The final goal of this research is to develop a condenser type micro ultrasonic sensor, which would be used as both receiver and transmitter. Polymer diaphragm is flexible and non-brittle, allowing good sensitivity and durability. Besides that, Parylene has good C-MOS compatibility, since it can be deposited at room temperature. Based on the FEM simulation results on the resonant frequency under tensile stress of Parylene, the diaphragm radius of 500〜1200 μm is employed to realize the bandwidth up to ultrasonic range of 40〜100 kHz. The influence of the number and the radius of acoustic holes on damping ratio is investigated by FEM simulation, in order to achieve a moderate damping of the diaphragm. Practical sensor devices are fabricated. They can receive an impulsive ultrasonic pulse transmitted by a spark discharge. The open-circuit sensitivity is 0.3 mV/Pa, in reference to B&K 4138 microphone. The ranging system using this sensor can detect the distance up to 1 m with the error less than 1 mm. The developed sensor can be approximated to be non-directional.

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This paper describes wall-climbing robot based on adhesion mechanism of ants. Adhesive pads which are similar to adhesive organs of ants were fabricated using micro fabrication techniques. In order to adhere the pad to a vertical wall, a small amount of liquid was supplied to the surface of the adhesive pad through micro channels using a micro pump. Normal and tangential adhesive forces between the adhesive pad and a glass surface were measured. Furthermore, a hexapod robot that walks in the same gait as that of an actual ant was fabricated and the adhesive pads were integrated in each foot of the robot. The robot successfully adhered on a vertical glass surface.

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This paper describes a biomimetic water strider robot with microfabricated water-repellent legs. Various kinds of supporting legs with water-repellent microstructures on their surfaces were developed utilizing microfabricaion techniques. Lift and pull-off forces of the supporting legs have been measured. The experimental results are in good agreement with theoretical values. Furthermore, an autonomous water strider robot with twelve microfabricated legs has been developed. A vibrating motor is utilized to move the legs for controlled locomotion. The robot can successfully stay afloat by surface tension and can also move forward and make left/right turns utilizing differences of resonant frequencies of the legs.

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This paper describes the development of a new flexible actuator for wearable robots. Some of pneumatic actuators are developed for actuating the wearable robots and the artificial limbs. These pneumatic actuators give the special structures with giving the strong pull of the elements like the conventional McKibben type artificial muscles etc. in the robot. A new type of pneumatic flexible artificial muscle actuator (abbreviated PFAMA) is consisted of the inner and the outer tubes. The inner tube is made of coming into inwards curve from outside of the outer tube by the pneumatic actuation and the outer tube is provided with holding the column shape for the tube not to increase in the radial direction of inner tube. Therefore, the inner tube extends the tube length as the displacement in the axial direction of the PFAMA. The experimental results indicate the fundamental results.

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A wearable actuator to stimulate stretch motion at the wrist is proposed in this paper which is designed to realize the physical therapist's technique. The actuator is composed of the spiral tube driven by pneumatics and a wire to amplify the displacement of the tube. The developed actuator could perform in enough wide range to stretch the wrist with its pushing the carpal which is required in the rehabilitation.

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This paper introduces an exoskeleton powered hand system that provides power support for hand and wrist activities of a human. The powered hand system has three degrees of freedom for an index finger and two degrees of freedom for a thumb. It also has three degrees of freedom at wrist joint. It therefore has eight degrees of freedom in order not to lose major freedoms of hand activities. Our proposed poly-articular tendon drive mechanism realizes a mechanical compliance of a human finger so that the system could keep comfortable and stable grasping even if some external force affects the grasping object. This paper also proposes a new mechanism and a control algorithm so that the powered system motions could synchronize wearer's hand activities without any external loads for a wearer. A tendon-driven mechanism and a dual sensing system enable wearer s fingers to move freely when they does not contact with any environments. A wearer ' s fingers receive power support from the system when a wearer generates a larger force. The wearer s generation force is measured from BEP(bioelectrical potential) signals of the corresponding part so that the supporting force is in proportion to that force. Through experiments it is confirmed that a wearer receives power support from the system during pinching motion and wrist activities.

