Acupoints can be identified as locations with lower impedance compared to the surrounding skin. However, since the measured impedance varies depending on the applied electrode force, it is necessary to keep the force constant, which is difficult for general users. To address this issue, this study proposes an impedance measurement method that compensates for variations in electrode force, allowing the measured impedance to be converted to an equivalent value under a constant force. Specifically, the relationship between electrode force and impedance is first experimentally determined to formulate a compensation equation. Then, using this equation, the measured impedance under varying forces is converted to the equivalent impedance under a constant force. By comparing the impedance values at multiple locations, the point with the lowest impedance is identified as the acupoint. To verify the effectiveness of the proposed method, experiments are conducted using electrical circuits that simulate acupoints and non-acupoints. The method’s ability to correctly distinguish between these circuits by compensating for variations in applied force is evaluated. Finally, the validity of the proposed method is further examined through experiments on actual human skin. Even in actual measurements on human skin, it was possible to identify areas with relatively low impedance and estimate the locations of acupuncture points without maintaining a constant pressing force on the electrode.

This study proposes the hands-free crutch featuring the load-sensitive locking joint. Traditional crutches often hinder the user's natural gait and pose risks of nerve paralysis due to pressure on the hands and armpits. In addressing these issues, we propose the hands-free crutch equipped with passive joints to facilitate a more natural gait. This paper outlines the development of the load-sensitive locking joint, which enhances safety by complementing the passive joint. Furthermore, we assess the performance of the proposed crutch by measuring joint and knee angles and walking symmetry by the symmetry index.

Overhead work in many industries causes a heavy burden on the neck because the head is always facing upward, and fatigue tends to accumulate in the neck and shoulders. In order to solve this problem, this study proposes the development of a head looking up posture support device to reduce the burden on the neck during upper overhead work. In this paper, we propose the device together with experiments in which the designed device is attached to a subject and electromyograms are measured. The experimental results show that the device can reduce the burden on the neck.

The purpose of this study is to develop an archery practice system that does not require a long range. The core of the system is the estimation of the arrow's trajectory. To estimate the arrow's trajectory, we need to know the position of the arrow's passage in a plane perpendicular to the arrow's direction of travel at two points in the trajectory, and the time required for the passage between these two points. In this paper, we propose a method for estimating the position of the arrow's passage on a plane perpendicular to the arrow's direction of travel. The proposed system consists of a pair of object detection sensors, consisting of infrared LEDs and phototransistors, arranged in array on the opposite sides of a rectangle flame with length 600mm and width 150mm. This one-dimensional array of optical sensors can estimate two-dimensional position information. This paper reports the results of basic experiments.

The overall goal of this research project is a study using RALL (Robot Assisted Language Learning) for Japanese students to improve pronunciation and prosody skills, and to provide more evidence of the effect of embodiment on RALL in English pronunciation and prosody. The subjects are divided into two groups: ten participants who use a robot (RALL) and ten participants who use a screen-based e-learning via computer (non-RALL). The robot had been used for the experiment was NAO from Aldebaran. The experiment took around 3 weeks for one participant to complete all the lessons including three pronunciation lessons and two prosody lessons. In order to assess the experiment, independent t-tests were performed regarding comparison of RALL and non-RALL scores difference. Dependent t-tests were performed to assess the performance of each group. The results shows that there was no significant effect of embodiment between RALL and non-RALL group. However, RALL system could improve Japanese students` English pronunciation, prosody, and overall pronunciation and prosody aspect better than non-RALL system.

The steerability of shopping cart varies with loading weight or position, affecting comfort and safety. The proposed active steering caster offers constant steerability of a cart. This caster consists of an electromagnetic clutch and a motor. The steering shaft is driven by the motor, and the transmission of that drive can be switched by the clutch. These casters are mounted at two diagonal points on the cart. By controlling the steering shaft of these casters according to the user's pushing force on the cart, constant steerability can be provided without being affected by the loading weight or position. In this paper, we propose the active steering caster with passive function and its arrangement on the cart with mixing the conventional casters.

