Theoretical Hill-Type Muscle and Stability: Numerical Model and Application
Figure 4
Model reactions to perturbations in foot orientation . Control target is the upright posture (). Left column shows the reaction to a ramp perturbation, middle column to a 1 Hz, and right column to a 0.1 Hz sinusoidal perturbation. Top row is without feedback, middle row with a simple P controller (direct torque controller gain: P 500; muscle controller gain: P 1), and bottom row with a PID controller (direct torque controller gains: P 500, I 50, D 500; muscle controller gains: P 1, I 0.3, D 0.3). The feedback signal is delayed by s.