Capacitive sensor guard diagnostics from redundant coupling measurement

US11378420B2 · kind B2 · utility

Assignee

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

Inventors

• Frank ALTHAUS · Neuhaus, DE
• Thomas Faber · Schweich, DE
• Erik HOLZAPFEL · Prüm, DE
• Michael Putz · Trier, DE

Key dates

• Filing date: Nov 27, 2019
• Grant date: Jul 5, 2022
• Expiry date: Nov 27, 2039

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B60Q9/00
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

A method of operating a capacitive sensing device for diagnosing a galvanic connection of at least one guard electrode. The capacitive sensing device includes at least one sense-guard capacitive sensor and a capacitive measurement circuit. The sense-guard capacitive sensor includes a first electrically conductive sense electrode and a first electrically conductive guard electrode and at least a second electrically conductive sense electrode, which is galvanically separated from the first sense electrode, and at least a second electrically conductive guard electrode. Each of the guard electrodes is proximally arranged to at least one of the sense electrodes and is galvanically separated from each of the sense electrodes. The method uses a calculated difference of imaginary parts of complex sense currents resulting from coupling mode measurements between at least two of the sense electrodes for assessing a status of the galvanic connection of the guard electrodes.