The Behavior of a Biped Walking Gait on Irregular Terrain

Abstract

Biped locomotion on nonlinear ground surfaces was studied using computer simulations of two- and three-dimensional bipeds with hip and knee joints. The dynamic models included all of the nonlinear terms in the equations of motion. The three-dimensional motion consisted of body torsion about the biped vertical axis. A walking gait was defined with a combination of linear and quadratic con straint equations that defined the biped joint motion. The gait was a dynamic walking gait that did not depend on a predefined location for the foot to land. Four gait variations were studied on the differ ent ground surfaces. The ground surfaces were rigid and included sinusoidal, randomized, and chaotic terrain. It was found that the gait had the potential to be used as a basic gait for locomotion over a wide variety of surfaces. There were certain gait features, such as the phasing of the knee constraint and the body torsional mo tion, that could be used to enhance the biped system's stability and efficiency. The importance of correctly defining the ground surface was clearly seen by the biped behavior on the different surfaces.