comparative validation and reports the results obtained in the execution of a sample task by a set of potential users, showing the increased performance in the case of compliant control. Indications are also provided on the improvement of acceptability, which is also affected by the enhanced performance.

This paper presents a research work on compliant control of an anthropomorphic robot arm used as a personal robot. In personal applications of robotics, human-robot interaction represents a critical factor for a robot design and introduces strict requirements on its behavior and control, which has to ensure safety and effectiveness. In this work, the problem of controlling the Dexter anthropomorphic robot arm with variable compliance has been investigated, not only to ensure safety in the interaction with humans, but especially to increase the robot functionality in tasks of physical interaction, performed in co-operation with humans. Two different control schemes have been formulated and implemented, to compare their performance experimentally. Both schemes aim at realising a self-controlled compliant behavior without using information from force/torque sensors. The experimental comparison outlines how the performance of the two control systems are inverted with respect to the theoretical considerations, based on the classical control theory, on their accuracy and effectiveness.

As changing the eating habit to low fiber and high fat diet, the pathology in the colon is growing up annually. Colonoscopy is an important medical procedure for the diagnosis of various diseases like cancer in the colon and rectum. But it requires much time for doctors to acquire a dexterous skill to perform the operation of colonoscope and the procedure is painful and long to the patient in many cases. Therefore, some studies on the development of autonomous and more convenient colonoscope are carried out. In this paper, we propose a smart colonoscope system that has the locomotive function, active camera system, and human-friendly user interface besides the basic functions of the conventional colonoscope system. Doctors will be able to concentrate on the diagnosis itself with this system. The dexterity required to doctors and the pains imposed to patients will also be reduced with this system. The concept and each component of the smart colonoscope system are described in this paper. We carried out in-vitro test to evaluate its validity.

The aim of the work is the integration of an anthropomorphic robotic platform, starting from a neurophysiological model of grasping, in order to provide tools for an experimental validation of the model and also to provide new anthropomorphic solutions for robot grasping. The resulting robotic system is composed of an anthropomorphic arm/hand system and visual and tactile sensors. Grasp planning, control and learning have been achieved by a neural approach, inspired by a model of the inter-connections among the brain areas involved in grasping, as formulated by neurophysiologists. After a description of objectives and specifications for the robotic platform, the system is illustrated and experimental results are reported. Finally, the results are discussed as a starting point for current activities, involving the development of novel human-like robotic components and the implementation of more sophisticated learning schemes.

This paper describes a novel microgripper, fabricated in a superelastic alloy (Ni/sub 50.8/Ti/sub 49.2/) by wired micro Electro Discharge Machining (/spl mu/EDM). The main features of the new microgripper are the use of a superelastic alloy to improve flexure performance by lowering stresses induced and the /spl mu/EDM fabrication technique. The microgripper was sensorized with commercial semiconductor strain-gauges and implemented in a force-feedback micromanipulation workstation developed in the authors' laboratory. Both FEM simulations and the results of experimental characterization in position and force are presented.

In this paper the authors illustrate the development of a semi-autonomous robot for colonoscopy. In particular they focus on two problems: the generation of an effective and reliable advancement in the colon, and the possibility to steer the robot in order to overcome acute intestinal bends. Both problems are present also during traditional colonoscopy, but they can be solved with an external pushing action produced by the endoscopist. The main feature of this work is the attempt to replicate the effects of external forces (generated by the medical doctors) by using just internal actions (generated by the robotic devices). The robotic solutions and the mechanisms illustrated in this paper could be in principle integrated in an "all inside" device, with electrical wires and service tubes, but without structural cables or rigid tails which are currently used for the advancement and orientation of traditional colonoscopes.

A research work on the interaction control of a cable-actuated robot arm, the Dexter arm, is presented in this paper. Firstly, general considerations on the cable-actuated structures and their application potential are provided and then the Dexter structure peculiarities are accurately analyzed in order to develop proper control solutions. Starting from the analysis of the limitations of the compliance control schemes in Cartesian space and in joint space, previously implemented and experimentally validated on the Dexter arm, a novel control strategy, named impedance-compliance controller, is developed. The proposed control strategy tries to combine the benefits of a compliance control scheme in Cartesian space with the benefits of an impedance control scheme in the operational space by compensating the dynamics of the sole proximal joints. The impedance-compliance controller is capable to achieve accurate smooth motions while guaranteeing functional control of the whole structure, even though a greater computational complexity is required The last section of the paper, dedicated to the experimental results, points out the differences with the previously experimented control solutions anti provides some proofs of the increased Dexter functionality.

