An experimental study of force control of an IPMC actuated two-link manipulator using time-delay control

Abstract

This study focuses on the force control of an ionic polymer metal composite (IPMC) actuator and a two-link manipulator actuated by the IPMC. As a polymer actuator that transforms electric energy into mechanical energy, IPMC has been applied to various mechanical devices. The time-varying property of IPMC makes it difficult to control the tip force of an IPMC actuator with a strip form, which requires a force control scheme with considerable robustness. In this study, time-delay control (TDC), which has shown exceptional robustness in various control systems, was applied to the force control of an IPMC actuator and a two-link manipulator actuated by IPMC strips. The experiments demonstrated that TDC could control the tip force of an IPMC strip so that, in spite of its time-varying characteristics, it closely follows the designed reference force with exceptional robustness. Moreover, the contact force of a two-link manipulator actuated by IPMC strips could be successfully controlled with the TDC law including the kinematic relation of the manipulator.