Research On Two-phase Hybrid Stepper Motor Control Based On Sliding Mode Algorithm Of Time-varying Boundary Layer

The stepper motor can control the displacement and speed of the motor by adjusting the number and frequency of input electrical pulses,with the advantages of easy control,high positioning accuracy,high reliability and good economy.Among them,the two-phase hybrid stepper motor has been more and more widely used in industrial production and actual life,building a high-precision and high-performance two-phase hybrid stepper motor closed-loop servo control system has become a very valuable research topic.In this paper,the sliding mode control algorithm is selected to complete the construction of the stepper motor closed-loop servo control system to improve the dynamic performance index of the stepper motor and the stability of the system,however,the chattering problem brought about by sliding mode control itself is urgently needed to be solved.Therefore,this paper proposes a sliding mode control algorithm with time-varying boundary layer from the perspective of boundary layer,which aims to weaken the chattering problem in sliding mode control It can take into account the good dynamic and anti-disturbance performance of traditional sliding mode control.First,this paper analyzes the internal structure and operating principle of the two-phase hybrid stepper motor,separately deduces the mathematical model of the motor in static and rotating coordinate systems,and further analyzes the vector control strategy and specific Driving scheme.Then,list the required state space equations based on the derived mathematical model,apply the sliding mode control strategy to the position control system and speed control system,and clarify the control scheme of each system.And for the chattering phenomenon in the control algorithm,the time-varying boundary layer algorithm is proposed and analyzed in detail,and the sliding mode position controller and sliding mode speed controller are optimized.Finally,in order to verify the effectiveness and superiority of the sliding mode control algorithm of the time-varying boundary layer,the position control simulation model and speed control simulation model of the two-phase hybrid stepper motor were built by Matlab /Simulink software.Comprehensive experimental verification was carried out through two types of simulation control experiments.The time-varying boundary layer sliding modecontrol algorithm was compared with the fixed boundary layer sliding mode control algorithm to verify its weakening effect on chattering,and then compared with the traditional PID control algorithm,in order to prove that it retains the superior characteristics of sliding mode control,that is,good dynamic performance and anti-disturbance performance.In addition,this paper also completed the construction of the two-phase hybrid stepper motor position control actual experimental platform,carried out the same experimental content,and comprehensively analyzed the experimental results and simulation results,it is more powerful to confirm that the algorithm proposed in this article does have certain advantages.