The research in the field of advanced robotics is turning its attention more and more to man and his assistance, by developing systems such as service robots, personal robots, and even humanoid robots. Interaction control of such robot manipulators is of paramount importance for an effective execution of manipulation and tracking and, over all, for a safe and effective interaction with the humans. The paper concerns the problem of the control of an 8 degree of freedom anthropomorphic arm named DEXTER, mounted on the mobile platform of the MOVAID System, a robotic system for household personal assistance. The goal is to realize a compliant control for this manipulator in tasks of assistance to disabled and elderly people. On the basis of the control theory applied to industrial robotics, a specific compliant control solution has been developed for the DEXTER peculiar mechanical structure and actuation system, which cause a coupled joint configuration. The solution provides the capability of regulating the robot compliance according to the level of stiffness of the interaction environment. The paper describes the theoretical model of the control system, the implementation on the MOVAID platform and the experimental results in the execution of a set of demonstration tasks.

We describe the design and results achieved in the development of a semi-automatic mechatronic tool for computer-assisted endoscopy. The aim of our research is to reduce the risk of damage to delicate anatomical parts in minimally invasive surgical interventions. To this purpose, in a stand-alone configuration, the mechatronic tool is able to detect contact between the steerable tip and surrounding tissues. With the addition of a localizer and an external control unit, a collision-avoidance mechanism prevents contact with pre-selected danger regions of the anatomy. This paper is focused on the architectural and functional description and on the experimental evaluation of the collision-avoidance mechanism. The results demonstrate that the endoscope is suitable for clinical practice, both in terms of spatial accuracy and reaction speed.

The field of humanoids robotics is widely recognized as the current challenge for robotics research. Developing humanoids poses fascinating problems in the realization of manipulation capability, which is still one of most complex problem in robotics. The paper, starting from an overview of current activities in the development of humanoid robots, with special focus on manipulation, presents the authors' approach to the design and development of anthropomorphic sensorized hands and of anthropomorphic control and sensory-motor coordination schemes. Current achievements at the Scuola Superiore Sant'Anna and Centro INAIL RTR (Research Centre on Rehabilitation Bioengineering) in the development of a robotic human prosthesis are described, together with preliminary experimental results, as well as in the implementation of biologically-inspired schemes for control and sensory-motor co-ordination, derived from models of well-identified human brain areas.

This paper describes a novel mechatronic tool for arthroscopy, which is at the same time a smart tool for traditional arthroscopy and the main component of a system for computer-assisted arthroscopy. The mechatronic arthroscope has a cable-actuated servomotor-driven multi-joint mechanical structure, is equipped with a position sensor measuring the orientation of the tip and with a force sensor detecting possible contact with delicate tissues in the knee, and incorporates an embedded microcontroller for sensor signal processing, motor driving and interfacing with the surgeon and/or the system control unit. When used manually, the mechatronic arthroscope enhances the surgeon's capabilities by enabling him/her to easily control tip motion and to prevent undesired contacts. When the tool is integrated in a complete system for computer-assisted arthroscopy, the trajectory of the arthroscope is reconstructed in real time by an optical tracking system using infrared emitters located in the handle, providing advantages in terms of improved intervention accuracy. The computer-assisted arthroscopy system comprises an image processing module for segmentation and three-dimensional reconstruction of preoperative computer tomography or magnetic resonance images, a registration module for measuring the position of the knee joint, tracking the trajectory of the operating tools, and matching preoperative and intra-operative images, and a human-machine interface that displays the enhanced reality scenario and data from the mechatronic arthroscope in a friendly and intuitive manner. By integrating preoperative and intra-operative images and information provided by the mechatronic arthroscope, the system allows virtual navigation in the knee joint during the planning phase and computer guidance by augmented reality during the intervention. This paper describes in detail the characteristics of the mechatronic arthroscope and of the system for computer-assisted arthroscopy and discusses experimental results obtained with a preliminary version of the tool and of the system.

