This paper investigates the use of Immersive Virtual Environment (IVE) to evaluate the process of emotion recognition from faces (ERF). ERF has been mostly probed by using still photographs resembling universal expressions. However, this approach does not reflect the vividness of faces. Virtual Reality (VR) makes use of animated agents, trying to overcome this issue by reproducing the inherent dynamic of facial expressions, but outside a natural environment. We suggest that a setup using IVE technology simulating a real scene in combination with virtual agents (VAs) displaying dynamic facial expressions should improve the study of ERF. To support our claim we carried out an experiment in which two groups of subjects had to recognize VAs facial expression of universal and basic emotions in IVE and No-IVE condition. The goal was to evaluate the impact of the immersion in VE for ERF investigation. Results showed that the level of immersion in IVE does not interfere with the recognition task and a high level of accuracy in facial recognition suggests that IVE can be used to investigate the process of ERF.

Social experience can deeply impact on gaming experience and is often used to increase enjoyment and retention. In the literature two main categories of social interaction can be identified: competition and collaboration. Player engagement has been widely studied under different conditions related to the type of social interaction taking place during the game. However, rich and newly available contexts based on emerging paradigms, such as those enabled by Natural User Interfaces, have not been yet extensively addressed. In the current study the impact of collaborative and competitive goal structures on player engagement, awareness and social presence is evaluated in the context of a jigsaw puzzle game taking place in a Shared Virtual Environment using a highly immersive setup exploiting natural user interaction.

A non-invasive Brain Computer Interface (BCI) based on a Convolutional Neural Network (CNN) is presented as a novel approach for navigation in Virtual Environment (VE). The developed navigation control interface relies on Steady State Visually Evoked Potentials (SSVEP), whose features are discriminated in real time in the electroencephalographic (EEG) data by means of the CNN. The proposed approach has been evaluated through navigation by walking in an immersive and plausible virtual environment (VE), thus enhancing the involvement of the participant and his perception of the VE. Results show that the BCI based on a CNN can be profitably applied for decoding SSVEP features in navigation scenarios, where a reduced number of commands needs to be reliably and rapidly selected. The participant was able to accomplish a waypoint walking task within the VE, by controlling navigation through of the only brain activity.

This poster introduces a fully immersive Mixed Reality system we have recently developed, where the user is free to walk inside a virtual scenario while wearing a HMD. The novelty of the system lies in the fact that users can see and use their real hands — by means of a Kinect-like camera mounted on the HMD — in order to naturally interact with the virtual objects. Our working hypothesis are that the introduction of the photorealistic capture of users' hands in a coherently rendered virtual scenario induces in them a strong feeling of presence and embodiment without the need of using a synthetic 3D modelled avatar as a representation of the self. We also argue that the users' ability of grasping and manipulating virtual objects using their own hands not only provides an intuitive interaction experience, but also improves self-perception as well as the perception of the environment.

This paper presents a novel fully immersive Mixed Reality system that we have recently developed where the user freely walks in a life-size virtual scenario wearing an HMD and can see and use her/his own body when interacting with objects. This form of natural interaction is made possible in our system because the user's hands are real-time captured by means of a RGBD camera on the HMD. This allow the system to have in real-time a texturized geometric mesh of the hands and body (as seen from her/his own perspective) that can be rendered like any other polygonal model in the scene. Our hypothesis is that by presenting to the users an egocentric view of the virtual environment "populated" by their own bodies, a very strong feeling of presence is developed as well.

ABSTRACT The use of stereographic systems is spreading out in modern society, from the revolution of cinematography to its adoption in high‐tech products such as portable gaming devices or photo cameras. However, the fruition of immersive stereographic systems by more than one person at a time is still a research issue. In more detail, the class of passive stereo systems presents technological limitations of displaying correct multiuser perspectives. In fact, the stereo image projected onto the screen is usually rendered according to a unique point of view (PoV). Nevertheless, in multiuser systems, the selection of an appropriate PoV can minimize both optical discomfort and perspective distortion. This paper aims to evaluate which among existing PoV calculation methods provides the best performances in terms of projection realism, optical comfort and overall system usability in multiuser passive stereo systems. The performances have been evaluated in three different “distance” scenarios to take into account also the effects of binocular disparity in the PoV calculation. To accomplish this objective, we administered a questionnaire to nine couple subjects, evaluating each of the investigated PoV calculation methods for each of the three distance scenarios. Copyright © 2013 John Wiley & Sons, Ltd.

This work presents the development and the preliminary experimental assessment of a novel EMG-driven robotic hand exoskeleton for bilateral active training of grasp motion in stroke. The system allows to control the grasping force required to lift a real object with an impaired hand, through the active guidance provided by a hand active exoskeleton, whose force is modulated by the EMG readings acquired on the opposite unimpaired arm. To estimate the grasping force, the system makes use of surface EMG recordings during grasping, developed on the opposite unimpaired arm, and of a neural network to classify the information. The design, integration and experimental characterization of the system during the grasp of two cylindrical objects is presented. The experimental results show that an optimal force tracking of the interaction force with the object can be achieved.

The combination of robotics and virtual reality seems promising for the rehabilitation of the upper limb by promoting intensive training on specific deficits with motor control and multimodal feedback in engaging game-like scenarios. In this paper we present the integration of a robotic system and virtual reality applications for the orthopedic rehabilitation of the arm, in terms of strengthening training and motion recovery. The system simulates the upper limb of the patient and their actions, and allows exhaustive exercising and motor control, giving visuomotor and haptic feedback and trajectory positioning guidance. The system allows assign specific tasks to perform within the virtual environments and aids to evaluate the mobility condition of the patient, to personalize the difficulty level of the therapy and provides kineseologic measures of the patient evolution. We present the results of a preliminary clinical assessment we are carried out on three patients in order to assess the usability and acceptance of the system.

