Design Of Electromechanical Actuator Control System Of Joint Direct Attack Munitions

In this dissertation, a set of electromechanical actuator is designed for some kind of Joint Direct Attack Munitions.This is an angle servo system with high precision which operates the actuator to move according to the signal given by the guidance computer. And the attitude and track of the missile are changed so that the missile is controlled to attack the target in accuracy. In general, the characteristic of this system is high precision, high bandwidth, small cubage, and heavy load.Firstly, a whole design project, that a direct current motor and a harmonic drive reducer are used to drive the actuator is determined. And then the mathematical model of the electromechanical actuator is derived based on both the voltage and torque equivalent equations of the motor and the technique to computing the equivalent torque and moment of inertia of the gears and load in the electromechanical system, which sets a solid foundation for the further design of the system. Secondly, the circuits of the system are designed in this dissertation, including power drive, isolation of the PWM signal, alarm, protection, brake, controller, communication interface, signal detective. Thirdly the software of the DSP is designed, which is composed of angle signal detective, armature current detective, the realization of control arithmetic of the position and current loop, the generating and output of PWM, communication and handling alarm. Furthermore a Personal Computer is programmed and becomes the command computer, so as to simulate the guidance computer, watch the states of the actuator and be operated by user.Finally, the block diagram of the system is built and its parameters are determined. And based on the transfer functions derived in our dissertation, the current and position loop are designed in turn. In detail, research work is done about how to determine the gain of the controller from the viewpoint of reference signals and the expected Bode plot is devised to meet the given criteria. Simulation results demonstrate that the performances of the system are satisfactory.