A Digital Speed Profile Generator for Stepper Motor

Rotation speed and angle characteristics of a stepper motor are subject to speed profiles and frequency of pulses. In recent days, most parts of a stepper motor driver have been digitalized by using digital signal processors (DSP), except for the step pulse generation part, which is usually implemented on a separate circuit. This paper presents a method to generate step pulses, which can be implemented by the DSP via Matlab/Simulink for stepper motor drivers. A condition used to discriminate a triangular or trapezoidal pattern drive and a relationship between the sampling period of the DSP and the maximum rotation speed are derived. Simulation and experimental results for a five-phase hybrid stepper motor show that the proposed method generates the excitation pulses properly.