Theoretical Hill-Type Muscle and Stability: Numerical Model and Application
Figure 2
Model of the inverted pendulum. S1 represents the leg-trunk segment; S2 represents the foot. COG indicates the center of gravity location of S1. is the angle of the foot (perturbation) and the deviation from the upright position of S2. (a) The joint is actuated by a direct torque generator with linear characteristics. (b) The joint is actuated by two antagonistic muscles.
