Simulation of Mechanical Systems With Multiple Frictional Contacts

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. Comments University of Pennsylvania Department of Computer and Information Science Technical Report No. MSCIS-92-16. This technical report is available at ScholarlyCommons: http://repository.upenn.edu/cis_reports/404 Simulation Of Mechanical Systems With Multiple Frictional Contacts MS-CIS-92-16 GRASP LAB 303 Y in-Tien Wang Vijay Kumar University of Pennsylvania School of Engineering and Applied Science Computer and Information Science Department Philadelphia, PA 19104-6389