A modified nonlinear forces compensation scheme based on decomposition control in high-precise servo system

This paper presents a modified compensation scheme of nonlinear forces in the DC motor system. The paper's contribution is to add repetitive control scheme into the decomposition-based control compensation scheme. Robust adaptive compensator is derived to compensate for the influence of the nonlinear friction forces and ripple force in the system. Moreover, the inducted repetitive controller is motivated by the attempt to improve the system motion trajectory tracking performance. The combination of the compensator and the repetitive controller yields the overall control law. The system stability and the uniformly ultimately position tracking performance are guaranteed by utilizing Lyapunov method. The effectiveness of the proposed scheme is demonstrated by computer simulations for high-precision servo system.