Safety control of cooperative manipulators in collision environment
In view of the possible physical collision between the end of the manipulator and the operator in the process of human-robot cooperation,a safety control method of the manipulator is proposed based on the adaptive admittance and sliding mode control.Firstly,the interference observer based on the generalized momentum is used to estimate the interference force of each joint and end effector.Then,a double-loop control structure is designed.The inner loop is a sliding mode trajectory tracking controller based on the double-power reaching law and interference observation,which can overcome the influence of external interference and achieve desired trajectory tracking accuracy.The outer loop is an adaptive admittance controller,which updates the desired trajectory according to the magnitude and direction of the external force caused by collision,so as to ensure the flexibility of manipulators in collision environment and the ability to quickly resume its working state after the collision is resolved.Finally,the proposed algorithm is verified by simulation and experiments.The experimental results show that the safety control algorithm can ensure the safety of human-robot collaboration and the continuity of manipulators'work,which meets the work requirements in the process of human-robot collaboration.
human-robot cooperationinterference observersliding mode controladaptive admittance control