Evaluation method for an inductive displacement sensor

US6604057B1 · kind B1 · utility

Assignee

• Wabco GmbH & Co. Ohg. · DE

Inventors

• Gerd Eden · Norden, DE
• Jürgen Früh · Hannover, DE
• Norbert Lissel · Barsinghausen, DE
• Eike Lustfeld · Stolzenau, DE
• Andreas Schäl · Nordstemmen, DE

Key dates

• Filing date: Apr 14, 2000
• Grant date: Aug 5, 2003
• Expiry date: Apr 14, 2020

Classification

• Technology area (CPC G): Physics
• CPC primary: G01D5/2013
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An evaluation method for an inductive displacement sensor first temperature-compensates a measured sensor value, and then calibrates same. The temperature compensation is carried out iteratively, utilizing two temperature dependent functions. The first function is based on the temprature-dependency of the measured sensor value, and the second function is based on the dependency of the temperature coefficient of the sensor model used. For a clutch sensor application, a calibration line is defined by two calibration points, which represent a completely engaged state and a just disengaged state, respectively. Continuous measurement of the displacement of an engaged clutch indicates the wear status of the clutch, so that a warning can be transmitted to the driver when the clutch lining has reached a predetermined thickness.