This paper presents a health economic system for motor recovery in patients with the commonest cause of death in some countries, stroke. The system is based on immersive, real-time motion capture (MOCA) available for private use and at the bedside. An interactive virtual reality (VR) interface designed with auditory and visual feedback. It consists on two scenarios and a 3D character that follows the user's arm movements by using the first and third person view metaphors of interaction. Two easy and enjoyable games are proposed for each scenario. The system is designed to be adapted to several tasks with different index of difficulty (ID) for gradual motor recovery in patients with stroke. The experiments carried out on eight healthy neurologically interact volunteers have shown that our system is suitable to be used at home on training programs, giving good references for future applications on stroke arm recovery.

This paper presents a system designed to induce, in healthy subjects, artificial hand-tremor that is observed in persons affected by neurological impairments. The objective is to allow a healthy user to feel in first person the effect of the impairment while performing common manipulative tasks in order for her/him to understand and gain empathy with the impaired person. The developed tool is based on a wrist-attached desktop haptic interface with a workspace that is comparable to that of the arm of the user. Such device is able to exert controlled forces on the user's wrist and induce hand-tremor whose frequency and amplitude is correlated with different pathologies. The control of the device is based on the recording and playback of tremor signals acquired by a motion tracker. In this paper, we present the system with its dynamic characteristics and three different types of controller are experimentally tested and compared.

During typical robot-assisted training sessions, patients are required to execute tasks with the assistance of a robot while receiving feedback on a 2D display. Three-dimensional tasks of this sort require the adoption of stereoscopy to achieve correct visuo-motor-proprioceptive alignment. Stereoscopy often causes side-effects as sickness and tiredness, and it may affect the processes of recovery and cortical reorganization of the patients' brain in an unclear way. It follows that it is preferrable for a robot-assisted neurorehabilitation therapy to work in a real 3D setup containing real objects rather than using virtual reality. In this paper, we propose a new system for robot-assisted neurorehabilitation scenarios which allows patients to execute therapy by manipulating real, generic 3D objects. The proposed system is based on a new algorithm for identification and tracking of generic objects which makes efficient use of a Microsoft Kinect sensor. We discuss the results of several experiments conducted in order to test robustness, accuracy and speed of the tracking algorithm and the feasibility of the integrated system.

This paper presents the development of an interaction-torque control architecture for a rehabilitation exoskeleton (RehabExos) with flexible joints equipped with internal torque sensors. The architecture consists of an outer control loop, which is based on the kineto-statics of the RehabExos, and on four identical-independent inner full-state joint-torque controllers (IJTFC). The considered IJTFC demonstrate good stability, responsiveness and accuracy in tracking the desired torques generated by the outer controller. Comparison with other control strategies available from the literature is shown via analytical and experimental results, which highlight the improved performances of the proposed IJTFC method in controlling the RehabExos robot.

This paper proposes a new multimodal architecture for gaze-independent brain-computer interface (BCI)-driven control of a robotic upper limb exoskeleton for stroke rehabilitation to provide active assistance in the execution of reaching tasks in a real setting scenario. At the level of action plan, the patient's intention is decoded by means of an active vision system, through the combination of a Kinect-based vision system, which can online robustly identify and track 3-D objects, and an eye-tracking system for objects selection. At the level of action generation, a BCI is used to control the patient's intention to move his/her own arm, on the basis of brain activity analyzed during motor imagery. The main kinematic parameters of the reaching movement (i.e., speed, acceleration, and jerk) assisted by the robot are modulated by the output of the BCI classifier so that the robot-assisted movement is performed under a continuous control of patient's brain activity. The system was experimentally evaluated in a group of three healthy volunteers and four chronic stroke patients. Experimental results show that all subjects were able to operate the exoskeleton movement by BCI with a classification error rate of 89.4±5.0% in the robot-assisted condition, with no difference of the performance observed in stroke patients compared with healthy subjects. This indicates the high potential of the proposed gaze-BCI-driven robotic assistance for neurorehabilitation of patients with motor impairments after stroke since the earliest phase of recovery.

Real-time 3D content distribution over a network (either LAN or WAN) has many possible applications, but requires facing several challenges, most notably the handling of the large amount of data usually associated with 3D meshes. The scope of the present paper falls within the well-established context of real-time capture and streaming of OpenGL command sequences, focusing in particular on data compression schemes. However, we advance beyond the state-of-the-art improving over previous attempts of "in-frame" geometric compression on 3D structures inferred from generic OpenGL command sequences and adding "inter-frame" redundancy exploitation of the traffic generated by the typical architecture of interactive applications. Measurements reveal for this combination of techniques a very effective reduction of network traffic and a CPU overhead compatible with the requirements of interactive applications, suggesting a significant application potential for Internet-based 3D content streaming.

Eye-tracking systems are playing an increasingly important role in assistive robotics as hand-free interaction interfaces for motor impaired people, but no noticeable applications have been developed so far for enhancing the robotic assisted training in functional rehabilitation. In this paper we propose a new gaze-based control to provide active guidance to the upper limb movement, through a robotic exoskeleton, in the functional rehabilitation of pick and place tasks. Experimental results on healthy subjects demonstrate the feasibility of the proposed approach and the breakthrough that the system introduces in the field of eye-based rehabilitation systems.

This paper describes the design, the preliminary evaluation and proposes a control strategy of a novel distributed tactile transducer for finger tip stimulation. The presented study has been conducted for the realization of a compact tactile device aiming at integration with a kinesthetic feedback systems. The transducer is a 5×6 array based on custom electromechanical mini-solenoid designed and optimized for reduced encumbrance and lightweight. The realized actuator has a diameter of 2.4mm and is capable of delivering a maximum force of 73mN. In the first section we present the electro-mechanical design, the optimization and the first experimental test of a prototype for the new transducer. In the second section we show the electronic design and a strategy for controlling arrays of transducers with a reduced number of connectors. This principle is based on active matrix addressing of LCD displays.

Tangential skin displacement at the fingertip is an effective means of communicating direction or displaying static friction in haptic application. A tactile device capable of stretching the skin of the fingerpad can be mounted directly on the fingertip or embedded in haptic interfaces and hand-held devices. In both cases low weight and small dimensions are important requirements. We have developed a miniaturized tactile device capable of displaying tangential skin displacement in two directions. The actuation for the device is realized by SMA wires, in order to reduce bulk and weight, and the displacements are measured by optical sensors. The performance of the device has been verified experimentally.

