Number of independent fingers for object manipulations based on compliance control

One of interesting issues on multi-fingered robotic tasks is to analyze how many fingers are required to manipulate an object. This paper investigates the number of independent fingers for object manipulating tasks based on compliance control. To this end, we first present the stiffness relation between operational space and fingertip space of a multi-fingered object manipulating system. Next, we describe a technique for modulation of the fingertip stiffness without inter-finger coupling so as to achieve the desired stiffness specified in the operational space. Finally, we analyze how many fingers are necessary to successfully implement the stiffness characteristics specified in the operational space of an object manipulated. Consequently, this paper provides a guidance that is closely related to justify the number of fingers for manipulating tasks.