Stiffness analysis and optimization of a novel cable-driven anthropomorphic-arm manipulator

The novel cable-driven anthropomorphic-arm manipulator (CDAM) mentioned in this paper is a 7-DOF hybrid redundant mechanism which fuse the advantages of redundant manipulator and cable-driven mechanism. This paper focuses on the stiffness of the CDAM and gives the Cartesian stiffness matrix calculation process. The process can be divided into three steps: firstly, the calculation of the stiffness of shoulder and wrist which are both four-cable-driven parallel mechanism; secondly, the stiffness in elbow which is a cable-driven single joint; lastly, by merging the wrist, elbow and shoulder stiffness to the joint stiffness matrix, the modified conservative congruence transformation (CCT) is used to get the solution of Cartesian stiffness matrix of CDAM. Base on the stiffness analysis of CDAM, a stiffness optimal algorithm is proposed to enhance the stiffness in motion and the simulation and experiment proves the effectiveness of this algorithm.