Dynamics Computation of Link Mechanisms Employing COG Jacobian

Abstract

We show the dynamics computation employing Jacobian that relates the center of gravity (COG) to joints of link mechanisms, in this paper. COG Jacobian is used for the behavior planning and the control of humanoids. And, it usually expresses the relationship between the joints and COG of a robot's whole body. However, in this scheme, it’s calculated regarding each link and not the robot's whole-body. Moreover, we can obtain the torques by relationship between COG Jacobian and the applied forces to COG by using principle of virtual work. The loaded forces to COG can be obtained by employing Newton’s and Euler’s equations of motion. By the scheme, we can calculate the inverse dynamics regardless of open- and closed-link mechanisms. In addition, the forward dynamics can be calculated by employing COG Jacobian.