Method and apparatus for synchronous demodulation of multiply modulated signals

US6714025B2 · kind B2 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Jens Mohaupt · Neckartenzlingen, DE
• Wolfram Bauer · Lörrach, DE

Key dates

• Filing date: Feb 19, 2002
• Grant date: Mar 30, 2004
• Expiry date: May 11, 2022

Classification

• Technology area (CPC G): Physics
• CPC primary: G01C19/56
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method and an apparatus for synchronous demodulation of the multiply modulated rotation rate signal of a rotation rate sensor which comprises a spring-mass system that oscillates at its natural resonant frequency, and at least one capacitor for ascertaining a Coriolis effect acting on the spring-mass system or a rotation rate, the rotation rate being ascertained by a time-variable capacitance change, brought about by the rotation rate, of the at least one capacitor by multiple demodulation of a multiply modulated electrical signal that comprises a time-variable first electrical signal and a second electrical signal, overlaid thereon, at the natural resonant frequency of the rotation rate sensor, the amplitude of the second electrical signal of the time-variable capacitance change of the at least one capacitor being correspondingly modulated. To substantially reduce the outlay for synchronous demodulation, the first electrical signal is generated so that it exhibits a time-invariant phase relationship to the natural resonant frequency of the rotation rate sensor.