Design Of High Integration Smart Electro-mechanical Actuator Controller System

Electromechanical Actuator is a complex mechanical-electrical integration system, is a critical part of the flight control system such as aircraft, missiles, etc. craft, its features directly determine the whole performance of aircraft. With the development of power electronics technology and permanent magnet motor, the new permanent magnet brushless DC motor has been widely used in the Electric servo system for its advantages of small size, high power density, simple structure and flexible control. In this paper, a flat brushless DC motor is used as the power sources of electromechanical actuator system, its structure characteristics, working principle and drive mode are analyzed respectively, and its mathematical model and transfer function are deduced. A set of hardware circuit boards with the features of small size, compact structure and high reliability are made. The position, speed and current closed-loops control algorithm for promoting accuracy are designed. In order to verify the reliability of the designed hardware system and the feasibility of the control strategy, an experimental platform is set up and the principle prototype test experiments are carried out. The experimental results show that the designed electromechanical actuator system satisfies the requirements of control performance, with the characteristics of smart integration and great application value. The main contents of this thesis are as follows:1. Put forward the key technical indicators of the electric actuator servo system. By analyzing the structures and basic principles of the brushless DC motor, the equivalent circuit diagrams are obtained, the mathematical models of the motor are established, and the transfer functions of the system are deduced.2. For the entire drive system, a set of intelligent power drive circuits with DSP and CPLD as the core control architecture are designed, including the main power supply filter and conversion circuit, current detection and over-current protection circuit, position detection and resolver excitation signal conditioning circuit, and serial port communication circuit.3. According to the running characters and mathematical models of the brushless DC motor,three closed-loops with position, speed and current are designed, the position loop use proportional integral control, the speed loop and current loop adopt proportional control.The control module, timer modules and sampling module are designed in the DSP main controller. The commutation logic, calculation speed direction logic and over-current protection logic are designed in the CPLD auxiliary controller.4. A complete experimental platform is set up, and the control performance test experiments are widely carried out on the principle prototype. At last, the experimental results are described and analyzed in detail.