Dynamic Damping Control of High-precision Servo System Based on Friction Model for Finite-time Position Tracking with Deteriorating Friction

The conventional methods of damping control usually involve making qualitative adjustments to the damping coefficient, without offering a quantitative calculation method. In this paper, a dynamic damping control strategy for finite-time position tracking is proposed, and a method for quantitatively calculating the damping coefficient in real time is also presented. Firstly, the study investigates the impact of friction deterioration on the performance of finite-time position tracking and the characteristics of the friction model. Secondly, the dynamic damping coefficient is quantitatively calculated by tracking the rate of change of friction torque based on the parameters of the suitable modified LuGre friction model and the motor speed. Then the rate of change of the modified friction torque by the dynamic damping coefficient tends to be 0. Thirdly, the parameters of the modified LuGre friction model are obtained using an offline method. Finally, the comparative experiments have been conducted on the test platform. The experimental results indicate that compared to the conventional control strategies, the dynamic damping control strategy improves the dynamic response by 53% and tracking accuracy by 50%. Additionally, the results also demonstrates that the dynamic damping control possesses stronger parameter robustness when subjected to a 50% positive or negative bias in the model parameters.