Adaptive multi-objective control explains how humans make lateral maneuvers while walking
Fig 3
Constant Parameter Model Results.
A) Simulated stepping time series (mean ± SD) of 1000 lateral transitions using the original, constant parameter model with ρ = 0.90 (red) and ρ = 0.55 (blue). For steps in the interval [–3, 0], we set zB* as the experimental mean zB during steady state walking before the transition. For steps in the interval [1,7], we set zB* as the experimental mean zB during steady state walking after the transition. For all steps, w* was defined as the experimental mean w during steady state walking. B) Stepping errors (mean ± SD) at each step relative to the stepping goals, [zB*,w*], for the same data as in (A). For both (A) and (B), gray bands indicate the middle 90% range from experimental data. C) Means and standard deviations of both regulated variables (zB and w) during a steady state step (Step -3; left) and during the transition step (Step 1; right) for all values of 0 ≤ ρ ≤ 1. Gray bands indicate 95% confidence intervals from the experimental data computed using bootstrapping. Green bands indicate ±1 standard deviation from 1000 model simulations at each value of ρ. Model simulations over the approximate range of 0.83 ≤ ρ ≤ 0.92 fell within the experimental ranges for all variables for steady-state walking (Step -3; Left), as indicated by the region highlighted in yellow. However, no such range captured the experimental data during the transition step (Step 1; Right).