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It is possible to say that the multi joint manipulator can work even if increasing of redundant quality,the numbers of links,and the complex structure. However, it becomes to fall down easily, because of the increasing of manipulator's weight,which is caused by the increasing of the numbers of links. Therefore, accuracy of end-effecter will reduce. And then in order to control, the bigger power will be needed. Here,I think a manipulator just like a human-being who can do some high accuracy work by a little power with attaching elbow. So in this paper it is compared the two movements, without attaching elbow and with attaching elbow. Then we can get the conclusion in the movement without attaching elbow,it can work better, under the condition of smaller power.

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A force control device with large dynamic range is developed. It consists of a spring and a fine actuator that are connected in parallel. By installing this device at a tip of an arm driven by an ultrasonic motor, large forces with high resolution under the existence of static friction is achieved.

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Recently, multiple locomotion gaits of snake has been realized by snake-like robots. For example, undulation propulsion, side winding propulsion and measuring worm propulsion are realized. In addition, a locomtion gait called "lateral rolling" that real snake does not achieve is realized. However, those previous locomotion gaits are limited on two-dimensional plane. In this study, we develop a snake-like robot that is constructed by assembling five units. One unit is composed by one pitch axis and one yaw axis, and can have two passive wheels. We realize previously presented locomotion gaits of snake with this robot. In addition, we realize cylinder climbing locomotion in three-dimensional plane that this robot coils itself to a cylinder and climbs it by lateral rolling.

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In near the future, it is expected that robots will live with human in living space. We will have many chances to touch robots in anywhere. Therefore, robot needs to have skin sensory besides conventional tactile sensing technologies. So far, we have developed skin sensor system for robot which is able to recognize various stimuli as tickle, scratch, stroke and rub. The shock sensors are using for detection of acceleration by given stimuli and system surface is covered by polypropylene film. This paper is describes the analysis of vibration mechanism between system surface and shock sensor. We understood that generated stimuli by finger movements on system are transformed into lateral vibration and self-excited vibration by this analysis results.

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In this paper, we have given weight to the construction of virtual deformable objects with rheological properties. We focused on rheological properties of the real object which are estimated and extracted from the experimental sequences of contact force transition and deformation analysis. The validity and effectiveness of proposed method is ascertained through the computer simulations.

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Power assist device "Skill-Assist" we developed for workers in the labor intensive manufacturing has become in practical use in automobile production lines. Not only hands-on control mode such as power assisting but also hands-off control mode such as automatic transportation from a distant location is important to improve the efficiency of the works by Skill-Assist. Our objective in this study is to verify the functionality of a safety switching method for transferring from hands-off control mode to hands-on control mode of Skill-Assist. A nonstationary impedance control law including time-varying impedance parameters is utilized to attain the objective. Experimental results show that control input, displacement, and velocity of Skill-Assist vary continuously in transferring from hands-off to hands-on control mode and we can confirm the safety switching control method of Skill-Assist.

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Recently, as robots and humans have increasingly come to share common spaces especially in the fields of the medicine and welfare, it has become necessary to consider the frequent physical contact or collision of robots and humans. Therefore, high safety is demanded from the robot of this type. This study describes the development of a manipulator using a smart flexible joint composed of ER fluid and pneumatic cushion. Further, the position control experiment, the collision experiment and the pressure change experiment in pneumatic cushion were done in the manipulator that developed. Results of them demonstrate the effectiveness of the manipulator.

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In this paper, we develop a compliance adjuster mechanism for robot arm. In this mechanism, an elastic plate is inserted between the joint part and the link part. Elastic deformation of the plate absorbs external force applied on robot arm. Furthermore, the characteristics of compliance can be adjusted by controlling the rotational angle of the plate around the principal axis of the link. We examine the fundamental characteristics of this arm through the model analysis and some experiments.

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This current research aims to model adaptive behavior selection in crickets fighting behavior from physiological knowledge. We have already proposed an action selection model by NO/cGMP cascade-OA model and it can be an adequate model for adaptive behavior selection in cricket's brain. In this report, we examine to model a condition for initiation/termination condition of fighting behavior after interaction between the crickets.

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Today's robots are controlled typically by "highly precise control algorithms": their joint angle trajectories are determined accurately at any time with vast amount of computation. This approach, however, causes serious problems, particularly in terms of energy efficiency and adaptability. On the other hand, recently, another extreme approach has been gaining a lot of attention. A good instantiation is the passive dynamic walker. One of the crucial points is that this approach has shed light on the fact that control system is not everything. More specifically, it is of highly importance to exploit intrinsic dynamics of a robot's body, leading to "cheap" control algorithms. In light of these facts, this paper intensively deals with how the body dynamics influences the behavior in the quadruped trasition as a practical example.

