Elastic energy savings and active energy cost in a simple model of running
Fig 6
Effect of work and force-rate costs on running using Actuated Spring-mass model.
(top:) Vertical CoM displacement vs. time, vertical GRF vs. time, and leg Power vs. time, for varying force-rate cost coefficient ϵ. (bottom:) Actuator work cost EW (thin blue line), Total cost EW + ER (work and force rate, solid black line), and Force-rate cost ER (difference between lines) vary with the coefficient. Impulsive actions (red arrows, V. GRF and leg Power) occur at Collision, and overall leg power (solid black line) includes contributions from the Spring and Actuator. All solutions are shown for v of 3 m s-1 and f of 2.94 Hz.