Next-generation vehicles: drivers optional

Freescale's Schulmeyer sees collision avoidance as a passing goal on the way to full autonomy, with all new innovations in automobiles pointing to increased automation. The path, he said, will progress "from simple convenience items like autonomous windshield wipers to safety systems like antilock brake [ABS] systems, to the next step, which is vehicle stability systems and adaptive cruise control. These will be the first systems that attempt to avoid collisions, rather than just minimize the damage, like pretensors and airbags."

Schulmeyer sees three distinct stages ahead for autonomous safety systems: First, radar will be proven out on adaptive cruise controls; next will come more-active safety systems, such as emergency brakes that apply maximum braking to minimize damage when an "inevitable collision" is detected; and finally, full collision-avoidance sys- tems will steer around upcoming obstacles to prevent collisions from ever happening.

Proven feasible
Since the 1960s, researchers have vigorously explored all sorts of schemes for self-driving cars--from Stanley-style total autonomy, where the vehicle's software makes all the driving choices, to central control, in which a "master" traffic computer sends out signals to coordinate "slave" vehicles on an automated freeway. Many of these technologies have been proven feasible in real highway field tests, even as the electronics footprint has shrunk from trunk-filling to chip-size. Today the technology for automated highways could easily be retrofitted into the dashboards of modern commercial and consumer vehicles. So why don't cars drive themselves already?

One reason is that vehicles need to be able to "drive by wire," meaning that all mechanical linkages, from accelerator to transmission to brakes and steering, have to be controlled by computer-activated electric servos. For instance, the computer directly controls antilock braking systems, and steering-by-wire is being installed in many cars today. BMW's "active steering" technology, for example, uses a computer to adjust the angle of the steering wheel independently of the angle of the car's front wheels--say, to compensate for side winds.

Planes like Boeing's X-45 Unmanned Combat Air Vehicle point the way.

BMW, Daimler-Chrysler, General Motors, Honda, Mercedes, Toyota and Volkswagen all plan to use drive-by-wire capa- bilities in their vehicles for reasons of convenience and safety--but not for full auton- omy. "People don't want a car that takes over the navigation, steering, brakes and just takes you to your destination as a passenger," said analyst Williams. "They don't want cars that drive themselves, because that takes all the fun out of driving."

Nevertheless, "I would argue that even someone who loves to drive will have to admit there are times when a self-driving car would be welcome," said Stanford's Thrun, himself the owner of a sports car, "because I love to drive."

If you could switch on the self-driving mode, he said, "you could become more productive--you could read or sleep or answer your e-mail, or even watch a movie." And such a car could keep the elderly, who might otherwise have to give up their driver's licenses, independent longer.