Dynamics of Rigid Bodies Undergoing Multiple Frictional Contacts

Yin-Tien Wang, University of Pennsylvania
R. Vijay Kumar, University of Pennsylvania
Jacob Abel, University of Pennsylvania

Article comments

University of Pennsylvania Department of Computer and Information Science Technical Report No. MS-CIS-91-70.

Abstract

There are several applications in robotics and manufacturing in which nominally rigid objects are subject to multiple frictional contacts with other objects. In most previous work, rigid body models have been used to analyze such systems. There are two fundamental problems with such an approach. Firstly, the use of frictional laws, such as Coulomb's law, introduce inconsistencies and ambiguities when used in conjunction with the principles of rigid body dynamics. Secondly, hypotheses traditionally used to model frictional impacts can lead to solutions which violate principles of energy conservation. In this paper these problems are explained with the help of examples. A new approach to the simulation of mechanical systems with multiple, frictional constraints is proposed which is free of inconsistencies.