Abstract: An occupant weight sensing system has a seat pan which is rigidly mounted to a seat frame which attaches to a vehicle body. A seat cushion on which the occupant sits is positioned over the seat pan. A rigid frame is positioned above the seat pan and receives and supports the weight of the occupant. The rigid frame is supported on four sensors which in turn are mounted on the seat pan. The sensors collectively measure the weight supported by the rigid frame and thus determine the weight of the seat occupant. The sensors used to measure the weight of the seat occupant can be of two basic types. The first type is a load cell which experiences very little displacement and directly measures the imposed load. The second type of sensor employs a spring, the spring constant of which controls the amount of displacement for a given load. A Magnetoresistive Effect (GMR) displacement sensor measures the amount the spring is compressed.

Abstract: An airbag deployment controller has a plurality of sensors interposed between a rigid member and a seat pan member such that the weight supported by a portion of the seat cushion which the rigid member underlies is transferred from the rigid member to the seat pan via said sensors. The sensors sense the magnitude of the force transferred therethrough. A device processes signals from the sensors to determine the weight that the portion of the seat cushion which the rigid member underlies is bearing. The signal processing device controls the activation and operation of an airbag as a function of the presence and weight of a seat occupant. Optionally, the tension on a seat belt may also be sensed and processed as a parameter for controlling the deployment of an airbag.

Abstract: A seat occupant sensing system has at least two sensors interposed between a rigid member and a seat pan member such that the weight supported by a portion of the seat cushion which the rigid member underlies is transferred from the rigid member to the seat pan via said sensors. The sensors sense the magnitude of the force transferred therethrough. A device, such as a microprocessor, processes a signal from the sensors to determine the weight that the portion of the seat cushion which the rigid member underlies is bearing. The signal processing device may control the activation and operation of a safety device such as an airbag or seat belt pretensioner as a function of the presence and weight of a seat occupant.