A Generalized Model for Compliant Passive Bipedal Walking: Sensitivity Analysis and Implications on Bionic Leg Design

The passive behavior of a compliant biped walking model, subject to variations in its design, is investigated. A biped gait model is developed that allows for studying the effects of leg impedance, geometry, foot curvature, and inertial properties on the stable gait performed passively. A set of nondimensional parameters has been produced that fully defines the compass gait behavior, eliminating the dependence of our results on scale. Models emerging from parameter combinations were tested on their ability to perform stable passive walking on slope, and the characteristics of the gait performed in each case were recorded. Investigation of parameter ranges allowed us to draw relationships between various gait characteristics and specific, nondimensional parameter selections. By mapping the changes in system behavior under simple design variations, this work facilitates the selection of design parameters at an early stage of designing bionic walking equipment, including prostheses and exoskeletons.