In Japan, deterioration of industrial plants, built during the period of high economic growth in the middle of the 20th century, has become a social issue recently. Above all, Corrosion Under Insulation (CUI) of piping in the plant is a pressing issue. As conventional methods, X-ray inspection and ultrasound inspection have been utilized for that but still have limitations because of consuming time and inspection cost. Therefore, easy and low-cost screening techniques for CUI are required. We developed a hammering-type inspection robot that moves inside the piping and proposed an acoustic analysis method to identify anomaly parts from the hammering sound using machine learning techniques. By using testing pipes, we could successfully identify anomaly parts by the acoustic analysis using Uniform Manifold Approximation and Projection (UMAP) as a dimensionality reduction method and a neural network as a classification method.

For the hanging-type external wall elevating robot under development in this research, we take a wall surface with the camera attached to the robot, localization of the robot from the image and generate the overall image of the wall. For image mosaicing, a method of performing matching using local feature quantities of an image is common, but there are cases where matching can’t be performed because sufficient feature points can’t be extracted on walls with poor edge features. In this research, we propose a robot pose estimation and image mosaicing using template matching.

We are developing a multicopter system for bridge inspection to take high-resolution images with a mounted camera while flying along a wall at a short distance. In the case of a 50m class bridge pier, it may be quite difficult for the user to remotely operate the multicopter so as not to hit the wall because of the long distance from the multicopter. In this paper we discuss the assist control system that keeps the distance between the wall and the multicopter automatically. Since GPS cannot be used under the bridge, the ultrasonic sensor was alternatively used to measure the distance. However, if the airframe is drifted by strong wind, it would collide with the wall due to the low sampling rate of the ultrasonic sensor. We thus propose a method to improve the stability of proximity control by using multiple sensors such as laser range finder and barometer with high sampling rate. We show the effectiveness of the proposed method by simulation using MAVROS.

We have been developing a compact crawler robot, named DIR-3, for infrastructure inspection and disaster survey. There has been an issue of higher place inspection by DIR-3 because the robot was designed to move on the ground. To solve the issue, we propose a novel microdrone-equipped crawler robot system to give DIR-3 a sensing function of higher places. In order to realize takeoff and landing by a drone from/to a small robot’s fixed position, we proposed a drone mooring system and developed a simple winding mechanism for winding the mooring wire from the crawler robot side with constant torque. In addition, we constructed a GUI system that can easily manipulate both microdrone and DIR-3 by switching control modes and receiving images of drone and DIR-3.

In this paper, we address preparation process to wall inspection with the wire-driven robot system. The key issue to hang and move the robot system along the wall is how to fix pulley or hook at the high position of the wall. As a more practical way, we propose the method to throw the suction unit with wire up and adsorb it on the wall. We thus develop the launcher system and the suction unit with shock absorber. Through the experiment, we realize the desired motion of suction to the wall.

This paper describes about the mobile robot by adopting the variable magnetic attraction self-weight compensation with Halbach Array in order to inspect the steel plate girder bridge. A mobile robot mechanism that can control the magnetic attraction force was proposed by adopting the Halbach Array composed of plural permanent magnets. When an inspection robot moves under the bridge girder, the robot is required the mobility in order to traverse the splice plate and to adapt the change of the flange thickness and the width. The robot will be approaching to traverse the splice plate, the variable magnetic attraction self-weight compensation unit will be effectiveness. Proposed moving control method of the bridge inspection robot by changing the magnetic force of the unit was discussed.

In this research, we are developing wall climbing robot with Universal Vacuum Gripper. Universal Vacuum Gripper (UVG) is based on Universal Gripper (UG). UG is the robot hand using jamming effect of powder inside an elastomer film to grip the material with uneven surface. UVG is a vacuum pad with the deformable skirt based on UG. If the skirt shape is deformed along with surfaces, the air leak can be avoided. Therefore, UVG can grip uneven surfaces such as tile, curved surface, and so on. The wall climbing robot we are developing is a triaxial robot. It consists of two linear motion mechanisms and one rotation mechanism. Moving the robot straight and pressing the UVG with two linear mechanisms. Move from floor to wall and from wall to ceiling by rotation mechanism.

