Abstract: A robot calibration system for calibration of a workpiece handling robot relative to a station. The workpiece handling robot includes a sensor mounted on an end effector. The robot calibration system also includes a target, which in coordination with the sensor, allows a control system to determine a center of the target. The target is a wafer in the shape of a disk. A pattern is on at least one side of the workpiece, preferably on a bottom side of the target. The pattern comprises alternating black and white areas. The workpiece handling robot is placed in front of the station which includes a cassette mounted thereon. The cassette has a support surface which supports the target. Once the z-height of the end effector is established with the end effector being in close proximity to a lowermost support surface of the cassette, the end effector proceeds to move in a search pattern searching the pattern for transition points from black to white areas.

Abstract: A robot calibration system for calibration of a workpiece handling robot relative to a station. The workpiece handling robot includes a sensor mounted on an end effector. The robot calibration system also includes a target, which in coordination with the sensor, allows a control system to determine a center of the target. The target is a wafer in the shape of a disk. A pattern is on at least one side of the workpiece, preferably on a bottom side of the target. The pattern comprises alternating black and white areas. The workpiece handling robot is placed in front of the station which includes a cassette mounted thereon. The cassette has a support surface which supports the target. Once the z-height of the end effector is established with the end effector being in close proximity to a lowermost support surface of the cassette, the end effector proceeds to move in a search pattern searching the pattern for transition points from black to white areas.