The convergence of Artificial Intelligence, the Internet of Things, and Robotics is no longer a futuristic vision; it is rapidly becoming the foundation of real-time, intelligent, and context-aware systems. AI enables perception and reasoning, IoT provides scalable sensing and communication, and robotics delivers embodied actuation. Despite significant progress in pairwise combinations such as AIoT and the Internet of Robotic Things (IoRT), there remains a lack of unified design frameworks that fully integrate all three. This survey synthesizes the state-of-the-art across these domains, emphasizing the emerging role of Small Language Models (SLMs) at the edge and Large Language Models (LLMs) in the cloud for distributed cognition and autonomous decision-making. We propose a modular system architecture that aligns with these trends, analyze persistent gaps in interoperability and feedback control, and classify existing work by integration depth. Our review highlights how hybrid SLM–LLM systems, when coupled with IoT infrastructure and robotic agents, can address challenges in real-time adaptation, scalability, and reliability. This work offers a conceptual and technical roadmap for designing next-generation AI–IoT–Robotic ecosystems that are modular, interpretable, and capable of learning within dynamic environments, paving the way for the emerging paradigm of Connected Robotics and Physical AI.

In large-scale shipbuilding, welding tasks represent a significant portion of all tasks, requiring automated robot operation. However, current welding robots are not automated for high and narrow spaces because they cannot pull heavy welding cables, causing deviations from the intended path and reducing the welding accuracy. This paper proposes a cable-towing stabilization method considering factors such as the self-weight of multiple vehicles, magnetic adhesion force, and force necessary to hold the cables. The proposed approach integrates welding robots, which perform welding tasks, with towing robots, which alleviate the load imposed by welding cables and wire feeders. Cable-towing on walls requires reducing excessive distances between vehicles, as well as their excessive acceleration, in addition to maintaining the mechanical stability of each vehicle. Therefore, the optimal positions and postures of the towing vehicles are sequentially calculated using an optimization problem. The proposed method was evaluated through simulations and real-world experiments, confirming stable cabletowing on a wall surface of approximately 3 × 1.5 m. The findings of this research enhance the safety and efficiency of managing deformable linear objects with robots, focusing on mechanical safety while expanding the operational range from single-vehicle wall-mounted operations to cooperative multi-vehicle wall-mounted tasks, thereby increasing applicability to various wall-towing scenarios.

This paper introduces an innovation of the Spherical Omnidirectional Wheel, designed to achieve omnidirectional driving motion. In previous models, the supporting shaft was placed at the center of the mechanism. However, achieving both smoothness and high load-capacity in such designs proved challenging. The mechanism proposed in this study features an offset design, enabling outer support for the wheel. A prototype was developed and its basic motion was experimentally validated.

To address the setup and changeover time issues in high-mix, low-volume production systems, we developed an end-effector capable of uniformly scooping, holding, and transporting a wide variety of objects, and demonstrated this system with prototype. Our experiments showed that the prototype was successful in scooping up and transporting a wide variety of objects and could be applied to high-mix low-volume production systems. In addition, the load testing of the spatula and modeling of objects that can be tilted backwards provided insight into further improvements of the scooping performance of this mechanism.

Soft actuators have several advantages, including large deformation, safety and adaptability to the environment, and shock absorbance. However, they are weak against sharp objects owing to their soft bodies. This paper proposes a novel protective skin mechanism with an exhaustive arrangement of tiny rigid bodies. Small pieces were sewed on an elastic sheet using Kevlar strings. We conducted some measurements of puncture resistance, elasticity, and descaling resistance of the scale mechanisms. The results indicate that the elasticity of the proposed scale mechanism was just 150% larger than a simple silicone sheet. In addition, approximately 15 N was required for descaling, which is seven times larger than that of the glued scales. There was no puncture even when pricked with a needle.

Roadmap-based path planning is a well-established method for multi-robot systems, where the free space of the environment is represented as a roadmap graph. The Voronoi diagram is known for its efficiency in creating roadmaps for single-robot systems due to its ability to generate paths with high clearance from obstacles. However, the design of the Voronoi diagram does not allow for redundant paths, as only one path is obtained between each pair of obstacles. In contrast, multi-robot path planning requires multiple path options for efficient solutions. Therefore, we propose redundant Voronoi roadmap graph, which incorporates multiple paths computed from the Voronoi diagram. In this approach, we introduce imaginary obstacles to modify the costmap and obtain a roadmap with more paths. Our proposed roadmap retains the high clearance feature of the Voronoi diagram and is suitable for multi-robot systems due to the availability of alternative route options. We demonstrate that our method can generate roadmaps in various simulated environments with different levels of redundancy. Additionally, we verify the efficiency of our proposed roadmap graph through graph analysis and multi-robot path planning experiments. Comparative analysis shows that the use of the proposed roadmap increases the success rate and solution quality compared to the roadmap obtained directly from the conventional Voronoi diagram.

Localization is crucial for various automation systems to provide awareness of the robot's position and orientation. Additionally, a localization system that offers portability, flexibility, and low computational and economic costs is required by a variety of robotics applications. However, no existing system can offer all the aforementioned features suitable for motion capture tasks involving ground swarm robots. In this study, we propose MoCArU, a novel Motion Capture system based on odometry and ArUco, robustly recognized through image data with low computational cost. We have evaluated the system's performance by comparing it with the ground truth trajectory and adopting different numbers of cameras. The results show that MoCArU can achieve a root mean square error of 0.1345±0.0065 m using ten cameras. Our findings add to previous knowledge by presenting a robust and cost-effective alternative to existing localization methods. Here, we show that MoCArU's use of lightweight camera stands and wireless communication ensures ease of installation, portability, and low computational cost, making it suitable for tracking swarm ground robot systems. We anticipate this system to be used in various applications, such as robot position control, navigation, and obstacle avoidance control. Overall, MoCArU provides a reliable and cost-effective solution for the real-time localization of robots, so its wider applicability in various environments is a significant advantage in robotics. An open-source implementation of MoCArU, as well as its related details, is open for public use at https://www.rm.is.tohoku.ac.jp/MoCArU.

Drop mitigation is an important function of micro aerial vehicles (MAVs) that are used for internal inspections of enclosed and cluttered structures (height: 5–10 m). The mechanism also allows continuous operation of drones, prevents the downtime required for maintenance and repair and also provides a safer environment for workers who are working below the drones. Some solutions include parachutes, auto-rotors, and active auto-rotors. However, these are inapplicable to MAV s with a protector shell because of their size and payload. We herein propose a new rapid response drop mitigation method for MA V s involving active autorotation with bendable wings and shells. Active autorotation enables faster deceleration during dropping motion as compared to parachutes or passive autorotation. Bendable wings can ensure optimal flight performance and enable sufficient deceleration during falling motion. This newly proposed fixture was shown to reduce the impact impulse by 32.2 % and horizontal oscillation by 34.4 %. From our flight tests conducted at heights of 5 m and 10m in both outdoor and indoor environments, the measured impact impulse for both profiles were attained at 0.93 N s. The minimum impact impulse that can cause harm to the human eye, which is the most vulnerable part, is 2 N s. Thus, this mechanism was successfully proven to provide a greater safety buffer based on the drop test conducted. We envision this mechanism to provide greater safety to drone operating environments in relevant fields involving indoor and urban drone flights. Furthermore, it can reduce damage to drones and structures and avoid injuries arising from drone crashes.

A large-scale dump truck that automatically transports earth and sand in cooperation with a human-operated backhoe is of interest to the construction industry. A human-operated dump truck generally drives slightly past the desired loading position and then backs up to it for loading the sediment. The turning and loading positions are subjectively decided according to the working posture of the backhoe and the surrounding environment, and the safety margin of cooperative works. Backhoe operators want to perform the same maneuvers for human-operated/automated dump trucks. The movements of the autonomous vehicle should be similar to those of a human-operated one. However, it is difficult to derive a human-like path that does more than minimize costs. This study proposes a path-planning method that generates a path including a turning back, according to the changing backhoe position and surrounding conditions. We modeled the positional relationship during loading between a backhoe and dump truck, determining the loading and turning positions and related parameters from operational data collected in trials with human-operated construction vehicles. The proposed method allowed the autonomous dump truck path to resemble a human-like one. The authors have retrofitted an existing large-scale six-wheeled dump truck for automatic operation. Automatic loading in cooperation with a human-operated backhoe was realized all 17 times using the retrofitted dump. The average stopping accuracy was 0.57 m and 9.7°.

There is an increasing demand for robots that can be substituted for humans in various tasks. Mobile robots are being introduced in factories, stores, and public facilities for carrying goods and cleaning. In factories and stores, desks and shelves are arranged such that the work and movement of personnel are reduced. The surrounding furniture is also set to ensure that a single task can be performed in the same place. It is essential to study the intelligence of robots using information from such layouts, wherein human labor and movements are optimized. However, There is no method of map construction or location estimation that uses the characteristics of furniture arrangements that facilitate human work in a work space. Therefore, this study proposes a method for object mapping using layouts in crowded workspaces. Graphically represent the characteristics of furniture placement that make it easy for people to work in a workspace. The links in the graph represent the connections between the objects in the layout property. The nodes are the objects, and the weights of the links represent the strength of the layout properties. This graph is optimized by GraphSLAM to construct a map that considers the arrangement's characteristics. Using the graph structure improves the map's accuracy while allowing for relative changes in placement. The results show a 50.44% improvement in accuracy in a space with 18 desks, followed by two variations of similar desk layouts. The same improvement in accuracy was also observed when the relative positioning of objects changed significantly in each variation, such as a change to the left or right on the same side.