This study develops the robotic IV pole and proposed forward moving scheme aiming to reduce the risk of falling. The risk of falling caused by pushing conventional IV pole while walking can be reduced by having the IV pole autonomously move side by side with user (user does not touch IV pole.). The Robotic IV pole is composed of omni-wheel, Light Detection And Ranging (LiDAR), Raspberry Pi, and Arduino Due. The proposed method that user's center of gravity can be obtained by LiDAR being attached to the lower center of the robot base of the IV pole, detects both feet of the user, and each center of gravity positions of both feet is estimated. Then, the user's center of gravity is estimated by using the estimated center of gravity positions of both feet. By controlling the robotic IV pole's motion so as that the estimated user's center of gravity and the position of IV pole be the same in forward direction, the robotic IV pole can autonomously move with the user. By conducting experiment, it is confirmed whether the proposed algorithm can automatically move side by side with user, and how range of walking speed is acceptable. As a result, the IV pole was able to automatically moves with the user at walking speed of about 0.3 m/s to 0.8 m/s.

The purpose of this research is to develop an omnidirectional low-floor mobility. The mobile platform and the interface have already been developed. The height of the mobile platform is 37 mm from ground to the boarding surface. Omnidirectional movement is realized by using four mecanum wheels. This mobility utilizes sway of the center of gravity of the users. In order to operate this mobility, the users voluntarily tilt their bodies. This body inclination is estimated from the load distribution information of eight load cells installed on the boarding surface of this mobility. This enables forward-backward, lateral, and turning movements. However, the motion of this mobility is oscillatory, because inertia of this mobility causes unintended human body movements, which are input to the interface. In this research, in order to solve this problem, the authors introduce not only an inverted pendulum model but also a human postural control model. In order to change the body inclination voluntarily to operate this mobility, it is indispensable for a human postural control model to be able to follow an arbitrary target inclination angle, not just an upright state. The authors have now achieved forward-backward movement. In this paper, the authors propose a control model for following target inclination angle in lateral direction. First, a control model for maintaining an upright posture is introduced. Next, the authors conduct a body postural maintenance experiment in lateral inclination. A model is identified as a control model for following target inclination angle based on the result of this experiment.

This research develops a walking promotion device. The device is worn by user’s forearm and leads to increase arm swing. The device’s motion principle is based on parametric excitation. The Authors manufactured the prototype named “linear motion device”, and evaluated amplification of arm swing in previous paper. The device could increase the arm swing by 10°. In this paper, the authors experimented whether the device can increase the stride and walking speed. First, the participants wore the device on the right forearm. Afterwards, the authors measured at left thigh angle for stride and gait cycle. Comparing two states of disable with enable, the stride and walking speed were not increased. Second, they wore the device on the both forearms. As a result, the stride was increased 0.13 m, and the walking speed was increased 0.20 m/s. Therefore, the effectiveness of this device in walking promotion was confirmed.

The purpose of this research is to develop an omni-directional low-floor mobility. The mobile platform and the interface of the mobility have already developed. The height of the mobile platform is 37 mm from road surface to the boarding floor. Omni-directional movement is realized by using four mecanum wheels. The operation interface is consisted of eight load cells. The operation for omni-directional movement is realized by using load distribution information obtained from eight load cells. However, movement of the mobility tends to oscillate due to unintended body movement caused by inertia of the platform. In order to solve this problem, this research proposes control method by introducing not only an inverted pendulum model but also a human postural control model. In this paper, we focus on forward backward movement. First, the estimation method of human body inclination using load distribution on the boarding surface is proposed. Next, a controller of the mobility is proposed by introducing the human postural control model, and is simulated. Finally, the effectiveness of the controller including the human postural control model is shown by comparing with the controller not including the human postural control model which is validated by preliminary simulation.

This research proposes the walking promotion device using arm swing induced by parametric excitation. Generally, the walking is promoted by amplification of arm swing. The proposed device is wearable on wrist such a watch. It consists of weight, link and motor. Moving the weight in the longitudinal direction of the forearm, it occurs parametric excitation. In order to design the link length and weight, the arm and device are modeled and simulated with their parameters. In the result, the weight of the device is set to 0.10kg, the link length of it is set to 0.02 m, and the target amplification angle is decided 1°. To perform a preliminary evaluation experiment, 2-links pendulum was made with following the simulation conditions. Comparing with the states of disabled and enabled the device, the shoulder angle increased 2.23° in average. In addition, an evaluation experiment with human arm was conducted. As the results, the device can increase the arm swing.

