Research Of High Performance Closed Loop Control System For Stepper Motor

The stepping motor is an important digital executor that is widely used in manyindustry fields，such as modern automotive industry,industry automation system, modernhigh-tech military equipments,etc.With the development of electronic technology, computertechnology and the theory of modern control, the people put forward higher request of theapplication system of stepper motor,and the good dynamic and static behaviors of steppermotor has been new research hotspot in the field of stepper motor control.Thus, it isimportant to study the control system performances of stepper motor in theory andengineering.This paper presents a closed-loop control system of the two-phase hybrid steppermotor.The closed-loop control system which is established includes speed closed-loop,current closed-loop, speed controller, current controller, current/voltage conversion andstepper motor.Theoretically, the stepper motor model is established according to themathematic model by ignoring the influence of some nonlinear factors of stepper motor. Thecontroller based on fuzzy PID algorithm was used to control the stepper motor.At the sametime,the space vector pulse width modulation method, vector conversion and subdivisioncontrol technology of stepper motor were studied. With the powerful model and simulationfunction of matlab, the simulation model of the doubled closed-loop control system forstepper motor is established on the basis of fuzzy-PID control algorithm, space vector pulsewidth modulation method, space vector conversion and mathematical modeling of steppermotor.The stepper motor control circuit with MC204chip is designed in hardware whichincluded power supply circuit, drive circuit, current feedback circuit, over-current detectioncircuit, encoder interface circuit, auxiliary circuit,etc.The closed control loop of current hasbeen verified by dsPICDEM. In this paper, the close loop control system of stepper motor has certain innovation inthe aspects of study method and applicable practice.The simulation results show that thecontrol system has favorable control performance and dynamics characteristics. Theexperiment of stepper motor closed loop control of current indicated that the precision ofstepper motor is improved and the acoustic noise is reduced.