Rescue robots that search around on debris during natural disasters require high mobility to overcome various shaped materials scattered in the environment. Our previous study developed a new tracked mechanism called Mono-wheel Track, an elastic track driven by a single wheel, having a high capability to get over obstacles. In designing the MW - Track, the track stiffness is an essential factor-the flexible track can adapt to the geometry of the obstacles, but the flexibility prevents grousers from anchoring to the environment steadily. If the track has different localized stiffnesses, both the adaptability and the stability might be archived. In this study, we developed an “anisotropic-stiffness track,” exhibiting different stiffness depending on the bending side, and investigated its deformation characteristics and the effects on mobility. The basic deformation characteristics of the track were confirmed by load tests. The effects on mobility were evaluated by step-climbing tests, ditch-crossing tests, and traction measuring with a mobile robot.

We propose a novel toroidal origami monotrack capable of smooth-skin driving and bending for closed-skin-drive robots. Monotracks are a promising solution for achieving high mobility in unstructured environments. Toroidal-drive mechanisms enable whole skin drive; however, conventional methods experience unexpected wrinkling and buckles that lead to a large resistance. In this study, we propose an origami bellows structure with multiple rollers that can maintain the skin tension and deal with the cause of large friction between the skin and the body. The origami structure design method is presented, and the bending angle range and required drive force were derived through a theoretical analysis. The validity of the effectiveness of the concept was verified through prototype testing.

Bridge inspection using drones has become considerably more attractive owing to the ability of drones to gather information safely in lesser time and at a lower cost than traditional inspection methods. However, one of the critical issues in drone-based bridge inspection is ensuring stable communication between the operation base and inspection drones. The inspection drone easily loses sight of the operation base because bridges have intricate structures. Therefore, this study developed a radio map-based flight planning method of autonomous repeater drones for bridge inspection in order to ensure stable communication. Based on the inspection scenario, the repeater drone needs to ensure the communication with a minimum movement even under position deviations caused by winds. First, we generated a three-dimensional radio map of the bridge. Then, under the assumption that the inspection drone adopted a predetermined path, we developed a path planning method for a repeater drone based on the radio map. Some path planning examples demonstrated that the generated path reduces the moving distance and is also robust against the position error, in addition to ensuring stable communication.

In this paper, HueCode, a meta-marker that robustly and simultaneously exposes the relative pose between a marker and a camera along with additional information, is proposed. It occupies the area of a single marker by overlaying multiple types of markers in different colored layers. Using perspective information from the first (most recognizable) type of element marker, the second or higher marker can be recognized with a better success rate. An experiment using a HueCode made from an ArUco marker and a QR code showed that the QR code within the HueCode is recognizable at an elevation angle of up to 15°, compared to 25° for a normal QR code. In addition, the versatility of HueCode is demonstrated using two robotic applications. The first is a lightweight estimation of absolute 6-DoF poses for mobile robots in a GNSS-denied environment, and the other is object annotation in two-dimensional image or three-dimensional space without any prior knowledge. The former realized pose estimation with a position error of less than 0.05 m, and the latter enabled annotation of a mirror and a transparent object, which are difficult for other sensors and machine learning to recognize.

Machines tend to use powerful actuators and large gearboxes to bear large loads, which are inconvenient in terms of responsiveness as they affect the duration of operations. Thus, to compensate the force to grasp an object, we propose a clamping mechanism implementing the internally-balanced magnetic unit (IB Magnet) as a force amplifier, which is a mechanism able to switch attached and detached states of a permanent magnet with an external force considerably smaller than its original attractive force. To realize the bi-parting constitution of fingers, a new compensation method using conical coil springs was designed to provide both precision and miniaturization. Relative to the constitution with a single motored screw, the prototype gripper for proof of concept successfully amplified the grasping force at most to 292.2% assisted by the magnetic attraction, while keeping the increase in power consumption of a DC motor only by 11.8%, making the force-energy efficiency 2.6 times larger. Thus, it was verified that the proposed gripper enables the use of actuators and current supplies that require less power.

In this study, we developed a real-time simulation method for non-deformable continuous tracks having grousers for rough terrain by explicitly considering the collision and friction between the tracks and the ground. In the proposed simulation method, an arbitrary trajectory of a track is represented with multiple linear and circular segments, each of which is a link connected to a robot body. The proposed method sets velocity constraints between each segment link and the robot body, to simulate the track rotation around the body. To maintain the shape of a track, it also restores the positions of the segment links when required. Experimental comparisons with other existing real-time simulation methods demonstrated that while the proposed method considered the grousers and the friction with the ground, it was comparable to them in terms of the computational speed. Experimental comparison of the simulations based on the proposed method and a physical robot exhibited that the former was comparable to the precise motion of the robot on rough or uneven terrain.

To detach a permanent magnet using a control force much smaller than its original attractive force, the internally-balanced magnetic unit (IB Magnet) was invented. It has been applied to magnetic devices such as wall-climbing robots, ceiling-dangling drones, and modular swarm robots. In contrast to its significant reduction rate with regard to the control force, the IB Magnet has two major problems in its nonlinear spring, which serves the purpose of cancelling out the internal force on the magnet. These problems include the complicated design procedure and the trade-off relationship between balancing the precision and the volume of the mechanism. This paper proposes a principle for a new balancing method for the IB Magnet. This method uses a like-pole pair of magnets as a magnetic spring, whose repulsive force should equal the attractive force of an unlike-pole pair. To verify the proposed principle, a prototype of the IB Magnet was designed using a magnetic spring and verified through experiments such that its reduction rate is comparable to those of conventional IB Magnets. Moreover, a robotic clamp was developed as an application example that contains the proposed IB Magnets as its internal mechanism.

Currently, drone research and development has received significant attention worldwide. Particularly, delivery services employ drones as it is a viable method to improve delivery efficiency by using a several unmanned drones. Research has been conducted to realize complete automation of drone control for such services. However, regarding the takeoff and landing port of the drones, conventional methods have focused on the landing operation of a single drone, and the continuous landing of multiple drones has not been realized. To address this issue, we propose a completely novel port system, "EAGLES Port," that allows several drones to continuously land and takeoff in a short time. Experiments verified that the landing time efficiency of the proposed port is ideally 7.5 times higher than that of conventional vertical landing systems. Moreover, the system can tolerate 270 mm of horizontal positional error, ±30° of angular error in the drone’s approach (±40° with the proposed gate mechanism), and up to 1.9 m/s of drone’s approach speed. This technology significantly contributes to the scalability of drone usage. Therefore, it is critical for the development of a future drone port for the landing of automated drone swarms.

Backhoe loads sediment onto the bed of dump trucks during earthmoving work. The prediction of backhoe loading time is essential for ensuring safe cooperation between the backhoe and dump trucks. However, it is difficult to predict the instant at which the backhoe is ready to load sediment, because of the similarity in motions observed during gathering sediment. Moreover, since operators have different skill levels, the prediction requires a unique model for each operator. In this study, we attempt to predict the instant at which the backhoe is ready to load sediment into the dump truck. For this purpose, the beta-process hidden Markov model (BP-HMM) is employed to build a backhoe motion model for a specific operator. Time series data of backhoe loading motions for crushed rocks and wood chips, which were measured using 6-axis inertial measurement unit (IMU) sensors equipped at the cab, boom, and arm of the backhoe, were used for modeling with the BP-HMM. Several primitive motions of the backhoe, which occur at the completion of preparation before the loading process begins, were discovered as a result of the motion modeling based on the BP-HMM. We developed the prediction of the instant using three primitive motions. At best, the proposed method could predict the instant with a probability of 67% and 100%, at 6.0 s and 0.7 s before the loading motions began, respectively. This phased prediction can be used to reduce the idle time and risk for dump trucks during earthmoving work with the backhoe.

We introduced the disturbance degree of ground and proposed an evaluation method to measure the mobile performance of a crawler on soft ground during direction switching. First, we developed a planar omnidirectional crawler, which had a configuration with two left and right unit crawlers for performing turning motion, as the target for evaluation. Second, by utilizing the proposed disturbance degree of ground evaluation method, we investigated how the turning and translational motions of the crawler mechanism affected soft ground by measuring the flow of sand on a horizontal surface. It was quantitatively shown that translational motion switched the travel direction with lesser disturbance to the road surface compared to turning motion. We confirmed that ground disturbance could be evaluated during direction switching using the proposed method.

Long flexible continuum robots have a high potential for search and rescue operations that explore deep layered debris. A general problem of these robots is in the control of the head motion because their thin bodies limit the space available to mount multiple actuators. This paper develops a biaxial active nozzle which can rotate the air jet direction along a roll and pitch axis in order to control the direction of reaction force and the head motion of a long flexible robot. A major challenge is how to change the air jet direction without a large resistance to the flow, which reduces the reaction force induced by the air jet. We propose a nozzle whose outlet is connected with a flexible air tube. The direction of the air jet is controlled by the smooth shape deformation of the tube. The nozzle should be compact enough to be installed on a thin robot, although the shape deformation of the tube may cause buckling. The flexible tube is modeled and simulated by a multiple link model used to derive the geometric parameters of the nozzle so that the nozzle is compact and the tube does not buckle. Based on the derived parameters, the biaxial active nozzle was developed. A basic performance experiment shows that the nozzle can change the reaction force direction by deforming the tube shape, while the magnitude of the reaction force is almost constant. We integrated the proposed nozzle with a conventional Active Scope Camera (ASC). The range where the robot can look around in a vertical exploration was significantly improved, which was three times larger than the previous ASC whose head was controlled by pneumatic actuators. The rubble field test demonstrates that the integrated ASC could move over rubble (maximum height of 200 mm) and steer the course.

