Continuum robots (CRs) show great potential in complex environments due to their excellent deformability. For practical applications, the position control of the CRs is an important research field. The common drives of the CRs are rigid motors with mature control schemes. However, the driving force of the rigid motors is often impactive, which may cause safety concerns during interaction. Soft drives based on pneumatic soft actuators (PSAs) can provide compliant driving force for the CRs robot bodies to solve this problem, but it is necessary to comprehensively consider the control of the soft drives and the robot bodies. This article takes a CR with soft drives as the research objective, and proposes a double closed-loop adaptive position control method to achieve the endpoint position control of the CR. This CR includes a length-variable robot body with millimeter-scale diameter and pneumatic soft drives. The kinematic model of the robot body is built based on the piecewise constant curvature (PCC) method, and the static models of the soft drives are derived from the three-element model. Based on these models, we propose a double closed-loop adaptive position control method. The inner loop is used to control the displacements of the soft drives, and the outer loop combines the endpoint position control with the nonsingular fast terminal sliding mode function to adaptively control the endpoint position based on the inner loop. By Lyapunov method, we prove the convergence of the endpoint position error. The effectiveness of the proposed control method is verified through experiments.

Speech Emotion Recognition (SER) is pivotal for achieving empathetic and adaptive Human-Robot Interaction (HRI) within Internet of Things (IoT) ecosystems. However, conventional SER methods face computational inefficiency of large self-supervised speech models for HRI system deployment. Moreover, utterance-level emotion labels introduce segment-level ambiguities, degrading model training. To mitigate these limitations, we proposed the Multi-View Logit-based Heterogeneous Model Alignment (MVLogit-HMA) framework, which transfers knowledge from a large self-supervised Trunk (TKG) encoder to a lightweight Package (PKG) encoder through the joint alignment of instance-level contrastive guidance and class-level prototype relations in both the logit space and probability distribution, thereby harmonizing representations across heterogeneous model architectures. Simultaneously, we introduce Ambiguity Fragment Self-Weighting (AFSW) to dynamically down-weight unreliable segments and enforce discriminative separation between high- and low-ambiguity groups via an adaptive boundary loss. Comprehensive evaluations on the IEMOCAP and RAVDESS datasets confirm the superiority of our method, achieving weighted accuracy (WA) of 74.17% and 90.02%, and unweighted accuracy (UA) of 74.47% and 90.39%, respectively. Furthermore, a preliminary application in a real-world HRI scenario validates the practical viability of our approach.

This paper proposes efficient modeling and control methods for a continuum robot (CR) composed of a three-segment robot body (two proximal segments and a distal segment with an endpoint) and soft drives. Each segment incorporates multiple mutually exclusive magnetic spacer disks for a flexible structure, and the soft drives are designed based on pneumatic soft actuators (PSAs) to ensure operational safety. For both computational efficiency and tracking performance, an open-loop control method based on the kinematic model of the robot body is adopted to operate the two proximal segments, and a feedforward-feedback control method based on the dynamic model of the distal segment derived from the Euler-Lagrange method is proposed to control the endpoint trajectory. During the dynamic modeling process of the distal segment, the magnetic potential energy is considered additionally by simplifying the magnetic spacer disks to multiple magnetic dipoles. Moreover, the relationship between the input pressures of the soft drives and the generalized force of the dynamic model is derived from the three-element model and the principle of virtual power. Experiments demonstrate the effectiveness of the proposed modeling and control method.

