Research On Piecewise Sliding Mode Control Method For Permanent Magnet Synchronous Motor Servo System

Position servo control is widely used in modern industry,equipment manufacturing,automation,electric vehicle driverless and other fields.Fast,stable and accurate control is the future direction of position servo control.The advanced control strategy can realize the precise control of the motor position,realize the fast response of the system and improve the stability of the system.This paper will mainly study the control effect of sliding mode control algorithm in servo system.Firstly,based on the mathematical model of vector control of permanent magnet synchronous motor(PMSM),the vector control mode of rotor field orientation is selected,and the space vector pulse width modulation(SVPWM)technology is adopted.In-depth study of sliding mode variable structure control technology,the generation of buffeting and its weakening countermeasures are analyzed.To improve the switching gain by adding error factor to the exponential reaching law,a sliding mode control strategy is proposed to improve the exponential reaching law,which weakens the chattering.In order to make the dynamic process of the system more smoothly,a piecewise sliding mode variable structure controller for position servo system is designed,and the simulation model of three closed-loop servo control system including current loop,speed loop and position loop is built.The simulation results show that the control algorithm can accelerate the response of the system,enhance the anti-interference ability of the system and change the parameters of the motor.The chattering effect of sliding mode variable structure can be weakened by adaptive adjustment of the load disturbance and the transformation.The hardware and software of the system are designed with DSP28335 asthe control chip,and the experimental platform of permanent magnet synchronous motor is built.The data are acquired by the data acquisition system of the upper computer,and the waveform of speed and position is drawn.The results show that the system can meet the requirements of position servo control.The application of piecewise sliding mode control technology in vector control method can improve the stability and anti-jamming ability of the system,enhance the rapid response ability of the system,and weaken the influence of sliding mode variable structure control chattering.