Adaptive Stability Control of the Robot Based on Extended State Observer

For the uncertainties which exist objectively in the robot system impact on the motion performance of joint robot system, an active disturbance rejection control method of joint robot system is proposed based on state observation and compensation. The uncertainties of the system are introduced by constructing extended state in the method, and uncertainties and state variables are estimated by an Extended State Observer (ESO) which has the form of nonlinear ordinary differential equations. Then, estimate of uncertainties is considered as the robust control compensation in the control. The method does not rely on the specific form of uncertainties and measurement of all state parameters. Simulations taking 2R robot as an example demonstrate feasibility and effectiveness of the method, and the results show the system has good stability. The method proposed can directly be applied to stability control of complex systems.