Decentralized control of internal wrenches in a multi-manipulators object transportation task

This paper presents a decentralized strategy for a team of N robotic manipulators cooperatively grasping and manipulating an object. A two-step strategy has been designed. In the first step, each robot runs N − 1 consensus-based estimators to estimates the wrenches applied to the object by its teammates even when direct all-to-all communication is unavailable. In the second step, each manipulator runs a local compliance controller to adjust its end-effector compliance, thereby reducing internal stresses and preventing potential damage to the object. The effectiveness of the proposed scheme is validated through simulations of a work-cell with four 7-DOFs manipulators by using a realistic dynamic simulator. Simulation results confirm the capability of the approach to limit internal wrenches, even under restricted communication conditions.