The transmission of high-frequency collision vibration can effectively deliver tactile characteristics in teleoperation of remote robots and the virtual environment. However, high-frequency vibrations also introduces audible noise. To address this issue, we modulated the frequency and amplitude of collision vibration to keep the perceptually similar while reducing the sound of the vibrations. Our experimental results showed that the sound pressure level of the collision vibrations (f = 675 Hz and 1012 Hz) is higher than the perceptual similar collision vibrations (f = 300 Hz and 450 Hz). These results suggest that our modulation method is able to reduce the sound level of the collision vibrations while maintaining the perceptual similarity.

This paper presents a blind multichannel speech enhancement method that can deal with the time-varying layout of microphones and sound sources. Since nonnegative tensor factorization (NTF) separates a multichannel magnitude (or power) spectrogram into source spectrograms without phase information, it is robust against the time-varying mixing system. This method, however, requires prior information such as the spectral bases (templates) of each source spectrogram in advance. To solve this problem, we develop a Bayesian model called robust NTF (Bayesian RNTF) that decomposes a multichannel magnitude spectrogram into target speech and noise spectrograms based on their sparseness and low rankness. Bayesian RNTF is applied to the challenging task of speech enhancement for a microphone array distributed on a hose-shaped rescue robot. When the robot searches for victims under collapsed buildings, the layout of the microphones changes over time and some of them often fail to capture target speech. Our method robustly works under such situations, thanks to its characteristic of time-varying mixing system. Experiments using a 3-m hose-shaped rescue robot with eight microphones show that the proposed method outperforms conventional blind methods in enhancement performance by the signal-to-noise ratio of 1.03 dB.

Unnoticed collisions compromise the success of remote exploratory tasks with mobile robots. We propose a vibrotactile stimulation method to represent frontal collisions that is based on the way people perceive impacts on a bar held with both hands. We observed that to estimate the impact point in a bimanual impact localization task people relied on amplitude and duration differences of the impact vibrations delivered to their hands. Then, to apply these results, we obtained a psychophysical function that relates impact points and vibration parameters. Finally, we used a differential drive mobile robot equipped with a high speed tactile sensor on the front bumper to evaluate our method in a simplified teleoperation task. We observed that participants required less time to complete the task when vibrotactile feedback was available.

For the past few years, unmanned aerial vehicles (UAVs) have been successfully employed in several investigations and exploration tasks such as aerial inspection and manipulations. However, most of these UAVs are limited to open spaces distant from any obstacles because of the high risk of falling as a result of an exposed propeller or not enough protection. On the other hand, a UAV with a passive rotating spherical shell can fly over a complex environment but cannot engage in physical interaction and perform power tethering because of the passive rotation of the spherical shell. In this study, we propose a new mechanism that allows physical interaction and power tethering while the UAV is well-protected and has a good flight stability, which enables exploration in a complex environment such as disaster sites. We address the current problem by dividing the whole shell into two separate hemispherical shells that provide a gap unaffected by passive rotation. In this paper, we mainly discuss the concept, general applications, and design of the proposed system. The capabilities of the proposed system for physical interaction and power tethering in a complex space were initially verified through laboratory-based test flights of our experimental prototype.

This study proposes a self-locking-type expansion mechanism for in-pipe robots. Previously, we proposed a highspeed locomotion mechanism using pneumatic hollow-shaft actuators; however, this mechanism lacked holding force and could not pass through a bent pipe. The proposed mechanism generates a large holding force and can easily pass through a bent pipe by invoking a self-locking phenomenon. We conceptualize and design the novel expansion mechanism and introduce its associated mathematical model to formulate the holding force and mechanism design. The characteristics and capabilities of the mechanism are elucidated by experiments. From the experimental results, we optimize the applied pressure and the design of the mechanism. The proposed mechanism generates a maximum holding force of 69.7 N, which is 5.2 times higher than that of the previous mechanism, and drastically improves the robot's bent-pipe-passing capability. Finally, the performance of this mechanism is confirmed in a simulated pipe test. In this trial, a robot equipped with the proposed mechanism smoothly and steadily moves through complex pipe configurations, including the vertical and bent pipes.

Disaster response robots for searching in a narrow area have limited space to mount tactile sensors, but the operators require sensory feedback to recognize contact situations with the surrounding environment. This study proposes a new approach to transmitting contact information of a remote-operated snake-like robot called Active Scope Camera (ASC) to the operator using simple configurations for the sensing and display methods. For the sensing side, we develop a contact estimation method with a limited number of tactile sensors. We establish the method to localize the contact position and the magnitude by sensing multiple propagated vibrations based on experiments and formulations. Preliminary experiments show that the developed method estimates a collision angle with high probability (93.8% at the worst condition) at several collisional situations. For the display side, we combine visual and vibrotactile feedback to provide the operator both directional and temporal cues to perceive contact events. The proposed visualization method uses colored bars, peripherally superposed on the video image, to show the estimated contact location and magnitude. A single DoF vibrotactile feedback is used for a joystick interface to control the head movement of the ASC. The effect of vibrotactile feedback on the response time to contact events is evaluated. Finally, we investigate the performance of the operation by identifying the contact behavior at simulated scenarios. Experimental results show that collision times per operation time is decreased by the developed feedback system compared with a simple video-based operation.

Tethered robots often experience entangling of their cables with obstacles in uncertain disaster environments. This paper proposes a spherical tether handling device that unfastens a robot's tether during surveys by releasing the tether and carrying it aside. By using a differential mechanism, the device drives shells and rollers that hold the tether. On flat surfaces, the device moves forward by driving the shells. When the device climbs over steps, the rollers are driven by the differential mechanism to pull the tether automatically. After prototyping the device, we confirm the surmountability of the proposed device against steps. The results show that the device can climb a height 90.9% of its diameter. We also demonstrate a scenario to handle the tether and untangle multiple tangles in an environment with several obstacles.

In large industrial plants, the inspection of production lines is a heavy and costly task that puts human inspectors at high risk. In order to overcome these challenges, we have developed an autonomous plant inspection system using a mobile tracked vehicle. In this paper, we propose an autonomous navigation method for tracked vehicles based on a contact force model that enables the robot to compensate for collisions with obstacles. The model considers the influence of the contact force on the linear and angular motion of the robot. Using the model, the controllable velocity range is derived during collisions. The experimental results show that the robot is safely controlled by complying with velocity constraints. In addition, our method can generate motions such as leaving wall, L-shaped curve and crosswise locomotion in straight passage while navigation alongside the walls. The method allows the robot to smoothly follow a target path, despite colliding with obstacles.

This paper presents a real-time image restoration method for aerial inspection images that are degraded by the appearance of a passive rotating shell of an unmanned aerial vehicle (UAV). Only images are required as the input. The method mainly consists of feature-based object detection for joints of the UAV shell, outlier rejection based on a sample consensus (SAC) approach and the geometrical model of the shell, reconstruction of the entire region that the shell appears in, and inpainting of the shell. Not only a pure algorithm for general UAVs with passive rotating shells but also an implementation specialized for a UAV that we have been developing are presented. The successfully implemented algorithm was evaluated for actual inspection flights under different conditions. The average rate of successful image restoration was 81.1% at 4.3 fps.

In recent years, several researchers focused their work on the mechanisms to protect the UAV from the dangerous collision with obstacles particularly the application of a spherical shell. However, this mechanism has some drawbacks when used in real-world mission especially in an outdoor environment. In the presence of wind, the spherical shell will experience significant air drag that will affect the flight performance of the UAV. In this paper, we focused our study on improving the flight performance of the UAV by reducing the drag force caused mainly by the spherical shell. We analyzed its structure and components to minimize the unwanted drag force. We evaluated two spherical structure, namely the 2V geodesic and fullerene. We also evaluated the spherical shell's component so-called joint by applying airfoil shape and compared it to a flat-plate design. CFD simulation and wind tunnel experiment were used as an evaluation tool to obtain a quantitative result. Based on our evaluation, changing from flat-plate to airfoil shape decrease the drag force of the joints by 72.31 %. Likewise, changing the structure from 2V geodesic to fullerene reduced the drag force of the connections by 12.42 %. The combination of fullerene structure and airfoil joints reduced the overall drag force by 34.74 %. An actual flight test in the bridge in the presence of wind further verifies the performance of the system by using the spherical shell with fullerene structure and airfoil joint.

Perception is the main key in enabling robots to react to and interact with their environment. Particularly, for multi-floor operations, the robot must robustly detect and localize stairs to allow for safe climbing. In this paper, we develop a graph-based stairway detection method for point cloud data, that can detect a large variety of stairways. Our approach first segments planar regions and extracts the stair tread- and stair riser-shaped segments. With these segments, a dynamic graph model is initialized that is used to detect stairs including the railing system in the surroundings. We show that our system can accurately detect and localize different stairways from a variety of different positions, including descending stairs. Our system's accuracy is higher than those of most state-of-the-art stairway detection methods even in case of sparse point cloud data.