Soft manipulators have been widely developed due to their manipulation safety, design versatility, and motion dexterity. However, accurate kinematic modeling and control of soft manipulators are still challenging due to the complex nonlinear hysteresis in their motion characteristics. This article presents the fabrication of an elephant-trunk-inspired soft manipulator (ESM) using pneumatic bellows actuators (PBAs) and proposes a kinematic modeling and control method considering hysteresis. The ESM contains three soft arms and a pneumatic claw, while each soft arm consists of four PBAs connected in parallel. The forward kinematics of the ESM are modeled using the piecewise constant curvature (PCC) method. The kinematic model of the ESM consists of three parts: actuator space, configuration space, and task space. To address the inability of the PCC method to characterize the nonlinearity of soft materials, the hysteresis of the PBA in the actuator space is modeled using the Prandtl–Ishlinskii model. The inverse kinematic model of the ESM is derived from its forward kinematic model, and on this basis, a feedforward controller is developed to achieve position control of the ESM. The positional workspace of the ESM is analyzed using the Monte Carlo method. The validity of the kinematic model is verified experimentally. Position control and application experiments are conducted to demonstrate the practical application of the ESM.

The realization and utilization of multimodal locomotion to enable robots to accomplish useful tasks is a significantly challenging problem in robotics. Related to the challenge, it is crucial to notice that the locomotion dynamics of the robots is a result of interactions between a particular control structure and its body-environment dynamics. From this perspective, this paper presents a simple control structure known as Attractor Selection Mechanism that enables a robot to self organize its multiple locomotion modes for accomplishing a goal-directed locomotion task. Despite the simplicity, the approach enables the robot to automatically explore different body-environment dynamics and stabilize onto particular attractors which corresponds to locomotion modes relevant to accomplish the task. The robot used throughout the paper is a curved-beam hopping robot, which despite its simple actuation method, possesses rich and complex body-environment dynamics.

Very long-reach snake-like robotic arms in the range of 14 meters are expected to be used in decommissioning work inside nuclear reactor containers. We developed a tendon-driven system which has the advantage of placing electronic devices protected in the arm's base part which stays out of the reactor container, and only few expensive highly radiation hardened sensors and tools are mounted in the arm tip. Generation of large joint torque is necessary to realize such a very long arm. We applied the concept of coupled tendon-driven mechanism formerly used to generate restricted two dimensional motions, and extended its concept by proposing a new joint arrangement which makes possible three dimensional motions in a large workspace. Mechanical design, compact storage method and derivation of the arm motion control are detailed. Moreover, we built a preliminary mechanical prototype called ”Mini 3D CT-Arm”, and the experimental results demonstrated the validity of the newly proposed concept.

Unmanned rescue, observation and/or research vehicles with high terrain adaptability, fast velocity and high reliability to reach difficult rough terrain locations are still demanded, but most vehicles increase rough terrain adapt ability at the expense of low velocity and/or complex mechanisms. We propose a novel vehicle consisting of a very simple blade-type crawler and active antennas with rollers, resembling a wharf roach. This configuration assures stable travelling over uneven terrain at high-speeds, with a very simple and reliable mechanism. This article presents the basic concept, mechanical design of the crawler and the antennas, and the basic motion control strategies. Moreover, we built and tested the first small mechanical prototype named KEIOS-I, and got successful results from experiments on uneven terrain at a high-speed traveling, and also lateral travelling and jumping motions. Future work will also implement roller skating mode using the active antennas equipped with rollers.

Humanitarian demining aims at clearing landmine affected areas, but the current manual demining techniques are still slow, costly and dangerous. Discrimination methods for distinguishing between real mines and metal fragments would greatly increase efficiency of such demining operations, but none practical solution has been implemented yet. Important information for discrimination are the depth which targets are buried, so estimation methods of this physical property are desired. In this research, a new, accurate and fast method based on Spatially Represented Metal Mine Detector Signals for estimating metallic targets depths using Metal Mine Detectors is presented, which takes advantage of high precision scanning of the minefield using robotic manipulator.

