Distributed Task-space Synchronization of Networked Robotic Agents without Task-space Velocity Measurements

In this paper, we investigate the problem of task-space synchronization of multiple robotic agents in the presence of uncertain kinematics and dynamics. Our control objective is to realize synchronization without the measurements of task-space velocity. The communication topology is assumed to be directed graphs containing a spanning tree. A decentralized task-space observer with kinematic parameter updating is proposed to avoid the reliance of task-space velocity. Based on the observer, we propose the distributed adaptive synchronization controller for two cases: 1) The leaderless consensus case; 2) The leader-follower case, where all the followers track the convex hull spanned by the virtual leaders and for each follower, it is required that there exists at least one leader that has a directed path to the follower. The asymptotic synchronization is proved with Lyapunov analysis and input-output stability analysis tools. Simulations with multiple robotic agents are performed to show the effectiveness of the proposed schemes.