2017 年 83 巻 856 号 p. 17-00328
An ionic polymer-metal composite (IPMC) actuator is an electric driven soft actuator. It is fabricated by chemically plating metal on both surface of an ion-exchange membrane. It is able to be activated by a simple driving circuit and low applied voltage (0.5-3 V). However, a precise control of the IPMC actuator is difficult because of individual difference and characteristics changes from environmental conditions. To solve this problem, we applied the stochastic ON/OFF controllers to the integrated IPMC actuator with parallel connections. The controller consists of a central controller and distributed controllers. The central controller broadcasts a control signal as an error signal to distributed controllers uniformly. The distributed controllers switch the ON/OFF states based on the broadcasted signal stochastically. The central controller dose not measure the states of each IPMC actuator, and the control signals is calculated by using the output signal of the integrated actuator and reference signal. The validity of the applied methods was investigated through numerical simulations and experiments of displacement control. The proposed method was demonstrated to be useful as in the case that some actuator elements fail.