Abstract
We select a three-legged robot to study passive walk. The robot consists of one leg (a knee joint and an ankle joint) and one pair of crutches. The crutch tips are passive joint. Therefore the robot behavior is passive while the robot is supported by its crutches. The angular velocity at the beginning of the crutches support phase decides a crutch tip trajectory throughout that phase. This research deals with a planar four-link model to simulate joint angle trajectories for crutches support phase and to generate a proper swing leg pattern. The walking pattern applies to the actual crutches-type walking robot on level ground.
