M1 Walking Inverted pendulum, GRF and energy recovery

Title

Walking is an alternating double-support mode of locomotion where the CM follows an inverted vault trajectory: the body rises in the mid-stance phase and descends in the transfer. The potential and kinetic energy of the CM are in push-pull, allowing a passive exchange that can recover up to 65% of the mechanical energy per cycle (Cavagna inverted pendulum model). Optimal walking speed (~1.4 m/s) minimizes metabolic transport cost; At higher speeds, the inverted pendulum model cannot sustain the pattern and moves in a hurry (Froude number 0.5). The vertical GRF has a double peak with a minimum at medium support (~80% body weight). The external mechanical work is that done to move the CM; the internal one, to move the segments with respect to the CM. The efficiency of the pendulum is quantified by the percentage of energy recovery (R%).

ID:1457