End-Effector Trajectory Tracking Control of Stacking Robot Based on LuGre Model

摘要

In order to realize the accurate tracking of the end-effector trajectory of the stacking robot, an end-effector trajectory tracking control method based on LuGre model is proposed. First, the dynamic model of the stacking robot including joint friction is established. In order to eliminate the influence of the joint friction of the stacking robot, the LuGre friction model is introduced into the stacking robot system. The genetic algorithm and the two-step dynamic response method are used to identify the static and dynamic parameters of the LuGre friction model. The identified parameters are feed-forward compensated to the controller, which greatly improves the robustness of the controller. Second, aiming at the problem that it is difficult to obtain the model parameter information of the stacking robot, an adaptive double fuzzy backstepping sliding mode controller is designed. The double fuzzy system is used to realize the online estimation of the model information parameters while the switching term of the sliding mode controller is continuous, and the adaptive adjustment robust gain is realized. Furthermore, the chattering problem caused by the sliding mode controller is eliminated and the stability of the system is proved. Finally, the experimental study on the trajectory tracking control of the terminal of the stacking robot is carried out. The results show that the method can well realize the joint trajectory and end-effector trajectory tracking control of the stacking robot. The mean error between the relative position points of the spatial trajectory is within 2.47 mm, and the chattering phenomenon is obviously improved.