Adaptive Distributed Event-Triggered Cooperative Manipulation of Multiple Manipulators Under Partial Time-Interval Error Constraints

This article investigates a distributed event-triggered control approach that integrates a partial time-interval error constraint (PTIEC) for multirobot cooperative manipulation of a shared object. Considering the scenario where only a subset of robots possesses accurate information regarding the positions (orientations) and corresponding velocities of the object’s desired local trajectory, a novel dual-layer control framework is established, comprising an estimation (first) layer and an actuation (second) layer. In the estimation layer, the desired local trajectory is estimated by means of the novel distributed prescribed-time estimators without the undesirable infinite gain issue. In the actuation layer, a stretching function is introduced and integrated with the barrier function to facilitate the error constraints within some partial time intervals (occurring at a noninitial moment), effectively converting the constrained system into a “constraint-free” one. Then, a distributed event-triggered control law is constructed, taking into account the unknown dynamics of both the robots and the manipulated object, as well as communication delays. The communication and actuation are executed at specific event times, thus alleviating the burden of control updates and communication costs of the robot system. Finally, the feasibility and effectiveness of the proposed dual-layer control technique are confirmed through simulations.