Several manipulators or exoskeleton are characterized by having a concave workspace in the operational space due to mechanical limits. This article proposes an online trajectory planning method for performing visually guided assisted reaching through a rehabilitation robotic exoskeleton, the L-Exos, in its concave workspace. To evaluate the proposed methodology in a rehabilitation application, we set-up a computer vision based system that can automatically identify target objects in the workspace and generate a robot assisted movement to reach them through the L-Exos.

The PERCRO laboratory of Scuola Superiore Sant'Anna has recently completed the development and functional assessment of the Body Extender (BE) system, an advanced wearable robot expressly conceived for augmenting the human strength for handling of heavy materials in unstructured environment. The system is composed by four robotic limbs with anthropomorphic kinematics and has a total of 22 independently actuated degrees of freedom. The leg locomotion and the force servo-amplification allow operations in environments that are hardly accessible by the conventional handling systems preserving the force sensibility during the manipulative tasks. Possible applications are handling of military materials in narrow spaces, rescuing of victims in natural and human provoked disasters and handling of heavy parts in the manufacturing of large products. The paper reports the system specifications taken as a reference for the design, the criteria and verification methods, the architectural solutions used for the implementation of mechanics, electronic and control components and the results of the preliminary experimental assessment.

The present paper introduces a novel type of haptic interface which is fully portable and employs only onboard sensors and electronics to solve accurate localization and force feedback generation. The device offers 2DOF force control while sliding on a plane and maintaining its orientation comfortable for the user. The device generates force feedback information without any intermediate link between the motion wheels and the grasping handle. The device has been designed for application in neuro-rehabilitation protocols and it adopts specific mechanical, electrical and control solutions in order to cope with patient requirements. The paper describes the mechanical and electronic solutions as well as the most relevant features of control implementation issues that were addressed in the system design.

Advanced robotics needs a new breed of actuators, capable to exhibit a large number of desirable features, ranging from high power/torque density, high efficiency, zero backlash and low noise, to low reflected mechanical impedance, high bandwidth and accuracy. Even if it is quite evident that to fully match these requirements new basic actuation principles have to be investigated and developed in the long term, there is still scope now for innovating the field by combining mature components into new actuation schemes. This paper reports the development and the experimental evaluation of a new actuator, aiming at improving the torque density and the mechanical efficiency. The device has shown impressive performances being able to exert up to 500Nm continuous torque and 800Nm peak torque with 85% mechanical efficiency and zero backlash, up to 60°/s maximum output speed for a total weight of just 6Kg, comprising the structural case covering the internal mechanics. The actuator has been expressly conceived as an actuation module to be integrated in a fully powered whole body exoskeleton intended for material handling in tight and unstructured environments (see Fig.1).

Technological and fundamental developments in robotics can emerge from various sources like publications or international research plans. Among the various sources of analysis, patents results valuable in expressing the efforts performed both by companies and research institutions. This work takes the occasion of the fifty years of robotics for presenting an analysis and visualization of trends in robotics by means of patent mining. This work focuses, in particular, on the domains of rehabilitation and surgical robotics. The discussed methodology highlights the role of haptic interfaces in these fields and the relationships between relevant companies.

A linear-quadratic-Gaussian regulator is proposed for the torque control of flexible robotic joints with built-in torque sensor. The regulator requires the joint-torque sensor information only and features: (1) a Kalman filter that, beside reducing the noise and evaluating the derivative of the torque sensor measure, is able to estimate all the external and internal torques acting on the joint; 2) a controller that optimizes system stability, responsiveness, accuracy and effort. The regulator is implemented on a flexible joint of a rehabilitation exoskeleton. Simulation and experimental results are provided which demonstrate regulator performance and efficacy.

The present work describes the design of a Sailing simulator that includes fundamental interaction stimuli and environmental phenomena such as wind and sea conditions, vessel and sails configuration, and actions performed by drivers on real maneuvers. The behavior of the simulator takes into account most of the static and dynamic effects caused by the wind, the pilots and the sea. The motion based simulator is operated by means of levers that control all maneuvers in the ship. Simulator feedbacks include audio, visual as well as inertial cues. An interactive simulation of the dynamics of the vehicle and of the environment physics is integrated into the interactive motion based sailing simulator in order to allow real time use within application. All mathematical components have been integrated in a parametric way giving the possibility to choose among differents boats and sails types. Several environmental effects such as wind control, can be interactively controlled by a remote operator while the boat is navigating into a virtual scenario. In the following the main feature of the simulator system will be described together with the relevant activities performed to create the real-time model of the simulator. Some experimental results will also be provided.

Technical developments, trends in popular culture and widespread interest in the scientific community can not account for the proliferation of robotic creatures in the art context, oddly neglected by art theory. In this paper we discuss robotic creation as a crucial domain for contemporary art theory taking as a point of reference the concepts of objecthood, interaction, conceptualisation and anthropomorphism.

In this paper, we present the mechanical design of a new fMRI compatible haptic interface with 3DOFs, based on electrical DC actuation, for the study of brain mechanisms of human motor control. The 1DOF manipulator, which was evaluated successfully on the compatibility with fRMI environment in the preliminary experiments, was extended to the implementation of a 3DOFs parallel manipulator with 3- UPU kinematics. Kinematic properties were studied in different configurations to select the stroke of the prismatic joint and the radius difference between the moving platform and the base. Due to the dimensional constraints imposed by the fMRI environment, the choice of the dimensions and the adopted mechanical solution was a result of an optimization process presented in this work. A further optimization of the mechanical design was then conducted in order to reduce the torque requested to the actuators for gravity compensation and improve the mechanical stiffness with elastic compliance of the manipulator. The final design resulted in a system capable of satisfying all the environment and user requirements.

