Design Of Electromechanical Actuator System For High Overload Guided Projectile

Aimed at the dynamic environment of high launching overload and high rotating speed and small volume requirements of guided projectile,the design and research of electromechanical actuator from the aspects of overall scheme design,mathematical model establishment,control strategy simulation analysis,rudder control system hardware circuit and software design and experimental verification were carried out to develop the electromechanical actuator to meet the performance requirements.In the aspect of overall scheme design of anti high overload electromechanical actuator,the overall design scheme of electromechanical actuator was determined,which took the brushless DC motor as power,the gear reducer as transmission mechanism and the resistance potentiometer as position sensor.The overload on the motor was reduced by the design of buffer structure.Polyurethane foam was used to encapsulate and solidify the steering gear circuit to improve the anti-overload ability of the steering gear.In the aspect of mathematical model establishment,the commutation principle of Brushless DC motor was expounded,the mathematical models of Brushless DC motor,power driver,reducer and load were established,the characteristic equation of electric actuator was deduced,and the mathematical model of three closed-loop control system of electromechanical actuator was established.In the simulation analysis of control strategy,based on the mathematical model of three closed-loop control system of electromechanical actuator,a three-loop PI control strategy was designed.The performance of the control system was analyzed in time domain and frequency domain and simulated.In order to meet the requirements of high frequency and high precision,the fuzzy PI control strategy and the fuzzy PI control strategy optimized by genetic algorithm were designed.The simulation results showed that the fuzzy PI control strategy based on genetic algorithm was superior to PI control strategy and fuzzy PI control strategy,which can improve the dynamic and steady performance of the rudder control system.In the aspect of rudder control system design,the hardware circuits were designed,including command receiving isolation communication circuit,power driving circuit,power supply circuit,strong and weak current isolation circuit,hall signal detection circuit and position sampling circuit.Taken the high reliability requirement of the steering gear into consideration,the power drive element was designed with large margin.The embedded software design and development of the electromechanical actuator control were completed,and the reliable control of the electromechanical actuator was realized.Based on the above design,the prototype of anti high overload electromechanical actuator was developed,and the high overload experiment and response characteristic experiment were carried out to verify the rationality of the overall scheme and hardware and software design.