Say "automotive electronics" and what comes to mind? Usually it's high-profile antilock braking, traction control, air bag and engine management controllers. Or maybe vehicle navigation, adaptive cruise control or even sound systems and cellular phones. Some of the industry's most amazing and important electronics, however, take the form of low-profile testing equipment.
Industry challenges such as increasing quality, reliability and fuel mileage, reducing development cycles, costs and emissions -- not to mention litigation -- will not go away. They'll be even more challenging in the future. As components become more complex, the hardware used to assure their quality and reliability needs to keep pace.
No longer can an automaker merely run a car into a brick wall to make sure crash-test dummies stay in the vehicle. Today they need an instrumented crash wall like the one being installed at Ford Motor Co. in Dearborn, MI, by Kistler Instrument Corp. of Amherst, NY. Instrumentation includes 47 quartz piezoelectric multi-component load cells that provide 141 output signals, which will give force data in three directions. The new wall will offer Ford engineers with information about the distribution of forces during vehicle impacts.
Even the tried-and-true crash test sled is undergoing a high-tech transformation. The new HYGE Sled at Lear Seating Corp.'s remodeled advanced technology and test center uses a digital, high-resolution camera system developed jointly by Lear and Eastman Kodak Co. Digital images captured during tests are downloaded into an automated motion-analysis system that eliminates delays caused by film developing and enhances the quality and accuracy of analysis.
Kodak also is helping Textron Inc. design and test the effects of air-bag deployment on interior components. Using a pair of Kodak EktaPro HS motion analyzers, Textron records air-bag release tests and views slow-motion replays to see how instrument panel and air-bag door designs perform. The Kodak device can record up to 4,500 full-frame images per second or up to 40,500 split-frame images per second with immediate slowmotion playback.
Advanced computers are even used to test seemingly low-tech components such as axles and driveshafts. Schenck Pegasus Corp. recently unveiled what it calls the industry's first axle and driveshaft road simulator. By merging a powertrain dynamometer and a servo-hydraulic axle test rig into one test machine, engineers will be able to perform overall verification tests of a full axle assembly in a laboratory setting.
The simulator's combined technology has the capability, says the company, of reproducing pre-recorded dynamic service loads with eight channels of structural load inputs combined with three channels of torque control for the axles and driveshaft. All input signals are recorded simultaneously at a test track and reproduced in a lab.
Modine Manufacturing Co., which makes radiators and other heat-transfer components, also brings the road into the laboratory via electronics. While driving customer prototypes on test runs, data recorders give Modine engineers information on vehicle vibrations. The tape is brought to the lab, transferred onto a computer disk and played through the supplier's own test equipment. Because the system is computer-based it is capable of compressing the testing cycle, so periods of time when component stress doesn't happen -- like waiting at stop signals -- can be eliminated from the program, trimming up to 70% of the time needed to complete testing.
"This method has proved to be a very efficient way to test durability and ensure quality," says Andrew Schmidt, a Modine design engineer.
When Fasco Controls Corp. decided to extend its automotive component lines into high-performance solenoid valves, it ran headlong into the industry's mandates for 100% testing of function, flow and leakage, plus full statistical process control data available on demand. Fasco Project Manager Allen R. Clapper says besides requiring statistical control with documentation traceable to individual products by serial number or production runs by date code, OEMs now want a supplier's test equipment to physically take control of discrepant materials by automatically discarding rejects.
Chicago-based InterTech Development Co. (IDC) custom built for Fasco a 12-station dial (rotary turntable) type test stand allowing the supplier to test several parameters of air and brake fluid pressures. Within a single seven-second station pause, IDC's mass-flow sensing technology gives direct volumetric measurement of flow rate or leakage accurate to 0.05 standard centimeters per minute. "While the computer automatically monitors each test against pre-set limits," Mr. Clapper explains, "our technicians study real-time displays to relate any suspect data back to individual components within the valve. This warns us about any upstream process or material variations thay may need attention."
One of the biggest areas of concern for automakers in the '90s is noise, vibration and harshness. So naturally it is a big concern for suppliers. In addition to the HYGE Sled at the new Lear Seating test center, the company has installed equipment to test its products for NVH.
A computer-controlled multi-axis shaker table with 16-channel data-acquisition system simulates varying road conditions allowing the seat maker to test structural dynamics and seat comfort, evaluate squeaks and rattles and sound quality. In a typical test, an instrumented seat is bolted to the shaker table. Engineers use collected data to locate problem noises and refine seat designs.
"Because we have state-of-the-art test equipment in-house, we are able to better engineer the product, speed up developmental lead times and expedite product testing," says Art Vartanian, vice president of advanced technology at Lear.
Electronics are even being used to test the thickness of automotive coatings. Fisher Technology Inc.'s Fisherscope X-Ray System XDV measures and analyzes dual and triple coatings, alloy coatings and electroless nickel coatings, all considered difficult to gauge.
While on-board electronics systems save lives and make driving a more pleasurable experience, the lesser-known automotive electronics make sure the entire vehicle does its job.