This paper describes about the standard test method for the performance evaluation of the infrastructure inspection robot with remote control. Assuming the analysis by the camera image acquired by a robot, a test method to evaluate the visual inspection performance of the bridge inspection robot was considered based on the concept of the NIST/ASTM standard test method. The test piece for rusting was proposed and it was evaluated based on ASTM D610-01. From experimental results, the proposed test method was confirmed the effectiveness to evaluate the visual inspection performance of the robot.

The authors aim to realize the automatic structure measurement system using multiple Unmanned Aerial Vehicles (UAVs). Normally, in environments near facilities such as under the bridges, it is difficult to localize the self-position of UAV to blocking of GNSS signal and multipath. In order to solve this problem, our proposed system consists of some subsidiary UAVs that assist localization of an inspection UAV. Subsidiary UAVs are located to be able to receive GNSS signals and capture the inspection UAV, and estimates the position of the inspection UAV using GNSS information and relative measurement information between UAVs. In this paper, as a basic verification of system realization, under the premise that subsidiary UAVs are in a known position, we control the inspection UAV on the measurement information obtained from the fixed camera and perform inspection experiment.

We developed a hammering inspection system with solenoid and compliance mechanism for inspection of infrastructure construction with unmanned aerial vehicle. We develop a UAV with robotic manipulator arm to access wall of infrastructure surface. The hammering system is attached to the tip of the manipulator arm. The hammering module has solenoid for hammering, mike for record the hammering sound of the concrete surface, compliance system to access vertically to the inspection structure. To attach multi-copter and control the arm, the weight of the hammering system must be light, and we use SMA wire for the compliance to the inspection surface. In this paper, we describe the overview, design and evaluation of the hammering system.

Control mechanism for tailless flapping wing aerial robot is very different with those for rotorcraft or fixed wing aircraft. To control its orientation, the robot needs to produce pitch, roll, and yaw torques around three orthogonal body axes. In this research, a cross structure which is composed by two linear servos to change the position of flapping center which can change the flapping amplitude of both wings to generate pitch and roll torques, and a rotate servo that can move the root spars into two opposite directions to change the attack angle of both wings to generate yaw torque were developed

A variety of biomimetic underwater swimming robots which do not employ a conventional rotational propeller as a propulsion system have been developed. It is still challenging, however, to satisfy both high-speed and high-mobility performances. Here, we proposed a flapping-wing propulsion mechanism inspired by penguins. In this mechanism, a wing is driven by three servo motors to realize 3-DoF (degree of freedom) rotational motion, enabling active control of AoA (angle of attack) of the wing. The relationship between the amplitude of AoA and thrust of the mechanism was tested in a water tunnel where the mechanism was fixed to a load cell. It was found that the thrust of the flapping wing was maximized when the AoA was set to 25° which was higher than that maximized lift-to-drag ratio for the fixed wing.

This paper deals with the design, fabrication and results of preliminary experiments of a soft tactile sensor which is morphologically changeable. We are aiming at detecting the location of a sliding movement by the sensor system. We fabricated sensor consisting of a silicone rubber base with a chamber and a thin silicone rubber skin covering the chamber. A three-axis accelerometer is embedded in the silicone rubber skin. The sensor surface inflates when pressurizing the chamber by syringe, changing the accelerometer’s posture and its output voltage. Then, we conducted preliminary experiments to assess its ability. We let an indenter slide on the surface of the skin. From the obtained data of the accelerometer, we concluded that we can judge the location of the sliding movement of an object based on the graph patterns.

In this study, a mechanical element is proposed that contains sponges within an element having variable stiffness by employing the process of particle jamming. The proposed mechanical element can change its shape and stiffness through internal vacuum pressure. A mattress comprising the said mechanical elements wraps itself around an object and simultaneously hardens by evacuating the internal air. To eliminate gaps between the mattress and a wrapped object, the hardness of the sponges can be varied according to their corresponding locations inside the mattress. Evacuation of the internal air compresses the sponges according to their associated degree of hardness. Hence, the mattress can serially bend around an object’s surface without leaving any gaps.

