Robust Lead Compensator Design for an Electromechanical Actuator Based on H∞ Theory

In this paper, we design a robust lead compensator for a real Electromechanical Actuator (EMA) harmonic drive by introducing an approach based on H∞ control theory. Here, we address three main topics; experimental identification, uncertainty modelling, and robust control design for a real EMA harmonic drive system. This method verifies good tradeoff between the powerful H∞ controller and the unique features of compensators, such as: simplicity, low cost and easy implementation. The H∞ controller and the extracted compensator are almost identical within the EMA bandwidth range. Simulation and test results prove the effectiveness of the proposed approach and the superiority of the performance of the designed robust EMA with lead compensator based on H∞ controller over the original EMA; this preference is pertaining to its robustness to parametric uncertainties and high performance.