Development of flexible spherical actuator using flexible pneumatic cylinder

The purpose of our study is to develop a flexible and lightweight actuator which can be safe enough to be attached to the human body, and to apply it to a flexible mechanism and rehabilitation device. New types of flexible pneumatic actuator that can be used even if the actuator is deformed by external force have been developed in our previous studies. In this paper, we propose and test a flexible spherical actuator using the novel flexible pneumatic cylinders. The simple spherical actuator consists of two ring-shaped flexible pneumatic cylinders. They are intersected at right angle and are fixed on the base. The control system using the tested quasi-servo valves and a micro-computer was also developed. In addition, the spherical actuator was improved so as to suppress the vibration in control and to increase the stiffness of the actuator by changing the structure of the actuator. As a result, the large moving area of the actuator could be obtained using the tested spherical actuator with a simple structure. The control performance could be improved using the improved spherical actuator.