Research On Control Technology For EMA Servo Drive System

EMA(Electro-Mechanical Actuator) is a new type of servo actuator applied in the aviation field, its better servo performance and higher reliability compared with the traditional hydraulic actuator make it to be a development trend of future aircraft actuators. A set of EMA servo drive system choosing permanent magnet synchronous motor to drive the roller screw is designed in this thesis, the digital hardware and software platform based on DSP are designed and implemented, the control technology of the system is analyzed.First of all, the research status and some key technology of EMA servo system are introduced. The PMSM mathematical model is presented and the principle and implementation of SVPWM technology is introduced. Then the current loop, speed loop and position loop control using the traditional PID control based on motor vector control system model are designed. The all-digital hardware platform is designed with DSP F28335 as the control core and IPM as the power circuit core; the design of system software is introduced, the software structure and the functions of important subroutines are analyzed.A more complex control strategy of a self-tuning method is proposed based on system parameter identification in consideration of the servo performance degradation when the system parameters changes in the thesis. The identification of system electrical and mechanical parameters is introduced firstly, then the speed loop is regulated online according to the identification of system inertia. The method provides a better performance for speed control.The system physical model is built using the Matlab Sim Power Toolbox to simulate the basic functions of the EMA system. The dynamic and static characteristics of system under different servo instructions are studied, the simulation results demonstrate the feasibility and effectiveness of the parameter identification method and the self-tuning control.