Robust synthesized control of electromechanical actuator for thrust vector system in spacecraft

A kind of robust control of electromechanical actuator (EMA) system for thrust vector control in a spacecraft was investigated. In the flight of a spacecraft, the EMA system must overcome the influence of load disturbance and working point alteration to improve the robust control performances. Addressing this problem and considering the large inertia and low stiffness load of the EMA system, this paper studied the robust control technology of the EMA system by H∞∞ control and μμ synthesis theory based on the degree of freedom (DOF) mathematical model. The H∞∞ hybrid controller was designed and the EMA system experiments of three controllers including proportion-integral-differential controller, H∞∞ controller and H∞∞ hybrid controller were conducted. Furthermore, the μμ synthesis controller was designed and the simulation was made on the μμ synthesis controller and the comparison between the control effects of the H∞∞ controller and the μμ synthesis controller was conducted. The comparison results show that the robust synthesis control can more effectively handle the parameters perturbation and load disturbance.