Research On Permanent Magnet Synchronous Linear Motor Based On Improved Sliding Mode Algorithm

In recent years,there is more and more linear direct drive motion.The traditional schemes based on electric rotating machinery and gear-driven showed more and more disadvantages,such as overstaffed structure,limited precision,low speed and acceleration,which seriously restricted the development of linear direct drive motion.With the advancement of technology,semiconductor devices have made great progress,the performance of permanent magnet materials has been improved continuously,the drive system of linear motor has made great progress,and its dynamic performance and static performance have gotten a qualitative leap.Therefore,the linear motor drive system is more and more popular.Under this background,taking the STM32f407 MCU as the control core,this paper studied the drive system of permanent magnet synchronous linear motor.Firstly,according to the operation principle of permanent magnet linear synchronous motor,the mathematical equation is established.The mathematical mechanism of the linear motor thrust fluctuation is deduced,and the correctness of the thrust model is verified by experiment.On this basis,the simulation model of the permanent magnet synchronous linear motor is established,and the motor parameters are identified by mathematical method.The vector algorithm of the permanent magnet synchronous linear motor is introduced,and the double closed-loop control strategy of speed and current is determined.The double PI control strategy and the integral sliding mode variable structure control strategy are analyzed.On this basis,based on MATLAB / Simulink,the PI closed-loop control strategy and the integral sliding mode variable structure control strategy under vector control are established.The simulation results show that the improved scheme is correct for the shortcomings of the integral sliding mode variable structure control strategy.Secondly,the hardware and software of the experimental platform were built.The hardware is made up of the control core based on STM32f407vet6 MCU,three-phase full bridge drive inverter circuit which consists of the gate driver and the NMOS,the communication circuit and protection circuit.In software,the program design based on STM32F407VET6 was completed,and a simple operation interface was established by HMI.For this project,the software mainly completed the core algorithm,thecommunication protocol,and the sensor driver code and so on.The core control code of this design is completed by the code generation tool of MATLAB,and the simulation to code realization is described in detail,which makes the simulation algorithm of MATLAB have simulation significance as well as practical significance.Finally,based on the completion of the software and hardware platforms,experiments were performed to calculate the position and electrical angular velocity of the motor,to measure and collect the three-phase current,and to test the dynamic response of the motor mover speed.At the same time,the experimental results were analyzed to verify the effectiveness of the improved algorithm.At the same time,for the speed turn back experiment under the control of the improved integral sliding mode algorithm,the control effect is good,the motor is stable and achieves the expected goal under the condition of speed sudden change...