Fig. 6: The torque and power assistance profiles applied by the exoskeleton used in this study.
From: The economic value of augmentative exoskeletons and their assistance
a The torque profile applied by the bilateral ankle exoskeletons during the uphill walking task. The torque applied stems from the proprietary control strategy implemented by Dephy Inc and represents the state of the art. The mean profile is shown in solid teal, with a single standard deviation shown by the shaded region. Torque was quantified by using the measured q-axis motor current and the experimentally-derived, q-axis torque constant to calculate motor torque66, and then multiplying that value by the instantaneous transmission ratio. Gait cycle progression is defined as beginning and ending at sequential ipsilateral heel-strikes. b The power applied by the exoskeletons at the ankle during the walking trial. Power was calculated by multiplying the current-derived torque profiles in (a) by measured ankle angular velocities. The mean profile is shown in solid purple, with a single standard deviation shown by the shaded region. The average energy provided by the exoskeleton, obtained by integrating the power curves over time is 13.4 ± 2.9 J.
