Device and method for coordinate measurement

US7367133B2 · kind B2 · utility

Assignee

• DR. JOHANNES HEIDENHAIN GMBH · DE

Inventors

• Rainer Hagl · Cham, DE
• Herbert Reiter · Los Altos, US
• Erich Strasser · Trostberg, DE

Key dates

• Filing date: Apr 15, 2005
• Grant date: May 6, 2008
• Expiry date: Apr 15, 2025

Classification

• Technology area (CPC G): Physics
• CPC primary: G01B21/045
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

In a device and a method for coordinate measurement, a probe head generates a switching signal in response to contact with a workpiece. The device includes position-measuring units for each coordinate axis to be measured, with the aid of which the relative position of the probe head is measurable; and a processing unit, which operates in a discrete-time manner in time intervals of a controller clock signal. For coordinate measurement, position-measuring values are measured in time intervals of a probing clock signal, which is generated by a probing clock generator and has a higher frequency than a controller clock signal of a processing unit. The position-measuring values are stored in a position-data memory. A time span between a pulse of the controller clock signal and the occurrence of the switching signal at the switching probe head is measured in a time-measuring unit. With the aid of the measured time span, the position value in the position-data memory closest to the time of the switching signal is ascertained in the processing unit or in the position-measuring units.