Research and application of closed loop control system for stepping motor
                                                          XIA Si quan, ZHOU Yi min, YANG Yi bo, HUANG Song
                       （Public Experiment Center, University of Shanghai for Science and Technology, Shanghai 200093, China）

Abstract: Aiming at the actual running process of the stepping motor in the open loop state, the problem of step loss is caused by inertia, speed mutation or load. The mathematical model of stepping motor and the mathematical model of speed control were analyzed, the control method and the control algorithm of stepping motor were analyzed. A closed loop control system with photoelectric sensor detection angle was proposed. The fuzzy PID control strategy was adopted to optimize the output characteristics of the stepping motor, the running of the angular displacement was reappeared farthest. At the same time, the speed control method of the index was used to control the stepping motor. In order to facilitate the real time processing of the microcontroller, its speed control laws were discretized. The results show that the control system can reliably avoid losing step in speed and load mutation, it can improve the operating accuracy and reliability,dynamic performance and robust performance of the whole control system.

Key words: stepper motor; out of step; photoelectric sensor; fuzzy PID