Control of multifingered robot hands with rolling and sliding contacts

This paper deals with the kinematic analysis and dynamic control of multifingered hands with both rolling and sliding contacts. The research is motivated by the requirement for relocating or regrasping of arbitrary shaped objects without breaking the contacts. Three key issues are considered in this research: the control of the relative motions on the object; the tracking of a desired trajectory of the object; and the maintaining of desired internal forces. Based on the hand-object system in which the contacts are allowed to both slide and roll, a kinematic model of the system is derived, and the contact force is analysed. A coordinated control law is then proposed. The control law ensures the asymptotic tracking of the object trajectory together with the desired rolling and/or sliding motions along the surface of the object. The control law also guarantees the asymptotic convergence of the internal forces to their desired values. Simulation results are given to verify the theoretical developments.