Task-Space Cooperative Tracking of Manipulators via A Unified Inner/Outer-Loop Distributed Design

This paper addresses task-space adaptive coordinated tracking of networked manipulators with an inner/outer-loop closed control architecture, considering all the uncertain kinematics, dynamics, disturbances, and unavailable task-space velocities. One observation is that modern robotic applications may encounter situations that task-space controllers cannot be implemented on robots with the closed control architecture. In addition, it assumes that the combination of the inner/outer loop is stable and effects of unknown robotic dynamics are neglected. Existing papers in [9]-[12] provide task-space synchronization with an open control architecture and require each robot to fully access a desired global task, and to communicate via undirected or strongly connected digraphs. In contrast, this paper proposes a distributed framework over a directed graph so that a robust, distributed, outer-loop control scheme is developed to achieve task-space coordination with dynamic effects being considered and not modifying the inner control loop. Numerical simulations are presented to show the effectiveness of the design.