Delphi Technologies, Inc.

Delco Electronics Corporation

Aptiv Technologies Limited

Robert K Constable

Duane Donald Fortune

Morgan Daniel Murphy

Kevin D Kincaid

Stuart Stites Sullivan

William W Fultz

Dennis P Griffin

James Frank Patterson

Charles A Gray

Robert Allan Perisho, Jr

Pamela Ann Roe

Robert Joseph Myers

Gregory Allen Cobb

Terrell Anderson

Richard Joseph Ravas

Thomas L Voreis

William Lloyd Piper

Randall C Gray

Ronald Melvin Taylor

Gregory J Manlove

Paul T Bennett

Peter James Schubert

Charles A Cluff

Hamid Reza Borzabadi

Michael R Meier

Ashraf Kamal Kamel

Richard P Sickon

Shailendra Verma

Mark Robert Vincen

Aparna Vaidyanthan

George J Noland

Brian M Stavroff

Karl Edward Stone

Robert R McConnell

Joseph W Galles

John G West

Douglas R Champion

A dual-electrode occupant detection system configured to determine an occupant presence on a seat assembly. The system includes two electrodes that each generates an electric field in response to an applied excitation signal. The two electrode signals arising therefrom can be measured individually and/or combined to detect more reliably an occupant. Such a configuration advantageously avoids the added expense and complication of an electrode arrangement that relies on an underlying shield layer to reduce electrode signal degradation caused by a seat heater element.

Dual electrode occupant detection system and method

An occupant detection system with noise reduction, a controller having noise reduction for an occupant detection system and a method for reducing noise in an occupant detection system. A high order digital filter is used to filter harmonics of a noise signal from an electrode signal used to determine an occupant presence or absence of the occupant. A way of sampling the electrode signal and the implementation of the high order digital filter cooperate such that the signal processing can be performed by a lower cost general purpose microprocessor as opposed to using a higher cost digital signal processor.

Noise reduction for occupant detection system and method

A seat assembly including a seat cushion, a heating element, a heating circuit, a occupant sensing circuit, and an isolation circuit. The seat cushion has a seating surface, the heating element is adjacent the seating surface and is formed of electrically conductive material. The heating circuit is coupled to the heating element for supplying electrical current to the heating element for generating heat. The occupant sensing circuit is also coupled to the heating element for sensing the presence of an occupant near the heating element. The isolation circuit is interposed between the heating circuit and the heating element for isolating the heating circuit from the occupant sensing circuit.

Seat assembly having seat heating and occupant detection

A vehicle crash sensing system and method are provided for sensing a vehicle crash event. The system includes a linear acceleration sensor located on a vehicle for sensing linear acceleration along a first sensing axis and generating a linear acceleration signal. The system has linear crash sensing logic for determining a crash event along the first sensing axis as a function of the sensed linear acceleration. The system also has signal processing circuitry for processing the linear acceleration signal and generating a processed linear acceleration signal. The system has an angular rate sensor located on the vehicle for sensing an angular roll rate of the vehicle about a second sensing axis and generating a roll rate signal. The system further includes rollover crash sensing logic for determining a rollover event of the vehicle about the second sensing axis as a function of the processed linear acceleration signal and the roll rate signal.

Integrated vehicle crash sensing system and method

Image processing parameters of an imaging chip in a vision-based occupant sensing system are adjusted for each frame based on ambient illumination responsive information obtained in the idle period preceding that frame. The same sensing data is also used to determine if active illumination is needed to supplement existent ambient illumination during the ensuing image acquisition interval. The inter-frame ambient illumination is detected with an external light sensor or with selected pixels of the imaging chip, and the information is used to calculate and set the gain and integration time of the imaging chip. In applications where the resolution of the imaging chip significantly exceeds the resolution required for occupant sensing, intensity data from one or more otherwise inactive pixels is averaged with the intensity data from the normally active pixels to adapt the sensitivity of the imaging chip to changing ambient illumination.

Method of operation for a vision-based occupant sensing system

The capacitance of a shielded capacitive load cell is determined so as to minimize the effect of stray or parasitic capacitance between the load cell and other objects including the shield. The load cell conductors are coupled across input and output terminals of an operational amplifier that is tied to a reference voltage. A constant current is applied to the load cell, and the resulting rate of change in voltage at the amplifier output is measured as a representation of the load cell capacitance. In a vehicle seat sensor application including an electromagnetic interference shield between the load cell and the seating surface, the amplifier output is coupled to the load cell electrode furthest from the shield, the amplifier maintains the other load cell electrode at a virtual reference voltage, and the shield is tied to the reference voltage.

