Development and Analysis of Small-Sized Quasi-Servo Valve for Flexible Bending Actuator(Mechanical Systems)

Abstract

Today, the advanced age and less children society is growing up rapidly. The care and welfare equipments to support a nursing care and a self reliance of the senior and the disabled are actively researched. In a wearable system, there are power assisted devices using wearable actuators. However, the power assisted device requires many degrees of freedom. The total weight of the wearable devices increases because the number of actuator and control valves increases according to degrees of freedom. Therefore, in this paper, we propose and test a quasi-servo valve by using the small, light-weight and low-cost on/off control valves driven by the pulse width modulation method. The valve consists of two on/off valves and a microcomputer. We also propose the analytical models of the small-sized on/off valve and the tested valve. The system parameters of the valve are identified. By comparing the experimental results and the calculated results using the proposed model and the identified parameters, we confirm that the analytical model of the valve is valid. Finally, we construct the master-slave control system of the bending angle using the tested quasiservo valve and the flexible bending actuator. And it is confirmed that the tested valve is useful.