Abstract: In order to make the stepper motor reach the rated speed or target angle as soon as possible and avoid out of step, it is necessary to design the acceleration and deceleration profiles, such as trapezoid, S shape and so on. The traditional method of fixed design speed curve is only suitable for the situation that the target position, direction, initial speed, maximum limited speed and acceleration of the stepper motor have been determined in advance and will not be changed before the motor reaches the target position. In many applications of stepper motor, sometimes it is necessary to modify the operation parameters temporarily, and sometimes the initial speed cannot be determined in advance. At this time, it is necessary to modify the designed speed curve temporarily, which is very complex. In this paper, the tracking differentiator method based on ADRC theory is used to solve the problem of frequently modifying the speed curve. The method can optimize the complexity of the algorithm and reduce the amount of calculation. The algorithm is verified on STM32 micro controller, and has been applied in the control of manipulator driven by stepper motor.

Key words: stepper motor, speed profiles, tracking differentiator, ADRC