Seamless Manipulation by Multi-fingered Robot Hands Based on Global Expression of System Motion

Abstract

This paper proposes a new feedback control design methodology for multi-fingered robot hands applicable to multiple contact situations. We derive a general expression of the system motion valid for both the contact and non-contact situations, and design a linearizing compensator based on this expression. The compensator has inputs to control relative motion and constrained force. We show that we can control either of these variables if we set the input for the other variable zero, according to the current contact situation. The method can be applied to redundant manipulation systems, which we will call partially constrained systems, where the number of control inputs is greater than the number of constraints in the contact situation. As a design example for such systems, a catching/releasing task by a hand-arm robot system is provided.