Development of a quadrant photodiode plate for machine tool positioning performance testing

A position test is frequently implemented during a precision machine test for a machine tool and a coordinate measurement machine (CMM). Since implementing a complete test using traditional methods takes a great deal of time and some reference parts, this paper describes the development of a novel quadrant photodiode (QPD) plate, which does not need highly accurate reference parts, and is also faster and cheaper than traditional systems. It consists of 16 QPDs, 16 signal processors for the QPDs, one laser diode, one analogue-to-digital converter, and one personal computer. In this paper, in order to reduce the noise of the QPDs, each QPD has individual signal processors. Calibration, stability test, and machine tool repeatability test have been performed. The accuracy of the QPD plate has reached ±0.5μm. ? Authors 2010.