3D posture estimation for a hose-shaped robot is critical in rescue activities due to complex physical environments. Conventional sound-based posture estimation assumes rather flat physical environments and focuses only on 2D, resulting in poor performance in real world environments with rubble. This paper presents novel 3D posture estimation by exploiting microphones and accelerometers. The idea of our method is to compensate the lack of posture information obtained by sound-based time-difference-of arrival (TDOA) with the tilt information obtained from accelerometers. This compensation is formulated as a nonlinear state-space model and solved by the unscented Kalman filter. Experiments are conducted by using a 3m hose-shaped robot with eight units of a microphone and an accelerometer and seven units of a loudspeaker and a vibration motor deployed in a simple 3D structure. Experimental results demonstrate that our method reduces the errors of initial states to about 20 cm in the 3D space. If the initial errors of initial states are less than 20 %, our method can estimate the correct 3D posture in real-time.

We have developed a method to visualize search and rescue (SAR) dogs' activities from sensor data recorded by the SAR dogs' sensor vests. This paper proposes two methods for detecting continuous barking actions of SAR dogs, which locate victims by smell and then bark continuously to tell handlers where victims are located. Continuous barking action is detected from audio information and a dog's body motions. This detection method is based on dynamic time warping (DTW), which has been used successfully to analyze human audio information. Cyclic body motion was observed during dogs' barking motions. This cyclic motion can be detected by an inertial measurement unit (IMU) attached to the vest. A fast Fourier transform (FFT) is used to analyze a dog's barking motion. The proposed detection methods were evaluated using audio and IMU data recorded during actual SAR dog training sessions. The F-scores of the audio and motion-based barking detection methods were 0.95 and 0.90, respectively. As a trial, we marked victim locations on a map based on the body motion.

The purpose of this study is to establish a quantitative method that can evaluate the motor function of human lower limbs in dynamic situations. As an index of motor function, we focus on the mechanical impedance characteristics of the lower limbs. By controlling these characteristics, humans can improve motion stability and adapt their movement to disturbances in the environment. In this paper, we propose a method that can estimate the impedance characteristics of the lower limbs of a human subject applying torque perturbations during a pedaling exercise. To improve the accuracy of the proposed estimation method, the effects of inertia and gravity in the measurement data were considered by representing the lower limbs by a multi-link model. Experiments were performed in two participants to estimate the stiffness and viscosity at different phases of the periodic movement. The distributions of these parameters showed symmetric properties for both legs in a pedaling cycle-a tendency that was observed in both participants. This agreement suggests that our method could extract a component of human motor control strategy that adjust mechanical impedances during pedaling exercises.

Unmanned aerial vehicles (UAVs) such as multi-copters are expected to be used for inspection of aged infrastructure or for searching damaged buildings in the event of a disaster. However, in a confined space in such environments, UAVs suffer a high risk of falling as a result of contact with an obstacle. To ensure an aerial inspection in the confined space, we have proposed a UAV with a passive rotating spherical shell (PRSS UAV); The UAV and the spherical shell are connected by a 3DOF gimbal mechanism to allow them to rotate in all directions independently, so that the UAV can maintain its flight stability during a collision with an obstacle because only the shell is disturbed and rotated. To apply the PRSS UAV into real-world missions, we have to carefully choose many design parameters such as weight, structure, diameter, strength of the spherical shell, axis configuration of the gimbal, and model of the UAV. In this paper, we propose a design strategy for applying the concept of the PRSS mechanism, focusing on disaster response and infrastructure inspection. We also demonstrate the validity of this approach by the successful result of quantitative experiments and practical field tests.

This study proposes a high-speed locomotion mechanism for a pipe-inspection robot. As a result of the narrow and complex structures of pipeline networks, it is difficult for robots to move quickly within the pipes. The new pneumatic mechanism proposed here realizes high-speed locomotion along with advantageous features for pipe inspection including a small diameter, flexibility, and low weight. First, we present the design concept of the novel locomotion mechanism using pneumatic flexible hollow-shaft actuators, which was previously developed by the authors. The prototype constructed to realize this concept and the associated mathematical model are then introduced. Second, the basic characteristics of the proposed mechanism are evaluated in terms of the holding force (generated by an expansion mechanism against the pipe wall) and the impellent force that induces forward motion in the robot. Finally, the in-pipe movement performance is confirmed. The experimental results show that the designed robot can be propelled inside a 53-mm-diameter pipe at a maximum speed of 250 mm/s, which is exceedingly faster than conventional designs.

A novel gait phase detection method that can extract the timing of foot contact conditions (Heel Strike and Toe Off) by a single piezo film sensor attached on each leg is proposed. We focused on the occurrence of high-frequency vibrations (> 100 Hz) in the beginning and the end of stance phases during gait. After the features of vibration waveforms during gait were confirmed, we proposed the phase detection method. The optimal parameters were investigated to detect the phases robustly despite the walking speed and the shoe types. Experimental results showed that the detected ground contact events had high accuracy of timing. Finally, we confirmed the feasibility with the prototype wearable device in usual environments.

We propose a method by which a micro air vehicle (MAV) can hover without propulsion power. In this paper, we describe the design of a magnetic adhesion mechanism and a winch mechanism for an MAV that is used to perform search operations inside buildings. An MAV equipped with these mechanisms can adhere to an iron ceiling and search for a long time from an appropriate position. We designed a magnetic adhesion mechanism with an adhesion force of over 20 N. The magnetic adhesion mechanism comprises a magnet, dual coil springs, and a switching mechanism. Using models of MAV and the adhesion mechanism, we determined the parameters of the mechanism. The magnetic adhesion mechanism can be detached easily by a force less than the magnetic adhesion force. The winch mechanism comprises a structure to retrieve the adhesion mechanism, a strong, lightweight tether and a servo-motor that produces enough torque to lift the MAV by the tether. We confirmed that the MAV can hover without propulsion power by using these mechanisms.

Remote robotic explorations for collapsed buildings in a severe disaster are demanded. However, rescue robots cannot approach the rubble due to safety risks. This study proposes a remote vertical exploration system for collapsed buildings with a robotic inspection system hoisted by a crane. An Active Scope Camera (ASC) has many advantages for the vertical exploration such as a light and flexible continuum body to produce distributed driving forces. The purpose of this paper is to confirm the feasibility of the vertical exploration system with the ASC. The vertical explorations have proper problems related to contact and hanging conditions of the scope cable. We developed a new ASC that has a two-step bending mechanism to produce larger head movement in multi-DOF. We also evaluated the performances of the prototype when the contact areas were small. Finally, we conducted a remote vertical exploration experiments at the simulated collapsed building in 6 m height. The robot could explore in six different pathways by changing head directions and running the rubbles within seven trials. The experimental results showed that the proposed system has high potential to get inserted in the deep area in the rubble.

The Fukushima nuclear power plant accident that occurred in 2011 eastern Japan has created local spots with a high dose level in residential areas in eastern Japan. It is necessary to build a map of the distribution of radiation activities that shows the locations and intensities of radiation sources to assist in decontamination work. The proposed method estimates the intensities of point-like sources from the radiation dose measured by moving a dosimeter in three dimensions and 3D map of the environment, assuming that the radioactive sources are located on the ground surface. The radiation dose is measured as a few counts including a wide variability because in the proposed method, low levels of radiation are measured by moving a dosimeter. For estimating the intensities, the maximum a posteriori probability (MAP) estimation is computed on the basis of the radiation characteristics of attenuation and stochastic counts. Experiments of estimation in real environments were conducted. The experimental results showed that using the proposed method, it is possible to estimate the distributions of radiation sources using the radiation dose measured by a dosimeter and the measured 3D shape of the ground and building surface.

A novel flexible pneumatic linear actuator is proposed in this paper. The proposed actuator realizes high-speed reciprocating motion by the moving part which has multiple rollers moves smoothly along the flexible hollow shaft. An effective application of this actuator is its use in endoscope robots and tether robots because cables of cameras or sensors can be passed inside the actuator by using the hollow structure. First, we discuss the physical model of the actuator pressurized in the resting state, and we provide an analysis of the generated force of the actuator. The model relates the generated force to the relevant design parameters such as the applied pressure, the material of the pressure chamber, the size of the moving part, etc. Second, we describe the measurement experiment of the generated force, and we show the validity of our model by comparing the experimental results with the analysis results. Third, we present the motion evaluation using a prototype of the actuator. We found that the maximum velocity of the moving parts is 9 m/s and that the moving parts can move smoothly even if the actuator is curved. Finally, we present the drive mechanism that uses the actuator, as an application example.

This paper presents an initial data that could show a possible contribution of mechanoreceptor activity to the perception of forces applied on grasped objects. Here, we obtained detailed psychophysical characteristics of perceived force-magnitude in multiple degrees of freedom (MDOF) using multi-point suction pressure stimuli. To obtain such data, we developed a multi-point stimulation method that can represent MDOF perceived force on a tool. We characterized the perceived force response of human subjects to suction pressure stimuli through psychophysical experiments. Moreover, we analyzed the strain energy density (SED) on the finger pads considering the force applied through finite element simulation. The results of the psychophysical experiments showed that multi-point stimulation method is effective for evoking MDOF perceived force on a tool. Interestingly, we found that the results of the finite element analysis agree with those of the psychophysical data. Therefore, we have verified that it is possible to use multi-point suction pressure stimulation for representing perceived force on objects held in a hand. In addition, a preliminary insight into the role of SED for perceiving force on tools is provided.