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The importance of prevention of dementia is a crucial issue in this aging society. We propose co-imagination method for prevention of dementia. Co-imagination method aims to activate three cognitive functions: episode memory, segmentation of attention, and planning function, which decline at early stage of dementia. Participants of the co-imagination program bring images which represent episode memory and communicate with them. They take memory test for evaluation of the method whether they remember the images after the series of sessions. We held co-imagination program successfully at the welfare institution for elderly people in Kashiwa city. Each session was held one hour per week for five times. The effectiveness of the proposed method was validated through the experiment.

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The importance of prevention of dementia is a crucial issue in this aging society. We propose co-imagination method for prevention of dementia. Co-imagination method aims to activate three cognitive functions: episode memory, segmentation of attention, and planning function, which decline at early stage of dementia. Participants of the co-imagination program bring images which represent episode memory and communicate with them. We developed co-imagination support system for displaying user contributed images smoothly. We evaluated the system through comparing sessions with and without images. Communication of the sessions was analyzed by period, numbers and frequency of comments and descriptions. The result suggests that the communication with co-imagination support system was active with many comments, which requires segmentation of attention.

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Singularities induce serious problems in teleoperation since the operator is liable to move the slave arm to/around singularities unintentionally. When a dual-arm manipulator performs a cooperation task, if one of the arms runs into a singularity, it is not possible to accomplish the task. To solve this problem, we propose the singularity avoidance method by inputing angular velocity to a redundant axis during cooperative control of a teleoperated dual-arm robot. Using this method, the operator can avoid singularity on his/her own. Then we conduct verification experiments for whether the proposed redundant control method can successfully be done during cooperative control or not.

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We applied the Singularity-Consistent control method to derive a null-space vector for suppressing vibrations by a kinematically redundant manipulator mounted on a flexible base. To avoid the problem of algorithmic singularities, we control the end-tip motion via the pseudoinverse of the manipulator Jacobian. Experimental results show that vibrations induced during the manipulator motion can be effectivity suppressed.

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Nowadays, many people are suffering from stiff neck, lumbago and chronic stiffening muscle in Japan. The palpation of the stiffness of muscle is generally used for the diagnosis of these symptoms. However, the palpation method is not based on the quantitative measurements. In this study, the artificial symptom models (uniform and layers structure) using polyurethane gel as phantom tissues. The evaluation experiment was conducted between the palpation by medical doctors and the measurement system.

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This paper describes the method to identify the parameters of 2D FE (Finite Element) deformation model from the measured inner deformation of soft objects. First, we formulate 2D elastic deformation and apply FE method to compute the deformation numerically. Next, we describe the method to measure the deformation of soft objects. We propose to deform an object to be identified by another object of which physical parameters are known. During this process, inner deformation of the two objects are measured by CT or MRI technique. Soft objects are pushed by the objects which of the parameters identification is tested in advance. Finally, we formulate a method to identify the model parameters from the measured deformations.

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To realize an artificial tactile sensation, we study about the information process of tactile sensation. Aiming at reduction of displaying information, we research about minimal information for natural sensation. We are researching the natural nerve activity of mechanoreceptor to know minimal and enough information. In this paper, the energy conversion system of the Meissner corpuscle which is one of the mechanoreceptor was considered. There is a model that the collagen fibril drives Meissner corpuscle. By supporting this model, the possibility of stretch detection among epidermis was shown. The fibril driven structure of this detection is thought to be reasonable.

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Mechanical impedance control schemes are classified into torque-control-based and position-control-based. The former is used for a direct-drive manipulator. The latter is also called Admittance Control and often used for a geared manipulator, which control the position determined from a force sensor. Since the admittance control uses the high-gain position controller, the manipulator hardly move against the force without involving the force sensor. In this paper, we show the characteristics and structure of admittance control responsive to unmeasurable external force.