This paper deals with the mechanical and control design of an exoskeletric power extender for the whole human body. A critical issue in the design of such kid of devices is granting a sufficient level of transparency. The authors propose two design conditions based on tracking force threshold and equilibrium considerations that should be complied. This methodology has been applied to the specific design of a body extender for material handling that is currently being developed at the PERCRO (PERceptual RObotics) Lab of Scuola Superiore S. Anna of Pisa, Italy.

It is well-known that virtual reality (VR) is a powerful and promising computer-based technology for the motor recovery in stroke patients. The importance of using VR into arm rehabilitation has coined it as clinical VR; where its main sake is to improve the recovery process of post-stroke patients. In this regard, physical therapy and occupational therapy are provided by such technology. As we shall see into this contribution, interesting clinical VR applications have been designed for handling effectively the brain plasticity in chronic stroke patients. To this end, we use the so-called Light-Exoskeleton which has been presented for arm-robotic therapy such that it serves as the kinesthetic feedback stimulator for assisting the patient during the rehabilitation sessions.

In this paper we describe two concrete applications of visibility to robotics. Both applications are related to the situation in which a robot is in a known environment, of which a map is given. The basic concept on the basis of our contributions is that of mathematical visibility. The visibility polygon of a point or of an edge can be used in different robot tasks, i.e. obstacle avoidance, path planning and localization. The strength of visibility is that different information can be extracted directly from the map through an offline operation. Furthermore the computation of the visibility polygon of a point can be applied instead of the classical methods used for the sensor reading simulation based on ray casting techniques.

This paper presents a novel use of sensor sytem for human gait recognition evolution to be employed in virtual environments exploration. The system allows free human motion inside a virtual environment employing human gait recognition. Experimental sessions have been organized in order to acquire acceleration data related to walking and running of several subjects. We present an algorithm that recognizes a person gait in real-time. The recognized motion can be used to enhance the presence of the user in the virtual environment. A simple scenario has been developed to assess the system functionality. The experiments carried out show that our system is suitable to classify human motion, count steps and, moreover, can be used both in virtual and augmented reality (VR) environments for an improved interaction.

Body awareness has important implications for the use of Virtual Reality (VR) and its effectiveness. This involves the senses of agency and body ownership. The possibility of producing the Rubber Hand Illusion (RHI) in VE (the sense of feeling a fake virtual body part seems like the one's own part), has been proven in the past, by giving the user synchronous 3D visual stimulation and passive tactile stimulation on the hidden real right hand. In this paper we present a VR system consisting on a low cost data-glove and a hand/arm model as a tool for study presence and body ownership in VE. We present also a novel study of the RHI within highly dynamic VE sessions with synchronous pure virtual vibrotactile stimulation of the fingers. The hand/arm participant's movements are realistically reproduced on the VE and tactile stimulations are self-inflicted by the participant through actively touching the virtual objects. The results of the proprioceptive drift and the response ratings of a questionnaire applied seem to reveal that the RHI is possible in active and fully multisensored VE sessions

While control theory for bilateral teleoperation systems under constant time communication delay is well developed, the research on time-varying communication delay systems is still ongoing. Most wave-based approaches proposed in literature to deal with time-varying delay appear too conservative resulting in high degradation from the constant time delay case. We have already proposed a bilateral control scheme with energy balance monitoring over packet switched communication networks. In the previous work, we dealt with a simplify situation where the time-varying was in the communication channel from master to the slave. However, we did not implement and test the system with a more complex scenario in which the delay was in both communication paths. The paper presents a complete bilateral teleoperation control scheme to compensate nonlinearity introduced by an Internet like communication channel. The system implements intelligent strategies to maintain the system passivity while it deals with position drift compensation, packets loss and blackouts management. Experimental results using the proposed control scheme are shown.

A new prototype of portable device for haptic interaction with virtual environments is presented. It is a lightweight interface for the fingertips, designed for providing cutaneous feedback and displaying the contact - non contact transition in highly immersive virtual environments. The second version of the interface features a force sensor for controlling the force on the fingertip during contact, assuring a better haptic feedback. In this paper the kinematics, the mechanical design and the improved control system are described. The device has been mounted on a kinesthetic haptic interface which tracks its position: in this configuration, the overall system can provide both cutaneous and kinesthetic feedback and improve the fidelity of the haptic interaction. Finally the performance of the cutaneous device in a task of contour following has been evaluated.

Real-time 3D content distribution over a network requires facing several challenges, most notably the handling of the large amount of data usually associated with 3D meshes. The scope of the present paper falls within the well-established context of real-time capture and streaming of OpenGL command sequences, focusing in particular on data compression schemes. However, we advance beyond the state-of-the-art improving over previous attempts of ¿in-frame¿ geometric compression on 3D structures inferred from generic OpenGL command sequences and adding ¿inter-frame¿ redundancy exploitation of the traffic generated by the typical architecture of interactive applications.

Robotic interfaces combined with virtual reality provide an unparalleled platform for cognition research. Using a combination of design strategy, trend analysis and the programming of immersive virtual 3D worlds, we have developed a low-cost aesthetic multimodal experience. Our intent has been to design the “ultimate interface ” for creative interaction. This paper discusses the process, content, results, and impact on our engineering laboratory that this research has produced.

This paper deals with the mechanical design of a novel haptic hand exoskeleton (HE) that allows exerting controlled forces on the fingertip of the index and thumb of the operator. The proposed device includes several design solutions for optimizing the accuracy and mechanical performances. Remote centers of motion mechanisms have been adopted for delocalizing the encumbrance of linkages of the structure away from the operator's fingers. An improved stiffness of the transmission and reduced requirements for the actuators have been achieved thanks to a novel patent pending principle for integrating speed reduction ratio with the transmission system.

This paper describes the design, the development and the tests of an innovative 6 degrees of freedom (DoFs) mechanical tracker. The new device has a modular structure that exploits three mechanical units each composed of two rotational joints and allows to scale the usable workspace by substituting the connecting links. The sensing principle for the joint angles measurement is based on an innovative hall-effect angle sensor with high resolution, developed and conceived for low cost applications. The system that has been realized and tested is conceived for the tracking of portable haptic devices. Furthermore, the system includes a weight balancing system that allows to exploit the mechanical structure of the tracker for balancing a given weight located at the end-effector of the device.