This paper describes logical winnowing methods from multiple identification candidates using corresponding appearance identification results with chronological pedestrian tracking results. It is difficult to identify individual using appearance identification, because appearance identification has some properties. This research proposes two methods that logically winnow out the identification candidates as methods that effectively fuse different directional identification results without the directional information. Experiments were made to verify the validity of the proposed methods. A mobile robot equipped with a laser scanner and a camera was used in the experiments. A pedestrian tracking method uses the laser scanner. The appearance identification uses the camera. The experimental results verified the validity of the logical winnowing method taking the logical product of identification candidates determined by each round of identification. In this paper, the appearance identification properties, the proposed methods and the experiments are described.

Active Scope Camera (ASC) using a linear inchworm drive, which can run on various road surfaces assumed in disaster sites, have been developed as a snake-like rescue robot. However, it is difficult for the linear inchworm drive to run in crooked narrow pathways, because its rigid body actuator reduces the flexibility of the scope camera and becomes immovable when the scope camera is curved. There are many crooked narrow pathways inside collapsed houses and under rubble. ASC's search range could be vastly expanded if ASC can run in such environments. In this paper, we developed a flexible linear actuator, which has the bellows structure and the hollow structure, for ASC in order to solve these problems. The actuator was able to generate large force more than 6 N from 60 kPa of applied pressure even if it was curved at 200 mm bending radius. Moreover, we developed a flexible linear inchworm drive using this actuator. The flexible linear inchworm drive keeps the running characteristics on the various road surfaces of the conventional linear inchworm drive. The minimum width of 80 deg crooked pathway that the flexible linear inchworm drive could run through was 60 mm, which was one-thirds narrower than that of the conventional inchworm drive.

In this paper, an estimation method using the flexible multi-body dynamics model, inertial/magnetic sensor system, and probabilistic state estimation is proposed for estimating the shape of a flexible cable. Sensors mounted on flexible cables, such as endoscopes, are often picked up noise, and their size and number are restricted. The proposed method can estimate motion using the flexible dynamics model if there are few sensors. In addition, this method is robust against noise because it can integrate some types of sensor information by probabilistic state estimation. The proposed method uses the Absolute Nodal Coordinate Formulation (ANCF) as a flexible dynamics model and the Unscented Kalman Filter (UKF) for probabilistic state estimation. It can model a greatly deformed cable at any point using ANCF, and it can fit nonlinear motion and achieve high versatility about models because of UKF. In the second half of this paper, experiments using Active Scope Camera (ASC) are conducted to evaluate the proposed method. The ASC is a snake-like rescue robot, and its sensor system picks up strong noise. In the experiments, the proposed method estimates three types of motion, and it shows the effectiveness if the number of sensors decreases.

An active scope camera (ASC) is a special type of videoscope for search and rescue operations; the ASC has a self-propelled mechanism with a ciliary vibration drive. From an analysis of the problems encountered with the conventional ASC during applications to practical disaster environments, we propose a new tube-type ASC with enhanced mobility and practical functionality for rescue activities. We designed a smart structure to mount vibration motors on a long tubular cable without any rigid projections. A suitable tubular cable material was also selected experimentally to propagate the vibration efficiently. We integrated several practical functions such as a head bending structure, an auditory communication system, and a gravity indicator for the head orientation. We conducted several fundamental performance experiments. Finally, the enhanced performance of the tube-type ASC for practical use was demonstrated at a training site for first responders.

Previous surface shape presenting methods had difficulties in generating high-density tactile information owing to blurriness in tactile images caused by lateral skin deformations. In this study, a new surface shape presenting method is proposed, and it employs overlapping small-amplitude vibrations instead of a single vibration. This method represents the mechanism of stationary boundary contacts (SBCs), a vibrotactile sensitivity enhancement method proposed in a previous research. A series of psychophysical experiments showed that the vibrations overlapping method can significantly enhance the human vibrotactile sensitivity and lead to the production of sharp tactile images. Moreover, the stimuli intensity can be controlled not only by changing the vibration amplitudes but also by changing the phase deviations between vibrations; this enables the presentation of various surface shape patterns that cannot be presented by using the previous SBC method alone.

An experimental study was done to examine the relationship between vibrotactile amplitude displacement and softness sensation. Merkel Disk behavior relative to softness sensation was studied under psychophysical experimentation of human participants. Restrictions are carefully applied on contact area spreading so that vibration will be the only factor that would induce a sensation. A vibrotactile device was excited at constant frequency and its amplitude is adjusted at different levels to alter the amount of skin displacement. Volunteers participated in a two-alternative force choice experiment were ask to compare the perceived softness difference between voice coil and silicone rubber. Statistical analysis on the responses of participants showed a decline of spring constant. It was interesting to note, that even though contact area was significantly restrained participants were still able to discriminate softness sensation form vibrotactile stimulation. Such observation possibly shows that illusion of contact area spread rate can be reproduced by vibrotactile stimulation.

Perception of minute force through tactile feedback from a tool is an important aspect for humans to maintain dexterity during manipulation of embedded objects invisible to the naked eye, such as repairing tissues in minimally invasive surgery. Different pressure levels at finger contacts could be responsible factors concerning the perception of forces on a tool. In this paper, an experimental study was done to verify if pressure stimulation to the thumb and index fingers on a precision grip position could alter the perception of force. We requested participants to perform a psychophysical experiment by holding a grounded pen-type interface having a single degree of freedom which induces pressure sensation using air suction. Perceived force was observed to increase when pressure was applied increasingly. Experimental results suggested that vacuum pressure can be used as a complementary tactile stimulus for inducing force sensation. This study had confirmed that negative pressure stimulus can be used to augment force perception.

Tactile sensations experienced by humans, such as roughness and softness, require not only high-frequency (200 Hz) but also lower-frequency vibrations (< 50 Hz). However, such low frequencies are difficult to achieve with small actuators that can be integrated into mobile devices. Therefore, it is necessary to develop methods for enhancing human vibrotactile sensitivity. We focused on a phenomenon whereby simultaneous contact with vibratory and stationary surfaces enhances human vibrotactile sensitivity, which we call stationary-boundary-contact (SBC) enhancement. SBC produces a line sensation along the gap between the vibratory and stationary surfaces. In this study, we determined the detection thresholds for SBC-enhanced sensitivity under several conditions. Psychophysical experiments showed that the detection thresholds of SBC were reduced by more than three times at low frequencies as compared to those under normal conditions. We then investigated the mechanism behind SBC enhancement by using a finite element model for the skin. Static and dynamic deformation analyses indicated that the dynamic impact of skin against the edge of a stationary surface contributes to an increase in the vibration frequency of the skin. This hypothesis was also supported by the psychophysical experiment, which showed that an edge-rounded stationary surface had less effect on sensitivity enhancement. Finally, we investigated possible SBC arrangements for practical applications on the basis of line sensation.

This paper provides valuable information about 3-D map construction using a tracked vehicle at Disaster City. Disaster City is a training facility for the Federal Emergency Management Agency (FEMA) in the United States. FEMA staff used our rescue robot Kenaf to conduct simulated emergency testing. Kenaf is a tele-operated tracked vehicle that has high mobility suitable for use in outside terrains and inside buildings. We equipped Kenaf with a 3-D laser scanner that can measure dense and wide angle 3-D shapes. We collected about 50 3-D mapping data sets during the tests. A part of these data sets can be accessed at our website. In this paper, we explain the Kenaf's tele-operation system, the 3-D mapping system, and the comments about the usability of the 3-D mapping from FEMA staff. In addition, we discuss about the limit of our mapping method on the basis of the trials at Disaster City. This information will be helpful for researchers in the robotics to improve their method of 3-D map construction and their tracked vehicles.

Remote transmission of high quality sense of touch requires the representation of multiple tactile properties and compensation of communication delay. We developed a real-time remote transmission system that can deliver multiple tactile properties using a master-slave robot system. First, we assessed what type of tactile properties should be transmitted and how to connect them in real time. Three tactile properties - roughness, friction, and softness - were transmitted on the basis of the real-time estimated physical properties of three main wavelengths, a kinetic friction coefficient, and spring constants, respectively. Tactile stimulations were generated in synchronization with hand exploration at the master side by using local tactile generation models to compensate for communication time delay. The transmission of multiple tactile properties was achieved by the integration and enhancement of our previously reported methods for vibrotactile displays and tactile sensors. A discrimination experiment using different materials showed the feasibility of the total system involving the three tactile properties.

Gyro-based odometry is an easy-to-use localization method for tracked vehicles because it uses only internal sensors. However, on account of track-terrain slippage and transformation caused by changes in sub-track angles, gyro-based odometry for tracked vehicles with sub-tracks experiences difficulties in estimating the exact location of the vehicles. In order to solve this problem, we propose an estimation method with 6 degrees of freedom (DOF) for determining the position and pose of the tracked vehicles using terrain information. (In this study, position refers to the robot's position and pose.) In the proposed method, position are estimated using a particle filter. The subsequent position of each particle are predicted using a motion model that separately considers each contact point of the vehicle with the ground. In addition, each particle is analyzed using terrain and gravity information. Experimental results demonstrate the effectiveness of this method.

