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 crutches part and the leg part are linked by a hip joint. Two walking robots that the knee joint or the hip joint is permitted free rotation are designed. The lower leg is equipped with a solenoid magnet which fixes the knee joint straight. The hip joint shaft and a DC-servomotor are connected by an electromagnetic clutch. The robot behavior is passive while the robot is supported by its crutches. Referenced swing trajectory is generated by a planar four-link model simulation. The walking pattern applies to the actual two crutches-type walking robots on level ground.