The required tasks in fixed-base exoskeletons demand a fast position/force controller; yet robust against unknown disturbances due to the application itself is tightly coupled with a human in a wide range of operational conditions, which give rise to human-exoskeleton interaction dynamics, high nonlinear uncertain exoskeleton dynamics, noisy sensors and other parametric uncertainties, such as environmental contacts. These factors do not allow to account on a precise dynamical model, thus model-based (regressor-based) controllers are difficult to implement. This paper deals with a regressor-free smooth PID-like fast force/position controller which guarantees finite-time convergence within second order sliding modes, thus ensuring inherent robustness. Experimental platform allows assessing its performance for rehabilitation tasks, which validates its functionality in practical implementation.

Any teleoperation system involving two distant devices is affected by communication delay due to the physical gap between the devices. Several approaches based on wave variables have already been proposed to deal with time-varying delay. However, these approaches are too conservative resulting in high degradation from the constant time delay case. In this paper, we propose a new control scheme for bilateral teleoperation under time-varying communication delay entirely developed in the wave variables domain. The proposed method minimizes the performance degradation from the constant time delay case. Experimental results show the validity of the proposed scheme.

The present paper deals with a system architecture and a digital format to support the acquisition, storage and transfer of human skills. Virtual environments and haptic interfaces will be addressed as target platforms for the capturing and rendering of skills. There are several methodologies for approaching definition and modelling of skills, and the present work will focus on a specific approach that merges evidences from human sciences with present approaches in intelligent robotics and machine learning. This work presents a supporting tool that enables researchers to model, analyse and control the skill transfer process. In addition this work will provide an overview of a skill transfer framework, and information related to the models of skill representation that are being employed.

Fixed-Base Exoskeleton applications have increased rapidly in the last few years, evidently as part of promising rehabilitation robotic programs of the robotics worldwide community, where in particular Human-Robot-Interaction (HRI) plays an important role in its design and control because they are tightly coupled to human-limbs. Exoskeletons embrace HRI as well as technological and theoretical challenges towards real and effective rehabilitation. In this realm, some questions arise, to name a few, what is the relationship between the exchanged energy between human and exoskeleton? How can we assess rehabilitation factors under HRI philosophy? This paper attempts to establish answers to these questions, which can be embodied into rehabilitation HRI using a Light-Exoskeleton. A compliant haptic guidance scheme for human arm subject to minimum-jerk-trajectories criterion is proposed. Preliminary experimental results provide further insight of a haptic guidance scheme taking into account decisive factors into the HRI such as human pose, haptic guidance control, reaching and tracking tasks, the complexity of the virtual environment, and muscles activity.

A recent trend in virtual environments aims at making the user free of devices or limitations in its motion, at the benefit of immersiveness and interactivity. This work introduces an interaction paradigm that goes beyond motion based interaction, by making use of measured real forces exerted by the user in free space. The sensation of touch with virtual object is obtained by vibrotactile stimulation combining virtual contact information with measured forces. In this way the user has an additional dimension of interactivity at the benefit of immersivity, without incurring in the reduction of sense of presence introduced by grounded haptic interfaces. This paradigm is presented and discussed in particular in the context of a boxing training simulation, as one of the possible application scenarios.

The work addresses the topic of software integration in the context of complex virtual reality applications. We propose a novel method to render in a single graphical context objects handled by separate programs based on different VR frameworks, even when the various applications are running on different machines. Our technique is based on a network rendering architecture, where both origin and destination applications communicate through a set of protocols that deliver compressed graphical instructions and keep the machines synchronized. Existing applications require minimal changes in order to be compatible with our system; in particular we tested the validity of our approach on a number of rendering frameworks (Ogre3D, OpenSceneGraph, Torque, XVR). We believe that our technique can solve many integration burdens typically encountered in practical situations.

This paper presents the results of a clinical trial employing the PERCRO L-Exos (Light-Exoskeleton) system, which is a 5-DoF force-feedback exoskeleton for the right arm, for robotic-assisted rehabilitation. The device has demonstrated itself suitable for robotic arm rehabilitation therapy when integrated with a Virtual Reality (VR) system. Three different schemes of therapy in VR have been tested in the clinical evaluation trial, which was conducted at the Santa Chiara Hospital in Pisa with nine chronic stroke patients. The results of this clinical trial, both in terms of patients performance improvements in the proposed exercises and in terms of improvements in the standard clinical scales which have been used to monitor patients progresses will be reported and discussed throughout the paper. It is to be noted that statistically significant improvements have been demonstrated in terms of Fugl-Meyer scores, Ashworth scale and increments of active and passive ROMs on shoulder, elbow and wrist joints of the impaired limb.

This paper presents a novel method based on screw theory for the analysis of positioning accuracy in parallel manipulators with joint clearances. A general method is introduced, and a new analytical procedure is formulated which allows to determine analytically a sub-optimal estimation of the worst case condition for positioning accuracy. Moreover this procedure can determine exactly the worst-case angular accuracy in translating fully-parallel manipulators under the influence of joint clearances. The relevance of the method is demonstrated by two application examples, that clearly demonstrate how kinematic properties, such as kinematic isotropy, are strictly related to position accuracy in mechanisms with joint clearances.

In this paper, we propose a real time 3D gesture recognition system that relies on the state based approach. The novelty of this work is the introduction of probabilistic neural networks (PNNs) to characterize the uncertain boundaries of each state. The 3D gestures are modeled as a sequence of states in a configuration space; the number of states and their spatial parameters are calculated by dynamic k-means clustering on the training data of the gesture without temporal information. Gesture recognition is performed using a simple Finite State Machine (FSM), where, each state transition depends only on the output of its corresponding PNN and optionally on its time restrictions (minimum and maximum time permitted in the state). If a recognizer reaches its final state, then it could be said that a gesture is recognized. The approach is illustrated with the implementation of a real time system that recognizes the semantic meaning of seven basic gestures of the Indian Dance, the description of the system and the technologies used, it will be described in detail in the paper.