The following topics are dealt with: learning (artificial intelligence); medical signal processing; convolutional neural nets; feature extraction; mobile robots; human-robot interaction; neural nets; gait analysis; data analysis; optimisation.

This paper proposes the ungrounded force display device using the grooved cam. Using the human illusion, the user can feel the force in one direction when they use it. It is mainly configured the cam and the slider. The slider follows the cam and moves translational movement. We created the prototype using the grooved cam and evaluated it. From the evaluation, it was confirmed that undesirable vibration should be decreased. Hence, the inflection points are added in the cam profile. We show how to create the different cam shape and verify the difference in feeling by changing the cam shape in the two experiments. First experiment is for finding the sub-optimal cam rotation speed in each cam. Second is to investigate the relationship between the cam shape and the force magnitude which the subject perceives. As the result, we confirm that the movement of the slider with rapidly velocity changes gives the clear force presentation to user while the slider shows the asymmetric acceleration motion.

The purpose of this research is to develop the electric assist wheelchair system for hemiplegic users. The proposed system is able to move in any direction by operating only one hand rim on one side. The hand rim can detect the user's operational intention by measuring contacting force and status of grasp and its style. The proposed system enables straight ahead, go back, gradual turn, pivot turn and stop based on the force being applied to the hand rim, whether the hand rim is grasped or not, and rotational speed of the hand rim. After the user operates the hand rim and releases it, the moving mode shifts to the deceleration mode. In the deceleration mode, the pseudo inertia deceleration is reproduced by motors. In this paper, we focus on the proposal of the system and the inertia deceleration by controlling motors, and verify how much it can reproduce in the outdoor environment.

This paper proposes the ungrounded force display using the grooved cam. Using the human illusion, the user can feel the force in the one direction when they use proposed device. It is mainly configured the cam and the slider. The slider follows the cam and moves translational movement. In this paper, we create the new prototype which solving the problems that emerged from the previous prototype. We evaluate the device using the two experiments. One is the subjective evaluation. Second one is the force presentation from the new prototype as the quantitative evaluation. We could solve problems of previous prototype by changing the cam type from plate to groove and blushless motor, and the new one produce the force more clearly than the previous prototype.

The conventional robot arms applied in various fields are demanded to have high force output, high accuracy, high efficiency. But they are seldom applied in human life, because of large weight, rigidity, hazards to people caused by collisions. Therefore the soft robotic arm that is stretchable, light weight, softness without possible of hazards, and high precision control is suitable to deploy in human life. Thus the purpose of this research is to develop the soft robotic arm by using antagonistic pneumatic driven system. In order to realize this concept, the joint activation mechanism is the key component. This study focuses on the angle control of the joint. In this paper, the robot arm made by polyethylene is proposed. Air bags made of polyethylene inside the joint achieve antagonistic driven states. Helical tube made of polyethylene is adhered joint outside for realizing rigidity. It is characterized that control rigidity is realized by controlling the pressure in the helical tube and joint angle is preciously controlled in two degree of freedom by controlling pressure in the air bags. Furthermore, the joint angle can be controlled by controlling the air pressures in the air bags using stretch sensor measuring joint angle. The experimental result confirmed that the driving concept of the joint was well functioned, and the joint angle control was realized by feedback control.

The purpose of this research is to develop the wheelchair system for hemiplegic users. The proposed system is configured by the front wheel with active steering and hand rim for detecting user's driving force. The user's operational intention is distinguished by the sign and amplitude of force along the rotational axis of the hand rim. The steering angle of the front wheel is controlled by an actuator based on extracted intention from the hand rim. By proposed system, user can operate the wheelchair by using only single side hand rim. In particular, in this paper, we evaluate the designed hand rim by conducting some experiments.

