|
...accelerometers gyros. Sensors based Hall effect technology are widely used in such automotive safety applications as wheel speed sensing, as well as seat position sensing and seat belt buckle sensing. Silicon Hall seat position sensor switches and silicon Hall seat belt buckle sensor switches facilitate enhanced occupant safety in the event of crash or sudden stop. Moreover, Hall seat position sensors help protect the passenger from possible injury as a result of the deployment of the air bag by providing information about the position (location or zone) of the passenger seat to the ECU. This information can be used, along with data from other sensors, to determine and control the force of the air bag's deployment.
To further minimize the risk of air bag injury to young children or small adults, automotive occupant detection and classification systems-which can detect and suppress the air bag from deploying when a child seat, in a child in a seat, or a young child alone is in the passenger seat-are being developed and deployed, fueled by legislation (e.g., The National Highway Traffic Safety Administration's amendment in 2000 to FMSS 208, designed to minimize the risk of airbag-induced injuries and improve frontal crash protection for occupants in light vehicles.)
Various sensing technologies and schemes can be used in occupant detection/classification systems to detect the size, weight, or position of an occupant or an occupant's proximity to the air bag module. Technologies that are currently used include tactile force sensors (which use conductive inks and measure pressure distribution or force), silicon pressure sensors mounted under the seat cushion to measure an occupant's force on the seat, and strain gages situated at each corner of the front passenger seat frame to measure the occupant's weight. Additional sensing technologies that can be utilized in occupant detection and classification include visible CMOS image sensors/cameras, infrared thermopile arrays/thermal imaging cameras, electric field sensing, ultrasonic proximity sensors for detecting an out-of-position occupant, and fiber-optic tactile sensors that can be integrated into the seat cushion to monitor the pressure profile of the seat occupant and sense an occupant' presence/position and weight. Moreover, there is some potential for using analog Hall effect sensors as weight sensors in the passenger seat.
Current sensors are finding emerging opportunities in automotive applications, propelled by an increased need for more efficient monitoring of motors, monitoring the braking energy storage battery in hybrid vehicles that run on both gas and electricity, as well as for battery management in gas-powered vehicles, as the electronics content in vehicles continues significantly expand. Moreover, Hall effect -based current sensors are finding opportunities in non-automotive (e.g., industrial and consumer) applications, such as motor control, power distribution, welding equipment, industrial automation equipment (e.g., fork lifts, robots), uninterruptible power supplies, motor scooters, golf carts, recreational vehicles, hot tubs, marine battery monitoring, monitoring the backplane of rack-mounted systems, exercise equipment.
Hall sensors are finding significant use in occupant seat position sensing. Allegro MicroSystems, Inc. (Worcester, MA, 508-853-5000)(www.allegromicro.com), which has a Hall effect sensor business unit in Manchester, NH ( 603-626-2300), has been finding key growth opportunities for its two-wire, unipolar silicon Hall sensor switches in such areas as sensing discrete seat position zones and seat belt buckle sensing (to guarantee proper latching of the buckle to ensure that the occupant is properly restrained in the event of an accident or sudden stop). This year, Allegro expects to ship over 15 million Hall switches for seat position sensing and seat belt buckle sensing, with a majority...
NOTE: All illustrations and photos
have been removed from this article.
More articles from Sensor Business Digest
SENSITEC BOOSTS MR SENSOR BUSINESS.(magnetoresistive), November 01, 2004
NOVOTECHNIK IS A KEY FORCE IN LINEAR AND ROTARY POSITION SENSING., November 01, 2004
Looking for additional articles?
Search our database of over 3 million articles.
Looking for more in-depth information on this industry?
Search our complete database of Industry & Market reports by text, subject, publication
name or publication date.
About Goliath
Whether you're looking for sales prospects, competitive information, company
analysis or best practices in managing your organization,
Goliath can help you meet your business needs.
Our extensive business information databases empower business
professionals with both the breadth and depth of credible,
authoritative information they need to support their business
goals. Whether it be strategic planning, sales prospecting,
company research or defining management best practices -
Goliath is your leading source for accurate information.
|