In nature, flying animals such as insects display great flight performances with high stability and maneuverability even under the unpredictable disturbances in the wake of the buildings or vegetation. Unlike man-made mechanical systems like drones, insects achieve flapping wing motion by their flexible musculoskeletal system. In this study, flexible flapping mechanisms were fabricated, and the effect of flexibility on the gust response was evaluated experimentally. It was found that, while the flexibility in the mechanism can enhance the efficiency but reduces the stability, the wing flexibility can enhance the stability under the gust by the passive wing deformation. Therefore, by the combinations of appropriate flexibility, it is possible to enhance the robustness against the gust while enhancing the efficiency of flapping wings. Based on the findings, small-scale flapping mechanism for insect-sized flapping wing drone was designed and fabricated with torsion springs and flexible hinges.

Flexible electrostatic adhesive device with various electrode pattern was fabricated successfully, by introducing the fabrication process that was used electrode pattern mold made by 3D printer and the hydrophilic treatment. Therefore, the fabrication time got shorter and its accuracy was improved. In addition, the adhesive force for the electrostatic adhesive devices with the complicated electrode pattern was verified in the experiment. The experimental results showed that their adhesive force was generated 2kgf or more. The flexible electrostatic adhesive device is useful for a practical tool to handle a target object.

In recent years, Dielectric Elastomer Actuators (DEAs) are attracting attention as excellent artificial muscles. We have developed a driving module that has a large deformation capability by using DEAs. The driving module is in the shape of a tube and forms an antagonistic configuration through electrode pattern. We observed that the maximum bending angle was 24.9° and the generated force at maximum bending angle was 73.8 mN with the experimental results. We have developed an underwater robot using this driving module. The peak swimming speed of the robot was 43.7 mm/s (0.16 body length/s) at 1.5 Hz. From these results, the possibility of adapting the tubular driving module to the soft underwater robot was shown.

Skeletal muscle cells-driven actuators are attracted a lot of attention as actuators of soft robots. In producing methods, more stable productivity and reproducibility must be ensured. we produced skeletal muscle cell-driven actuator using 3D bio-printer. The 3D bio-printer can set print parameters according to a program. Compared with the conventional method, skeletal muscle cell-driven actuator can produce automatically, productivity and reproducibility can be ensured. In this work, we used BIO X (3D bio-printer, CELLINK) and examined materials and culture methods. As a result, we successfully could print GelMA (gelatin-based Gel) by adjusting the viscosity by contorting its temperature. Also we could successfully culture skeletal muscle cells with printed GelMA.

We proposed a variable stiffness mechanism with a cord-like structure using comb joints. To provide effective support for disaster response, grippers that can firmly grasp complex shape objects are required. However, high rigidity structure had not been realized by the conventional variable stiffness mechanism and was difficult to grasp heavy objects. For that reason, we developed an articulated cord mechanism that can change the rigidity significantly by using multiple-disc plates in the joints. First, the structure of the comb joint and the basic principle is presented.

Next, the holding torque was analyzed based on Newton’s law. Finally, the characteristics of the prototype were measured, and the effectiveness of the proposed principle was verified through experiments.

Thin Mckibben muscles are receiving a lot of attention as having high performances including high contraction ratio, high flexibility, and productivity. It is one of the challenges for pneumatic actuators including the thin Mckibben muscle that they generally need air-hose and mechanical air sources which causes bulky systems. To free pneumatic actuators from those bulky systems, we have proposed a new approach that utilizes electrolysis and synthesis of water by a Polymer Electrolyte Fuel Cell (PEFC). Though the method could have high applicability to the thin Mckibben muscle, development of a tube-shaped soft PEFC prevents the realization of an electrically driven thin Mckibben muscle. This paper describes a proposal of an electrically driven thin Mckibben muscle with a tube-shaped soft PEFC realized by flowing non-electrolytic plating method.

