Iee International Electronics and Engineering S.a.

Ingrid Scheckenbach

Christoph Wendt

Stephen Fuks

Frank Althaus

Guenter Goedert

Claus-Christian Kedenburg

Edmund Marx

Thomas Krautheim

Oleg Zeiler

A vehicle seat occupancy detection system includes at least one capacitive sensor member having at least one sensing electrode, an impedance measurement circuit for determining a complex impedance or a complex admittance of the at least one sensing electrode, an evaluation unit for generating an output signal based on a determined complex admittance of the at least one sensing electrode and comparison of the determined complex admittance to at least one predetermined value, and at least one electrically conductive ground connecting member that is intentionally electrically connected to the reference electrode and that is arranged in close proximity to the at least one sensing electrode. The at least one ground connecting member and the at least one sensing electrode are galvanically separated such that, when the seat gets wet, the sensing electrode is directly electrically connected to the reference electrode by the at least one ground connecting member.

Capacitive seat occupancy detection system operable at wet conditions

An automotive vehicle has arranged therein a vehicle seat and is equipped with an occupant detection system for detecting whether an occupant is present on the vehicle seat, the system including a first antenna electrode arranged in the seat and a sensing circuit associated with the seat where the sensing circuit includes an oscillation circuit connected to the first antenna electrode for applying to the first antenna electrode a first oscillating signal and a current detection circuit also connected to the first antenna electrode for determining a first current flowing in the first antenna electrode in response to the first oscillating signal being applied, the first current indicating whether an occupant is present on the vehicle seat, where the vehicle is further equipped with an appliance including an appliance control device arranged in the vehicle compartment at a location where it can be operated by an occupant of the seat and the occupant detection system is configured for detecting whether the occupant attempts to interact with the appliance control device, in particular, the occupant detection system includes a second antenna electrode arranged together with the appliance control device, and an oscillator is operatively connected to the second antenna electrode for applying a second oscillating signal to the second antenna electrode and the current detection circuit is configured for determining a second current flowing in the first antenna electrode in response to the second oscillating signal being applied to the second antenna electrode where the second current thus indicates whether an occupant of the vehicle seat has a part of their body proximate to the appliance control device.

Automotive vehicle with occupant detection system

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&#xb0;-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, and outputs an output signal indicative of the occupancy state.

Capacitive occupant detection system

Growing community of inventors

Ferschweiler, Germany

Ingrid Scheckenbach