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Recently, robot research that coexists with people and is helpful for them is active. Such a robot needs both safety and flexibility. Then, we use a pneumatic actuator as driving source of robot hand. We originally develop a pneumatic actuator driven by low pressure because we consider that conventional pneumatic actuator is inadequate for driving source of robot hand. We develop five fingered robot hand using the pneumatic actuator. The robot hand has both safety and flexibility. We construct master-slave system to let the robot hand do the same movement as man. Next, we make a joint model that has one degree of freedom using a pneumatic actuator. We construct control system for the joint model and verify its control performance.

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Robot safety is an important issue, since many new concept robots for interaction and work with human are investigated, recently. In this paper presents strategies for reducing the impulsive force reduction from the collision of manipulator, especially, from viewpoint of robot safety. From the discussion about dynamics of impact, we concluded the reducing of reduced mass, relative velocity and reduction of impact duration time method are effective to reduce the impulsive force. Moreover, the extension the impact duration time and increasing of impact area are also effective. Collision experiment by real 3-link manipulator with the high decelerate method with coupling inertia are introduced.

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This paper studies the experimental measurement, numerical simulation, and control of the rhythmic and cyclic flapping-of-wings flight of a butterfly to clarify the principle of stabilization of the flight. A wind tunnel experiment with actual butterflies measures the aerodynamic force and the flapping-of-wings motion. A dynamical model is derived by Lagrange's method. For the aerodynamic forces, we apply a panel method considered the induced unsteady flow. Validity of the mathematical model is examined by comparing the measured data with the numerical results. Using the derived mathematical model, a periodic orbit of a flapping-of-wings flight is searched. Though derived flapping-of-wings flight is unstable, a nearly periodic orbit can be searched. Moreover, it is shown that free-vortices in wakes make the unstable level smaller but a control is necessary because the derived periodic orbit is still unstable. Finally, a controller is designed for the periodic orbit and its stability is examined by numerical simulation.

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In order to conduct the long time exploration-based learning experiments with a physical robot, there was necessity to build a durable robot. Therefore, we built a novel robot with a tendon-based actuation mechanism which can afford elasticity at each joint of the robot. Each of the arm joints is actuated by an antagonistic pair of two motor-spring assemblies. By controlling the tension in the spring with a classic PID controller, the joints are being torque-controlled. Because of inherent nonlinear characteristics of the developed system, standard PID control schemas cannot be applied to the system. Therefore, we employ the RNN to construct the inverse model which plays the role of controller. In this paper, we report the result of preliminary experiment using this controller.

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This study is intended to intensively discuss how control and mechanical systems should be coupled by taking a 2D serpentine robot consisting of multiple body segments as a case study. In order to realize "well-balanced" coupling between control and mechanical systems, we have investigated the role of multiarticular muscles, which specify the long-distance correlation between the body segments, in the generation of behavior. Preliminary simulation results indicate that a certain degree of long-distance correlation derived from the multiarticular muscles enhances the adaptability and the controllability without sophisticated sensory feedback mechanisms. We expect that this "embodied" intelligence allows us to significantly reduce the complexity of control systems.

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This study deals with visual-tracking control for a quadruped robot. The control system is composed of two blocks: First one is visual-guidance control system that directs cameras toward a target. And the other is motion controller with non-linear oscillator network that perform motion control for follow its target. Real-time visual-tracking control is implemented with proposed control system and verified the efficiency through numerical simulations and hardware experiments.

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This paper describes the general-purpose onboard robot control system. This onboard system also has not only the computational function but also interface function such as A/D converter, motor driving capability, and communication capability with host computer. Two kinds of onboard systems are produced. One pursues the easiness of development, and the other is pursues the real time control. The after case uses a host microcomputer and multiple slave microcomputers according to the number of driving axis. The slave microcomputers are controlled by the host microcomputer connected by a wired/wireless telecommunication line. The I^2C bus is used for an inner bus lines. It connects the slave microcomputers and the host microcomputer. Several onboard systems has been designed and manufactured, and they are evaluated successfully by applying it for some robots.

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The mechanism of the vehicle with wide rage CVT has been improved. The wide range CVT consists of a half-toroidal CVT and a differential gear which obtain a reduction gear ratio from forward to backward continuously. The support structure of power roller has been improved to equalize the contact forces between the disks, which reduces the slippage between them. A suspension mechanism is added to the vehicle in order to improve its surmounting capability of road surface undulation.