In this paper, we discuss the development of the sprawling-type quadruped robot named “TITAN-XIII” and its dynamic walking algorithm. We develop an experimental quadruped robot especially designed for dynamic walking. Unlike dog-like robots, the prototype robot looks like a four-legged spider. As an experimental robot, we focus on the three basic concepts: lightweight, wide range of motion and ease of maintenance. To achieve these goals, we introduce a wire-driven mechanism using a synthetic fiber to transmit power to each axis making use of this wire-driven mechanism, we can locate the motors at the base of the leg, reducing, consequently, its inertia. Additionally, each part of the robot is unitized, and can be easily disassembled. As a dynamic walking algorithm, we proposed what we call “longitudinal acceleration trajectory”. This trajectory was applied to intermittent trot gait. The algorithm was tested with the developed robot, and its performance was confirmed through experiments.

In recent decades, the devastating earthquakes, which can damage a lot of houses and buildings, have frequently happened. To slow down or prevent the disastrous damages of the earthquake, the various technologies have been required. Of these technologies, the ground motion simulator of the earthquake can be used to alert people to the dangers of the earthquake. This paper introduces a potable earthquake simulator, called a Jishin-The-Vuton 3D, which realizes the up-and-down motion with the holonomic omni-directional motions in order to simulate three-dimensional ground motion of the earthquake. Focusing on the design concept, structure, and feature of this new simulator, the authors discuss its implementation and verify its feasibility with preliminary experimental results.

Home oxygen therapy (HOT) is a medical treatment for patients suffering from severe lung diseases. Although walking outdoors is recommended for patients to maintain physical strength, patients always have to carry a portable oxygen supplier which is not sufficiently light weight for this purpose. Our ultimate goal is to develop a mobile robot to carry an oxygen tank and follow a patient in an urban outdoor environment. We have proposed a mobile robot with a tether interface to detect the relative position of the foregoing patient. In this paper, we improve mobile platform mechanisms and active wheels to maximize the step height which can be negotiated, and to allocate sufficient space in the main body to carry an actual oxygen tank. The following control algorithm is also improved and its effectiveness is demonstrated in an outdoor experiment.

Landmines continue killing and injuring people even many years after the end of conflicts. Mechanical systems and robots have been used for assisting in landmines location and improving the quality of humanitarian demining tasks. These new systems are expected to enhance safety, efficiency, time duration, etc, but many improvements are still needed in order to realize a practical system. In this paper, new vision techniques for improving the effectiveness of terrain mapping using stereo vision camera under high-contrast light conditions, i.e., mixed direct sunlight and shadowed areas, are introduced. Furthermore, trajectory optimization taking in account the obtained terrain map is also analyzed, which greatly reduces time consumption for landmine location marking tasks. These newly introduced methods greatly contribute to overall increase in reliability and efficiency of humanitarian demining tasks.

Foot mechanism of walking robots needs to adapt to rough terrain enough because the walking robot is requested to have the ability to walk stably on rugged ground. However, the foot mechanism of multi-leg walking robots have been often modeled as a point foot or a disc sole so far, and there is a problem that the robot can not fully use the sole area as a support polygon on rough terrain. To solve the problem, the terrain adaptive sole is developed which can adapt to the ground with small ruggedness and support the ankle moment to acquire stable footholds on uneven terrain. The terrain adaptive sole is composed of a deformation mechanism, a shape-fixing mechanism and a vertical force sensor, which are developed for quadruped walking robot TITAN VIII. The deformation mechanism changes the shape of the foot according to the terrain and the shape-fixing mechanism fixes the shape after the foot landing. These functions are achieved by a passive mechanism to be robust and lightweight. We demonstrate that TITAN VIII with the proposed terrain adaptive sole can successfully negotiate a rough terrain.

This work presents the development of an arm-equipped tracked vehicle named HELIOS IX for search and rescue tasks in urban environments. HELIOS IX operator has to tele-operate several tasks such as opening of doors, negotiation of stairs and handling objects. However due to the complexity and kinematics of the system, these tasks are difficult to be carried out without some level of automation. This study proposes one of the shared autonomy type operator-supporting system for HELIOS IX. It is based on a laser range finder (LRF), finger-attached LED beam guiding systems and on a finger 3 axes force sensor interfaced by a novel reinforcing metal plate. Carrying out several experiments we could demonstrate that, tele-operation task can become easier by the introduction of the 3D space approaching assistance of the LRF, object grasping assistance of the LED beams attached on the fingers, and by the force following assistance of the force sensor attached to the wrist.

