Control System Design And Safety Assessment For The Flap Actuator

Electromechanical actuator(EMA), cancelling airborne hydraulic systems, is one of actuators which are successfully powered by wire. The application of EMA can greatly reduce empty weight of aircraft, effectively improve the efficiency and reliability of the actuator system, and reduce its maintenance cycle costs at the same time. These advantages make EMA be one target which the all-electric aircraft actuation technology will achieve in the future. Through an investigation of domestic and foreign research status of EMA, the key technology of EMA is studied based on its application to the flap system of civil aircraft.Firstly,through the research on the working principle and mathematical model of EMA,a nonlinear continuous robust controller is developed and proved based on nonlinear control theory. The numerical simulation results show that the controller can make EMA achieve accurate position tracking control result and has strong robustness as well.Secondly, combined with the safety and reliability requirements of EMA in the flap of civil aircraft, a kind of hybrid redundant electromechanical actuator(HREMA) with two motors is proposed. For the force fighting problem in HREMA, a feedback compensation control system, which is based on the current error adjustment, is developed and verified by the numerical simulation. The simulation results show that this control scheme can realize the dynamic equilibrium control of double torque channels.Finally, with a certain type aircraft flap as the platform, the electromechanical actuator architecture is designed. And the system safety assessment process is launched based on the proposed architecture. In a case of the loss of the flap without notification, the safety requirements of electromechanical actuator in the flap are analyzed and confirmed.