Relevant friction effects on walking machines

Abstract

Dynamic modelling is an important issue in legged locomotion. However, friction has been neglected in most studied models. The aim of this work is the experimental determination of frictional effects over leg dynamics. For this purpose, previous work on friction modelling in robot manipulators (1), (3), has been followed and similar results have been achieved. However, a new friction component has been experimentally identified, which is the meshing friction in gear teeth. The meshing friction is responsible of friction torque oscillations whose amplitude has been found to be up to 12 percent of the average friction torque at low speeds. This friction component should be taken into account if an accurate friction model is desired.