FIGURE 7.

Case2: Joint behavior statistics (curve: mean; shade: STD) under random perturbation forces in the first squatting cycle with respect to time for 200 simulated environments. (A) Hip, knee, ankle dorsiflexion/plantarflexion, ankle inversion/eversion joint angles with respect to time in the first squatting cycle. The learned STDs $\text{Σ}$ (in Eq. 4) of the joint angles are very small (less than 0.08). (B) Corresponding joint torques in the first squatting cycle. (C) Magnitudes of the random perturbation forces applied on the three parts of the exoskeleton: hip, femur and tibia during testing.