Observer‐based adaptive control of cooperative multiple manipulators using the Mastroianni operators as uncertainty approximator

Abstract

AbstractThis article addresses the multi‐objective problem of pose and force control in a cooperative system comprised of multiple n‐degree‐of‐freedom (n‐DOF) robotic arms that move a payload. The proposed controller should be capable of maintaining the position and orientation of the payload in the desired path. In addition, the force exerted by robot end‐effectors on the object must remain limited. The system has unmodeled dynamics, and measuring the robot joint velocities is impossible. In other words, joint positions are the only measured states. Therefore, a Mastroianni operator‐based observer is first designed to estimate the uncertainty and velocities based on its universal approximation property. Then, using these estimations, a feedback controller is proposed to establish a robust and precise tracking performance. The stability of this system is confirmed based on Lyapunov's stability theorem. This article is the first study on utilizing the adaptive form of Mastroianni operators in robust adaptive controller design. Moreover, the introduced structure is regressor‐free and does not depend on velocity measurements. Finally, the proposed adaptive observer‐controller is applied on two 3‐DOF cooperative robotic arms carrying a payload, and the results are precisely analyzed. The results of the proposed approach are also compared with a state‐of‐art powerful approximation method.