Distribution of Natural Compliance in Force Control of Space Manipulator
Yoshiaki Ohkami* and Osamu Okamoto**
*Tokyo Institute of Technology, 2-12-1 Ohokayama, Meguro-ku, To' vo, 152 Japan
**National Aerospace Laboratory, 7-44-1 Jindaiji-Higashi, Chofu, Tokyo, 182 Japan
This paper presents results of investigation on the force control of space manipulator when it constitutes a geometrical loop. It is shown that without natural compliance, the system becomes indeterminate when the tip touches the object on the common base. A simple force feedback control could be applied, but the control is demonstrated to be incapable of changing the situation for rigid and kinematically controlled arms. Based on the evaluation of the extended inertia matrix, it is shown that the natural compliance should be assigned to all directions of the contact (6 DOF) and that the force control must be compatible to this condition that the total system is determinate over the entire range of operation.