Patent ID: 7684898

Claim:
A method for calibrating a tool center point (TCP) of tools for industrial robots comprising a calibration apparatus that has at least two light barriers which are angled to one another with a vertex angle (α) greater than zero in each case and cross one another at a crossing point (R), exhibiting the steps of: a) fixing DESIRED TCP positional coordinates of a DESIRED tool center point (TCP DESIRED ) of the tool with reference to a tool reference point (W) of an industrial robot, and to a TCP coordinate system referred to the tool center point (TCP), b) moving the tool directly to the DESIRED tool center point with reference to the TCP coordinate system through the light barriers without searching the crossing point (R) such that the tip of the tool corresponding to the tool center point (TCP) interrupts the light barriers successively, and deviation of the tool center point is determined from the temporally offset interruption of the individual light barriers, c) recording ACTUAL TCP positional coordinates upon the interruption of a respective light barrier, d) determining the differences between the DESIRED TCP positional coordinates for the interruption of the light barriers at a DESIRED tool center point (TCP DESIRED ) and the corresponding recorded ACTUAL TCP positional coordinates for the ACTUAL tool center point (TCP ACTUAL ), and e) calculating the deviation of the ACTUAL tool center point (TCP ACTUAL ) from the DESIRED tool center point (TCP DESIRED ) for the number of planes that is prescribed by the light barriers from the differences and the known position and vertex angles (a) for the light barriers.