Development of Portable Rehabilitation Device Using Flexible-Extension-Type Soft Actuator with Built-In Small-Sized Quasi-Servo Valve and Displacement Sensor

Abstract

Welfare pneumatic equipments to support nursing care and rehabilitation for the elderly and the disabled are being actively studied and developed. The total weight of a wearable device increases according to the degree of freedom of the device. In this study, a low-cost extension-type soft actuator with a longer displacement was proposed and tested. A maximum displacement of 270 mm (235%) could be obtained. By using the actuator, a disposable flexible robot arm was developed. As a result, we confirmed that the robot arm is able to extend straight and bend in any direction. An analytical model of the arm is proposed to predict the attitude of the arm. To control the actuator, a flow rate control-type quasi-servo valve with a built-in driving circuit using an embedded controller is also proposed and tested. In addition, a portable rehabilitation device using the low-cost robot arm with disposable displacement sensors, and three quasi-servo valves is developed.