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The small size mobile robots are useful to use in situations such as surveillance inside the buildings or search activity of the victims on disaster site. Recently, small size search robots have been developed in various research institutions. robots in those situations, size of robots makes difficult the long distance movement and movement on unflat surfaces, and run over the obstacle. We have developed the miniaturized comfort mobile mechanism which uses for improvement of mobility of the small size mobile robot. In this paper we describes about basic mechanism and performance of the miniaturized comfort mobile mechanism.

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This paper describes the mobile control and the standing and sitting motion of I-PENTAR which is an inverted pendulum type human assistant robot aiming at coping with both safety and work capability. I-PENTAR consists of a body with a high powered waist joint, safely designed two arms, and a wheeled mobile platform. In a mobile control it is modeled as a three dimensional robot; an inclination angle, a horizontal position, and a steering angle, and controlled by a state feedback control method based on the LQR method. The motion planning of a standing and sitting motion which is an important motion for an inverted pendulum type robot in practical use is proposed. In the motion planning several conditions are considered to realize the motion, and the robot can achieve the motion by resolving the conditions. It was experimentally confirmed that I-PENTAR could realize the fundamental motions required in practical use, standing, running and turning, and sitting stably.

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This paper deals with robust stabilization of running self-sustaining two-wheeled vehicle with varying running speed. Recently, some researches about stabilization of Two-wheeled vehicle have been reported. These researches have achieved the stable running only by the steering control. However, an actual two-wheeled vehicle is stabilized by not only the steering control but the control of a vehicle's center of gravity. We have proposed the stabilization control method of Two-wheeled vehicle in the state of stillness, and have shown the effectiveness. In this research, we construct the control system for the running stabilization of Two-wheeled vehicle. H_∞ mixed sensitivity problem is used to design the controller to achieve running stability even if the running speed changes. The experimental results show running stability even if the running speed changed.

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This paper suggests a dynamic skating method propelled by switching skates with swing motion in frontal plane. On switching skates, directional characteristic of skate separates swing motion to motion for propulsion and motion lifting former contact leg. The swing motion is maintained by alternate sinusoidal leg extension. A robot with slider-crank mechanism for leg extension is developed and leg extension cycle to obtain a limit cycle of swing motion is experimentally found. The robot performed dynamic skating with speed of 2.34km/h.

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In this paper, how to solve a nonholonomic constraint on wheel and a closed loop structure are discussed. To solve a bicycle model, first, derivated equations of velocity constraint and virtual open looped structure model. Second, calculated a constraint force using the method of Lagrange multipliers. Third, solve a differential algebraic equation (DAE).

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In our research group, the project, riarried "networked robotic system for disaster mitigation", has been carried out. In the project, multiple robots are coordinately operated via wireless communication network. The robot system consists of a large-mobile-robot and small-mobile-robots. The small robots are aimed to be conveyed by the large robot and to be distributed inside collapsed buildings. Therefore, the large robot should surmount some debris and bumpy terrain to approach the target buildings. To enable such motion, it has six wheels to form into rocker structure. In this research. we aim to propose a suitable remote control method for navigation of the large robot. Our developing "robot-dynamics simulator" is used to discuss a performance of the robot's control.

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A mobile manipulator consisting of a 6 d.o.f manipulator and an omni-directional moving platform with four wheels is developed. The four wheels are controlled by DC servo motors respectively in order to position the moving platform on the ground. The system has torque redundancy which can be used for improving the control performance of the moving platform. A criterion for exploiting the redundancy is proposed to avoid the slippage of wheels, and fundamental experiments are done to show the control characteristics of the developed mobile platform.

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In the ground test of a jet engine, a remotely controlled measurement is being inquired for data acquisition and observation under severe environment such as under extreme sound level or high temperature. This paper introduces an revised measurement system satisfying above needs. Telepresence Over IP System is enabled quasi-realtime vision on PC and smooth diving. The revised system was applied to the ground test of a turbojet engine and showed sufficient performances in operation and measurement.

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This paper describes a method of fault diagnosis of internal sensors and actuators for a wheeled mobile robot. We handle hard fault and scale fault of three sensors (two wheel-resolvers and one gyro) and hard fault of two actuators (two wheel motors). The hard fault of the gyro is diagnosed based on mode probability estimated with the interacting multi-model estimator. The hard fault of the wheel resolver and motor is diagnosed based on the gyro output as well as the mode probability. The scale fault is diagnosed based on estimating the robot velocity with an in-vehicle laser range sensor via a scan matching method. The iterative closest point algorithm is applied for the robust estimate of the robot velocity in usual indoor environments. Experimental results validate the effectiveness of our method.

