UC Santa Cruz

This paper presents a hybrid control approach for grasping objects by multiple agents without rebounding. When multiple agents grasp an object cooperatively, the motion of the agents is constrained due to the geometrical and frictional conditions at the contact points. In this paper, each agent acting on an object of interest is controlled by a hybrid controller which includes a position controller, a force controller, and some logic to coordinate grasping. The proposed approach provides a method to steer the agents to grasping positions on an object along appropriate directions and to asymptotically exert stabilizing forces at each contact point. The stability properties induced by the hybrid controller can be asserted using Lyapunov stability tools for hybrid systems. The set of allowed initial conditions guaranteed is characterized using sublevel sets of Lyapunov functions. The proposed algorithm is verified in simulations.