Research On The Closed-loop Electromechanical Actuator And Its Characteristics

In modern times, with the rapid development for guidance weapon in the direction of miniaturization, high precision, high response, as its key part, the performance of closed-loop electromechanical actuator will directly affect the winged missile’s overall performance and determine its shooting rates. By the aid of a cooperation project of my lab and some national institute of aerospace, this paper carry out the study of electromechanical actuator. According to domestic electromechanical actuator which widely using the low performance DC motor, developing a small, high efficiency, high response closed-loop electromechanical actuator AC servo control system driven by PMSM.AC PMSM is superior to the DC motor both on the size, weight, and efficiency with power density. Hence, it is a important tendency to use AC PMSM as the power source for highly efficient, electromechanical actuator in the future.According to the related technical indicators of electromechanical actuator, determine the overall structure scheme of electromechanical actuator, and finish the detail design and optimization of electromechanical actuator’s every link on the basis of the overall scheme. Adopting the SPMSM as driving source for electromechanical actuator, and then using the electromagnetic simulation software JMAG-Designer determine the size parameters of SPMSM by repeatedly computing and optimization, such as slot-poles number, air gap, inner diameter and outer diameter of the stator and so on. Due to electromechanical actuator outputting large torque finally, and PMSM can’t drive actuator directly. So design a small, high efficiency decelerate and transmission device, and output torque and rotational speed by the device with the PMSM. To satisfy the control needs of electromechanical actuator, magneto electric encoder needs to be designed for detecting angular position information of motor rotor and the missile rudder surface, and the control precision of closed-loop electromechanical actuator is influenced directly by the accuracy of position detetction for the angular position information of motor rotor and the missile rudder surface.Electromechanical actuator is a position servo control system, to achieve the high precision control, need the minute design for actuator controller, including hardware design and software algorithm programming of controller. For hardware of actuator controller, design the power supply circuit of actuator controller by taking advantage of missile’s power supply reasonablly; in order to realize the control and drive of SPMSM, need design three phase current feedback detection circuit, magnetoelectric encoder communication circuit and power amplifier circuit of PWM control signal; for the purpose of realize reliable communication between electromechanical actuator and the missile’s Upper Computer, efficient communication circuit need to be designed.Control strategy of electromechanical actuator choose mature and reliable position-speed-current three closed loop PID control algorithm. To avoid the hidden defects in the overall design, establish overall mathematical model of closed-loop electromechanical actuator, and then use the Simulink module of MATLAB software to carry on the simulation analysis for tracking response of instruction. In addition, this paper also constructs equivalent hardware-in-the-loop experiment platform of electromechanical actuator, and carry out related research for electromechanical actuator system by means of the simulation platform and physical experiment platform, laying a solid foundation for the physical platform of electromechanical actuator in the future.