This paper describes a novel 4-axis microgripping system consisting of two fingers, each driven by a 2-axis moving coil actuator taken from a CD-lens assembly. These electromagnetic actuators are small, very linear, virtually frictionless and low cost. We measured the electrical actuator parameters and characterized the actuator performance in terms of displacement vs. current, force vs. current and resonant frequency. Experimental results indicate that the proposed microgripping system can be an attractive solution to the problem of micromanipulating small objects for precision manufacturing and biotechnology with high accuracy in a relatively large workspace.

If we could obtain robots which act as humans, does this imply that both have the same structure and are made of the same "substance"? The paper addresses this open question by implementing a basic robotic motor task using anthropomorphic hardware and an anthropomorphic computational approach. Two different algorithms implementing reinforcement learning both at a psychological and bio-mimetic level are presented and discussed. The performance achieved during the experimental trials suggests that similar performance can be achieved by the formal mathematical model of reinforcement learning and by the locally bio-mimetic architecture. This is very promising for the achievement of the adaptability, versatility and flexibility required of a humanoid, whilst still at acceptable levels of computational burden.

We first discuss some general aspects of micromanipulation and possible different approaches. Then, we present new results in the micromanipulation of mechanical and biological objects. The apparatus we use is a purposely developed workstation comprising macro- and micro-manipulators. The most innovative component of the workstation is a micro-gripper fabricated using LIGA technology and actuated by piezoelectric actuators. We describe the design, fabrication and performance of a few prototypes of LIGA micro-grippers. Results are presented which demonstrate the ability of the system to manipulate effectively both micro-mechanical and biological micro-objects.

The capability of autonomously discovering relations between perceptual data and motor actions is crucial for the development of robust adaptive robotic systems intended to operate in a changing and unknown environment. In the case of robotic tactile perception, proper interaction between contact sensing and motor control is the basic step towards the execution of complex motor procedures such as grasping and manipulation. In this paper we propose an approach to the development of tactile-motor coordination in robotics, based on a neural model of the human tactile-motor system. The definition of such model is based on the features of biological systems as investigated by neuroscience. The autonomous development of tactile-motor coordination achieved through the implementation of the neural model is evaluated by experimental trials using a sensorised prosthetic hand and a robotic manipulator. The proposed neural network architecture linking changes in the sensed tactile pattern with the motor actions performed is described and experimental results are analysed and discussed.

A robotic system which imitates the development process of stable grasping in infants is presented. The sensing devices of the system are tactile and visual sensors based on anthropomorphic design. The sensory data are processed and fused by the internal learning system based on artificial neural networks implementing the psychological aspects of the reinforcement learning paradigm. The design of the robotic system is modelled on the principles of synthetic psychology in order to obtain a human-like behavior, an important step towards "humanoids". Experiments show that the robot is able to find the best procedure to hold an object using the learned force with an average of 9 successful grasps over 10 trials.

A general framework of artificial perception for personal robots is proposed, and a subset of the framework, devoted to the face problem of robotic grasping and manipulation, is implemented. A series of experiments has been carried out using an anthropomorphic approach, both in the sensory system and in the processing modules. In particular planning of the pre-grasping hand shaping, learning of motor co-ordination strategies, exploration and grasping of an object and object classification based on the visuo-tactile information perceived during the exploration phase are described. Experiments indicate that the proposed framework may lead to practical results towards the implementation of "humanoid" robots.

Colonoscopy is an important procedure for the diagnosis of various pathologies, in particular cancer of the colon and of the rectum, the second most malignant tumor in industrialized countries. At present however, colonoscopy is a procedure often painful for the patient and complex for the doctor. This is mainly due to the characteristics of current colonoscopes, which are quite rigid and require the doctor to perform difficult maneuvers for insertion. In this paper we present the concept and describe the design and fabrication of a new system for colonoscopy based on a microrobot capable of being propelled semi-autonomously along the colon. The microrobot system comprises a mothership incorporating devices for clamping the colon wall and tools for diagnosis and intervention. The actuation system is based on purposely developed shape memory alloy (SMA) pneumatic microvalves. A human/machine interface allows the doctor to teleoperate or supervise the functioning of the microrobot and to receive visual and other information during endoscopy. Particular attention has been paid to investigating a reliable and safe method of locomotion and to develop an efficient clamping system for the microrobot. The resulting configuration of the microrobot is very simple and potentially suitable for real clinical application. A prototype microrobot system has been tested in vitro with promising results.

