Sensing and safety is fully embedded in vehicles

Automotive Design & Production,  Nov, 2006  by Lawrence S. Gould

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In operation, ESC monitors vehicle velocity information (wheel speed, yaw rate, and lateral acceleration) and driver inputs (such as steering, throttle, and master cylinder pressure). With this data, the ESC performs two functions. First, it determines the driver's intended path. Second, when the vehicle starts to diverge from the driver's intended path, the ESC intervenes and brings the vehicle back to the intended path. ESC intervention includes activating the brakes on one or more of the vehicle's wheels, as well as reducing engine throttle.

TRW is enhancing its ESC with electric steering systems--steering torque control (STC)--that "coach" a driver to correct vehicle instability by actually turning the steering wheel in the proper direction to avoid skidding/sliding. In so doing, STC helps reduce braking distances by as much as 8% at 50 mph on some road surfaces. TRW has also integrated ESC with ACC to provide precrash and automatic emergency braking. Together, the systems can slow a vehicle significantly--up to 0.6g--before a potential accident.

Says Carl Munch, senior technical specialist for TRW Automotive, Safety and Electronics Group, people don't see or feel these safety systems in 99% of the applications. "The only time they notice them is when something bad happens." Or better yet, they see these systems embedded as major selling points in car commercials, as is happening right now.

RELATED ARTICLE: "Printing" Sensors

Sensata Technologies, Inc. (Attleboro, MA; www.sensata.com) applied novel production techniques to their capacitive ceramic sensor technology, which is at the core of their APT products (automotive pressure transducer) used in automotive air conditioners, and in fuel, oil, and manifold air pressure applications. In the past, Sensata individually formed and pressed, then assembled, discrete ceramic elements to make APTs. No longer. Enter "APsquared," the next-generation APT. Sensata now "prints" these ceramic elements on a plate in a process akin to semiconductor wafer fabrication. Because the plates are formed in a high-volume process, the cost of the plates winds up being far less than the cost of the conventional individual elements. The sensors can handle pressures ranging from 100 to 3,400 kPa (other ranges are available), provide EMC protection to 200 V/m, and for generation II or III conditioning electronics, their accuracy is [+ or -] 1% Vcc. A new aluminum hexport of the APsquared pressure sensors is half the weight of their APT counterparts, and provides four times the corrosion protection.

By Lawrence S. Gould, Contributing Editor

COPYRIGHT 2006 Gardner Publications, Inc.
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