Abstract: The passive dynamic walker is different from the active controlled robot, which walks down a slope only with gravity and forms the steady periodic gait. The passive walking features low energy consumption and natural gait. Because of the limitation of the theoretical calculation and experiment, a 3-D model of passive dynamic walker with straight legs and arc feet is built by using ADAMS in order to observe the passive walking gait and research contact process while walking. By adjusting the parameters of the model, contact parameters and initial condition, the periodic steady walking is achieved, which is described with limited cycles. With the IMPACT contact model in ADAMS, the information of reaction force and contact track are gotten. By changing the contact stiffness and damping coefficient, the phenomenon of bouncing and a periodic bouncing gait is observed. By changing the friction coefficient, the phenomenon of slipping is observed. Then the effect of contact parameters on the passive walking gait is analyzed by researching the above-mentioned phenomena.

Key words: Contact Bouncing, Gait, Passive walker, Slipping