Paper abstract

 Title:  A Configuration Space Analysis of Bodies in Contact--Part II: 
	2^st Order Mobility 
 Authors:  E. Rimon and J. Burdick
 In :  Mechanism and Machine Theory, vol. 30, no. 6, 1995.

ABSTRACT

Using a configuration space approach, this paper develops a 2^nd order mobility theory for a body, B, in frictionless quasi-static contact with rigid stationary bodies A_1,...,A_d. This analysis ultimately leads to a coordinate invariant 2^nd order mobility index, an integer that captures the inherent mobility of B in an equilibrium grasp. The 2^nd order index differentiates between grasps which are deemed equivalent by 1^st order, or instantaneous, theories, but are physically different. We further show that 2^nd order effects can be used to lower the effective mobility of an equilibrium grasp, and hence can be used to prove new lower bounds on the number of contacting bodies needed to immobilize an object.