Dynamics and control methods for cooperating manipulators with rolling contacts

In this paper, the authors present a new control algorithm for multiple cooperating mechanisms manipulating a common object, with rolling contact between the end-effectors and the object. The algorithm is based on a new dynamic formulation, in which the rolling degrees of freedom between the end-effector and the object are modeled as one or more unactuated joints of the manipulator. Such an augmentation of the rolling contacts imparts each manipulator with additional degrees of freedom and could also make it kinematically redundant. This can be exploited for the satisfaction of a secondary subtask criterion such as collision avoidance. In addition, a control law can be specified that enables simultaneous control of the object trajectory, the internal forces in the object and the trajectories of the contact points on the object or the end-effecters