Research on Global Sliding Mode Control of Braking Deceleration for Main Shaft Hoist

The traditional sliding mode controller of the main shaft hoist system has problems with brake deceleration chattering and overshoot. This study proposes an improved exponential convergence law, which adds a natural logarithm function term to make the sliding mode motion of the system located on or close to the sliding mode surface at the beginning of the braking process. The simulation verification results show that the proposed nonlinear global sliding mode control scheme has a maximum overshoot of only 0.013m/s² in braking deceleration, which can more effectively track the desired braking deceleration and has better braking efficiency, thereby reducing chattering phenomenon, eliminating overshoot problem, and improving its tracking performance.