In this paper, we report on a multi-layer casting process of a Nafion membrane to produce a monolithic thin film robot (MTFR). This robot is developed on the basis of the novel concept of a soft robot, which has both a body part and an actuator part and does not require a mechanical and electrical assembly process. A MTFR is made from only one thin film that has thicknesses gradient. The thick parts of the membrane act as bone structures, and the thin parts of the membrane function as actuators. This multi-function structure of the MTFR realizes an assemblyless manufacturing process. To fabricate the monolithic film with a distributed thickness, we propose a multilayer casting process. To demonstrate the potential of a MTFR for use in a biomimetic application, we manufactured anomalocaris-like MTFR and conducted self-sustaining driving experiment in water.

A McKibben artificial muscle consists of a rubber tube and a sleeve which is knitted fibers. In order to make the artificial muscle more useful, researches for embedding sensors into the artificial muscle were carried out, however most of them were realized by integrating the actuator and the sensor which were fabricated separately.

In this report, we propose a McKibben artificial muscle with an optical fiber in the sleeve for detecting the displacement. This optical fiber works as the essential element for both actuating and the sensing. In addition, it can be integrated during fabrication of the McKibben artificial muscle by a braider. The amount of propagating light in the optical fiber varies with curvature changing of the fiber. Therefore, the optical fiber in the sleeve has possibility to detect the displacement of the artificial muscle. The prototype artificial muscle with the optical fiber was fabricated by the braider. Experimentally correlation between the sensor output from the optical fiber and the displacement of the artificial muscle was confirmed.

Musculoskeletal trunk with 76 degree of freedom driven by thin McKibben muscles has been developed. Trunk mechanism of conventional musculoskeletal robots is simplified or underactuated and do not have all muscles of human because it is difficult for conventional actuators to be attached. Because thin McKibben muscles are small enough to be densely attached, we can overcome these problems by applying them to the back of the musculoskeletal robot.

There are behaviors on the roots and branches of plants that extend and branch the torus structure. From the viewpoint of engineering, the authors aim to realize a branched extension torus as found in proboscis of Nemertea that extends and branches at a much faster rate than the plant. In this paper, we focused on the function to move and cut, as the 2-dimensional fastener mechanism, necessary for realizing this branched extension torus. As the primary prototype of the cutting and moving mechanism, we report on the effectiveness of principle devising, design and trial manufacture, actual machine experiments.

In this paper, we developed a robot as a simplified physics simulator to elucidate the tongue of the anteater and exploit its moving principle. Furthermore, the middle term purpose of the research is to extract the functions of the soft switching bodies entering and leaving at high frequency, implement them as mechanism elements, and utilize as an application such as cleaning devices. As a long term, the major objective is to lead to an interactive academic development of both biology and robot engineering.

Wearable devices are being expected for utilization in daily life, so that the elderly can improve activity of daily living. However, there are some unique concerns about the wearable robot, especially when the intention of a human and the robot are mismatched. In this study, the effect of assist pattern on fall recovery motion against tripping during walking was observed and analyzed. Margin of stability of recovery steps became significantly larger when the assist torque was continuously applied that it stopped. Thus, it was suggested that the assist torque perhaps decrease the fall risk.

For most mammals and vertebrate animals, tail plays an important role for their body providing variant functions to expand their mobility, or as a limb that allows manipulation and gripping. In this paper, we propose an exploratory biomimicry-inspired anthropomorphic tail design to allow engineering and expanding human body functions. The proposed tail consists of adjacent joints with a spring-based structure to handle shearing and tangential forces, and allow managing the length and weight of the target tail. The internal structure of the tail is driven by four pneumatic artificial muscles providing the actuation mechanism for the tail tip. Here we describe the design and implementation process, and highlight potential applications for using such prosthetic tail.

The purpose of this study is to develop a lighter and smaller auxiliary device that can assist the user’s arm to reduce burden on workers. The auxiliary device consists of a mounting part and a linkage mechanism in order to use a passive gravity compensation mechanism. In this paper, we used a spring without power supply. The spring is used to adjust the posture of the arm part. The effectiveness of the proposed auxiliary device is verified by the result of the experiments.

