Fig. 5.

Parameter dependency of the performance of the hexapod robot. Shown are the mean and SD of the traveled distance in 1 min for different parameters. (A–D) Exhaustive parameter scan. For each panel, all other parameters are varied in their gray shaded regions indicated in A–E. (E–G) Single scans for standard parameters (see black lines in A–E and G) with 10 initialization conditions each (random seed for noise and robot’s initial height). (A) Activity parameter (Methods). (B) Time scale for learning dynamics, Eq. 3 in s. Note logarithmic scale. (C) Time delay of delayed sensor values in $1/50$ s. (D) Time lag between y and $x\prime$ in $1/50$ s. (E) Strength v of additive colored sensor noise [Ornstein–Uhlenbeck with $\theta =0.1v,\sigma =\sqrt{0.1}v,\mu =0$ (10 time steps correlation length), and $\sigma =\frac{1}{2}v$]. (F) Strength v of additive white noise uniformly distributed in $\left[-v,v\right]$. (G) Inverse time scale (in 1/s) of threshold learning dynamics (0 means disabled).