Mobile platforms when negotiating steps and stairs should be able to control theirs posture in order to avoid sudden tilting or falls. In particular, when considering applications for search and rescue operations where users have a very limited time of operation, the motion on stairs should be automated as much as possible. In this way operators can concentrate on their tasks (i.e. search of survivors and/or exploration of dangerous environments) rather than having to focus on the stability of the vehicle. A simple but very effective mechanism called ldquotailrdquo is introduced. The mechanical design and its control method is presented together with several tests and experiments carried out with a simple tracked vehicle in real environments.

Fire brigades and special agencies are often demanded to operate for search and aid of human lives in extremely dangerous scenarios. It is very important to first verify the safety of the environment and to obtain remotely a clear image of the scenario inside buildings or underground spaces. Several studies have been addressing the possibility of using robotic tools to carry out safe operations. This contribution presents the development of the HELIOS team, consisting of five tracked robots for urban search and rescue. Two units are equipped with manipulators for the accomplishment of particular tasks, such as the handling of objects and opening doors; the other three units, equipped with cameras and laser range finders, are utilized to create virtual 3D maps of the explored environment. The three units can move autonomously while collecting the data by using a collaborative positioning system (CPS). After an overview on the specifications of the team of robots and with respect to previous publications, detailed information about the improvements of the robot mechanical design and control systems are introduced. Tests of the CPS system and HELIOS IX vehicle together with a typical mission experiment are presented and discussed.

For the purpose of detecting CO2leaks during ocean CO2sequestration, there is a need for independent underwater robots that can make observations while maintaining their position over the seabed against the current for long periods of time. In order to achieve this objective, a novel tether mooring type underwater robot was proposed. The robot is moored and its position is controlled by changing the length of the tether. In addition, it can sustain itself with a sea current power generation system. After that, the prototype underwater robot ¿Anchor Diver¿ was developed. Anchor Diver is moored by one tether, moves using horizontal and vertical rudders and moves upstream by reel mechanism. In addition, the use of a movable anchor and generator as a propeller enables Anchor Diver to enlarge its range of activity. This paper describes the detailed development of Anchor Diver and underwater experiments.

The inspection of high-voltage transmission lines is a dangerous and time-consuming job, that relies on especially trained workers operating tens of meters above the ground, and close to live lines with thousands of volts. This paper presents the development of a tele-operated robot designed for preventive maintenance of high-voltage lines. The robot was designed with mobility in mind, so that cable spacers, suspension clamps and other obstacles, which so far have prevented the use of robots for inspection of high-voltage lines, would not hamper the operation of the machine. After careful considerations on mobility, the robot was designed, and a prototype was built. Results of tests, performed on facilities reproducing real field conditions, are also presented in this paper.

There have been several works proposing mobile robots for inspection of high-voltage transmission lines. Those studies addressed mostly locomotion issues, with little attention paid to the sensing task. However, the deployment of sensors around the cables is not an elementary operation. This work indicates which sensors may be most suitable for the inspection of transmission lines, and describes their assembly in a simple and compact structure (Sensor-Unit). In addition, it proposes several manipulator mechanisms (Sensor-Arm) to deploy sensors around the cables and to remove them when necessary. The mechanisms are compared taking into account practical aspects such as assembly, reliability, functionality and results of field experiments. Finally, the design of a high-quality camera for detailed inspection is also described.

Fire brigades and special rescue agencies are often demanded to operate for search and aid of human lives in extremely dangerous scenarios. The use of robotic tools can make those operations safer for the operators and more efficient in terms of time and allocation of resources. This contribution describes the development of the newest tracked vehicle HELIOS IX. This mobile platform equipped with a manipulator represents the first stage of a Japanese national founded project. It aims to the development of a robotic system to be utilized in extreme environments such as rescue operations in heavily stricken urban areas. With respect to the previous prototypes the mechanical design and the system architecture is described. A new gripper is also introduced and tested together with few mobility experiments of the platform.

