Abstract
We consider that the stability of biped walking motion depends on the contact forces interacting on the foot in order to walk well. In this point of view, this report suggests a method based on the contact forces for design of joint trajectories of biped walking robot. The relation between the contact forces obtained using Newton-Euler method and joint motions are derived. After that, the joint trajectories are decided by substituting the contact forces based on the ZMP criterion as design parameters into the relation. The most important point of this method is that the derived equations between the contact forces and the joint motions are able to be applied to the both cases of one leg supporting phase and two legs supporting phase by changing the restraining condition to the swinging leg.
