抄録
This paper tries to decompose the vector space of muscle contraction forces of robot arms driven by biarticular antagonist muscles into the direct sum of its subspaces. To this end, we define two linear maps: one maps muscle contraction forces to joint torques while the another maps muscle contraction forces to joint stiffness. Then we can prove that the kernel and the image of these maps decompose the muscle contraction force space into the following three subspaces: subspace of contraction forces that contribute motion of the robot arm, subspace that determine joint stiffness, and subspace that have no effect on neither motion nor stiffness.
