Novel Control Methods for Multi-fingered Haptic Interface Robot

Abstract

Haptic interfaces presenting force and tactile feeling at human fingertips are used in the area of tele-manipulation of robots, simulation and design in virtual reality environments, educational training, and so on. Multi-fingered haptic interface is required to be safe, to work in wide operation space, and to present not only force at contact points but also weight feeling of virtual objects, to have no oppressive feeling when it is attached to humans, and to have no weight feeling of itself. The paper presents two control methods for the multi-fingered haptic interface, which is a redundant robot. First is redundant force control, which takes into account moments at tip of an interface arm. The second is a combination of the force control of the fingers and the position control of the arm, which optimizes the manipulability of haptic hand and minimizes variation of joint angles of the interface arm. Experimental results of free space and constrained space are shown. The control methods are well suited not only for the multi-fingered haptic interface but also for the multi-fingered robot hand for grasping and manipulating an object.