Arthroscopic techniques are very popular in orthopaedic surgery for intervention on articular joints, especially on the knee. From an engineering viewpoint, current arthroscopic techniques can be improved in two ways: a) by augmenting visual information for the surgeon; b) by improving existing instrumentation. In our laboratory we are addressing both problems by developing an integrated system for computer-assisted arthroscopy. In this paper the procedures and instrumentation currently adopted for arthroscopy, and the limitations of both, are described first. Then the main characteristics of the integrated system we are developing are presented. The design requirements for new and better instruments for arthroscopy are discussed in detail and the fabrication and testing of a prototype of shape memory alloy-based actuator developed for steering the distal part of an arthroscope are discussed. The prototype steerable end-effector can rotate of /spl plusmn/90/spl deg/ and exert a maximum force at the tip of about 1N.

This paper presents an integrated approach to tactile perception, both in terms of data acquisition and data interpretation. In humans, touch sensing is implemented through a number of different sensing elements embedded in the skin. The interpretation of perceived data to the level of detection of basic features, such as material, shape of surface, shape of contact, is achieved by integrating the different sensorial inputs at a low level, with no involvement of high level cognitive processes. The approach we propose in this paper follows this anthropomorphic model of tactile perception, by including, on one hand, a miniature fingertip integrating different sensors and, on the other hand, a parallel data interpretation module implemented through a fuzzy neural-network which processes all the different inputs at the same level. The paper describes the characteristics of the integrated fingertip sensor and of the neuro-fuzzy system, and discusses experimental results achieved during exploratory tasks on a set of common objects are discussed in detail.

This paper describes a teleoperated mobile microrobot incorporating a novel type of electromagnetic micromotor. The overall dimensions of the microrobot are 10 mm/spl times/10 mm/spl times/10 mm. Two micromotors are used to actuate the two wheels of the microrobot. The micromotor is based on variable reluctance working principle and moves step by step. The micromotor is driven by a sequence of current pulses and performs about 200 steps per revolution. The micromotor generates a torque of 350.10/sup -6/ Nm at each step and a maximum speed of about 180 rpm. The heart of the control circuitry is the PIC16C73 microcontroller, that implements the control algorithm which allows the microrobot to move forward, backward and turn left or right. The operator controls the microrobot by a remote joystick and flexible ultraminiature wires. The microrobot has a maximum speed of 10 cm/s and can climb a slope of 15 degrees. The paper describes the design, fabrication and performance of the microrobot and of its components.

In this paper, a framework for vision-based relative positioning called affine visual servoing (AVS) is presented, in which the changes in shape of image contours are used in order to control the positioning process. A feedforward control strategy complements the feedback loop, thus enhancing both speed and the overall performance of the system. The full linearization of the visual servoing problem results in a dramatical reduction of the computational burden for both the control and vision subsystems. Good simulation results with stable behavior show that the approach may be successfully applied for the design of complex positioning tasks, such as navigating by means of natural landmarks, or mimicking human gestures.

This paper describes preliminary work on a non-intrusive gaze-driven interface for man-machine interaction based on vision techniques. The current computer screen location pointed at by the user is evaluated using a linear model of image-to-screen mapping, which can be easily auto-calibrated at run-time on the basis of the current relative position of camera and user and camera settings. A simple active deformable model of the eye is defined, which is used both to track user's movements and estimate the current position of the user's pupil in the image in a decoupled fashion. Experiments show that the proposed approach is fast and accurate enough for the design of low-cost man-machine interfaces, with applications ranging from the assistance to the disabled people to multimedia systems.

Although major research efforts were devoted in the past to the development of tactile sensing systems for robots, a truly usable, robust, reliable and cheap system is not available yet. This paper presents the design of a tactile sensor system which could fulfil the above requirements. The sensor incorporates multiple sensing subsystems for detecting distributed contact forces and surface characteristics. The fabrication and experimental evaluation of the tactile system and of its electric interface are described. Results indicate that the system provides reasonable performances for practical applications requiring manipulation with tactile feedback.

