Design And Implementation Of High Dynamic Performance Driver For Stepper Motor

Stepper motor has been widely used in industry and daily life because of its high precision and easy to control initially. But the conventional control strategy has over shooting, stepping out and low frequency oscillation problems, which makes it incompetent in some high dynamic performance and high precision demanded condition.To solve these problems, international research mainly focus on promoting the motor’s structure, optimizing the driving method and improve the performance of microchips, while these methods are still limited by processing technology, voltage, etc. This thesis studies the back EMF’s influence on motor’s dynamic performance, raises a mixed recirculation algorithm, solves the stepper motor’s stepping out and overshooting during acceleration and deceleration significantly and implements a stepper motor’s high dynamic performance driving system.Firstly, this thesis models the stepper motor and simulates in Simulink, analyzes the reason why stepper motor has problems during operation and points out the key effects of motor’s back EMF. And then, by analyzing the H bridge recirculation’s influence on back EMF and comparing the current recirculation methods, this thesis raises the mixed recirculation algorithm which can release the back EMF and follow the given current effectively. To demonstrate the efficiency of this algorithm, this thesis designs and implements the simulation, hardware and software of DSP based AD digital stepper motor driving system. Based on this system, this thesis implements the subdivision driving method based on mixed recirculation algorithm and verifies this algorithm by comparing its control result with other recirculation methods.The final test results show clearly that the system based on mixed recirculation algorithm can achieve rapid four-quadrant operation without over shooting or stepping out, follow the given current and eliminate the low frequency oscillation. That means the system has a great dynamic performance and totally matches the design requirements.