Control of Robot Manipulators with a Model for Backlash Nonlinearity in Gears

This paper presents a model for backlash nonlinearity in gears based on torque input-output equation. By combining the robot dynamic model with backlash, a stable sliding mode controller is developed and the asymptotic stability of the closed-loop system is shown using Lyapunov method and Barbalatʼs Lemma. The proposed method is produced no chattering in the control torques and the tracking performance is desirable. Effectiveness of the controller is verified by comparative studies with numerical simulation. Finally, experimental results are presented to demonstrate the efficiency and capability of the proposed controller in dealing with backlash nonlinearities in gears of a five-bar manipulator.

Keywords:

Nonlinear control , Robot manipulator , Modeling , Backlash nonlinearities