An Examination of the Effects of Deformable Foam Contact Surfaces on Robotic Locomotion

Abstract

The ability of foam to reduce the impact of terrain irregularities on robotic locomotion was studied. A test bed was developed to conduct static experiments to attempt to measure and quantify how statically positioned foam feet reacted to changing terrain profiles. The average height of the terrain profile was varied linearly by moving a ledge under the foot, which, according to our hypothesis, should have resulted in a linear variation of the height of the foot. These experiments were repeated for two different ledge heights (3 mm and 12.8 mm), two different foot sizes (2 cm and 3 cm cubes), and five different foot stiffnesses. Foot behavior approached full linearity as stiffness increased for both foot sizes on the 3 mm ledge, but did not approach full linearity for either foot size on the 12.8 mm ledge. Although foam feet have desirable properties, their behavior was not consistent enough to create a predictive model for their behavior for a given stiffness, size, and ledge height. Some insight into a manner for obtaining design curves was obtained, however, and other avenues of research appear promising.