Adaptive sliding mode control for chain driving system with disturbance observer

Abstract

The design and implementation of adaptive sliding mode control with disturbance observer for chain driving system driven by permanent magnet synchronous motor with parameter variation, meshing impact and large friction are addressed in this study. First, an adaptive model compensation control law is designed for perfect position tracking, while a nonlinear disturbance observer is investigated to estimate the normalized disturbance, which is fast changing due to the severe polygon effect, the meshing impact and so on. To further improve the robustness and the control performance, the translation-width idea is embedded into the adaptive sliding mode control with disturbance observer system, which can suppress the chattering phenomenon caused by imperfect switching in traditional sliding mode control. Moreover, the translation width is online updated using an adaptive mechanism, which is delivered in the Lyapunov sense. Thus, the stability of the closed-loop system is guaranteed in the Lyapunov stability theorem sense. Experimental results show that the proposed adaptive sliding mode control with disturbance observer scheme is insensitive to parameter variation, meshing impact, large friction and so on, and has a better control performance compared with the traditional adaptive sliding mode control and the disturbance observer–based sliding mode control.