Calculation of the instantaneous centre of rotation for a rigid body.

The mathematical procedure presented is used for the calculation of the instantaneous centre of rotation for a rigid body based on kinematic measurement data. For every rotation angle interval observed an average centre of rotation is calculated by an appropriate optimizing calculation similar to data approximation by moving average. Practical applicability of this procedure has been proved by means of two planar and one three-dimensional test measurements of known movements (pure rotation, rolling motion and motion of a ball-and-socket joint.