Recently, due to the ageing in Japanese society and the decreasing birthrate, an important problem of providing nursing care for the elderly has occurred.As a result, it is necessary to develop wearable systems to aid in nursing care. To realize the system, we require not only wearable soft actuators, but also compact and flexible control valve that can drive the soft actuator such as a pneumatic artificial muscle. The purpose of our study is to develop a flexible, lightweight and compact control valve which can be safe enough to be attached to the human body.In this study, we proposed and tested a new type of control valve. The valve consists of a vibration motor and a check valve that made of a steel ball and an orifice in flexible tube.The operating principle of the valve is as follows. The valve is normally closed as a function of check valve. When the vibration is applied, the inner ball in the check valve moves and the valve opens. By giving continuous vibration, the valve can keep open. As a result, we find that the valve can control the relatively larger flow rate compared to their weight and size.

Recently, old and dilapidated infrastructures such as bridges, chimneys and tunnels have become very serious in Japan. Inspection of the infrastructure was done by climbing the ladders that were set up. However, the inspection becomes dangerous as it is necessary to climb into very high areas and unpredictable weather and conditions. In this study, a lightweight inspection robot that can climb ladders in adverse weather conditions was proposed and tested. To grasp a ladder pillar without hurting, the wrapping motion is required. Therefore, the flexible robot arm that can grasp the ladder pillar while approaching and release it while going away was also proposed and tested. The automatic ladder-climbing inspection robot that consists of two pillar grasping flexible robot arms and a lifting robot arm was proposed and tested. The control system of the robot, driven by four on/off valves and an embedded controller, was also constructed. The ladder climbing experiment using the tested robot was carried out. As a result, it could be confirmed that the robot can climb up and down a ladder with soft gripping the ladder, and the soft robot can be also operated by using only four valves.

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