This video captures human-robot interaction which occurred during an evaluation of a novel, snake-like search and rescue robot assisting with victim management. Most of the observations confirmed previous findings- That a 2:1 H-R ratio ratio is appropriate, Team coordination is enhanced by shared visual perception, and Poor interfaces continue to lead to incomplete coverage. However, the victims responded to the robot in two surprising ways: grabbing the robot and being concerned about its appearance.

In this study, a tactile-roughness transmission system applicable to master-slave systems with a communication time delay is developed. The master-side system constructs a local model of target objects placed in the slave-side environment. Tactile feedbacks presented to an operator at the master side are produced by combining the physical properties of target objects in the local model and the kinetic information of the operator. The time delay between the operator's motion and the tactile feedback is cancelled because the stimuli are synchronized with the exploratory motions. The proposed system is applied to the transmission of tactile-roughness. The tactile stimuli presented to the operator are vibratory stimuli whose amplitude and frequency are controlled. These stimuli are locally synthesized by combining the surface wavelength of target objects and the operator's hand velocity. Using the developed tactile-roughness transmission system, an experiment for transmitting the perceived roughness of grating scales was conducted. As a result, the roughness perceived by the operators was found to highly correlate with the roughness of the scales in the slave-side environment with a coefficient of 0.83.

We propose a new framework for a self-propelled flexible cable in which the freedom of lateral motion with sliding movements is increased on the basis of simple shape information.We developed a large-scale prototype of the flexible cable that has a ciliary drive mechanism and precise shape sensors to investigate our concept.We developed a kinetic model for the prototype by employing the nonlinear driving force model and the lateral friction model for representing slippages. Further, we proposed a sliding motion control method that focus on the shape and length of the straight element. We applied the method to control the running direction. The experimental results and dynamic simulations demonstrated the effectiveness of sliding motion for controlling the running direction.

The tactile display for handheld devices requires compact hardware and useful applications. To satisfy these points, we have proposed the concept of `virtual active touch' that implements virtual exploration with a cursor on a screen through a pointing-stick-type tactile interface. The objective of this study is to present three-dimensional shapes on a two-dimensional screen without force feedback devices. It is possible to present three-dimensional shapes such as a bump using a lateral force. In order to represent human perception of geometric surface shape, instead of the lateral force, we use the cutaneous sensation of friction that occurs when a human finger strokes object surfaces. First, we confirmed that the virtual active touch interface could present cutaneous sense of friction. Second, we evaluated the perception of surface height in the context of bumped shape induced by the friction display. The experimental results agreed with our expectation that faster and longer increases in friction sensation were perceived as higher bumped shapes.

Haptic interaction with handheld devices is limited by space and size constraints that inhibit free hand exploration. We developed a compact haptic interface called Vib-Touch, which is operated by fingertip via a pointing-stick input device containing a tactile feedback. A cursor on the screen could perform virtual exploration as a substitute for the finger movement. We call this technology virtual active touch. We also propose a tactile stimulation method to represent not only tactile sensations, but the whole touch experience, including kinesthetic senses and a sense of shapes perceived by a fingertip. This study reports on the first prototype of the vib-touch interface for handheld devices. We confirmed that the prototype could provide friction sensation and geometric shape information using the proposed friction display method.

Tactile display is a technology that gives an artificial sense of touch to operators of information terminals or master-slave systems. The generation of tactile stimuli in response to the hand movements of the operators is associated with active touch and is considered to be one of the effective display methods, however which inevitably causes delayed tactile feedbacks from tactile displays. The knowledge of the detection threshold of system latency between the hand movements and the stimuli is helpful in designing the tactile displays. In this study, the identification of the thresholds through psychophysical experiments of 13 participants revealed two types of thresholds. One was the time-delay at which the participants observed the existence of latency. The other was the minimal time-delay that could affect the subjective feelings of the operators while they were not conscious of the latency. The means of the thresholds were 41 ms and 59 ms, respectively. The participants reported that the time-delay stimuli caused various changes in their subjective feelings. The empirical results suggest that the two types of thresholds depend on different sensory processes. This paper also proposes a design policy for tactile display systems in terms of system latency.

A small tactile display that can be attached to a mobile terminal device or a handheld game controller will enhance user experience in virtual worlds. This paper proposes an ultrasonic vibrator which has a compact mechanism to produce vibratory stimulation on human skin using a pin array driven by a single piezoelectric actuator. Amplitude modulations of the ultrasonic vibration can generate tactile sensations even if a finger is fixed on the vibrator. To generate enough stimulation to deform the skin, resonance of the piezoelectric actuator was designed. We proposed a new mechanical design method to arrange arbitrary distributions of vibration for the pin array using the principle of a dynamic vibration absorber. Detailed designs were conducted by finite element analysis. We successfully designed a smart vibrator which had a size of 17 times 17 times 3.65 mm and a weight of about 4 g. The vibrator could mount on the joystick of the PlayStation2 controller. Trial experiments of tactile presentation showed that the prototype vibrator could generate vibratory feelings in the range of 30 - 50 Hz and 200 - 300 Hz. In addition, stimulation corresponding to joystick operation generated some rubbing-like sensation.

In the search and rescue situation at the disaster area, the searching task should be conducted by robots in order to avoid the second disaster. We study crawler robots that can traverse rough terrains and are used in such search operations. This paper describes the designing of an online simulation environment using which we can develop control algorithms for crawler robots, especially for the robot named “Kenaf.” We use USARSim that can simulate three-dimensional space. By employing realtime simulation, we connect a real robot controller and the simulator directly and realize online simulation using the real robot controller. The tests show that the created simulation system can be used for the development of control algorithms.

IRS Soryu is rescue robot which used for victim search in disaster area. We aim at development of display method for wide view angle and high definition images for controlling the rescue robots and searching for victims. In our study, we developed small size multi camera system and displayed a wide view angle and high definition image. However, it is too hard for an operator to recognize the robot and environment intuitively. We need to develop a display method of these multi camera images for intuitive recognition. In this paper, we develop the on-line simulation system for the verification of multi camera based wide field of view display. This system has some requirements that; a. Simulation of IRS Soryu dynamics, b. Simulation of multi camera system, c. Flexibility of camera setting. We developed such simulator based on USARSim. Using the simulator, we examined some experiments for the verification of of the display methods.

We have developed a positioning system that uses a phased array sensor to measure the distance and direction of multiple landmarks relative to the position of a mobile robot so that the robot can self-localize. The positioning system can control the strength and the width of the beam from the phased array sensor and observe the multiple landmarks at the same time. By using the distance and direction of plural landmarks, our positioning system is able to use various self-localizing methods. A main part of our work has been incorporating our various techniques for making a robot positioning error smaller into a system in which the most suitable self-localizing method is selected on the basis of sensitivity, which is defined as the ratio between localizing and sensor errors. We propose using a set of indices to evaluate the accuracy of self-localizing methods. The indices are derived from the sensitivity. We used these indices to compare the accuracy of three methods for the self-localizing of a mobile robot using landmarks, and we demonstrated a rational way to minimize a localizing error.

A practical active scope camera for urban search and rescue is developed using ciliary vibration drive mechanism. Optimization of design parameters such as material, a diameter, density and an inclination angle of cilia, and specifications and density of vibration motors is performed on the basis of experimental evaluation of test pieces and prototypes with changing surface materials. A prototype of a scope camera 8 m long crawls at a maximum speed of 47 mm/s, climbs slopes of 20 deg, surmounts obstacles 200 mm high, follows walls, and turns on floors. Experiments at Collapsed House Simulation Facility of International Rescue System Institute, Kobe Laboratory demonstrate its practical advantage in rubble piles.

A rescue crawler robot having flipper arm has high ability to get over rough terrain, but it is hard to control its flippers in remote control. The authors aim at development of a semi-autonomous control system for the crawler robot. In the system, moving direction is specified by an operator at remote place. Joypad (Sony PS2 controller) is used as input devise. For increasing its stability and robustness about change of the environment, its flippers are controlled according to sensor informations which can be obtained in real-time. Concretely, the robot recognizes the environment (upward step or downward step) using its physical model, its postural information, flippers' contact and distance between the body and ground, and controls these flippers. In this movie, we show you performance of our proposed control method using "Aladdin".

A rescue crawler robot with flipper arms has high ability to get over rough terrain, but it is hard to control its flipper arms in remote control. The authors aim at development of a semi-autonomous control system for the solution. In this paper, the authors propose a sensor reflexive method that controls these flippers autonomously for getting over unknown steps. Our proposed method is effective in unknown and changeable environment. The authors applied the proposed method to Aladdin, and examined validity of these control rules in unknown environment.

Tactile telepresence has been expected to be technology which encourages operators of robotic systems to remotely maneuver objects or recognize materials being touched through robotic arms. In remote environments, temporal disparity in tactile sensations is caused by temporal latency between a touch motion of the operator and a tactile stimulus applied on him. A framework of tactile telepresence systems, which is suitable in remote environments, has been proposed in the present paper. In the framework, a tactile display locally generates the tactile stimulus in synchronization with the touch motion of the operator in order to cancel communication delay. The tactile stimulus is generated by combining the motion and tactile factors, which are sensed by a tactile sensor. The factors are characteristic parameters of objects and effect on tactile sensations. In the present paper, physical parameters of the objects are selected as the factors because the tactile stimuli can be computed using physical models involving the motions and the parameters. Based on the proposed framework, a roughness feeling telepresence system was implemented and successfully transferred a roughness factor to the operator.

