Dynamics computation of closed kinematic chains for motion synthesis of human figures

This paper discusses the dynamics computation of closed kinematic chains, especially those found in motions of human figures. A number of efficient dynamics computation algorithms have been established in robotics for open kinematic chains and particular types of closed kinematic chains such as parallel five-bar link mechanisms and the Stewart platform. The dynamics computation of closed kinematic chains, however is still challenging and among open research issues. In this paper, we describe the mobility of closed kinematic chains by the minimal set of independent variables, which we call the generalized coordinates of a closed kinematic chain. We then develop a systematic procedure to find them out, and establish the computational algorithms for the inverse and forward dynamics of any closed kinematic chains. The numerical examples show the effectiveness of the algorithms in particular for computing high-degrees-of-freedom human/animal motions