Sensata Seeks to Improve Seat Belt Alert Systems
DETROIT --- Sensata Technologies recently demonstrated several occupant-sensing approaches that the company says can help engineers design more accurate seat belt alert systems. The company is showing a new piezo electric sensor, as well as a current Monocrystalline Silicon Strain Gauge (MSG) force sensor, both of which give engineers a range of design options. Sensata Technologies said the new piezo electric sensor solves the problem of traditional weight-only detection systems, which often cannot differentiate between a person or a heavy object such as a box, bag of groceries, etc., creating annoying false seat belt alerts. A piezo electric wire, incorporated into a pad easily mounted under the seat cushion and providing input to an electronic module, senses the frequency response of a human and can determine the relative position of the passenger. "Consumers will use seat belt alerts that accurately determine if a passenger is really in the car. A box or laptop bag won't annoy them anymore because the system thinks it's a person," said Michael Mainvielle, market segment manager at Sensata Technologies. The Sensata piezo sensor is easily integrated into a variety of seat structures, including A- or B-surface mounting, and accommodates all seat covering options including ventilated seats. A three-position sensor is available for rear seats. This technology is also being considered for use with new Federal Motor Vehicle Safety Standard 208 classification air bag deployment systems. Sensata is also demonstrating its MSG Occupant Weight Sensor (OWS) that employs a silicon MEMS strain gauge element glass bonded to a stainless steel diaphragm. Four MSG sensors are mounted within the seat structure to create accurate weight measures for safe airbag deployment and compliance to FMVSS208. The sensors are available in several designs: an axial or flange rigid sensor; a rigid sensor with a Stress Reduction Component (SRC); or an SRC at flange center style. These options give designers a range of design and mounting flexibility.