A method is proposed to control human grasping force unconsciously by generating small distributed vibration stimuli on a finger based on a human reflex action against detection of partial slippage of contact. Human beings can increase grasping force before the grasped object slips off the fingers based on afferent signals from tactile receptors that detect the expansion of the partial slippage area. We assumed that vibration stimuli that have an appropriate frequency and distribution generate a virtual sensation of partial slippages and induce a reflective grasping force increase. Grasping experiments with minute distributed vibration stimuli using ICPF (ionic conducting polymer gel film) actuators were performed. Experiments results showed that the effective vibratory frequency was 30 Hz, which is the most sensitive range for Meissner's corpuscles that are closely related to detection of partial slippage. We also found that distribution of vibration stimuli were important to produce human grasping force increase

Proposed new actuation mechanism realizes active or semi-active mobility for flexible long cables such as fiberscopes and scope cameras. A ciliary vibration mechanism was developed using flexible ciliary tapes that can be attached easily to existing cables. Driving characteristics of the active cables were confirmed through experiments and numerical analyses. Finally, the actuation mechanism was applied for an advanced scope camera that can reduce friction with obstacles and avoid stuck or tangled cables

Our research objective is simultaneous localization and mapping (SLAM) in rubble environment. The map construction requires estimation of robot trajectory in 3D space. However, it is hard to estimate it by using odometry or gyro in rubble. In this paper, the authors proposed real-time SLAM based on 3D scan match. 3D camera is used for measurement of 3D shape and its texture in real-time. 3D map and robot trajectory are estimated by combining these 3D scan data. ICP algorithm is used for the matching method. The authors modified ICP algorithm as fast and robust one for real-time 3D map construction

To realize a telepresence system with tactile feedback and force feedback, real-time estimation of various tactile sensation must be conducted. Because several types of tactile sensation consist in touch and human tactile feeling has high time resolution. A man feels active touch extraordinary with time delayed transmission of tactile information. Our proposing human finger mimetic sensor covers three tactile factors, which are roughness, softness and friction of objects to touch. Current tactile telepresence systems represent just one tactile sensation in addition to kinesthetic information. For augmented reality, wider tactile factors must be sensed at a tactile sensor system and transferred to a tactile display system with small time delay. We realized quick estimation of vibrational frequencies of the sensor and softness of objects to regenerate touch feelings to human skin by tactile displays, which usually need time-consuming samples and make it hard to address tactile telepresence system. Quick estimation of vibrational frequency was conducted by emulating impulse emission of Meissner's corpuscles. Quick estimation of Young's modulus of objects was solved by computing strain distribution in a sensor

At the time of a large-scale urban earthquake disaster, human search activities and information collection are the most important processes of rescue operations. Robots for search and rescue (e.g., aero-robots, crawler type robots) have been studied extensively recently. We have developed a cable driven balloon robot for information acquisition from the sky during disaster rescue and recovery operations. The balloon, from which hang several sensors (sensor unit, SU), uses "a natural shape balloon". Three cables connect the SU, and the balloon, with its sensors, is driven by expansion and contraction of the cable length. Cameras and several sensors or wireless relays are loaded onto the SU. The attitude stability of the SU is required to eliminate camera shaking resulting from wind. Such stability is necessary for high-precision information collection because this robot is used in the open air. This study verifies the attitude stability of an SU using a cable arrangement between the balloon and the SU; it statically calculates the movable scope of the SU at an arbitrary wind speed and direction

This paper presents a useful tactile display method that can control multiple tactile sensations such as roughness, pressure, and friction sensations using simple vibratory stimulations. Our concepts are based on two points: frequency range selection for making selective stimulation on different tactile receptors types and timing control of the stimulation in response to hand movements. The selective stimulations were realized by selecting reactive frequencies of vibratory stimulation based on temporal response characteristics of tactile receptors. For representing roughness sensation, vibrating frequencies were modulated in response to hand velocity considered as a temporal coding perception of FA I type receptor. Two reactive frequencies were also selected for representing pressure sensation and friction sensation corresponding to SA I and FA II type receptors respectively. A wearable tactile display using ICPF (ionic conducting polymer gel film) actuators verified our proposed methods. Finally, we conducted a total texture feeling display combined with our methods for roughness, pressure, and friction sensations in a parameterized manner. Comparison with real clothes showed that some combinations of multiple tactile sensations could express texture feels of the expected materials.

Research objective of the authors is 3D map building and localization of search robot for rescue use. In this paper, the authors propose a novel method of dense 3D map building and present its trial result. For building a map, it is necessary to estimate robot motion. However, on rubble, it is difficult to estimate robot motion by using odometry or gyro. Therefore, in this framework, rough 3D map and discrete robot motions are derived using SLAM based on 3D scan matching. ICP algorithm is used for the matching method. Then, the dense 3D map is reconstructed from the rough 3D map and texture images.

The final goal of this research is to develop a mobile system to collect 3D information and panoramic image in rubble to search human bodies and situation in the rubble. This system has abilities to collect and deliver information and cooperate with other robots etc. As a part of this project, multiple CMOS cameras are integrated in a sensor head, and software for generating panorama image and distance information is developed.

At large-scale urban earthquake disaster, human search is the most important process in rescue activities. This research develops a parallel cable-driven robot focusing on information acquisition from sky at crushed structures at landslide caused by huge earthquake. This robot is driven by multiple cables to move a sensor head with 6 degrees of freedom. This paper proposes the concept of this new search system, and illustrates usefulness of the human body searching strategy by several experimental results.

This paper reports a new dynamic programming environment for FDNet. The FDNet was designed as a flexible system that can accept new functions by reforming the network itself. Another feature that the relation networks in FDNet are described by XML can help to expand the network scale easily. Our new dynamic editing system uses the feature, and communicates via TCP/IP network for editing. Some trials reported in this paper shows a capability of an automatic self-editing function in the imitating robot system.

In this paper, we discuss the development and proliferation of robot test arenas that provide tangible, realistic, and challenging environments for mobile robot researchers interested in urban search and rescue applications and other unstructured environments. These arenas allow direct comparison of robotic approaches, objective performance evaluation, and can ultimately provide a proving ground for field-able robotic systems such as those used at the World Trade Center collapse. International robot competitions using these arenas require robots to negotiate complex and collapsed structures, find simulated victims, and generate human readable maps of the environment. A performance metric is presented which quantifies several pertinent robot capabilities and produces an overall score used to evaluate and compare robotic implementations. Future directions for the arenas and the competitions are also discussed.

This paper deals with the software architecture of a rescue robot, named FDNet. This architecture provides the rescue robot with intelligence and flexibility. When this architecture is used, the robot system is described using networks. These networks are composed by data and processing units. The data, referred to as "data", is a distributed component. The processing units, referred to as "relation", are a distributed and parallel-processing component, which can refer to any existing Data. We consider nodes that can formally connect to any other node, and relations that can be organized according to human's or any other network's pattern. This architecture was called FDNet (flat-distributed networks for rescue robots). We describe proposition of the architecture and its implementation for a robot. Then, we report some experimental results. We provide this architecture for any intelligent rescue system.

In order to display delicate touch feeling of surface of some materials, active touch of human hand movements should be considered. In this paper, a wearable stimulation device that can produce various distributed stimuli on human skin in response to hand movements was developed using ICPF (Ionic Conducting Polymer gel Film) actuators. Characteristics of touch feel of roughness were measured using vibratory stimulation. The results showed that the threshold amplitude under active touch were smaller than under passive touch. A stimulation method which generate selective stimuli to sense receptors in accordance with velocities and accelerations of hand motions was proposed. It was confirmed experimentally that some kinds of pattern of driving waves express touch feels in response to hand movements.

This study presents a tactile feel display of virtual reality for subtle fine touch of clothes. The device developed using soft high polymer gel actuators could express subtle differences of touch of clothes, especially rough materials such as a towel and denim. Considering the superiority of vision in the multimodal sensational perception, a virtual tactile feel display integrated with visual information which express more real touch of cloth was proposed. In order to evaluate the influence of visual information adding to the tactile feel quantitatively, a factor analysis was performed using adjective pair scales. Factor analysis applied to the real materials showed that the roughness factor is highly correlated with the visual sensation although the softness factor is relatively independent from image information. The same analysis applied to the artificial tactile feel showed more complex results. It was confirmed that vision could help the recognition of tactile feel only when the characteristics of the material was expressed well by visual information although could also mislead tactile perception when visual information was not appropriate. The superiority of visual information was also evaluated by applying wrong visual information different from the artificial tactile feels.

Molluskan robots perform their tasks by freely deforming their shape like slugs and amoebas on the basis of soft actuator materials. This paper presents a new actuator model, Fukuhara-Tadokoro model of a high polymer actuator, ICPF (or IPMC) as a fundamental of design, fabrication, control and application of future molluskan robotics. Ionic migration in actuator material causes electric unbalance of sulfo groups producing lateral strain in addition to volume change by water unbalance. Simulation results show internal state change according to the motion principle.

