Capacitive occupant detection system

US7656169B2 · kind B2 · utility

Assignee

• IEE INTERNATIONAL ELECTRONICS & ENGINEERING S.A. · LU

Inventors

• Ingrid Scheckenbach · Ferschweiler, DE
• Stephen Fuks · Ann Arbor, US
• Frank ALTHAUS · Neuhaus, DE
• Thomas Krautheim · Belleville, US
• Christoph Wendt · Mettendorf, DE

Key dates

• Filing date: Feb 6, 2007
• Grant date: Feb 2, 2010
• Expiry date: Feb 17, 2028

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B60N2230/30
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

A capacitive occupant detection system has an oscillator and an electrode operatively coupled to the oscillator, to which the oscillator applies an oscillating voltage signal. In response to the oscillating voltage being applied, an electric current is caused to flow in the electrode, the current being responsive to an electric-field-influencing property of an object or occupant proximate to the electrode. The current caused to flow in the electrode has a first current component in phase with the oscillating voltage signal and a second current component 90°-phase-offset with respect to the oscillating voltage signal. A sensing circuit is operatively coupled to the electrode and to the oscillator so as to generate a first signal indicative of the first current component and a second signal indicative of the second current component. The first signal indicative of the first current component and the second signal indicative of the second current component are provided to a processor, which is operatively coupled to the sensing circuit and which determines an occupancy state based upon the first and second signals indicative of the first and second current components, respectively, an…