Design and Analysis of the Multi-Directionaly Flexibly Constrained Revolute Pair Driven by Elastic Wires

Abstract

The flexibly constrained revolute pair (FCRP), which is a revolute pair with flexible kinematic constraint, has been proposed for human-safe robots. In order to drive the FCRP actively, the wire-driven active FCRP (AFCRP) is proposed. The structure of the AFCRP is synthesized as an underactuated mechanism driven by two elastic wires to simplify the structure. In this paper, design methodology of the AFCRP to have high actuation-force transmission, the desired rotational stiffness and the desired flexibility in the constraint directions is proposed. Besides, a method for kinetostatic analysis of the AFCRP is proposed. Finally, an example of the AFCRP is designed, and its motion accuracy and stiffness characteristics are examined with the proposed analysis.