Cooperative Manipulation of Deformable Objects by Single-Leader–Dual-Follower Teleoperation

This article proposes a method for single-leader–dual-follower teleoperation, where one robot (direct-follower robot, DFR) is directly teleoperated and the other robot (assisting-follower robot, AFR) can autonomously cooperate with the DFR to hold and move a deformable object, with the contact force regulated to a desired value. Since the AFR does not know its partner’s movement, first, it achieves position alignment with the DFR by using the contact force. Second, we develop an adaptive movement estimation algorithm according to the Lyapunov theory, such that DFR’s position is estimated in the presence of dynamic uncertainties. Finally, we adopt the impedance control to generate a reference trajectory for the AFR to track, in order to maintain the desired contact force. Several simulations are conducted on a platform with two three-degrees-of-freedom robots. Experiments are performed with a dual-arm robot (Baxter), results of which demonstrate the feasibility and effectiveness of the proposed method.