We develop an assistive, head-mounted pointing device which helps surgeons in the endoscopic surgery to instruct their tasks smoothly. However, the device has a difficulty in intuitive control because users have to tilt their heads when moving a cursor. We tackle this problem by clarifying the possible range of head tilt. After that, we conduct the evaluation experiments to confirm that the performance is improved.

In the upward work, the workers need to keep the upper limbs with their own muscular strength and the work burden is large. The authors developed a supporting device using a self-weight compensation mechanism to reduce the burden on the upper limbs during upward work. However, there were wearers who felt strange about the wearing feeling, because there was not designed according to the physique of the wearer. In this study, we had the subjects of various physique wear the device, and investigated the relationship between the physique and the wearing feeling at shoulder joint movements. As a result, the subjects with greater shoulder width felt difficulty moving and small in size in the movement in the direction of ir/er. The influence on the ease of motion and size feeling was small in direction of flex/ext and add/abd.

Lumbago may be caused by the muscle fatigue and muscle tension of the erector spinae in the Half-Crouching Position[HCP]. In this study, we developed a HCP supporting device to maintain the HCP by supporting the chest with structural materials without using power and suppress the muscle activity of the erector spinae. In addition, since the reaction force to the chest is not oriented in the compression direction of the lumbar intervertebral disc, it can be considered that the load of the intervertebral disc by the device is suppressed. Furthermore, we could confirm reduction of activity of the erector spinae muscle by equipping the HCP supporting device from ARV.

Kyphotic curvature causes balance change of the body. Balance changes in the body causes increase in activity of lower limb muscle during walking motion. Therefore, it is important to keep a sustained ideal posture. The purpose of this study is to develop a posture retention assist device driven with McKibben type artificial rubber muscle which has a lightweight and flexibility. In this paper, the structure of device is described, and support method is discussed. Finally, effectiveness of this device is verified from experiments in which subject wears this device actually.

In this paper, we present a power assist suit that supports and transports heavy objects with a single motor. The leg mechanism of the power assist suit is made of upper and lower parallel links and springs. It is designed to be located inside the wearer's legs so that the power assist suit becomes small and light-weight, and the stability during transportation is improved. We measured the surface electromyogram (EMG) during luggage lifting experiments and confirmed that the burden of the wearer's back and legs is reduced when wearing the developed power assist suit.

Lower back pain is the most serious problem for workers in various fields and therefore sophisticated and simple solution are required. As one solution, we have been developing Muscle Suit using pneumatic artificial muscle though, due to the size of artificial muscle, there is a limit to the miniaturization of Muscle Suit. Also, Muscle Suit has a fault that it is hard to squat down deeply because of how to change the support torque. Therefore we developed a new compact device using a gas spring, which has a feature that it is easy to squat down. This paper shows the functions and mechanisms of this device.

Recently, the aging problem is attracting great attention in Japan. One of the important technologies to solve this problem is a power-assist system which is able to assist the motion of physically weak persons such as elderly or disabled persons in various situations. This paper presents a method to estimate the human motion intention based on integrated information of EMG and force information for an upper-limb power assist exoskeleton robot system. The effectiveness of proposed method is evaluated through experiments.

In order to suppress tremor of tremor patients, such as essential tremor patients, many kinds of devices have been developed. In this paper, a new tremor suppression method is investigated. When a vibration stimulus is applied to a human muscle, a sustained contraction called the tonic vibration reflex occurs in the stimulated muscle. Suppression of the user’s tremor might be possible using tonic vibration reflex by applying vibration to the muscles. In this study, vibration is added to pronator teres muscle and supinator muscle, and the out-of-phase motion of the tremor is generated during the vibration stimulation.

In this paper, we considered how to mount AOA(Assist Oriented Arm) on user and where to fix it on mounting devices. The mounting position and fixing are one of the most important matter in wearable robot arms. The position needs to be considered so that it can support user properly in user’s task space. The fixing parts need strength for not braking down. Therefore, we calculated position and way of fixing for using the wearable robot arm.

