Unified Dynamics Calculation employing COG Jacobian for Link Mechanisms


We show the unified dynamics computation employing Jacobian that relates the center of gravity (COG Jacobian) to joints of link mechanisms. COG Jacobian is used for the behavior planning and the control of humanoids. Also, it usually expresses the relationship between the joints and COG of a robot's whole body. However, this scheme that is suggested by us calculated regarding each link and not the robot's whole-body. Moreover, we can obtain the torques of the active joints in mechanisms by relating COG Jacobian to the applied forces to COG and by using principle of virtual work. The COG Jacobian is obtained via the process calculating the accelerations at COG of links and the equation of motion expressed matrix forms by using COG Jacobian. Therefore, we can compute the equation of motion of a mechanism effectively, and the forward dynamics which can be calculated by the obtained equation. We can calculate the inverse dynamics regardless of open- and closed-link mechanisms.

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