Centipede locomotion in varying terrains

Animals which move via waves of body undulation and/or few numbers of limbs have been extensively studied.Limited progress has been made studying animals with many degrees of freedom in their bodies in coordination with numerous limbs (i.e. myriapods like centipedes). To discover principles by which body undulation and limb dynamics in concert with body mechanics leads to high performance in diverse environments,we challenged Scolopocryptops sexspinosous (body length of ~4.5 cm, 23 pairs of legs) to traverse both a flat terrain and a Gaussian distributed rough terrain (12 x 12 cm with variable height of blocks). On flat terrain, centipedes maintain a constant out of phase traveling wave along their limbs during locomotion. In contrast, on rough terrain, centipedes will symmetrically use their limbs when their various segments are at different heights. We hypothesize that the centipedes will modulate the use of their limbs in order to overcome heterogeneities. Insight from a robophysical model suggests centipede limbs integrate passive dynamics allowing the locomotorto traverse myriad environments.