Currently, various force display device are under development. There are two types of devices in terms of mounting method: grounded and ungrounded. The conventional grounded type force display device can accurately present the force by mounting on the desk or floor, but the movable range is limited. The ungrounded type device is wearable type, the user is burdened to some extent and there is a great restriction on force display. In order to solve this problem, the force display device that can be handled in the hand using a slider crank mechanism has been proposed. This device uses human sensory characteristics, and force can be presented by asymmetric acceleration motion. Since this device uses rotating bodies and crank mechanisms, there is room for improvement in terms of size and weight. Therefore, we adopted a cam to generate asymmetric acceleration motion for the improvement. By using cams, it is possible to reduce the number of devices and downsize them. In this paper, we propose the mechanism using cam and confirm the realization of left-right asymmetric acceleration motion for force display. In addition the performance of the force display was confirmed through both experiments: quantitative and subjective.

The purpose of this research is to develop the soft robotic arm by using a pneumatic system. To activate the arm, the joint is the key component. Therefore, this paper focuses on the structure of the joint and angle control. This joint has a helical tube outside to change the stiffness, and two pairs of air bags made of polyethylene inside for configuration antagonistic driven system. The features of the proposed joint are that: totally made with soft material, inflatable structure and can be change the stiffness of the joint by controlling the pressure in the helical tube. By controlling the air pressures in the air bags, the joint angle can be controlled. By the experimental result, it was confirmed that the driving concept of the joint was well functioned, and the joint angle control was also fairlv realized by open loop control.

The ultimate goal of this research is to develop the design guidelines for a mobile robot that allows people to easily recognize its movement direction in the scenes where a person and a robot pass each other. In general, the design of a robot coexisting with people often incorporates the human movement and the sensory characteristics in order to let the robot behave like a human. This study also adopts this methodology and take into account with the human behavioral characteristics so that a person can easily recognize the robot's moving direction. Therefore, in this study, we clarify the characteristics of human appearance and movement in the period immediately before passing each other in case of person to person. By adopting its characteristics, we propose the design guidelines of the mobile robot in the point of view of robot shape and movement. In this paper, we performed the experiments ((1) Which body parts of oncoming pedestrian are often gazed by the other pedestrian? (2) Phase difference of yaw angle of the shoulder and the loins, (3) Impression evaluation to derive the most human like shape) to determine robot shape. As a result, we are elucidated as follows. Results of (1): pedestrians are considered to determine their own avoidance direction by seeing the movement of the upper body of the oncoming pedestrian. (2) The rotation of loins shows phase lead to shoulder in case of angle of walking direction change is shallow, on the contrary the shoulder is phase lead to the loins. (3) The most human like shape is that the width of the upper part of the robot, the width of the middle part and the height of the middle part are intermediate, and the width of the lower part is slightly wide.

Recently, some spraying systems have been proposed that use a drone towing a liquid tube. However, towable tube length is limited due to the payload of a drone, and there is a possibility of liquid leakage from the tube or that the drone will fall. To solve these problems, this research proposes a liquid feeding system where the tube and cables are towed cooperatively by multiple drones. By using multiple drones, the length of the towable tube can be longer, and the working space can be enlarged. In addition, if the power cable is also towed together with the tube the amount of working time will be increased because a battery will not be necessary. In particular, in this paper, it verifies that it is possible to estimate the position of the drone by measuring the tensile force vector of the cooperative towed tube with the tensile force sensor attached to the other drone. In result, we showed that the position of the end points of the tube that was cooperatively towed by the drones can be estimated by using the tensile force sensor attached to the drone.

Sensorimotor synchronization (SMS) is a behavior co-ordinated with a rhythmic external stimulus. In previous studies, neural entrainment related to auditory stimuli and motor activity was observed during SMS to auditory stimuli. This study investigates the cross-modulation responses to oscillations of auditory stimuli and motor-related activity. The results suggest that a population of output neurons, which occur products of the two input oscillations caused by stimuli and motor activity, could exist. It has not been clarified, however, whether cross interaction is observable in the EEG during SMS while using visual stimuli. This paper presents the results of an analysis of electroencephalogram during SMS to visual and auditory stimuli. We observed cross-modulation responses during SMS not only to auditory stimuli, but also to visual stimuli. Our results confirm the existence of output neurons, which result as a product of two input oscillations.