Haptic interaction with virtual objects is typically tool mediated, or in alternative it constraints userpsilas body in someway, like it happens in exoskeletons that cannot be totally transparent. Encounter type haptic interfaces aim at hands free haptic interaction, that is more natural and can be applied in contexts in which the user moves in the space around the interface. This paper presents a system that allows a palm based haptic interaction in a large workspace using the principle of encountered haptics. The system is evaluated in a surface exploration task and compared against the same task performed with a standard haptic interface. In this type of task this type of interface is better suited, providing a smoother feedback to the hand during the movement over the surface.

The EU funded RTD project "HAPTEX" addresses the challenge of developing a Virtual Reality (VR) system for the realistic and accurate rendering of the physical interactions of humans with textiles, through the real-time generation of artificial visual and haptic stimuli. This challenge concerns the development of both the SW and the HW components of the VR system, as well as it implies a substantial advancement in the understanding of the mechanisms underlying the human haptic perception of fine physical properties like those of textiles. This paper reports some important details relating to the technical implementation of the developed HW and SW components with special emphasis on the issues related to their integration into a single VR system. Furthermore some preliminary results relating to the functional tests carried out on the integrated system are also reported.

This work presents a study of performance improvement of unskilled people to drawn simple sketches. We have assisted the unskilled people when drawn using a haptic interface which acts as a virtual guide taking advantage of its force feedback capabilities. In the first part of the study, an application has been developed to extract fixed templates from image files; the application extract the principal edges in the images to build output trajectories (templates) that are used by haptic interface controller, after that, the user can "fill" the virtual templates with the assistance of the force feedback capabilities of the interface. Based on the obtained results for fixed templates, a second application was developed; the user can generate interactive templates indicating where he/she desires to put a geometrical template (circle, line or arc) inside the haptic interface's workplace; once that the position of the template is defined, the interface shows its position graphically and then user can fill it assisted by the haptic interface force feedback.

In this paper the design and construction of a novel wireless Dataglove based on new flexible goniometric sensor technology is described. The device is characterized by a low cost and rugged construction and no requires calibration before its use. Indeed, the sensors used are purely goniometric, so they are not sensible to dimensions of the user's hand. The Dataglove can measure the angular displacement of the fingers hand using 11 sensors, each sensor has a resolution of 0.2 degrees, with 3 degree of accuracy in the worst case. The communication between the Dataglove and its computer Host is carried out using a 2,4 gigahertz wireless Bluetooth radio protocol, in a guaranteed range up to 10 meters with a refresh rate of 100 Hz.

This paper presents the synthesis and the analysis of the kinematics of a new robotic parallel wrist for laparoscopic surgery applications. The main properties of this new wrist are the wide singularity free orientation workspace and the capability of making large rotations of the end-effector with small rotation of the actuators. First, it is shown how these features suit the application of minimally invasive surgery. Secondly, the kinematics is described showing its working principle that allows the achievement of rotation multiplication. The forward kinematics problem is solved geometrically. Afterwards, a methodology based on screw theory for the solution of the differential kinematics is proposed. Finally a workspace representation is presented making a comparison with another known parallel wrist

Achieving realistic rendering of thin and spatially sharp objects (needles, for example) is an important open problem in computer haptics. Intrinsic mechanical properties of users, such as limb inertia, as well as mechanical and bandwidth limitations in haptic interfaces make this a very challenging problem. A successful rendering algorithm should also provide stable contact with a haptic virtual object. Here, perceptual illusions have been used to overcome some of these limitations to render objects with perceived sharp features. The feasibility of the approach was tested using a haptics-to-vision matching task. Results suggest that lateral-force-based illusory shapes can be used to render sharp objects, while also providing stable contact during virtual object exploration

The creation of applications of Virtual Reality enabled with Haptic interaction and dynamic simulation requires usually to cover many implementation details that increase the development time and the effectiveness of the application itself. This work presents one game application that has been developed using a Haptic toolkit for the rapid application development, that integrates 3D graphics,haptic feedback and dynamic simulation.The resulting application can be easily deployed on the Web directly to the final user.

Since their first usage simulators have been employed in training staff in civil aeronautics and in military fields to improve driving skills without compromising safety of people and machines. The system proposed in this paper is suited to transfer this activity into the industrial field, in particular an innovative fork-lift simulator is presented. Actually most frequent causes of accident with fork-lifts are wrong manoeuvres accomplished by drivers. This simulator aims to improve skills in driving and handling materials using a fork-lift. The system can reply inertial feedback on the operator and allows the user to control all the tasks of a fork-lift as driving and handling materials. The paper presents an overall view of the system including Stewart platform, supporting structure, physical based model, wash-out filter, system architecture and a video system mounted on board of the moving platform

The present paper describes the conceptual and technical design of a new multimodal device named Haptic Desktop System (HDS). Haptic Desktop System is an integrated system, which merges haptic functionalities, and VDT systems into one. Specific care has been given to HDS design for enhancing and improving human-computer interaction from the following points of view: esthetical, ergonomic and functional. In order to improve the quality of the interaction, the HDS fully integrates proprioceptive, visual, audio and haptic functionalities, into a desk while minimizing the visual interference of the physical components. In the proposed approach classic input devices (i.e. keyboard and mouse) have been replaced by new features integrated within audio and haptic. Such features allow commanding and rendering natural force stimuli in such a way that they are completely coherent and co-located with respect to the visual information. The new features of the HDS are designed for reducing considerably the mental load required to the users during interaction operations. In the present paper the design guidelines and the achieved results are reported.

