Fig. 3: Speed-adaptive control.
From: Personalizing exoskeleton assistance while walking in the real world
a, The Speed-adaptive controller interpolated between previously optimized assistance parameters to estimate the optimal parameters for each step based on walking speed on the previous step. Optimized values are normalized to the allowable range for each parameter. b, Ground truth and estimated walking speed for a representative participant. Speed was estimated on each step using a model that took stride period as an input (Extended Data Fig. 2) with a root-mean-square error (RMSE) of 0.06 m s−1. The shaded region represents the mean ± one standard deviation. c, When participants (n = 3) walked on a treadmill that varied speed sinusoidally between 0.75 m s−1 and 1.75 m s−1, Speed-adaptive assistance reduced the metabolic cost of walking more than the fixed Generic assistance.