This paper presents a new motion base design for creating virtual acceleration using a parallel cable-drive mechanism architecture, WARP. It has several advantages: 1) the rotational motion range is large, 2) the traveling room can be grounded on the floor, 3) a scene projection is possible for all the walls, and 4) the redundancy improves the safety for cut of cables. Optimal mechanism design is performed for a class of WARP mechanisms to develop a prototype. A trajectory planning method for long-term virtual acceleration is proposed. A low frequency component of acceleration is realized by rotational motion, and a high frequency is produced by translational motion. Experimental results creating the virtual acceleration of jet coaster trajectories demonstrated the effectiveness of this new design.

It is difficult for the conventional tactile displays to express fine touch as a surface of cloth. A mechanical device appropriate for minute distributed stimuli on human skin does not exist. This paper proposes a ciliary device using soft high polymer gel actuators (ICPF) as a solution to this problem. This new device can generate various distributed stimuli to human sense receptors. It was experimentally confirmed that, combinations of vibratory stimuli of high frequency and low frequency produced complex tactile feels. Comparison of the artificial tactile feels and cloth material samples demonstrated that this device developed could display subtle distinction in the touch of cloth.

The Japanese Government plans to hold the International Robot Games Festival in 2001, which is called "RoboFesta 2001". The RoboFesta 2001 will be held both in the Osaka area and Kanagawa Prefecture in Japan, and will consist of several authoritative robot games, an international forum, and lots of robot-related exhibitions during the summer and autumn in 2001. The article describes the aims and organisation of the festival, then describes the various games.

This paper introduces the RoboCup-Rescue Simulation Project, a contribution to the disaster mitigation, search and rescue problem. A comprehensive urban disaster simulator is constructed on distributed computers. Heterogeneous intelligent agents such as fire fighters, victims and volunteers conduct search and rescue activities in this virtual disaster world. A real world interface integrates various sensor systems and controllers of infrastructures in the real cities with the virtual world. Real-time simulation is synchronized with actual disasters, computing complex relationship between various damage factors and agent behaviors. A mission-critical man-machine interface provides portability and robustness of disaster mitigation centers, and augmented-reality interfaces for rescue parties in real disasters. It also provides a virtual reality training function for the public. This diverse spectrum of RoboCup-Rescue contributes to the creation of the safer social system.

The ICPF (ionic conducting polymer gel film) actuator is a new high polymer gel actuator by which revolutionary robotic mechanisms are expected. Actuator models for CAE are essential to the robotic design. However, present black/gray-box models of ICPF cannot express its nonlinear characteristics with enough accuracy. In this paper, a white-box actuator model is proposed on the basis of physicochemical hypotheses on the motion principle which are supported at present. In this model, travel of sodium ions and water molecules in the actuator membrane is modeled. Internal stress is generated by swell and contraction of the gel by water content change, electrostatic force of fixed sulfonic acid groups, and momentum conservation effect. Simulation results show higher accuracy on transient response and nonlinear characteristics in comparison with conventional models.

Disaster rescue is one of the most serious social issues which involves very large numbers of heterogenous agents in the hostile environment. The intention of the RoboCup Rescue project is to promote research and development in this socially significant domain by creating a standard simulator and forum for researchers and practitioners. While the rescue domain is intuitively appealing as a large scale multi-agent domain, it has not yet been given thorough analysis of its domain characteristics. We present detailed analysis of the task domain, challenges, and outline benchmark evaluations.

The Great Hanshin-Awaji (Kobe) earthquake killed more than 6500 on January 17, 1995. Many people barely escaped from the debris and actively saved buried people. Rescue facilities are really important for robust social systems. Robotics and mechatronics are effective for advanced rescue equipment and systems. However, there has been little research and development performed until now. In order for robotics researchers to start, analysis of the tasks and requirements is necessary. In this research, the processes of rescue activities just after the disaster were investigated. Specifications of rescue robotic facilities are proposed on the basis of the analysis.

The RoboCup Rescue project aims to simulate large urban disasters and rescue agents' activities. The simulator must support both simulation of heterogeneous agents such as fire fighters, victims' behaviors and interface to disaster's environments in the real world. The RoboCup Rescue simulator is a comprehensive urban disaster simulator into which a new disasters simulator or rescue agents can be easily plugged. In the paper, the simulator's specification based on the Hanshin-Awaji Earthquake and the simulator's architecture are described.

In order to design emotional actions of computer graphic characters, the authors analysed the actions of a Bunraku puppet which is manipulated by an expert of puppet manipulation. The puppet's action is decomposed into a main part which is the motion of the puppet's axis and the accompaniment which is the relative motion with respect to the motion of the axis. The emotional actions of the puppet are explained by the phase factor and the amplitude factor of the motion of the puppet's axis. Based on this analysis, a simple method to design emotional actions are obtained.

A redundant wire-driven parallel robot, the WARP manipulator, is a new robot mechanism which is suitable especially for high speed assembling of lightweight objects such as semiconductors. In this paper, a WARP manipulator was designed from the viewpoint of working space by considering conditions that the travelling plate must be abbe to generate arbitrary amounts of force and moment and the wires are not to be in contact. Simulation results of working space proved the validity of the design procedure described. A prototype of WARP manipulator was constructed. The kinematic parameters were calibrated for position control.

Presents a multi-degree-of-freedom (DOF) micro motion device developed using a soft gel actuator, ICPF. It is superior to conventional micromanipulators in softness and compactness. 3-DOF motion was realized by a parallel mechanism with 4 ICPF actuators, and 6-DOF motion was created by a 3-actuator mechanism. The 3-DOF device had a maximum displacement of 2 mm and a fast response up to 13 Hz. Experiments of teleoperation using a joystick proved that the device had enough ability for micromanipulation in which dynamic condition was important.

Essential points in robotic facilities for search and rescue at large-scale urban earthquakes were investigated. A parallel robot driven by multiple cables is proposed for transfer of debris. It is portable and is assembled rapidly in destroyed houses. An identification algorithm of mechanism parameters peculiar to this portable robot was studied. On the basis of identification error analysis, optimal number of measurement points and the size of an identification reference frame were obtained.

It is desirable that soft objects like organs are manipulated by soft actuation devices. This paper presents a newly developed device using a large number of actuator elements made of a soft gel material, which applies a distributed driving force on objects. The material used in the device is an ionic conducting polymer gel film and the structure of the elements is elliptical friction drive. Experimental results showed that an object placed on such a device could move at a speed of 0.62 mm/sec. This paper refers also to fundamental experiments and a concept for a more efficient drive.

Time series is composed of many pairs of values and times. The time means when the value appears. Suppose that we observe same phenomena plural times and obtain plural time series. Although the same values happen plural times, their appearing times fluctuate. The problem to correct these time fluctuation is called "time normalization". We propose a new method of time normalization and apply it to action time series of a Bunraku puppet.

The ionic conducting polymer gel film (ICPF) actuator is a perfluorosulfonic acid membrane plated with platinum on its both surfaces. It bends in water and in wet condition by applying a low voltage of 1.5 V to its surfaces. This phenomenon was discovered in 1992. The principle of the motion is still unknown. This paper discusses 2-dimensional linear approximate modelling of the ICPF actuator. The authors are proposing a dynamic model of the actuator consisting of an electrical stage, a stress generation stage and mechanical stage. In the stress generation stage, time derivative of current generates the internal stress with a second degree delay. Expansion and contraction of each surface induce bending motion in the mechanical stage. Simulation results were in agreement with actual responses.

The ICPF (ionic conducting polymer gel film) actuator, which has advantages such as low driving voltage, high speed, and capability for underwater motion, was discovered in 1992. This paper presents a new actuator element using an ICPF which generates an elliptic motion, as used in ultrasonic motors, to drive objects by friction. A method of forming a pattern of ICPF on a membrane was developed for production of the element. The experimental elements effectively functioned as driving devices and successfully drove a rotary motor as an application. Experiments and modeling revealed the relation of the resultant elliptic motion to control signals and design parameters.

Home robots must have actions with emotion, in order to cooperate with human being. To clarify "what is the emotional factor of actions", the actions of a Bunraku puppet are analyzed. The hypothesis that "the action is decomposed into the functional factor, the emotional factors and the random factors" is presented. This hypothesis is examined based on the experimental data of real actions of the puppet.

In this paper a motion planning method for mobile robots that coexist and cooperate with human beings to avoid collision is proposed. Human motion, which has large uncertainty, is predicted by a motion predictor using a stochastic process model to generate probability distribution maps of human existence. An evaluating function is defined considering the danger of collision and efficiency of trajectories. A genetic algorithm determines the robot trajectory by optimizing the function. This procedure is repeated for each sampling time. The robot moves maintaining high safety against various possible human motion. Simulation results revealed that robots can reach goals avoiding danger along appropriate trajectories and that this method is effective especially for the case where optimal trajectories dynamically vary according to change of human motion.

Complete equations of motion for 6-DOF direct drive wrist joint's based on the Stewart platform are derived and analyzed. Although the derived equations are highly complex, the dynamics of the wrist joint are simple if the centroid of the hand is close to the platform, and if the centroid; of the actuators are close to the base. In the case of a specific position and orientation of the platform, it is found that the dynamics of the actuators cancel each other and that the equations are simple because the actuators in the Stewart platform are placed in parallel. The equations are simple and so is the design of a controller for the wrist especially when the mechanism of the wrist joint is symmetrical and uses actuators.>