A proximity detection system for detecting motion and proximity of an occupant seated in a vehicle. The system includes a sensing electrode located proximate to the occupant and configured to transmit a signal representative of a current in the sensing electrode. The system includes a receiver including a controller and coupled to an antenna. The receiver is configured to detect a change in the transmitted signal received by the antenna based on the proximity of the occupant. The receiver is configured to determine the presence of the occupant based on the amplitude of the signal received by the antenna and the rate change of the amplitude of the signal received by the antenna. The receiver is configured to generate a control signal to change a state of a vehicle component when at least one of the amplitude and the rate of change of the amplitude exceed a predetermined threshold.

An impedance measurement circuit for determining a sense current of a guard-sense capacitive sensor operated in loading mode. The circuit includes a periodic signal voltage source for providing a periodic measurement voltage, a sense current measurement circuit, a differential amplifier that is configured to sense a complex voltage difference between the sense electrode and the guard electrode, a demodulator for obtaining, with reference to the periodic measurement voltage, an in-phase component and a quadrature component of the sensed complex voltage difference, and control loops for receiving the in-phase component and the quadrature component, respectively. An output signal of the first control loop and an output signal of the second control loop are usable to form a complex voltage that serves as a complex reference voltage for the sense current measurement circuit.

A capacitance measurement circuit for determining a sense current of a capacitive sensor with a sense electrode and a guard electrode. The measurement circuit includes a periodic signal voltage source, a sense current measurement circuit configured for determining the sense current with reference to a reference voltage, and at least one remotely controllable switch member. In a first switching state, the at least one switch member electrically connects the sense current measurement circuit to the periodic signal voltage source for providing a first reference voltage, and in a second switching state, the at least one switch member electrically connects the sense current measurement circuit to a second reference voltage that is different from the first reference voltage.

A switch assembly for a vehicle seat belt buckle comprising a switch housing defining an interior and a pocket, a cable extending into the interior and including hook-shaped ends extending around posts in the interior of the switch housing. In one embodiment, the interior of the switch housing includes first and second posts positioned in a co-linear and spaced apart relationship and the hook-shaped ends face each other and extend around the first posts and abut against the second posts. In one embodiment, the Hall Effect sensor is positioned in the pocket of the switch housing in an inclined relationship.

A sensor system is operable to: communicate a first ID signal at a first frequency between a first perimeter sensor and a first sensor circuit through a body of a first user in a first vehicle chair, determine interaction with an interactable element corresponding to the first sensor circuit based on sensed signal data from a first sensor circuit indicating changes in electrical properties of an electrode of the first sensor circuit; determine the interaction is via the first user in the first vehicle chair when the sensed signal data indicates detection of the first frequency; and when the sensed signal data indicates detection of the first frequency, perform a first vehicle functionality of a set of vehicle functionalities based on configuration data corresponding to the first user.

A system includes multiple capacitive sensors, a multiplexer, a programmable gain amplifier, an oscillator, a switch, and a controller. The sensors are coupled to the multiplexer, the multiplexer is coupled to the switch, and the switch is coupled to the amplifier and the oscillator. The controller may control the multiplexer to select each of the sensors. The controller may control the switch to activate the amplifier or the oscillator. The controller may measure voltage output by the amplifier or frequency output by the oscillator. The system may be included in an occupant support such as a vehicle seat.

The invention relates to a system for seat occupancy detection, comprising a vehicle seat for a driver with an upper part and at least one suspension-damper system, an acceleration sensor being arranged on the upper part which is designed to determine a characteristic of an acceleration of the upper part as a function of time, an evaluation unit being provided which is designed to create an evaluation of the characteristic of the acceleration and optionally to send a signal to a higher-level control unit, the evaluation unit also being designed to assign the evaluation to a value of a mass of an object with which the vehicle seat is currently occupied.

A system for detecting the presence of an occupant of a seat. The system includes a sensing mat that includes an upper conducting layer and a lower conducting layer. At least one of the conducting layers comprises a printed electronic circuit separated into conductive zones by at least one resistive zone. The mat also includes a plurality of sensing zones and each of the sensing zones include a conductive zone from the upper conducting layer and a conductive zone from the lower conducting layer. Each of the conducting layers are connected to a controller configured to detect a change in capacitance of each of the sensing zones resulting from a change in distance between the upper conducting layer and the lower conducting layer. The controller is connected to a vehicle network and is configured to provide data to the network that indicates the absence or presence of the occupant.

A capacitive seat occupancy detection and classification system with a capacitive sensor having at least two distinct antenna electrodes and a method of operating is proposed to reduce an impact of the sensor-to-object impedance Z.sub.SO on an object-to-ground impedance Z.sub.OG measurement that the system performs. By measuring the impedance between the different antenna electrodes by the system, additional information is obtainable that can be used to compensate the impact of the sensor-to-object impedance Z.sub.SO on the object-to-ground impedance. As one effect of combining both impedance measurement results, the proposed system is able to determine the object-to-ground impedance Z.sub.OG completely independent from wear of ISOFIX anchorages or human objects touching the electric ground of the vehicle, thus ensuring a stable classification of the object over the entire vehicle lifetime. The method further enables high-resolution seat occupancy classification.

A vehicle system equipped with an apparatus for detecting a vehicle buckle may include: a buckle switch device which is turned on or off depending on whether a vehicle seat belt buckle is fastened; and a buckle detection apparatus that determines whether the vehicle seat belt buckle is fastened based on an on or off operation of the buckle switch device and diagnoses a failure of the buckle detection apparatus.