Research On The Control Technology Of Ultrasonic Motor Rudder

The steering gear is the guidance and control executive mechanism of guided weapons,and its performance will affect the accuracy of weapon guidance.In the process of flight control,the rudder control frequency is fast,and the location response needs to meet the needs of fast response,small overshoot and high accuracy.This requires that the servomotor of the steering gear has the function of real-time speed adjustment,and it can start and brake frequently.Electromagnetic servo motor is generally used in electric rudder,because the working principle is restricted,this kind of motor can't overcome its solid defects: slow start,slower braking,high frequency control internal current fluctuation,and the need to match the speed through the reducer.In contrast,the ultrasonic motor can overcome the above problems.The motor stator can convert the electrical energy into the mechanical energy through the reverse piezoelectric effect,which has the advantages of quick start response,self-locking and low speed torque.It is suitable to be used as the servo motor of the electric rudder.The operation mechanism of the ultrasonic motor is complex,which makes the dynamic characteristics of the motor show high nonlinear and time-varying,so the research on the driving and controlling technology of the motor has always been a hot spot in this field.In this paper,the control technology of traveling wave ultrasonic motor steering system is studied from the angle of precise control of steering gear position.According to the theory of thin plate vibration,the condition of motor stator traveling wave is analyzed.By simplifying the condition of the contact surface of the stator and rotor,a simplified contact model for simulation analysis is established.The model computer simulation is carried out,and the response characteristics of the motor to voltage amplitude and driving frequency are analyzed.The driving circuit of H-bridge is built by the SIMULIK electrical toolbox.The equivalent circuit is used to replace the motor model,and the response characteristic of the drive circuit is analyzed.It is simplified as a first order time-delay inertial system,which is used for the simulation of the steering control system.The dynamic recurrent neural network(DRNN)is used to establish the motor model.The pseudo random sequence is used to motivate the motor to obtain the identification data,and the model topology and weight of the Differential Evolution(DE)optimization are selected by the generalization evaluation factor.After the simulation verification,the identification accuracy of the optimal network model is 0.0747 and the prediction precision is 0.0782.A dynamic recurrent neural network adaptive speed controller is established,and the steering speed control system model is established by SIMULIK.The simulation results show that the speed response time of the rudder speed controller is less than 0.02 s,and the stability time is less than 0.08 s.There is no static error and no overshoot,and the system has good robustness.The outer ring PID position controller is set up.The simulation results show that the response time of the actuator position control is less than 0.05 s,the stabilization time is less than 0.2s,and there is no overshoot and no static error.