Research On Predictive Functional Control Of Continuous Rotary Electro-Hydraulic Servo Motor

With the rapid development of our country's economic level and the enhancement of science and technology strength,flight simulator is used more and more in aerospace and defense industry and plays an important role in the national economy and the people's livelihood.It is the continuous rotary electro-hydraulic servo motor,which is the core component of flight simulator,requires to have perfect super low speed,high frequency response,wide speed range and high precision.Based on the above,continuous rotary electro-hydraulic servo motor and its control system are studied in this paper.Through consulting a large number of relevant reference literature at home and abroad,this paper makes a brief review on the development of continuous rotary electro-hydraulic servo motor applied to simulator.Then the structures,characteristics,common control strategies and applications of electro-hydraulic servo system are introduced.This paper also summarizes the current situation and development of predictive functional control(PFC),and then puts forward the research contents under this background.Aiming at the two main factors friction and leakage that affect the low speed performance of continuous rotary electro-hydraulic servo motor,this part starts from the mechanism of internal leakage of the motor.Considering the surface roughness of the moving parts,according to the parallel plate clearance flow equation,the paper establishes the internal leakage equation of the key parts of the motor.The effects of surface roughness,inlet pressure difference and rotation angle on internal leakage are also analyzed in turn.The mathematical model of continuous rotary motor electro-hydraulic positon servo system and the friction disturbance torque model are established.Low speed tracking performance curve simulation is performed under different leakage coefficients by Simulink software.The paper analyzes the effects of internal leakage on low speed stability.The connotation of predictive control is expounded.The operation process of predictive function control is also described in detail.This paper proposes a predictive function controller algorithm on the basis of internal mode control structure.Friction torque of low-speed is simplified reasonably.The system is given a ramp signal and a sine signal and the PID control,PFC control,PID-PFC composite algorithm are simulated.The results prove that the PID-PFC composite algorithm can overcome the external disturbance and parameter perturbation problem.The response speed and tracking accuracy of the motor have greatly improved.The bandwidth is broadened so that the double ten requirements can be meeted.The low-speed stability of the system have also been further enhanced.