Siemens Vdo Automotive Corporation

Continental Automotive Systems Us, Inc.

Seimens Vdo Automotive Corporation

Harald Lichtinger

Brian Michael Curtis

Robert Graf

Daniel Reich

Ralf Oestreicher

Josef Dirmeyer

Maria Kremer

Scott Morrell

Jeffrey Allen Clark

Michael Allan Dingman

Maria T Kremer

Marten Swart

Horst Belau

Charles R Cook, Jr

Scott M Morell

Dave Talbot

KunKun Singh

Predrag Janic

Ronald Cook

Kenneth Francis

A system for measuring the weight of a seat occupant is used to control airbag deployment. The system is incorporated into a vehicle seat supported on inboard and outboard track assemblies. The inboard and outboard track assemblies are mounted to a vehicle structure such that a center track portion remains unsupported. A first sensor assembly is mounted to the inboard track assembly and a second sensor assembly is mounted to the outboard track assembly. The first sensor assembly generates a first signal in response to measuring deflection of the inboard track assembly due to seat occupant weight. The second sensor assembly generates a second signal in response to measuring deflection of the outboard track assembly due to seat occupant weight. A central processor determines seat occupant weight based on the first and second signals. The central processor communicates with the airbag system to control the deployment of the airbag based on seat occupant weight.

Method and apparatus for sensing seat occupant weight

A method and apparatus is provided that classifies a seat occupant into one of several different weight classes based on an estimated value of the seat occupant weight. An occupant's measured weight varies when the occupant's seating position changes or when the vehicle travels over adverse road conditions. A plurality of weight sensors are used to measure the weight exerted by a seat occupant against a seat bottom and are used to determine center of gravity for the seat occupant. A seat belt force sensor is also used to assist in classifying the seat occupant. Compensation factors using the seat belt force and center of gravity information are used to generate an estimated weight value. The estimated value of the occupant weight is compared to a series of upper and lower weight thresholds assigned to each of the weight classes to generate an occupant weight sample class. Over a period of time, several estimated weight values are compared to the weight class thresholds. Once a predetermined number of consistent and consecutive occupant weight sample classes is achieved, the occupant is locked into a specific occupant weight class. When the weight class is locked, the separation value between the upper and lower thresholds is increased to account for minor weight variations due to adverse road conditions and changes in occupant position.

Sensor assembly for seat occupant weight classification system

A system for measuring seat belt forces is used to control deployment of vehicle airbags. The system includes a rigid plate member having one end attached to a portion of the seat belt and an opposite end mounted to a vehicle structure. The seat belt is used to secure passengers or an infant car seat to the vehicle seat. A sensor including a strain gage is mounted on the rigid plate between the ends and is used to measure the magnitude of forces exerted on the seat belt by the passenger or car seat. The strain gage generates a signal representative of the tension in the seat belt, which is used to control deployment of the airbag. The airbag is not deployed if the tension in the seat belt exceeds a predetermined limit.

Seat belt force sensor system

Weight classification system

An occupant restraint assembly and for a motor vehicle operates to sense the tension forces on a seat belt to detect the presence of a human occupant or a child restraint seat. A sensor attached to the seat belt measures tension forces. The sensor is mounted in line with the seat belt. A strain gauge senses tension on the seat belt. An additional embodiment of the sensor includes three prongs attached to a common beam that allow the sensor to be slipped onto the seat belt without modification to the seat belt. A middle prong includes the strain gauge to sense movement relative to outside prongs. The seat belt threads over the outside prongs and under the middle prong such that tension on the seat belt forces the middle prong transversely to tension exerted on the seat belt.

Belt force sensor

A vehicle seat assembly includes a sensor assembly that is used to provide data for an occupant classification system. The data is used to determine such characteristics as seat occupant weight and position. These characteristics are used to control deployment of a safety restraint mechanism such as an airbag. The sensor assembly is part of a mat that is placed on top of a foam cushion used to form a seat bottom. Various attachment methods can be used to permanently secure the mat to the foam cushion. Preferably, the mat includes mounting portions that are wrapped around the foam cushion to engage a bottom surface of the foam cushion. Fasteners, adhesives, hook and loop attachments, and other similar attachment members are associated with the mounting portions and are used in various combinations to secure the mat to the foam cushion.

Method and apparatus for attaching a seat sensor mat to a foam cushion

A system for measuring seatbelt forces includes a guide that isolates a seatbelt force sensor from input loads applied to the seatbelt at an angle. The system includes a rigid plate member that supports the seatbelt force sensor , and which has one end attached to a portion of the seatbelt and an opposite end mounted to a guide bracket . The guide bracket includes a pair of circular bosses at one end for pivotally mounting the bracket to a vehicle structure such as a B-pillar , for example. The bracket guides the seatbelt in such a manner that input loads to the seatbelt that are applied at an angle do not affect the bending of the sensor

Seatbelt force sensor assembly with guide member

A vehicle weight classification system recognizes the various factors that influence system performance. Some of the factors are compensated for using analog signal processing circuitry or techniques. Other factors are compensated for using digital signal processing techniques. The unique combination of analog and digital approaches, rather than pure analog or pure digital, provides an effective solution at addressing the various factors that influence signals and system performance in a vehicle weight classification system while keeping the cost and complexity of the system within acceptable limits.

Signal processing in a vehicle weight classification system

A vehicle seat weight classification system includes a recalibration strategy to ensure sensor accuracy over time. A controller preferably is programmed to periodically sample outputs of the sensors when a seat is unoccupied. Average sensor output information is compared to a currently stored calibration value. If the newly determined average value meets selected criteria, then the sensor is recalibrated using the new information. The system and method of this invention compensates for changes in sensor performance over time caused by changes in system characteristics, such as material offset drift.

Calibration for a vehicle weight classification system

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Auburn Hills, MI, United States of America

Harald Lichtinger