Robust and perfect tracking control for direct drive EMA system

The direct drive Electro-mechanical Actuator (EMA) system integrates the ball screw on the motor rotor directly, which eliminates the disadvantages of traditional gear transmission device. However, such construction of system brings challenges to the control strategy for high positioning precision and outstanding load disturbance-rejection ability. To meet the requirement of high static and dynamic performances of EMA system, a control method named Robust and Perfect Tracking (RPT) is applied in this work. Firstly, we address the architecture description of an EMA with a dual three phase permanent magnetic synchronous motor (PMSM). Afterwards, we obtain a decoupled model of motor and cast the overall servo system design into a RPT design framework. Finally, the comparison of simulation results between the conventional and proposed methods demonstrates the feasibility and efficiency of RPT control strategy for EMA system.