Cooperative Quasi-Static Planar Manipulation With Multiple Robots

In this paper we address the modeling, control, and planning of planar manipulation tasks with multiple robots equipped with simple end-effectors. Each robot is able to influence the motion of an object either by exerting forces through the end-effector or by contact through a robot body. We develop a quasi-static model for the planar manipulation task that incorporates mathematical models of the object-ground contact, the object-robot contact and the compliant end-effector. This model allows us to predict object velocities for specified robot motions. We use this model to develop a simple motion planning algorithm for object manipulation that allows robots to select grasps, regrasp when necessary and manipulate an object along desired trajectories. Our experiments validate the mathematical models and demonstrate the feasibility of multirobot manipulation using the quasi-static model and the motion planning algorithm.