In this paper we describe our approach to the design of proximity sensor arrays. Each sensing element of the proximity sensor array is a composite sensor, i.e. a sensor which is composed of an in-air ultrasonic rangefinder and an infrared detector. This sensor arrangement is capable, in principle, to achieve a perception of the explored objects that is not necessarily limited to their geometrical properties (size, shape and location relative to the sensor); possibly, the perception can be extended to other relevant features. In this paper, we show that, in principle, a sort of perception of the surface reflectance (the color) is achievable. The concept of the proposed sensor array spans a wide range of potential applications in flexible industrial automation, service robotics and autonomous mobility. The system described, in particular, is intended for providing an advanced wheelchair with the navigational capabilities required for improving the driving skills of disabled users.

The traditional approach to automation and robotics has focused so far mainly on assembly problems, whereas the managing of manufactured products at the end of their life cycle has been almost entirely neglected. However, disassembly and recycling are becoming important factors as the ecological and economical implications of manufacturing raise increasing concerns. As an initial investigation of the very general problem of disassembly, in this paper the authors outline first the motivations and the potentially very important perspectives of this approach for robotics and automation research and for industrial application. Then the authors present a robotic system for the extraction, recognition and sorting of individual objects from an "agglomerate". Such operations are of crucial importance in several disassembly tasks, such as recycling and raw materials recovering. The system is based on the integration of different sensory modalities with motor actions. An example of application of the system is described and experimental results are discussed.>

The development of autonomous systems capable of executing intelligent exploratory procedures requires the understanding of the interactions between touch and motor control modalities. In robotic tactile perception this is the basic step toward the execution of highly sophisticated motor procedures such as grasping and manipulation. In this paper, the problem of autonomous learning of tactile-motor coordination is investigated in the case of a robotic system composed of a multi-functional tactile probe mounted on a robotic manipulator. A neural network architecture linking changes in the sensed tactile pattern with the motor action performed is described, and experimental results are analyzed. The generation of motor control procedures for actively estimating surface curvature is considered as an example of application of the proposed approach.>

This paper reports the current state-of-the-art in medical robotics. Three general areas of advanced robotics are identified: macro robotics, micro robotics and bio-robotics. Macro robotics include the development of robots, wheelchairs, manipulators for rehabilitation as well as new more powerful tools and techniques for surgery. Micro robotics could contribute to the field of minimally invasive surgery as well as to the development of a new generation of miniaturised mechatronic tools for conventional surgery. Bio-robotics deals with the problems of modelling and simulating biological systems in order to provide a better understanding of human physiology. According to this classification, a review on the most important past and ongoing research projects in the field is reported. Some commercial products already appeared on the marker are also mentioned, and a brief analysis of the economical potentialities of robotics in medicine is presented.>

Disassembly and recycling are becoming increasingly important in our society, especially for their ecological implications. In this paper the authors present an approach to disassembly problems, which is essentially based on the concepts of multisensory integration and fusion and on the use of purposive actions to simplify perceptual tasks. The authors present a robotic system for the recognition and sorting of individual objects from a group, operations that are extremely important in most disassembly tasks. An example application of the system is described and experimental results are discussed. The effectiveness of the system in operating in a partially structured environment, shows how problems which are difficult to manage by using a single sensory modality can be solved by integrating multisensory data.>

This paper reports part of the work related to the design and development of the URMAD system, a mobile robotic unit purposely devised to assist the severely disabled in a household environment. A supervisory system based on distributed decision making and functional distribution has been designed and implemented on a VME/OS9 architecture. This system is capable of executing typical domestic tasks expressed in a synthetic command language extracted from everyday vocabulary. The user's requests can be easily specified by using a Windows-like graphical user interface and are translated into the command language by an interpreter running on a personal computer. In the paper, a general overview of the URMAD system is provided. A detailed description of the proposed modular architecture for the supervisory system, of its various modules and of the command language, is presented. Finally, the hardware and software implementation of the first prototype of the system and some preliminary experimental tests and simulations are reported.>