Recently, some spraying systems have been proposed that use a drone towing a liquid tube. However, towable tube length is limited due to the payload of a drone, and there is a possibility of liquid leakage from the tube or that the drone will fall. To solve these problems, this research proposes a liquid feeding system where the tube and cables are towed cooperatively by multiple drones. By using multiple drones, the length of the towable tube can be longer, and the working space can be enlarged. In addition, if the power cable is also towed together with the tube the amount of time the drone can be used will increase because a battery will not be necessary. In particular, this paper describes the movable range of the drones while considering tube tension.

We discuss adaptive behavior acquisition for collision avoidance among multiple autonomous mobile robots which are equipped with the locally communicable infrared sensory system (LOCISS). The LOCISS is a local sensing device for collision avoidance by which robots can detect other robots and obstacles and discriminate them by exchanging relevant information. We (1996) reported previously a collision avoidance method between two robots based on the predetermined rules using LOCISS. It is, however, difficult to realize collision avoidance among three or more robots by the predetermined rules only because situations around the robots become more complicated as the number of robots increases. Thus, it is desirable for the robots to have an adaptive capability for acquisition of the behaviors to avoid collision with other robots and obstacles. To acquire the adaptive behavior, the reinforcement learning is introduced in this paper. It is shown that appropriate behaviors for collision avoidance can be successfully acquired through the proposed learning process.

A concept of mutual transportation by cooperative multiple mobile robots is proposed in this paper, which enables robots to process complicated or heavy-duty tasks, and overcome the large obstruction in an environment. A method of mutual transportation utilizing forklift mechanisms is introduced with discussion on the lifting process and moving process. Cooperative mobile robots including a holonomic omni-directional platform and a forklift mechanism are developed. Finally, as an example of applications of mutual transportation, step-climbing motion is presented, and the motion realized by the developed mobile robots is shown.

This paper proposes a new strategy for knowledge sharing among multiple autonomous mobile robots using newly developed intelligent data carriers (IDCs) to make the multi-robot system more flexible and robust against complex environmental conditions and, to reduce the amount of global communication for mutual exchange of information which is useful locally in a limited area. The IDC is an immobile but portable device (data carrier) for information storage and management with a unique mushroom-like structure to be easily handled by a forklift mechanism which can be mounted on actual mobile robots. A robot can place a unit at a specific location in its working environment and write locally relevant knowledge into the unit. Other robots can share the knowledge which should indicate the existence of specific instruments, objects or topographies, e.g., dead ends, drop-offs, steps, etc., by reading from the placed IDC units. The handling method of the IDC unit is examined through the experiment using an omni-directional mobile robot. It is shown that the robot succeeded in placing the unit at an appropriate location to share the information indicating that a dead end exists.

A new driving mechanism for holonomic omnidirectional mobile robots is designed, which enables 3 DOF motion control by three correspondent actuators in a decoupled manner with no redundancy. A prototype of the omnidirectional mobile robot with the driving mechanism is developed including a parallel link suspension mechanism. The kinematics of the omnidirectional mobile robot is also analyzed, and simulation for velocity control of the robot is performed by a method for velocity modulation with interpolation to achieve the given target position and velocity.

Distributed autonomous robotic systems which are composed of multiple robotic agents have been attracted the attention of many researchers as a new strategy for flexible and robust robotic systems. For cooperative multiple mobile robots in distributed autonomous robotic systems, recognition of the dynamic environment is required. In this paper, a new sensory system with local communication functionality is developed utilizing infra-red devices. Based on the discussion on sensing and communication for cooperative multiple mobile robots, requirements for the sensory system are derived. Then, the infra-red sensory system is designed and developed taking account of the required function. This system enables not only detection of collisions against obstacles or other robots but also local communication between robots. This system can also detect interference of plural infra-red signals. Finally the developed system as introduced, and its performance obtained as a results of experiments is shown.

