Let 'magic fingers' do the driving
ARVIDSJAUR, Sweden - If you thought doing wheelies in the church parking lot was fun, try turning off ITT Automotive's Automotive Stability Management System (ASMS) on the slippery blue ice of Lake Arvidsjaur.The ASMS system controls individual brakes and engine torque to help keep the vehicle stable. As the car yaws, "magic fingers" seem to keep it on track. As WAW pushed the BMW 325 tds around a
March 1, 1995
ARVIDSJAUR, Sweden - If you thought doing wheelies in the church parking lot was fun, try turning off ITT Automotive's Automotive Stability Management System (ASMS) on the slippery blue ice of Lake Arvidsjaur.
The ASMS system controls individual brakes and engine torque to help keep the vehicle stable. As the car yaws, "magic fingers" seem to keep it on track. As WAW pushed the BMW 325 tds around a 200-meter circle carved into the lake, steering slightly to the right at about 45 mph (72km/h), these "fingers" gently kept the car moving in a smooth arc. With the system, drivers also can easily navigate the slick slalom course. Turn it off, and the car skids out of control and spins after one pass around the post.
That's fine in a controlled "press trip" environment, but what happens when the average driver starts slipping during a blizzard in Wisconsin? Panic sets in as the car fishtails and most drivers overcompensate. The ASMS momentarily activates the brakes at individual wheels to keep the vehicle stable. "The prime task is to control braking, not speed," says Johannes Graeber, ASMS program manager. "It will engage at the limit of cohesion."
The system works like this: An interactive network of sensors electronically look at the driver's steering input, individual wheel speeds and how the vehicle is taking corners. If it thinks the car could fly out of control, it activates individual brakes, and, if necessary, adjusts the engine torque. There are three sensor systems. One - the same sensors used in traditional ABS to detect potential wheel lockup - monitors wheel speed. Another sensor in the steering column assembly checks the steering wheel's angle. The third, a yaw-rate sensor in the center of the vehicle, decides how far the vehicle is pivoting on its vertical axis. As a network, they take continual snapshots of vehicle dynamics and driver inputs.
The ASMS system detects spare tires, is not affected by a locked-up differential and, if engaged, turns off the cruise control and does not turn it back on.
It's due out in three years in upscale European and American vehicles. ITT has eight dedicated programs, five in Europe and three in the U.S., says Timothy D. Leuliette, president of ITT Automotive. One of the first will be in a BMW 3-series around 1997. The Mercedes luxury SUV to be built in Vance, AL, beginning in 1996 will get the ITT system sometime in the future.
ITT is not the first with such a system. Mercedes-Benz introduced its Electronic Stability Program (ESP) in the S 600 coupe in Germany last month and adds it to the S 600 and SL 600 later in the year. The ITT system promises to be cheaper in the long run. When the company has enough business to build 500,000 a year, the "cost should be the same as the cost of ABS today," says Dr. Klaus Lederer, who heads ITT Automotive brake operations.
The future most likely belongs to the ABS maker that can provide good, quality, reliable ABS systems at the lowest price. It's big business. Mr. Leuliette points out that if the ABS business, now worth about $1.4 billion a year, is taken out of ITT Automotive, that business would be a "Fortune 300" company.
By 1997-'98 look for a one-chip ABS system. Currently, the inability to combine power and digital logic makes one-chip technology impossible, but ITT's Frankfurt, Germany, operation is working diligently to find a way to marry those two elements.
Such new technology is the tip of the iceberg, ITT says. It will invest $3 billion in new technology over the next five years. "Software is our key technical product," says Mr. Leuliette. "We'd like to be the Microsoft of the auto industry... We are looking for software engineers."
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