One of the principal guidelines in the design of haptic devices is to provide a suitable mechanical design that can improve control performance and the force-feedback fidelity. Unfortunately these guidelines may conflict with other design objectives (reflected mass, balancing, dexterity) as well as with specifications given by users and applications. For haptic interfaces based on tendon driven actuation it is highly important to achieve an accurate model of friction losses in the transmission system, in order to be able to compensate for them through an active control. In this paper it is reported a method for modeling and control complex tendon transmissions used for driving haptic devices and robots. The presented approach can operate in realtime with very low complexity; it is applicable to all kinds of serial manipulators and provides enough flexibility to allow identification of parameters and modeling of distributed friction phenomena all along the transmission. The approach has been implemented and tested on a 4 DOF exoskeleton system, the PERCRO L-EXOS.

The research of the anthropomorphic flutist robot at Waseda University, for more than ten years, has focused on reproducing as best as possible the human organs physiology involved on the human flute playing to clarify the mechanism from an engineering point of view. This research is based on the need to develop useful robots for practical uses in the human living environment. As a result of our research, the newest anthropomorphic flutist robot WF-4 (Waseda Flutist No. 4) with 24-DOF has been developed, which not only improved the expressiveness but reduced also the dimensions of all their mechanisms as closer to human size. The flutist robot is used as a tool to help a human professor to improve the sound quality of beginner flutist players. In such a case, the robot is not only used to reproduce human flute playing but to evaluate also pupil's performance and to provide useful verbal and graphical feedback in order to improve his/her performance. Therefore, while robot is transferring the basics of the skill to students; teacher is taking care about how to motivate them (student's psychology). An experimental setup was designed to compare the added value of using the flutist robot for teaching to beginner students against the conventional way of teaching. Students' performances have been analyzed through different methods. The results demonstrated that the performance of pupils were better when the robot was used.

The development of the anthropomorphic flutist robot was started since 1990. The aim of this research has been to reproduce the functionality of human organs to interact musically with humans and to clarify the mechanism involved in human flute playing from an engineering view point. The newest version of the flutist robot (WF-4) has improved considerably the functionality and human-like shape of the organs involved in the flute playing. Up to now, the flutist robot has been used to reproduce as best as possible the human performance, although it is desirable to be also useful to improve some of the required skills that beginner flutists must acquire; in this case, the sound quality. The robot could demonstrate several times the correct way of playing and provide useful feedback based on the analysis of the harmonic structure of the student's performance. Therefore, it becomes necessary to find performance indexes that enable the robot to classify and evaluate quantitatively learners' performances to provide feedback (verbal and/or visual) to correct their executions. In this paper, we briefly describe some of the improvements done on the newest version of the flutist robot and we present different ways how the robot can evaluate the human performance by an experimental setup.

This paper presents a methodology for the evaluation of the performance of a given haptic display. The procedure can be carried out through the own proper sensors/actuators which equip the haptic display and allows to characterize the device from a static/dynamic point of view.

The global scope of the CREATE project is to develop a mixed-reality framework that enables highly interactive real-time construction and manipulation of photo-realistic, virtual worlds based on real data sources. This framework will be tested and applied to cultural heritage content in an educational context, as well as to the design and review of architectural/urban planning settings. The evaluation of the project is based on a human-centered, constructivist approach to working and learning, with special attention paid to the evaluation of the resulting mixed reality experience. Through this approach, participants in an activity "construct" their own knowledge by testing ideas and concepts based on their prior knowledge and experience, applying these to a new situation, and integrating the new knowledge gained with pre-existing intellectual constructs. CREATE project uses a high degree of interactivity, and includes provision for other senses (haptics and sound). The application developed in CREATE are designed to run on different platforms, and the targeted running systems are SGI and PC driven, with immersive stereo-displays such as a workbench, a ReaCTor (CAVE-like environment), and a wide projection screen.

This article describes the architecture of the "Museum of Pure Form", a virtual reality system where the user can interact, through the senses of touch and sight, with digital models of 3D art forms and sculptures. Two different realizations of "Museum. of Pure Form" systems are currently being developed at PERCRO, Pisa, Italy. In one realization "The Museum of Pure Form" is conceived as a system placed inside several museums and art galleries around Europe and made available to people visiting such institutions. In the second realization the system will be placed and tested inside a CAVE environment. Considerations on technological aspects concerning the implementation of a virtual environment endowed with haptic feedback for cultural heritage applications are reported throughout the paper.

A 2-DOF force-feedback joystick was employed to simulate the force response of a manual gearshift of car during drive. The control law is based on an hybrid model. A state machine determines the active state of the system, according to the simulation, and changes the parameters of the dynamical model. The operator can move the gearshift lever whether such a movement would be allowed in an actual transmission under similar circumstances. The obtained performance was compared to the experimental data, measured on a real car. The simulated and experimental results match satisfactorily and the joystick gives a realistic feel of an actual manual transmission.

Many motion base simulators have been developed in the last thirty years for many different types of vehicles. In order to make a simulation more realistic, linear accelerations and angular rates are exerted on the pilot by moving the platform on which the mock-up vehicle is located. This has to be accomplished without driving the simulator out of its workspace. The software component that is in charge of this is commonly referred to as washout filter. Washout filters have been widely investigated in the past, mainly in the field of flight simulators. We present a washout filter designed for a motorcycle simulator. The solution is preliminary and follows, as a reference point, techniques previously adopted for large aircraft simulators. Differences between motorcycle and aircraft simulation are analyzed and a preliminary customized solution is proposed. The washout filter to be used to drive a motorcycle simulator currently being built at PERCRO, has been tested off-line showing good results and will soon be tested on real riders.

Many motion based simulators have been developed for many different types of vehicles. In order to make a simulation more realistic, linear accelerations and angular rates are exerted on the pilot by moving the platform on which the mock-up vehicle is located. This has to be accomplished without driving the simulator out of its work-space. The software component that is in charge of this is commonly referred to as the washout filter. Washout filters have been widely investigated in the past, mainly in the field of flight simulators. We present a washout filter designed for a motorcycle simulator. The solution is preliminary and follows, as a reference point, techniques previously adopted for large aircraft simulators. Differences between motorcycle and aircraft simulation are analyzed and a preliminary customized solution is proposed. The washout filter, which will be used to drive a motorcycle simulator, currently being built at PERCRO, has been tested off-line showing good results and will soon be tested on real riders.

