Stepper Motor Motion Control: Advanced Control Strategies, Micro stepping and Closed-Loop Performance Optimization

Abstract

This paper presents a comprehensive study of stepper motor motion control covering fundamental operating principles, excitation modes, and advanced closed-loop control strategies for precision positioning applications. The proposed control architecture integrates trajectory planning using S-curve and trapezoidal velocity profiles with adaptive micro stepping, a PID-based position and velocity feedback controller, and a PWM current-mode driver for winding current regulation. The system is implemented on an STM32F4 microcontroller interfaced with a DRV8825 stepper driver, operating on a 200-step/revolution hybrid stepper motor. Experimental results demonstrate that closed-loop control achieves a positioning accuracy of 0.4 arc-minutes, a settling time of 12 ms, and a velocity ripple below 1.8%, representing improvements of 89%, 73%, and 78% respectively over open-loop operation. The effect of resonance suppression through micro stepping (1/8 to 1/128) is quantified and a comparative analysis of control methods—full step, half step, micro stepping, and closed-loop—is presented. The proposed system is validated on a CNC-axis positioning rig and a robotic joint mechanism, demonstrating industrial suitability.