A design of co-contraction level of antagonist muscles with muscle contraction dynamics for tracking control of human limb

This paper considers a design of co-contraction level of antagonist muscles with muscle contraction dynamics for tracking control of human limb. It is known that the co-contraction of antagonist muscles play a important role for the joint stiffness and stability. Some experiment results show the existence of co-contraction. However, the performance for the responses and energy become worse in the simulation. Thus, the co-contraction level which depends on the angular velocity of the human limb is proposed. In the stability analysis by using a robust integral of the sign of the error (RISE) controller, the convergence of tracking errors and the region of attraction are indicated. The tracking control is demonstrated and the performance and stability are verified in the simulation.