Shielded capacitive load cell apparatus responsive to weight applied to a vehicle seat

A vehicle seat occupant classification system uses a pressure responsive, fluid filled bladder and pressure sensor adapted for engagement with an underside of a foam seat cushion so as to generate a pressure signal corresponding to the weight of an occupant on an upper side of the foam seat cushion. A humidity sensor responds to relative humidity of air adjacent the pressure sensor and/or foam seat cushion to generate a humidity signal that is used to compensate at least one of the pressure signal, a stored reference pressure value and a stored threshold value, from which at least in part; an occupant classification is determined. The system preferably includes a time delay between the reading of a humidity value and the full use of that humidity value in compensation; and the time delay may be responsive to an activity factor derived from dynamic variations in the pressure signal associated with a pumping action on the foam tending to increase the rate of exchange of air between the foam and the atmosphere outside the foam. Preferably, the temperature adjacent the pressure sensor and/or foam seat cushion is also determined and used in conjunction with the humidity signal to provide au additional cross-correlation compensation.

Seat foam humidity compensation for vehicle seat occupant weight detection system

An improved vehicle restraint system includes a seat belt tension sensor and an occupant detection control module for characterizing the occupant of a vehicle seat to determine whether to allow or suppress deployment of supplemental inflatable restraints for the occupant. The belt tension sensor includes on-board signal processing circuitry and is coupled to occupant detection control module via a two wire interface that both powers the sensor and its signal processing circuitry and supports communication of belt tension data to the occupant detection control module. The sensor produces an electrical signal responsive to seat belt tension, and the processing circuitry generates one of a specified number of messages pertaining to the range of the measured tension, and then modulates the current through the two wire interface to communicate the generated message to the occupant detection control module.

Restraint system interface arrangement for a seat belt tension sensor

A weight estimation apparatus for the passenger seat of a motor vehicle, in which a single bladder substantially encompassing the seat bottom is evacuated and then inflated with a known volume of air. The average pressure in the bladder is determined to estimate the passenger weight. According to a first embodiment, the apparatus continues to monitor the average pressure, and the process is re-initiated if the average pressure changes by at least a predetermined percentage. According to a second embodiment, a bleed valve allows the pressure in the bladder to slowly escape, and the apparatus monitors the rate of change in pressure as a corresponding indication of passenger weight; in this embodiment, the process of evacuating and inflating is re-initiated if the monitored change in pressure does not correspond with the estimated weight. The sides of the bladder may be pleated to permit the bladder to expand under the weight of an occupant without stretching the bladder, and thereby affecting the average pressure. A temperature sensor may be disposed in proximity to the bladder provides a temperature signal for compensating the weight estimation for temperature variations. Also, the pressure sensor may be configured to sense the gage pressure--that is, the differential pressure between the bladder pressure and atmospheric pressure; alternatively, the pressure sensor may be configured to detect absolute pressure, and a second absolute pressure sensor responsive to atmospheric pressure may be used to compensate for changes in atmospheric pressure.

Vehicle occupant weight estimation apparatus having controlled volume

An improved weight estimation apparatus includes a closed elastomeric bladder filled with fluid and installed in the foam cushion of a vehicle seat bottom, with at least one pressure sensor installed in a closed exit port of the bladder. A temperature sensor disposed in proximity to the bladder provides a temperature signal, and a controller estimates the weight of the occupant based on the temperature and pressure signals. The pressure sensor is preferably configured to sense the gage pressure--that is, the differential pressure between the fluid and atmospheric pressure--at the center of gravity of the fluid in order to provide a stable output independent of changing atmospheric pressure and changing orientation of the bladder due to vehicle pitch and roll.

Vehicle occupant weight estimation apparatus having fluid-filled seat

A strain gauge has a stainless steel substrate with a dielectric coating comprising two dielectric layers. A circuit comprising conductors, resistors and piezoresistors in a Wheatstone bridge configuration is formed on the dielectric. One dielectric layer is to adhere to the steel and a second is to form a barrier against diffusion of the first layer into the piezoresistor material. An amplification and signal conditioning circuit is applied adjacent the bridge. The steel substrate is to be welded or bolted at its marginal portions to a structure subject to strain.

Strain gauge with steel substrate

The firing circuit of an inflatable restraint system is tested to verify operation of two FETs in series with a squib which are used to apply current to the squib. For the test the squib is biased to an intermediate voltage and each FET is turned on alone to apply battery or ground voltage to the squib. High and low voltage detectors sense the voltage excursion past respective thresholds to verify FET operation. A current detector for each FET senses a short when its FET is conducting, and a logic circuit immediately turns off the FET to result in a very brief FET on time. In addition, the voltage detectors may be used to detect shorts prior to FET testing and also to turn off or hold off the FETs when a high or low voltage is detected upon FET testing.

Fast acting FET test circuit with current detection for SIR diagnostics

The firing circuit of an inflatable restraint system is tested to verify operation of two FETs in series with a squib which are used to apply current to the squib. For the test the squib is biased to an intermediate voltage and each FET is turned on alone to apply battery or ground voltage to the squib. High and low voltage detectors sense the voltage excursion past respective thresholds to verify FET operation, and a logic circuit immediately turns off the FET to result in a very short FET on time. If a short is present before the FET is commanded on, a detector and the logic circuit prevents FET conduction to avoid firing or degrading the squib.

Fast acting FET test circuit for SIR diagnostics

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Kokomo, IN, United States of America

Robert K Constable