In this paper, we present a mechanical design of a wire drive mechanism for power assist suits that realizes linear luggage lifting movement and nonlinear knee fixation-and-release movement using a motor. The nonlinear fixation-and-release movement is realized by a mechanism using a piston and a crankshaft. We developed an algorithm to find the design parameters that minimize the error from the optimal wire movement. We developed a prototype wire drive mechanism and verified that it works as designed. In addition, we carried out lifting experiments and confirmed that luggage up to 20 kg can be lifted. We measured the surface electromyogram (EMG) and confirmed that the burden of the wearer’s arms was reduced during luggage lifting.

We present a wearable haptic assistance robotic system for motor learning. This system comprises two robotic arms that are mounted on a user’s body and are used to transfer one person’s motion to another offline. The system pre-records the arm motion trajectories of an expert via the mounted robotic arms and then plays back these recorded trajectories to share the expert’s body motion with a beginner. The system is an ungrounded system and provides mobility for the user to conduct a variety of motions. In this paper, we focus on the temporal aspect of motor skill and use a mime performance as a case study learning task. We verified the system effectiveness for motor learning using the conducted experiments. The results suggest that the proposed system has benefits for learning sequential skills.

In order to realize a space-saving and high-output actuator system, we aim to achieve synchronous drive using multiple twisted string actuators (TSA). In the preliminary research, the output actually obtained was smaller than the output expected, and the obtained value alone resulted in strict confirmation of cooperativeness. Therefore, in this study, we developed a synchronous drive device that can adjust the parameters of TSA in order to investigate the influence of each parameter of TSA on its performance. As a result of the experiment, TSA has confirmed that synchronous driving can be achieved by adjusting the parameters so that parameters related to synchronization such as delay can be aligned even for TSAs with different properties.

Fishing-line artificial muscle, namely twisted and coiled polymer fiber (TCPF), is one of the soft actuators attracting a lot of attention in recent years. A TCPF actuator is actuated by heat, and is easily made from a commercially available polymer fiber. It is a low-cost, light-weight, large-force, large-stroke, and quiet actuator, however, its efficiency and its response speed are low. This paper focuses on improving the low response speed. We develop a new cooling system with a cooling fan as well as a heating system by a Nichrome wire. A microcomputer (Arduino) controls the system using PWM signal. The proposed system is demonstrated in experiments.

McKibben pneumatic actuator (MPA) known as one of the artificial muscles has been used as actuator of various robots because of high power density, lightness and passive characteristics like the skeletal muscles. In this paper, we focus on jumping motion as one of a dynamic locomotion of legged robot, and analyze the influence of a robot’s knee structure on the jumping motions. We propose a legged robot model that has cantilever knee, and derive equation of motion of the robot model. After confirming that the robot can jump with periodic pressure input on simulation, we analyze that how physical parameter and input parameter effect to jumping height of the robot model. From simulation results, we confirmed that structure of robot’s knee, input pressure’s frequency and phase difference effects these jumping motions and jumping heights.

Animals use various coordination to realize their walk. Among their coordination, in this study, we focus on the muscles coordination and investigate the cooperative mechanism among muscles. In this paper, we apply force feedback to 1-DOF pendulum model using pneumatic artificial muscles and verify the effect of force feedback by numerical simulation. Simulation results suggest the force feedback can generate the actuators’ autonomously cooperation and there are several patterns in cooperative relationship. In addition, we perform verification experiments using a 1-DOF pendulum robot. Through some experiments, the actuators’ cooperation and periodic pendulum motions are verified.

McKibben pneumatic actuator(MPA), that is one of the soft actuators, has various good features as an actuator for robots. However, in many cases, control of these robots is performed by trial and error since it also has complicated nonlinear characteristics. To overcome the problem, we focus on the TEGOTAE based control which is one of the autonomous distributed control. In this paper, we make a quadruped robot whose forelegs are replaced with passive wheels and hind legs are driven by three MPA and a spring. At first, we confirm that the developed robot can walk with feedforward control if an appropriate phase difference between right and left hind leg is chosen. Next, we confirm that the robot can walk with TEGOTAE based feedback control even with the inappropriate phase difference. Through these experiments, we verified that TEGOTAE based control can be adaptable to a walking robot driven by MPA.

