Patent ID: 7236853

Claim:
A method for aligning a movable arm with a target, comprising the steps of: bringing a spherical portion of a probe on the movable arm in contact with a pin on the target, the probe contacting the pin at a first probe position; moving the probe to contact the pin at two additional probe positions; determining a location of the pin based on the location being a solution for an intersection of three spheres, each of the spheres being centered at a respective one of the probe positions and having a radius equal to a radius of the spherical portion of the probe plus a radius of a spherical portion of the pin; moving the probe to contact the pin at a further probe position when there is no solution for the intersection of the three spheres and returning to determining the location; and repeating the steps of bringing, storing, moving and determining for at least two additional pins on the target when the solution is determined.