The next step in vehicle safety will combine electronic stability control and its subsystems with electric steering and chassis controls, and tie them together to make a whole greater than the sum of the parts. "This safety system requires intelligent integrated systems to define a 'cognitive' safety system," says Dr. Alois Seewald, Global Director, R&D and Integrated and Passive Safety Technologies at TRW Automotive (Livonia, MI; www.trwauto.com). Seewald likens the intelligence guiding its response to that of the driver's, but supported by a higher level of situational awareness and capability.
"A single sensor type isn't enough to make a 'serious' safety system of this type," says Seewald. That's because overlapping sensors using different technologies give a diverse view of the situation and can confirm-or deny-that an obstacle ahead is of concern. Thus, combining a 24 GHz medium-range radar sensor (a long-range 70 GHz sensor, he says, is needed for the autobahn) with a single lens mono-view camera to look at the vehicle's lane placement, obstacle width and classification, and the vehicle's closing speed meets Seewald's definition. Several layers of warnings-audio, visual, haptic-provide the initial alert before combining as the situation worsens. As this occurs, the electronic control units prepare the braking and safety systems for maximal action in minimal time, a moving target as the time and safety cushion contracts. Only when the crash is unavoidable, does the system, for example, initiate full emergency braking.
"We don't want to interfere with or reduce the options available to the driver in terms of steering around the obstacle," says Seewald, "nor do we want to create a situation in which the obstacle-in this case another vehicle-drives off undamaged while your car, and those behind it, are involved in a serious accident because of the level of response necessary to avoid the impact completely." Seewald also suggests these systems will be capable of autonomous response that does not require driver input. However, this autonomy won't fully be realized due to the current regulatory climate-governments are leery of cars that drive themselves while automakers are unwilling to increase their liability exposure-and the concern it would lead to a sharp spike in accidents in the short term. "I am worried about the level of control that you take away from the driver and place in the vehicle systems," he says, "as some drivers may not use the technology as intended." He recounts how drivers looked to ABS systems to get them out of situations they previously would not have placed themselves in as an example of the gap between expectation and reality. "In the short run it would have the effect of increasing speeds and the number of accidents until perceptions changed," he says. For now, engineers will have to settle for devices that aren't as powerful, autonomous, or safe as they know is possible.