Controlling grasp and avoiding object slippage is very important in hand prosthetic systems. At present the amputee must use vision to monitor grasp, and adjust grasping force based on this estimate. We investigate the problem of measuring normal and tangential forces at the gripper-object interface, and design a slip tactile sensing system for this purpose. In this paper we discuss the design, fabrication and testing of a tactile sensing system intended for application to a myoelectrically controlled hand prosthesis, and outline a control strategy for preventing object slippage using sensory feedback.>

Among several applications of robotics in medicine, robotic surgery represents one of the most promising scientific challenges for the research community. Its main expectations are to increase the quality of interventions, to decrease the intervention time and to reduce health care costs, by combining the analysis capabilities of imaging systems with the precision of robot manipulators. This paper introduces our surgical robotic system, describing in details the presurgical planning, surgeon-robot interface, matching between the virtual image and real robot workspace, safety considerations, knee implantation procedure, and experimental analysis about precision and errors.>

The authors present motivations for the long term research program on the various aspects of disassembly undertaken in their laboratory, and outline a theoretical framework for approaching disassembly problems. An application is described which is derived from such a framework in the context of a specific case-study of disassembly.

The problem of developing a sensing system for robots moving in a partially or completely unknown environment is investigated. A model of a generalized sensitive skin based on different types of sensors to be located on the whole surface of a robot is illustrated. A logic and hardware structure of the low-level layer of the skin is proposed to guarantee modularity and consistency of sensory data. A configuration including ultrasonic and infrared proximity sensors was chosen for the implementation of a prototype of the skin. A possible physical layout for obtaining a conformable skin to be used on any kind of robot surface is also presented. Local and general rules for low-level sensory data fusion are defined, and possible improvements of real-time obstacle avoidance path planning strategies are discussed by introducing sensor-based instinctive behaviors. A simulation of a modified potential field-based real-time planner for a mobile robot operating in a partially unknown environments is discussed to demonstrate the feasibility of this approach.

A system for visual recognition derived from a previously developed theoretical framework on the overall organization of the human visual system is proposed. The system operates dynamically by analyzing different parts of the input scene at variable levels of resolution through an attentional spotlight. A constant amount of information is gathered from the scene and a fixed dimension icon is produced, so that a trade-off occurs between the extension of the examined area and the level of resolution at which data are analyzed. The position of the spotlight and its dimensions are determined on the basis of the evolution of the recognition process. The icon is processed by a bottom-up path composed of a five-layer artificial neural network. The results of this net are analyzed by a planning module which determines if recognition has been achieved, or which action to undertake next. A top-down path, including a set of nets trained by the backpropagation algorithm, evaluates the parameters of the next sampling of information. The application of the system to object recognition with varying viewpoint and range from the camera is investigated.

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A description is presented of the social organization of societies of cellular mobile units featuring instinctive behavior. Each robotic unit has its own personality and lives independently from the others. Useful tasks are carried out through collaboration rather than by individual effort. The behavior of each unit derives from a subsumption-like control structure, which emphasizes the roles of innate personality, external stimuli, and communication. A number of different robotic personalities are described and techniques of implementing them in real robot units are outlined. The implementation of instinctive behavior is described for the case of a robotic vehicle system (ROBBIE).>

Describes the architecture and the components of a robot workstation designed to investigate active perception, with particular emphasis on tactile sensing procedures. The workstation is centered around a multifunctional finger-like probe equipped with different types of sensors, and a PUMA 562 manipulator to carry out exploration. The system operates under the control of a distributed architecture in which different sensory information is processed in parallel, whereas exploratory parameters (contact force, direction, velocity) are set in real time. Dedicated exploratory procedures allow to extract specific object features and to sort different objects out of a given set.>

Presents an approach to the implementation of the concept of 'distributed robotic system' (DRS), based on the notions of 'instinctive' response and cooperation. The proposed DRS is composed of cellular robotic units which operate in a constrained unstructured environment and are dedicated to environmental monitoring. This specific application, of potentially wide practical interest, poses a number of constraints to the control of the DRS, which can be solved efficiently by using the proposed approach.>