Robotics research can help search and rescue operations with developing practical mobile platforms and tools for urban and industrial disaster response. Crawled vehicles, because of their terrain adaptability, have a considerable importance for rescue operations and tasks performed in unstructured environments. In this contribution we present the newest version of HELIOS robot (HELIOS VIII). It consists of the same mechanical concept introduced with its predecessor. Nevertheless all the efficient motion capabilities of HELIOS concept were maintained and improved. In this paper we will focus a lot on the development of a new gripper for HELIOS vehicle. It consists of four fingers actuated by one actuator and they can adapt to the grasped object surface. Besides we introduce also a special docking mechanism utilized for the connection of the vehicle with auxiliary crawler units.

Manipulator operations are complicated by sensor noise, mechanical compliance, and system bias. These uncertainties are compounded in field environments, such as those encountered in humanitarian demining. By taking advantage of the generally flat and static structure of the terrain, a series of adaptive corrections and filters refine a sensed topographical model and generate a trajectory that is robust to inherent inaccuracies and modeling errors. Experimental testing on a mobile robot using stereo-vision as modeling sensor indicates that this method provides a tracking precision of plusmn5 mm on relatively flat ground. As such, it will keep the attached mine sensors close to the ground, improving effectiveness

This research aims to build a practical mobile robotic system to be used in actual humanitarian demining tasks. The basic system consists of a manipulator mounted on top of a mobile platform. For the purpose of building a practical and versatile mobile platform, the authors have already developed a 4-wheel autonomous buggy system called "Gryphon", as discussed in previous works. This paper addresses the development of an energy-efficient weight-compensated manipulator, which is composed of a 5-node parallel linkage. The manipulator was especially designed for antipersonnel mine detection and removal tasks. The weight-compensation concept and the principle of operation are discussed in detail, and the validity and usefulness of the manipulator, as well as of the whole robotic system, are demonstrated by real experiments.

In this research an arm-equipped vehicle for search and rescue operations is presented. The important features for tracked vehicles are introduced through an overview of the solutions so far developed. The concept and the motion capabilities of the new vehicle Helios VII are explained. Afterwards the first assembled prototype is validated by means of mechanical computer simulations and basic experiments on the real vehicle.

Landmines represent a clear threat to the civilian population in war-ravaged countries, and hamper peacekeeping and reconstruction efforts. The seriousness of this issue demands immediate automation of the mine detection and removal tasks, but until now only partial mechanization has been available. This paper proposes a versatile and feasible automated system based on mobile platforms to improve humanitarian demining, taking into account field requirements. Details of the development of the mobile platforms are presented, as well as experimental results. Special tools and components, also briefly described, are under development in order to maximize the range of applications of this system.

The demand for mobile robots for hazardous field tasks, such as rescue operations in disaster scenes or landmine detection and removal has been increasing in recent years. Since electrical infrastructure is seldom available in such situations, robots that rely on chemical batteries or/and tethered connections to external electric generators suffer severe limitations in operation time and mobility. A different approach is being sought in this research, which involves the use of a combustion engine for on-board electric generation. For practical purposes, the authors used a commercial 4-wheel buggy as the base platform. Some mechanical adaptations in the steering, throttle, gearshift and brake mechanisms were performed, and the developed mobile platform (Gryphon-I) can be computer controlled. This paper introduces new strategies for the control of Gryphon-I over uneven terrain, and the effectiveness of the proposed methods is evaluated experimentally.

Currently, most of the robotic systems use electric actuators and depend on chemical batteries as source of energy. However, this results in severe limitations to their range and time of autonomous operation, making it difficult to employ those robotic systems in remote areas or fields. In order to solve this problem, the authors have developed a mobile platform with energy-generation capability and mechanisms to drive it automatically. In this paper, a new autonomous control for the mobile platform is proposed, including telemetry features, especially focused on hyper-tether applications Those applications may include landmine detection/removal and forestry works in environments where the currently available systems cannot operate uninterruptedly for long periods of time.

