Adaptive multi-objective control explains how humans make lateral maneuvers while walking
Fig 8
A) Model parameters. Here, in addition to adapting the stepping goals (Fig 6) and ρ (Fig 7), additive noise (σa) was also doubled at the preparatory and transition steps. B-E) Results obtained from 1000 simulated lateral transitions using the parameters in (A), with data plotted in an identical manner to Figs 6 and 7. Adding σa modulation again emulated experimental stepping time series and errors (B-C), as well as the qualitative changes in the aspect ratio of the fitted ellipses during the maneuver (D-E). Furthermore, modulating σa emulated the experimentally observed increases in ellipse areas. Modulating σa also affected orientations of the fitted ellipses, although not entirely in the same ways as the experimental data (D-E). Therefore, adaptively modulating the stepping goals ([zB*, w*]), control proportion (ρ), and additive noise (σa) in our existing model can elicit changes in stepping dynamics qualitatively similar to those observed in humans during this lateral maneuver.