Intention tremor severely compromises everyday life tasks in patients suffering with multiple sclerosis or Parkinson's disease. The paper reports the current achievements in the analysis of subjects' movements. The trajectories produced by patients affected by tremor are investigated. Indexing procedures for the evaluation of the tremor which is present in the trajectories are proposed. Such indexes should be sensitive to tremor while they are not to ordinary movements. The properties of the indexes have been verified both with analytical considerations and with numerical tests. An experimental setup has been realized for the analysis of tremor on patients affected by multiple sclerosis tremor. The data collected within this experiment have been compared with expected results. Furthermore the indexing procedure has been applied for the evaluation of a filtering system. The case of handwriting has been chosen as the reference task for the evaluation of achieved results. The results of clinical tests are presented. Finally the applicability of the index-based procedures to the control of filtering systems is discussed. The control architectures in the case of force-feedback less interfaces as well as haptic interfaces are presented and discussed.

The hand force feedback system is an anthropomorphic haptic interface for the replication of the forces arising during grasping and fine manipulation operations. It is composed of four independent finger dorsal exoskeletons which wrap up four fingers of the human hand (the little finger is excluded). Each finger possesses three electrically actuated DOF placed in correspondence with the human finger flexion axes and a passive DOF allowing finger abduction movements. Each exoskeleton finger has three points of attachment to the operator's finger (two for the thumb) at the middle of the phalanges. Mechanical fixtures guarantee that just a force perpendicular to the finger and in its sagittal plane is exchanged at each point of attachment. Such force component is sensed and it is actively controlled in feedback. The paper illustrates the design and testing of the controller for the thumb exoskeleton. First the mechanical system is analyzed and the features which influence the controller design, such as the presence of unidirectional tendon transmission, are modeled. Then haptic controllers, i.e. feedback controllers aiming at improving the performance of the device when used as a haptic interface for virtual environments or telemanipulation, are designed and tested experimentally. Finally the experimental results are discussed.

Haptic interfaces have ordinarily been used as tools in the exploration of virtual environments as well as masters in teleoperation systems. In these systems the haptic interfaces have been commonly employed only to reproduce and simulate contact experience with a simulated or remote environment. This use is good enough for the realization of high quality simulators such as VETIR. All actions in simulators are generated by a precise set of rules which determine the correct feedback stimuli to be presented to the operator. In the article, haptic interfaces are presented as stand alone systems having their own and independent control. Consequently we explore the control capabilities and we identify a new extended interaction paradigm which provides to the machine the capability of interpreting the human actions and organizing a new high level feedback. The paper introduces a general structure for such a type of systems called reactive systems. A large set of interactive systems, such as tutors, trainers as well as technological aids for rehabilitation can be easily realized with the presented architecture.

This paper describes the results of the design of the actuation system of the MORIS two-wheeled vehicle simulator for motorcycle design and development. Firstly, a general overview of the simulator is shown. Secondly, the description of the strategy manager and of the software design tool is reported. Finally, the numeric results of the basic design manoeuvres and of the overall simulator are described.

We present an immersive virtual environment (VE) including visual, auditory and haptic feedbacks, which has been designed specifically to help to recover or improve the motor dexterity of the arm and hand in patients affected by disorders of motor coordination. The realization of an effective haptic feedback on the human arm and hand is the most critical issue for such application. Innovative approaches have been followed for the monitoring of upper limb movements; the replication of forces on the human hand, the real time simulation of interactions between user upper limb and virtual objects, including the simulation of stable grasps; and the accurate synchronization of the various sensory feedbacks. The rehabilitation exercises, which have already been implemented and tested on healthy subjects are described. The major technical solutions adopted are discussed.

Summary form only given, as follows. Realistic rendering of the virtual body limb movements represents one of the most interesting research areas for the design and implementation of the component of a virtual environment system. The paper addresses the description of a complete experimental virtual environment system including real time graphical rendering of upper limb movements as well as force feedback capabilities to the user. The virtual arm and hand are modeled with a set of 40 nonuniform B splines: mono and multiprocessor algorithms have been used in order to convert parametric surfaces in polygon meshes. Upper limb movements are recorded by means of joint rotation sensors (optical encoders) integrated on a 7 degrees of freedom mechanical structure wrapping up the whole arm and possessing the same joint rotation axes. The same mechanical structure is devoted to replicate virtual contact forces to the user's hand. Data from joint rotation sensors are used to move the control points of the parametric surfaces. In this way, a realistic representation of the shape of the virtual hand and arm, including the deformation of the skin, has been empirically obtained. Collision detection algorithms as well as modules for the modeling of physically based behavior of the virtual hand in contact with virtual objects have been developed. Results of experimental tests aimed at verifying the performances in terms of frame rates and force feedback capabilities during practical manipulative and exploratory tasks of virtual objects are presented.

This paper presents a new control model, ideal for teleoperation, which takes into account the problems arising with heavily delayed communicating systems. This is done with the help of a general purpose neural network and a specific dedicated training structure which is able to train the network and to minimize the network errors due to convergence problems. The principal aim of this model is to give more stability to the data flux reducing the uncertainties due to a variable delay present in the communication support.

The control of exploratory and manipulative procedures in teleoperation and virtual environments requires the availability of adequate advanced interfaces capable not only of recording the movements of the human hands and arms, but also of replicating sensations of contact and collisions. In this paper the problem of replicating external forces acting against the remote/virtual arm is addressed. The design of an arm exoskeleton system developed in the authors' laboratory is presented. The exoskeleton consists of a 7 DOF actuated and sensorized mechanical structure wrapping up completely the human arm and directly supported by the shoulders and the trunk of the human operator. Emphasis is given to the implemented control procedures and to the description of the transputer-based control architecture.>

Deals with the problem of the control of grasping procedures of virtual objects in virtual environments according to realistic behavior. The authors present a complete theoretical solution to the problem with particular attention to the constraints imposed by real time application in virtual reality. The authors describe the system architecture utilized for carrying out preliminary tests of the grasping procedure. First experimental results are presented.>

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.>

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 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.