Model-inverse Time Delay Control (MiTDC) for Force Control

Abstract

Even though it has been an important issue to control the output force of actuators accurately;especially physical human-robot interaction (pHRI) fields, it is very difficult due to interaction with the complex and time-varying system dynamics and surrounding conditions. In this study, a robust control strategy named model-inverse time delay control (MiTDC) was proposed to realize an ideal force-mode control of the series elastic actuators (SEA) without an accurate model of the control systems and its surroundings. In order to compensate for delay in tracking performance caused by inherent characteristics of TDC, a new reference position was introduced, using the inverse of model dynamics. To verify the performance of the proposed control strategy, free oscillation of a pendulum was demonstrated with a SEA module.