BODY VIBRATION OF A LEGGED WALKING MACHINE

Unlike wheeled vehicles, compliance in walking machine systems changes due to the variation of leg geometry, as its body proceeds. This vari ation in compliance will cause vibration, even if external loads remai n constant. A theory is thus developed to predict the body vibrations of a walking machine during walking. On the other hand, dynamic foot f orces under body vibrations can be computed by application of the exis ting numerical methods. As an example, the body vibrations of a quadru pedal walking chair under different walking conditions are simulated i n terms of the developed theory. The results show that the influence o f body vibrations on the foot force distribution is essential and, in some cases, the walking chair may lose its stability due to its body v ibrations, even though it is identified to be stable in a quasistatic analysis. The developed theory can also be extended to other similar m ultilimbed robotic systems, such as multifingered robot hands.