Radar system makes this a smart car

Adaptive cruise control senses traffic and automatically brakes or slows

By Michael Fitzgerald
Globe Correspondent / July 25, 2011

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You’re driving down the highway, the cruise control set to 70. You come up behind a slow-moving car. There’s no room to pass, yet no need to hit the brakes. The car slows automatically.

When the outside lane is clear, you flip on your blinker, pull out, and let the car speed itself back up to 70. Your foot has not touched a pedal.

That’s the promise of the smart system known as adaptive cruise control, which uses radar to sense where traffic is, then automatically decelerates or even brakes to keep your car at a safe distance. Radar is used in other systems to warn drivers to brake hard to avoid collisions, and to make sure they know there’s a car in the blind spot.

Car radar is not new. It has been sold for about a decade, mostly as an option on luxury cars - last year, about 2 percent of new cars sold in the United States had adaptive cruise control. But radar may be showing up on more cars soon, due to better, cheaper antennas, sensors, and signal processors made by Analog Devices Inc., the chip maker based in Norwood, as well as companies like Austin-based Freescale Semiconductor Inc. and Infineon Technologies AG, of Germany.

Today’s car radar is dramatically different from what was available a decade ago, said Mike Thoeny, director of engineering for electronic controls at Delphi Automotive LLP, which makes the adaptive cruise control system used in the Ford Focus. He said the systems were originally almost handcrafted, but now can be mass-manufactured. The industry has “miniaturized this old military-style radar, come up with new and creative wave forms and chipsets, new antennae concepts,’’ Thoeny said.

A number of chips are used in car radar systems, each specialized for different functions: generating the radar signal, transmitting the signal, serving as antennas to receive the echo made when the signal bounces off an object, and converting that echo into digital form so it can be processed into data the car can understand.

What the chips don’t do is make 360-degree sweeps of the horizon, because they are mounted to specific areas of the car to survey segments of the environment.

Coming next are systems that do more work with fewer components.

Thoeny said that today’s adaptive cruise control systems use three radar antennas in the front of the car. Freescale will release a chip next year that combines radar radio frequency functions with some digital ones. Such integration “helps [lower] costs,’’ said Dan Viza, director of business initiatives in Freescale’s sensor and actuator unit.

Also coming are more easily programmable components. Companies like Delphi build radar systems from components that have to be optimized to work as adaptive cruise control, blind-spot detection, or collision warning. But the next wave of radar systems components will combine multiple functions.

For instance, new antennas that can handle long-range radar used for adaptive cruise control and short-range radar signals used for blind-spot detection will be less expensive next year. They still won’t make 360-degree sweeps, but a single set of components can be used for different functions, reducing costs and size.

“Before, you did it one way for forward-looking radar and another way for blind-spot detection,’’ says Samuel Weinstein, a marketing and applications manager at Analog Devices. In May, the company announced sensor components that can be programmed to work either for cruise control or blind spots.

Analog Device’s new product takes more than 30 components and reduces them to just a few chips. It’s about the length and width of an iPhone - which makes it easier to design to fit into smaller cars. Smaller parts should also use less power.

In March, Ford in Germany made adaptive cruise control an option for one of its Focus models. Ford won’t say when it might be offered on Focuses sold in the United States. A company spokesman noted that in Germany, the Focus is marketed as a family vehicle, not as the compact car it is here, and buyers could be expecting more safety features.

But David Alexander, an ABI Research analyst who follows the market for advanced driver-assistance systems, said adaptive cruise control is “all of a sudden this year’’ becoming a mass-market technology. He projects that five years from now, one-third of cars sold in the United States will have radar-based adaptive cruise control and collision warning.

Car radar that uses the new, smaller ADI part should appear in about 18 months. By then, the next generation of car radar will be under development.

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