TRW Develops Occupant Sensing Technologies for Adaptive Restraints
25 February 1998
TRW Develops Occupant Sensing Technologies for Adaptive Restraints
DETROIT, Feb. 25 -- To help improve air bag technology and
address anticipated National Highway Traffic Safety Administration (NHTSA)
requirements for adaptive restraints, TRW is working on a number of occupant
sensing technologies which could offer enhanced protection to children under
12 years old, small adults and out-of-position occupants.
Some of these technologies are being demonstrated by TRW at its booth
(#2101) at the 1998 SAE International Congress & Exposition at Cobo Center
here this week.
"TRW is exploring a number of occupant sensing approaches, so that we'll
be ready to help automakers meet new requirements as they emerge," said Ronald
D. Sugar, executive vice president & general manager for TRW Automotive
Electronics Group. "We are gaining extensive insight on the myriad of
possible combinations of factors such as occupant size, weight, position,
dynamics and environment -- and what approaches best fit these scenarios."
TRW is working with several occupant sensing technologies which could be
used individually or in combination to meet various automaker needs and
marketplace requirements. Included are:
* Ultrasonic sensing - A technology capable of measuring distance to an
object by bouncing inaudible sound waves off the object, ultrasonic sensing
offers wide coverage throughout the vehicle interior and is capable of
detecting occupant presence and location, as well as the use of rear-facing
infant seats;
* Infrared sensing - A technology capable of measuring distance to an
object by reading reflected, invisible light beams, infrared sensing can
provide good coverage through the use of a series of beams and detectors which
are incorporated into vehicle interior structures;
* Weight sensing - Use of a strain-based technology (in seat frame rails
or other seat component) to measure the weight on a seat, thereby helping to
determine occupant presence and relative size; and
* Capacitive sensing - A candidate for driver-side out-of-position
applications, it determines occupant presence and position by reading changes
in an electric field generated by the system.
As part of its development effort, in the past year TRW has used a test
vehicle equipped with occupant sensors to collect real-world occupant position
profiles of nearly 1,000 volunteers -- including some 800 elementary-age
children, since potential front-seat risks are greater for children in this
size/weight range.
TRW has also conducted tests on its weight sensors with about 100 children
... each sitting in several positions in the passenger seat of its test
vehicle. Such tests, according to Sugar, are helping TRW develop a system
logic that can discriminate between small children and inanimate objects of
similar weight and/or size. To address another situation involving potential
front-seat risks -- the use of a rear-facing infant seat -- TRW will be
gathering additional profiles on infants in a variety of rear-facing seats or
carriers.
To help ensure its sensing technologies offer maximum accuracy when the
occupant is moving during severe braking -- common in pre-crash situations --
TRW has also conducted braking tests. These tests helped to verify the
performance of the TRW system when more than 1/2 G of deceleration force moved
test dummies within 10 inches of the passenger air bag.
TRW Automotive Electronics Group is a leading producer of electronic
safety, security and convenience systems for the global automotive market. In
addition to occupant sensing, its major product lines include air bag crash
sensors, remote keyless entry systems, switch and control systems, advanced
theft-deterrent and security systems, driver information systems, body
controllers and electrically assisted steering control units, as well as
engineered fastening systems.
With 122 automotive locations in 23 countries, TRW Inc. is one
of the largest independent OEM automotive suppliers in the world. In 1997,
the company's automotive businesses recorded sales of $7 billion, nearly 65
percent of TRW's total $10.8 billion in sales. Based in Cleveland, Ohio, TRW
also provides advanced technology products and services for the space and
defense, and information technology markets worldwide.
SOURCE TRW Inc.