Evaluation of kinematic coupling stability via centroid tracking of a lighted pinhole

Kinematic couplings are simple devices that provide rigid, repeatable connections between objects. The stability of these couplings cannot be measured using interferometry due to the repeated separation and engagement nature of the components. In this work, a measurement technique that is based on centroid tracking of a lighted pinhole is described. It is essentially based on a miniature target attached on an object surface that is recorded and tracked using a microscope. The technique has the advantage of being invariant to object rotation. An analysis of the performance limits as well as a simple experimental demonstration of the technique is presented.