Collaborative Manipulation with Multiple Dual-Arm Robots under Human Guidance

This paper presents the control strategy and experimental results of multiple dual-arm robots cooperatively manipulating an object whose load and size is beyond the capability of a single robot. The multi-robot system is required to stably grasp and transport the load through frictional contacts. The human operator provides motion guidance by directly manipulating the load. Through contact force sensing, the multi-arm/multi-robot system infers the human intent for motion while maintaining the contact force closure con- dition. The contact forces at the end effectors need to be carefully managed to avoid possible loss of contact. This is particularly challenging during motion, where the motion-induced inertial force adds a disturbance to the static stable grasp condition. We propose a feedforward force compensation scheme using support vector regression to estimate the inertial force. This enables the robots to coordinate their motion to maintain contacts, avoid slippage, and follow hu- man hand-guided motion. Experimental results with three Baxter robots are included to show the efficacy and limitation of the proposed method.