Research On Power By Wire Actuator Of More-Electric-Aircraft

In the recent years, the research of more electric airplane(MEA) in the field of aircraft design has been concerned by more and more researchers around the world. Power by wire technology(PBW)as the core technology of the MEA has attracted much attention in the area of aircraft transmission.The Electro-Hydrostatic Actuator(Electro-Hydrostatic actuator, EHA), which contained a model of motor, a model of hydraulic pump, a model hydraulic cylinder and a model of load, was established in the paper. This paper has derived the EHA system transfer function, and has carried on the model design and simulation by MATLAB/Simulink, using the classical PID control as control scheme. The Brushless DC motor(Brushless DC motor, BLDCM) in the EHA system realized the conversion from the electrical energy to mechanical energy, also as the power input source. The Brushless DC motor were fine modeled, hysteresis current and speed closed loop control of double loop control scheme were designed. In order to avoid the situation that the mathematical model may not cover the model of the hydraulic components of the sector influenced by the nonlinear factors, this paper applied MATLAB/Simulink hydraulic toolbox and mechanical toolbox of physical to modeling and simulation experiments. Considering the EHA system with nonlinear friction influence, this paper established the nonlinear model of EHA, and according to the requirements of computer control, the model was discretized. Then, the continuous system of sliding mode control( SMC) theory was applied to the discrete system, sliding surface and controller was accordingly designed and the simulation research was then carried out.Based on the research of the structure and working principle of EHA, this paper realized the sliding mode variable structure control theory used in EHA control field. The paper also solved the problem that the response time of EHA nonlinear system was too long, while the bandwidth was narrow during the work.