It may take us a while to get to full "drive-by-wire" the same computerized guidance and control that now steers airplanes and smart bombs in flight but the automotive industry is taking major steps toward implementing a more thoroughly electronic vehicle system. The electronics content of automobiles is increasing rapidly, especially in the areas of analog, mixed-signal and power devices. While worldwide automobile production has been increasing steadily at a modest 3 percent annual growth rate, the market for automotive semiconductors is growing at a 13 to 15 percent annual rate.
And it's not just air bags, ABS brakes and engine controls that are driving this growth. If the prognosticators are right, the cars of the very near future will have plug-in buses for wireless Internet browsers, GPS-based navigation systems, hands-free cellular phone sets and multimedia entertainment systems as elaborate as any home theater-all controlled by a Microsoft Windows-based PC in a car-radio form factor. Further on, we'll see radar-based "autonomous cruise control" systems that take control of steering and brakes on a highway, and a replacement of hydraulic brakes with a more thoroughly "mechatronic" system.
Analyst Paul Hansen is convinced that as the PC migrates into the auto, the stage will be set for smaller companies to participate in an industry now dominated by giants.
The PC, with its plug-and-play hardware and software, ready access to Internet services-and its rapid turnaround on new products-has been the inspiration. Automotive manufacturers have been dismayed about the difference in design cycles between cars and electronic devices, according to Tom Mock, director of engineering for the Consumer Electronics Manufacturers Association (Arlington, Va.). In his contribution to this week's Signals section on automotive electronics, he notes that design cycles for automobiles run three to five years and new electronic systems appear every nine months. Thus, a new car coming out in model year 2002 will still have last year's (1998) electronics-unless some kind of change is made.
The proposal of the Automotive Multimedia Interface Collaboration, the intelligent transportation systems data bus, is meant to bring the car industry same kind of standardization and plug-and-play upgradability now enjoyed by the PC industry. It will enable automakers to plug in the latest electronics-automotive PCs, navigation, telephony and entertainment devices-just before the car leaves the factory or the showroom. At the center of this revolution in automotive electronics is the automotive PC, detailed in the article by David Wright, director of automotive business and marketing at Microsoft Corp. (Redmond, Wash.). Essentially, the Auto PC-a personal computer in a car-radio form factor-will run the Windows CE operating system and applications software. With speech command-and-control interface and a liquid-crystal display, it will serve as the control console for entirely new hardware and applications software such as navigation systems, cellular phones and entertainment electronics. Extensions of this platform are described in two articles later in the section by Michael Kasparian, market development manager at STMicroelectronics (Lexington, Mass.), and Jim Heckroth, strategic marketing manager at Cirrus Logic (Austin, Texas).
Indeed, "the auto PC is the hottest trend to hit the automotive industry in 11 years," according to analyst Paul Hansen, of Paul Hansen Associates (Rye, N.H.). Hansen tracks the auto industry's use of semiconductors and electronic subsystems in "The Hansen Report on Automotive Electronics" (www.hansenreport.com/home.cfm). "This will dramatically change the way people use their time in automobiles," he said. More significantly, it will alter the automotive supply chain, allowing smaller, entrepreneurial companies to participate in the auto industry for the first time.
Hansen foresees Internet sites expressly designed for automotive use within three to four years. Already, companies like InfoGation (San Diego) are marketing speech-activated navigation aids for the Auto PC. The company's Odyssey application allows drivers to verbally ask a Clarion AutoPC "where am I?" and receive speech output of position. Japanese carmakers, in fact, demonstrated navigation equipment with Internet links almost two years ago at the Tokyo Motor Show.
But entertainment, communication and navigation aids are not the only places where the revolution in automotive electronics will be felt, said Hansen. High-end automobile makers like Mercedes, BWM and some Japanese companies are exploring systems for electronic throttle control. In principle, an automotive drive-by-wire" system would control a vehicle on the highway in the same way fly-by-wire systems control airplanes in the sky. On a highway, for example, the radar system on a car moving at 65 miles an hour might detect an object ahead moving at only 55 mph. The radar system could then check the adjacent left lane, and, if there are no cars there, turn the steering wheel to shift the 65-mph car into that lane to avoid hitting the 55-mph car or truck. If the left lane is occupied, however, the drive-by-wire system applies the brakes. An early generation of this is being implemented as "autonomous cruise control" on Mercedes S-Class vehicles.
Such drive-by-wire systems will depend on two developments. One is an authoritative automotive radar, described in this section by David Li, chief scientist for microwave antenna maker Epsilon Lambda Electronics (Geneva, Ill.). Operating at 76 GHz, a bumper-mounted radar can detect objects along with their speed and direction as far away as 200 meters. As with ABS brakes, thoroughly autonomous cruise control will take some getting used to. Otherwise somnambulistic drivers might object to having the steering wheel pulled from their hands or their car brakes applied without their initiative, explained Dave Sreniawski, Epsilon Lambda's marketing manager. A likely scenario will implement drive-by-wire in stages: A "collision warning" radar system will be implemented first, in which a buzzer or beeper sounds to warn of the potential for colliding with another car, and it is up to the driver to slam on the brakes. Studies seem to suggest that as many as 60 percent of all recorded collisions could have been avoided with as little as a half-second warning to the driver, writes Epsilon's Li.
The other development necessary to implement drive-by-wire is a thoroughly electronic braking system, said Hansen. Auto engines (throttles) are already under electronic control, but braking systems still reflect Rube Goldberg-like hydraulics. A hydraulic system amplifies brake pressure, which triggers an electronic ABS sensing and control system that depends on hydraulics to apply pressure to the brake pads. A major step toward drive-by-wire will require hydraulic brakes to be replaced with motor-drive electromechanical clamps.
But such a replacement-along with the new control and console electronics-will require a literal revolution in the way an automobile is powered. A fully equipped midrange to luxury car now consumes 800 to 1,500 W from a 12-V battery (14-V alternator), said Tim Phillips, product planning supervisor for transportation business at Cherry Semiconductor (East Greenwich, R.I.). This is a load of 60 to 110 A. Add brake-by-wire, electronic steering, an Auto PC and attachments, and the power consumption of this vehicle in 2005 will likely be between 3,000 and 7,000 W, Phillips said. The only way to handle this power with a 12-V system is to increase the current-carrying capability of the wiring harness (use thicker wires), but that involves more cable weight and space in an already heavily burdened system. The solution is to go to a higher operating voltage, to distribute loads (dc brushless motors) throughout the car, and to rely on multiplexed controls, said Phillips. In his article, Randy Frank , technical marketing manager in Motorola's Semiconductor Components Group (Phoenix, Ariz.) discusses the implications of the 42-V system.