As a flexible and robust intelligent robot system, we have been developing an autonomous and decentralized robot system called ACTRESS, which is composed of multiple robotic agents who have various kinds of functionalities. In order to achieve a given mission in multirobot environment, cooperative behaviors by autonomous agents are essential. In this paper, we focus on the case that multiple robots execute a task cooperatively with functional complement, especially for sensing function. We discuss cooperation of multiple robots using communication in a multi-agent robotic system, and propose a method of functional complement by multiple agents, including group organization and cooperative motion control. Finally, we show the experimental result to verify the proposed method.>

The paper describes the human interface system in the autonomous and decentralized multi-agent robotic system ACTRESS. The human interface system coordinates the interaction between the human operator and robotic agents, monitors system's activities and presents them do the operator. The operator can send commands to individual robotic agents or a group of agents through the human interface. He can also intervene in the system based on monitored system status if and when necessary. The human interface also acts as a window through which the robotic agents contact the operator for judgment and advice. The paper presents the architecture of the human interface system. The architecture was designed so as to allow the operator to interact with the system through consistent interface in the real environment and in the simulator environment, in which robotic agents' programs are developed.>

As a flexible and robust intelligent robot system, we have been developing an autonomous and decentralized robot system called ACTRESS, which is composed of multiple robotic agents. In this paper, introducing an idea of cooperative action with group organization and a strategy for cooperative task processing using communication, a method for team organization by efficient negotiation is presented. The efficient negotiation is realized by a newly developed communication functionality called groupcast and a learning mechanism utilizing historical records on past negotiation. The negotiation procedures for team organization are implemented, and as a result of simulation experiments, the efficiency of the learning mechanism is verified.>

This paper addresses a method for synchronizing motion by multiple autonomous mobile robots using radio communication. The autonomous and decentralized robot system, ACTRESS, is a multi-agent robotic system including multiple autonomous mobile robots. The autonomous mobile robots are developed so as not only to act individually, but also to cooperate with the other robots if they cannot accomplish the task alone. The synchronized motion is sometimes required to execute such cooperative tasks. Every agent of ACTRESS is equipped with the communication system, which enables a message passing between any robotic agents. The prototype ACTRESS system is introduced, and cooperation among multiple robotic agents is discussed. A method for synchronization using the communication system is proposed. The method is applied to the prototype system, and side-by-side motion on the actual mobile robots is implemented as a example of synchronized motion.

An autonomous and decentralized system called ACTRESS (ACTor based Robot and Equipment Synthetic System) is being under development as an intelligent robot system which can execute high level tasks. ACTRESS is composed of multiple robotic agents. Each robotic agent is called robotor. A robotor may be a robot, a computing system and any other equip- ments. While researching in this field, many research issues need to have solutions, such issues may include, the communication among the agents and protocols, cooperation among a group of agents, describing the tasks to be executed, multi-agent motion planning, multi-agent task planning, task description, human interface role, solving deadlocks ... etc. The aim of this paper is to develop a simulation environment for an autonomous and decentralized multi-agent robotic system. For this purpose, it is neces- sary to simulate and analyze the main functions of each agent, design and analysis of the actions to be carried out by each agent, analyzing their real time behavior with a variety of situations considering their environ- ment and the treatment of unexpected events. Also, it is aecessary to find out an efficient strategy to realize effective means for the agents to form a cooperating manner that support task execution and problem solv- ing. In parallel with the mentioned purposes the ACTRESS structure is simulated as functions and behavior using the developed simulation environment. This simulation includes a group of mobile robots, human interface and global environment manager. Then, software integration that deal with various aspect of the overall problem is developed. Different experi- ments are performed to analyze the performance of each individual robotor and the overall system.

An autonomous and decentralized robot system, ACTRESS, is being developed as an intelligent robot system which can execute high level tasks. The concept of ACTRESS is introduced, and the communication framework between robotic agents that compose the robot system is proposed. Taking a task of pushing objects by multiple mobile robots in a certain working environment as a case study of ACTRESS, the strategy for organizing the robot system is discussed, and the required functions for the robot system are introduced. The optimal distribution of the functions is designed based on communication evaluation. An algorithm for static path planning and a strategy for dynamic path planning are proposed.>

An autonomous and decentralized robot system, ACTRESS, is being developed as an intelligent robot system which is composed of multiple robotic agents. The basic concept and strategy for path planning in a dynamically changing environment with multiple autonomous mobile robots are introduced. Collision avoidance with dynamic path planning according to the complexity of the situations is also discussed. A method for collision avoidance based on rules and negotiation by communication is presented. Finally, this method is applied to a developed prototype system consisting of two mobile robots, and the result of experiments operating on real robots is given.>