Patent ID: 7302355

Claim:
A method of calibrating an object using a computer tracking system, the object having a planar portion and a circular portion at least partially opposite said planar portion, the circular portion having a diameter, the method comprising the steps of: providing a calibration device having a tracking member thereon which is located and tracked in three dimensional space by the computer tracking system; determining a position and orientation of at least two object contacting portions of the calibration device using the computer tracking system; abutting said object contacting portions against said circumferential edge of said circular portion; while abutting a planar reference surface of the calibration device against said planar portion of the object; determining spatial coordinates of at least two points on a circumferential edge of said circular portion of the object which are in contact with said object contacting portions; calculating the center point of said circular portion using said spatial coordinates of said at least two points and a geometric parameter representative of the diameter of said circular portion; and using the calculated center point to calibrate the object using the computer tracking system.