Distinguishability and identifiability of contact states

An important component of machine perception is the estimation of contact states during task execution. This paper addresses two fundamental questions that must be answered when formulating mathematical descriptions of the contact states: Are two contact states distinguishable from each other? Can the unknown or imprecisely known parameters in these descriptions be identified? A technique is presented to answer these questions, which is based on a Taylor series expansion of the contact state´s constraint equations. The approach is illustrated through several examples.