Summary: RAPID NEGOTIATION OF ROUGH TERRAIN BY
THE DEATH-HEAD COCKROACH.
R.J. Full*, K. Autumn and J. Chung. Univ. of California,
2D and 3D dynamic models of running hexapods suggest the
possibility of self-stabilizing mechanisms in many-legged,
sprawled posture animals. Previous studies of insects and
robots negotiating rough terrain have shown that legged
mobility systems use a follow-the-leader gait, precise foot
placement and extensive tactile feedback when moving slowly.
To test these models and hypotheses in rapid runners, we
constructed rough terrain approximating a fractal surface. The
terrain consisted of 1cm posts of random height with a
variance of 0.5cm, the height of the animal's center of mass.
Extremes of height and depth reached 3 times the height of the
animal's center of mass. We video taped cockroaches (Blaberus
discoidalis) running over the terrain using three high-speed
cameras operating at 500 fields/s. Cockroaches ran over the
rough terrain rapidly and explosively. 3D kinematic analysis
showed variation in pitch, yaw and roll nearly 10-fold greater