Meeting Abstract

72.4  Saturday, Jan. 5  Dynamic climbing of near-vertical surfaces with a legged robot BIRKMEYER, P. M.*; GILLIES, A. G.; FEARING, R. S.; Univ. of California, Berkeley; Univ. of California, Berkeley; Univ. of California, Berkeley paulb@eecs.berkeley.edu

Geckos are able to ascend challenging, smooth vertical surfaces with speed and robustness to perturbations that robot designs have yet to match. Studies of these animals reveal that they have fluid, efficient body dynamics during climbing as well as adhesives that are capable of providing very large adhesive forces relative to body mass. We have developed a 10 cm, 19 gram legged robot that we are using to study the effects of foot design, adhesion, and body dynamics on climbing ability on smooth, hard surfaces. The robot uses a microstructured rubber adhesive with shear-induced adhesion qualitatively comparable to that seen in geckos. A bio-inspired ankle and tendon system is used to promote conformation with a surface as well as engagement without generating peeling moments. Automated foot testing shows the feet are capable of normal adhesive loads of 0.37N with a shear load of 1N with only minor performance degradation when the feet are significantly misaligned with the climbing surface. Early climbing trials on a hard near-vertical surface show that the maximum velocity possible while climbing decreases as the incline increases. The robot demonstrated climbing speeds of 10 cm per second on 70-degree inclines and was limited to inclines of 75 degrees and below. A fundamental model describes the effect of incline on climbing speed. Other evidence also shows that this performance limit is due to body dynamics and adhesive limitations. New models and system modifications, and engagement methods are leading to improved climbing performance and robustness of the robotic platform.