Robust ‘hands on steering wheel’ classification based on a relative measurement system

US12015398B2 · kind B2 · utility

Assignee

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

Inventors

• Thomas Faber · Schweich, DE
• Frank ALTHAUS · Neuhaus, DE
• Thomas Meyers · Fremont, US
• Oliver Lion · Merzig, DE
• Laurent Lamesch · Reichlange, LU
• Michael Putz · Trier, DE
• Alan Koehler · Igel, DE

Key dates

• Filing date: Nov 24, 2021
• Grant date: Jun 18, 2024
• Expiry date: Nov 24, 2041

Classification

• Technology area (CPC H): Electricity
• CPC primary: H03K2217/96078
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

A method of operating a capacitive sensing device that includes a capacitive sensor having at least one sense electrode, a measurement signal source for providing an alternating electric measurement signal with at least three fixed predefined signal frequencies to the at least one sense electrode, and an impedance measurement circuit for determining an unknown complex impedance of the at least one sense electrode from a response to the provided electric measurement signal. The method includes, for each predefined signal frequency: determining statistical quantities and signal parameters regarding a number of determined momentary values of an unknown complex impedance; eliminating portions up to a predefined hand touch movement lower limit frequency and from a predefined high-frequency limit down to a predefined hand touch movement upper limit frequency; excluding statistical outliers from determined momentary values; and using an eliminated frequency portion for calculating a momentary reference value for the unknown complex impedance.