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We have been developed an autonomous running method for a wheel mobile robot in an uncertain 3D world including a slope plane. The developed new robot is an autonomous type which is able to run on two wheels and mount an ultrasonic sensor and a PSD (Position Sensitive Detector)sensor, but without a visual sensor. And, this robot can be identified its self-position with a dead reckoning by wheels. Then, the recognition and the running method for an uncertain slope plane with ultrasonic sensor without run off the slope by recognizing for a step of slope edge with the PSD sensor was developed. Therefore, the path-planning algorithm to direct the robot to a goal while avoiding obstacle in an uncertain world including a slope plane could be developed.

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Now, mobile robots and AGVs in factories are mainly navigated by the method using the guide such as magnetic tape on the ground. However, the guide must be changed every layout change. That is the reason why the total costs are high. In our research group, navigation method of a mobile robot guided by laser spots are proposed. To realize the expansion of navigation area and increasing the navigation speed, omni-directional mobile robot with the laser tracking table which can control the direction of optical sensor array are developed. This paper also describes experimental results to evaluate these functions.

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In this research, we propose a method of mobile robot navigation system with a simple environmental data expression, graph-map. In general, autonomous mobile robot has to estimate its position. Usually it is necessary for a robot to correct cumulative error. For this purpose, the technique using the RFID tag in the environment as a local landmark and the technique matching distance data to environmental data have been proposed. However, they require complex preparation before the robot being navigated. In this paper, we verified the effectiveness of the system by the experiment, using a robot.

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A small laser range sensor is suitable as an external sensor for a small mobile robot because of its size and weight. We investigate is performance of indoor and outdoor environmental recognition by constructing indoor and outdoor environmental maps and using the map for autonomous mobile control for environment.

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In this paper, action of wheeled type robot is determined from the obstacle configuration and the robot's self-state using a neural network (NN), and multiple moving obstacles avoided. In order to avoid obstacles with the minimum movement time, the design parameters of the NN are optimized by genetic algorithm (GA), using the data collected from several environments, in which each environment has a different obstacle configuration.

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This paper describes a path smoothing method that results in paths with clothoidal curvature and which includes a safety margin from obstacles. The method modifies grid based A^* results, and tries to push the given path away from obstacles. A technique to take into account the initial direction of robot is also shown.

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In this paper, We discuss a method of decision making of a behavior-based robot with some modules which decide robot's action. Subsumption Architecture(SA) makes the modules a layered structure, and upper layer module's action is employed in priority to lower layer module. Such a easy adoption way gives easy implementation but has the problem that lots of inefficient actions are employed. This problem is caused by employing upper module regardless of other modules. Then, We find solutions to this problem by the method to represent actions by Potential Function(PF). This method adopt the action which collects maximum votes from modules. With event driven state transition, robot makes decision of its action with appropriate set of modules which is changed depending on situation. We apply this method to navigation tasks in some corridor environments and show simulation results.

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This paper describes new path planning method for robot vehicles in consideration with physical constraints, which involve kinematic, dynamic, and environmental constraints. In order to drive a robot vehicle in real world, path planner has to generate an admissible path under these constraints. The method we propose in this paper is named KDEP (Kinodynamic and Environmental Planning). At first, KDEP calculates limitation of control input in every moment by using physical constraints. Some path candidates are generated by the results of integrations with the control inputs under the constraints. KDEP can successfully generate some good admissible paths in every numerical simulation.

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Force and torque induced by the traveling motion and moving operations of a mobile manipulator effect dynamically to the objects being carried on it. If the induced force and torque are bigger than the static friction force and torque, the carrying objects may slip on the mobile manipulator. Since this slipping motion may cause a collapse of carrying objects, it is dangerous. And it interferes with accurate moving operations. A purpose of this research is to make a model of mobile manipulator which is carrying objects, to analyze the influences of the slipping to the traveling motion and to discuss a constraint conditions for the controller of guidance and moving operations to avoid slipping. In this paper, we evaluate the proposed guidance control method of mobile manipulator by simulations.

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