Abstract: A system for measuring seatbelt forces is used to control deployment of vehicle airbags. The system includes a seatbelt anchor assembly having a bracket mounted to a vehicle structure adjacent to a vehicle seat. A seatbelt mechanism has a belt portion that is looped through the bracket. The seatbelt is used to secure passengers or an infant car seat to the vehicle seat. A sensor is engaged with the anchor assembly and is used to measure the magnitude of forces exerted on the seatbelt by the passenger or car seat. The sensor generates a signal representative of the seatbelt forces, which is used to control deployment of the airbag.

Abstract: A sensor assembly is used to measure the weight of an occupant seated on a vehicle seat. The sensor assembly is integrated into a bracket that is mounted between a seat structure such as a track assembly and a vehicle structure such as floor or riser. One bracket is mounted on an inboard side of the seat and a second bracket is mounted on an outboard side of the seat. Each bracket includes opposing end mounts that are mounted to the vehicle structure. Between the opposing ends, each bracket includes a pair of deflectable portions that define a mount interface for attachment to the seat structure. A central body extends between the deflectable portions to form unitary bracket member that includes the end mounts, the deflectable portions and the central body. A strain gage is mounted on each deflectable portion to measure the weight of the seat occupant.

Abstract: A vehicle seat assembly 12 is mounted to a vehicle base member 24 such as a riser or a vehicle floor. Weight sensor assemblies 32 for measuring weight on the vehicle seat are mounted to a seat structural component. The weight sensor assemblies 32 each include plate 44 having a bendable center body portion 46 for supporting a strain gage 48. The strain gage 48 measures bending in the center body portion 46 caused by normal weight force applications on the vehicle seat 12. A secondary resilient beam member 34 is mounted between each weight sensor 32 and the vehicle base member 24. The beam member 34 and the weight sensors 32 deflect to prevent failure of the weight sensors 32 in response to an overload force applied in an opposite direction to the direction of a normal weight force application. The beam member 34 prevents permanent deformation of the plate 44 and strain gage failure by allowing the weight sensor 32 to deflect upwardly away from the vehicle floor.

Abstract: Weight sensor assemblies for measuring weight on a vehicle seat are mounted at the connecting points between a seat bottom frame and a seat mounting member. The weight sensor assemblies each include a beam member having a bendable center body portion for supporting a stain gage. The strain gage and associated traces are screen printed on the surface of the beam. The beam acts similar to a dual constrained cantilever beam, concentrating the bending at a reduced neck section that narrows in the middle of the center body portion. The strain gage measures strain resulting from bending in the center body portion caused by a weight force being applied against the seat.

Abstract: 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.

Abstract: A system for measuring the weight of a seat occupant is used to control airbag deployment. The system includes a plurality of weight sensors that have a first end mounted to a seat riser and a second end mounted to a seat frame or track member. The weight sensors have a central bendable portion that extends between the first and second ends. A groove is formed in one of the external surfaces of the central bendable portion to localize strain. A full bridge strain gage assembly is mounted on a surface of each of the weight sensors, opposite from the groove, for generating a weight signal in response to measuring deflection of the central bendable portion. A central processor determines seat occupant weight based on the weight signals and an airbag control module communicates with the processor. The control module controls deployment force of the airbag based on seat occupant weight.

Abstract: 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.