Research On Nonlinear Position Servo Control System Of Magnetic Coupling Rodless Cylinder

As a pneumatic actuator,the magnetic couple rodless cylinder is widely used in industrial occasions such as the machine tool processing and electrostatic painting.However,with the gradual development of automated production technology,the production site has higher and higher requirements for the position servo control accuracy of the magnetic couple rodless cylinder.Therefore,in order to improve the servo control accuracy of the magnetic couple rodless cylinder position and improve the control performance,this paper analyzes the nonlinear mathematical model of the magnetic couple rodless cylinder position servo control system,and propose the position of servo intelligent control algorithm of the magnetic couple rodless cylinder.The main contents are as follows:(1)Analyze the working principle of the magnetic coupling rodless cylinder position servo control system,select the pneumatic components,sensors and control elements in the experimental system and analyze their working principles and characteristics.Then,the experimental platform of the magnetic couple type rodless cylinder position servo control system is built.The characteristics of the proportional directional control valve and the magnetic couple rodless cylinder in the system is tested by experiments.The characteristics of the proportional directional control valve are tested through experiments.It is found that when the control voltage was 5.08 V,the valve core was located in the middle position of the valve body,and the relationship between the effective area of the valve port opening and the control voltage was nonlinear.The friction characteristic of the magnetic couple rodless cylinder is experimentally studied by using the Stribeck friction model.In addition,the unknown parameters in the Stribeck friction model were obtained through experimental tests and theoretical calculation,and the nonlinear friction law of the magnetic couple rodless cylinder motion was finally summarized.The research on the characteristics of the proportional directional control valve and the magnetic couple rodless cylinder lays the foundation for establishing the mathematical model of the nonlinear position servo control system of the magnetic couple rodless cylinder.(2)The physical structure of the proportional direction control valve is analyzed in this paper.In addition,the principle of gas flow in the spool of the proportional direction control valve during forward movement and reverse movement is studied.The mass flow equation of the gas flowing through each valve port was further derived.Furthermore,by building the experimental platform and using the MATLAB fitting toolbox,the mathematical relationship between the effective area of the port opening of the proportional direction control valve and the control voltage,and the mathematical relationship between the flow coefficient of the valve port and the spool displacement were obtained.On this basis,the energy equation and dynamic equation of the system are established.Through the filling and discharging experiment of the fixed chamber of the magnetic couple type rodless cylinder and the position servo control experiment of the magnetic couple rodless cylinder,the correctness and validity of the nonlinear mathematical model of the magnetic couple rodless cylinder pneumatic system and the mathematical model of rodless cylinder nonlinear position servo control system are verified respectively.(3)Based on the mathematical model of nonlinear position servo control system of magnetically coupled rodless cylinder,this paper proposes a rodless cylinder motion control strategy based on particle swarm optimization algorithm to optimize PID parameters and a rodless cylinder motion control strategy based on RBF neural network to tune PID parameters.Furthermore,based on two control strategies,the positioning experiment and trajectory tracking experiment of rodless cylinder are carried out.Then the experimental results are compared with the experimental results of PID based on NCD optimization and traditional PID.The experimental results show that the position control accuracy of the rodless cylinder motion control strategy based on RBF neural network tuning PID parameters is the best,the stability of the rodless cylinder motion control strategy based on Particle Swarm Optimization PID parameters is the best.