In this paper, we propose a new method for improving the contracting abilities of pneumatic artificial muscle. Thin McKibben muscles, which are a flexible and lightweight actuator, have the contraction ratio equivalent to that of human muscles. However, the contraction ratio is sometimes insufficient in the actual use. Therefore, in our previous research, we achieved to improve the contraction ratio of thin McKibben muscles by braiding muscles again. The flexibility of thin McKibben muscles let us braid the muscles. In this research, we tried to braid the braided thin McKibben muscles again and improve the contraction ratio further. As a result, we achieved to increase the contraction ratio as follows: original single muscle 28%; once braiding muscle 37%; twice braiding muscle 41%. These improvements will help us to develop and improve soft robotic abilities.

We introduce a tri-tube soft actuator, consisting of three flexible tubes with helical grooves and a driving unit with three DC motors. The flexible tubes, which are located at the vertices of an equilateral triangle, pass through the driving unit. As with the rack and pinion mechanism, a rotational motion of the DC motors moves the flexible tube laterally, allowing serpentine robots to elongate, shorten and bend in all spatial dimensions. We build a soft serpentine robot with the tri-tube soft actuators and demonstrate the potential of locomotion with large and soft deformation. Our study helps lay the foundation for soft robots that achieve complex locomotion such as overcoming obstacles.

To perform both high compliance and large gripping force in collaborative robots, switchvable backdrivability is required. The gear unit installed in industrial robots require a non-backdrivable element so that thier arms can support heavy loads with low energy. However, in cooperative tasks with human, robots need a backdrivable element to reduce human damage. This paper proposes a planetary gear mechanism that can control its backdrivability by vibration. Proposed planetary gear unit have simple structures and large reduction ratio, being non-backdrivable. From the equilibrium of forces acting on the teeth surface, parameters affecting backdrivability are found to be coefficient of friction and teeth number’s difference between fixed and input gears. In the experiment, planetary gear unit got backdrivability as the number of number of teeth difference increases. We also confirmed the switchable backdrivability of the non-backdrivable planetary gear unit by vibrating the gear-unit.

Low back pain is one of the most aware osteopathic symptom. There are cases use a corset as one of methods of treating low back pain. However, wearing the corset at all times may possibly cause muscle decline. In past study, an active pneumatic corset with an extremely lightweight soft actuator is proposed. This study propose the assist corset with a posture feedback control function. By utilizing a posture feedback control, it is possible to change the rigidity against the muscle load. This paper describes basic experiments for design a soft actuator to generate a torque, angle measurement system for posture feedback control, and evaluation by an EMG test to the assist corset.

We propose a micro mobile robot using the smallest set of micro ultrasonic motor and micro planetary gear. The micro mobile robot will move on the land with various surface condition. The length of the robot will be between 10-12mm. The goal of this paper is to make a like car micro mobile robot which is can move on very small pipe or hole or even hard environment to search victims of natural disaster. And to make the mobile robot move vertically through the wall. Also for further goal, we hope that our research also can be used to make capsule robot in medical purpose.

This paper presents a mechanism which can adjust inertia, containing a flywheel, a group of clutches, a direction converter, and a magnetorheological hydraulic actuator. Conventionally, among impedance factors of the mechanical system, inertia seems to be unchangeable, not like damping factor or elasticity. However, changing inertia might bring different behavior to mechanical networks. In this study, by controlling the flywheel energy collected from the motor pump to release to the object, the resistance of actuator motion can be adjusted. We call this the pseudo-inertia adjustable mechanism (pIAM). The experimental results shows that the machine can release the maximum torque about 7 Nm and the maximum speed about 800 deg/s with 1000 rpm of the flywheel speed, which reveals the feasibility of this mechanism.