A push-pull actuator for commanding the motion of the interphalangeal joints of anthropomorphic robotic hands is proposed. The actuator, based on coil springs, made of the shape-memory alloy Nitinol, is compact enough to be easily incorporated into the phalangeal structure of a robotic finger, thus eliminating the complex routing of the cables and tendons usually adopted for transmitting motion from conventional actuators (e.g. DC servomotors) to the joints. The performance of the SMA actuator is illustrated, and the concepts of temperature, strain, and stress limits for the control of the whole push-pull actuating system are emphasized. The methods adopted to improve the usually limited frequency response of SMA actuators are also described. Finally, the control of the whole system and some experimental results demonstrating promising actuator performance are discussed.>

The authors discuss the application of intrinsic tactile sensing (ITS) to grasp and manipulation control. A brief description of ITS, i.e., contact sensing based on force/torque measurements at fingertips, is provided. A method for using sensory feedback in the control of grasp forces to augment grasp robustness against slippage is discussed with respect to a simple grasp type; simulation and experimental data are provided. The possible generalization of this sensor-driven approach to the control of optimal grasp force in complex grasp configurations is addressed.>

The design of a robot system capable of carrying out complex sensory-motor sequences intended for collecting information on some body functions through palpation is proposed. The main features of the robot system, which consists of an articulated finger incorporating joint force and position sensors as well as piezoelectric polymer skin-like sensors, are discussed. The subroutine PALPATION, aimed at detecting hardened regions embedded in soft biological tissues through an exploratory procedure which replicates the operation of the physician's finger, is presented. A simple model for the behavior of the piezoelectric polymer fingertip sensor is proposed, and preliminary experimental results indicating both the validity of the model and the feasibility of the proposed automated palpatory procedure are reported.>

In this paper we approach the problem of replicating some of the human tactile perceptual paradigms through the development of an anthropomorphic robotic testbed consisting of a single exploratory finger and of a sensorized platform. This artificial tactile sensing system has been purposely devised to execute simple humanlike sensory-motor acts ("tactile subroutines") which form the basis for more complex exploratory strategies. After describing the features of the hardware components of the tactile sensing system, both the phylosophy and the practical implementation of a set of exploratory subroutines are discussed. Finally, the results of a few experimental tests carried out in order to evaluate the usefulness of the proposed exploratory approach in the context of a robot workstation for the assistance of disabled persons, are reported.

This paper addresses the problem of optimal geometrical design for tactile sensors. To this aim the particular case in which sensor-object contact information can be reduced to the form of a binary tactile image is considered. Possible criteria for the evaluation of space-invariant (orthogonal and hexagonal grids) and space-variant (retina-like and "multifovea") dispositions of sensing elements are discussed. Simulation studies are carried on to compare space-invariant configurations in terms of rate of success in pattern recognition, and to evaluate the efficiency of the multifovea disposition in the calculation of position and orientation of sample objects. Finally, results obtained by applying different pattern recognition algorithms to the analysis of pseudovisual images provided by a real sensorized static platform are presented.

To investigate basic issues related to tactile sensing for robots, a sensorized scenario has been devised which comprises a multisensor static platform and a tendon actuated, 4 degree-of-freedom exploratory finger. Multiple sensory information is fed to the finger control unit: most significant is that obtained through a composite, skinlike tactile sensor, developed in our laboratory and based on the technology of ferroelectric polymers. In this paper we discuss the design and describe some components of our sensorized scenario. The main features of the articulated exploratory finger are presented and a hybrid type of control, purposely devised for object exploration with tactile feedback, is outlined. Emphasis is also given to the discussion of design criteria for skin-like tactile sensors and to the description of the fingertip multifunctional ferroelectric polymer tactile sensor. Finally, some preliminary experimental results are presented.

This paper describes a composite transducer for tactile sensing, whose skin-like structure makes it potentially useful in prosthetics as well as in robotics. Such transducer comprises an "epidermal", thin film, polyvinylidene fluoride (PVF2) sensor and two inner layers consisting of a conductive rubber sheet and of an array of 128 PVF2sensors, which are intended to reproduce in part some mechanical features and sensing capabilities of the human dermis. The proposed transducer has been tested and its ability to detect, by touch, hardness, thermal conductivity and surface texture of objects, as well as contact pressure has been assessed. Although much work is still needed to obtain a really usable device, sensitivity, linearity and bandwidth of the present tactile transducer, along with its wide range of sensorial capabilities, strongly encourage further development.