Analysis and Control of a Wearable Control Valve for Agricultural Supporting System

Today, the aged workers in agriculture are growing up rapidly in Japan. The development of a human friendly supporting system which can assist the agricultural work is strongly desired. It is needed to have a wearable pressure control system that can control the supporting force. The typical electromagnetic servo valves for pressure control are larger, heavier and more expensive. Therefore, the small-sized quasi-servo valve that consists of two and three-port on/off valves was proposed and tested. The analytical model of the valve was also proposed. The validity of the model was confirmed by comparing the calculated results with the experimental results. In this study, as an analytical design, the control performance with various input duty ratio to compensate the dead zone of the valve was investigated analytically. As a result, the optimal control parameters were obtained.