A continuously variable transmission (CVT) can be advantageously used to drive a robot in its most efficient operation region for a wide range of external loads. The paper describes an optimal load-sensitive control algorithm for an actuator unit comprising a CVT and an electric motor. The introduced control algorithm takes into account both the electrical motor and the CVT efficiency. The validity of the proposed method is demonstrated by simulations and experiments carried out on an actual stair-climbing mobile robot "HELIOS-VI".

We are developing the "HELIOS" series, platforms for off-road vehicles and powered wheelchairs that are able to ascend and descend stairs. At present, we are developing an endless rotation locomotion type terrain adaptive vehicle "HELIOS-VI" that is propelled by 2 crawler belts. This vehicle has two continuously variable transmissions to change the velocity and direction of locomotion. The vehicle also has two active arms attached to the axis of the one drive pulley of the active crawler. One of the arms has two passive tires installed at its tip, and improves the vehicle's terrain adaptability in rough terrain; the other arm carries payload and adjusts payload posture. We introduced a structure that can change the posture of this load dynamically. This paper first outlines development process of the HELIOS series, and then discusses the configuration of terrain adaptive crawler vehicle HELIOS-VI and the design of its driving mechanism.

This paper introduces a new research on tethered connections called "hyper-tether", to provide tethering among different mobile robot types, such as a robot with the environment and a robot with humans and animals. Hyper-tether's basic function is to actively control the tether's tension and/or length, but it also considers tether launching, anchoring, power delivery, data communication cabling and built-in trajectory command generation capabilities. In this paper, the implementation details, advantages, potential applications and research topics of the proposed hyper-tether are explained.

Some methods of mobile manipulator control for the articulated body mobile robot "KORYU (KR)" are analyzed. KR is a class of mobile robot composed of serially connected "unit segments", configuring a long articulated body which resembles a train or a snake in shape. This configuration has an intrinsic advantage of making possible the use of the body's degrees of freedom (DOF) not only for "locomotion", but also for "manipulation". In order to demonstrate this characteristic we built a real mechanical model called KR-II, equipped with a 2 DOF manipulator in its foremost part. In the paper, two configurations for augmenting the number of this manipulator DOF are considered. The first method "fixed manipulator" considers the robot fixed to the ground, so that the manipulation control issue can be studied using well-known standard manipulator control theories. In the second method "mobile manipulator" special attention is paid to integrating manipulation tasks with body locomotion (steering) freedom. We verify that mobile manipulation can be smoothly integrated with a steering control method already developed in earlier works. Experimental results are shown to demonstrate the validity of the proposed augmented manipulation configurations and respective control methods.

This paper investigates an optimal steering control method for the articulated body mobile robot KORYU-II (KR-II), considering energy consumption and trajectory tracking performance as the optimization criteria. The computer simulations of the basic control methods of KR-II's /spl theta/ axis (bending motion between the segments) and s axis (rotation motion of the wheels), lead to the conclusion that the best methods are: the "/spl theta/2 method" combined with the "/spl theta/4 method" for the /spl theta/ axis, and the "s3 method" for the s axis. The "/spl theta/2 method" takes the moving average value of the foremost segment's control angle /spl theta//sub 0/ over a traveled distance L (intersegment length) as the next segment command /spl theta//sub 1/ and then shifts /spl theta//sub 1/ to the following segments according to the moved distance. The "/spl theta/4 method" entails setting a small position control gain for the /spl theta/ axis. The "s3 method" controls the forward velocity of the robot by equally distributed torque commands for all wheels. The experiments by the mechanical model KR-II demonstrated that the introduced control greatly reduces the energy consumption and produces very smooth locomotion; although the trajectory tracking performance is somewhat deteriorated.>