Sensitive Safety From The Top Down

Article From: 8/1/2007 Automotive Design & Production

At least that’s the way the folks at Bosch see it. By adding sensors and interlinking active and passive safety systems, survivability increases. Just don’t expect this trend to start anywhere other than the premium sector.

It was an interesting statement, and one that would act as a defining message for Bosch’s 58th International Automotive Press Briefing: “Let’s drop our obsession with premium cars!” It wasn’t that Bernd Bohr, chairman, Bosch Automotive Group was suddenly turning away from the upper end of the automotive market—though the company does have a strategy for positioning its technology for use on low-cost vehicles designed for developing markets—but that the focus of regulators and special interest groups on the most costly members of the automotive fleet does little good, and this fixation could slow the development of new technologies for mainstream cars and trucks. It was a point echoed by Rainer Kallenbach, executive v.p. Sales, Automotive Electronics: “Premium vehicles are our major field of innovation, and many of these systems make their way to the middle and compact classes as demands and volumes increase, and prices drop with each successive generation.”

This drop in price also means new technologies can be added to existing ones—and electronically interlinked—to create new safety systems. And though Bosch calls its development in this area the “sensitive car,” this new safety platform has nothing to do with crying during sad movies or cleaning the house without being asked. It is a concept that makes the car open to its surroundings through outward-looking sensors—radar and ultrasonic, as well as cameras—and using the gathered information to support the driver. “By networking these systems,” says Kallenbach, “the systems can interpret the situation and respond more quickly and reliably.” And though Bosch expects to have just such a system available in 2010—it will be capable of identifying lane markings, stationary and moving objects, track driver attentiveness, and “read” road signs and present their message in a display—the driver will still be able to override the system and take control of the vehicle.

Just below this level—but not entirely separate from it—is Combined Active and Passive Safety (CAPS), which uses information from one system to prepare the other to react faster to an accident situation. In it, the latest generation airbag controllers act as switching centers for the complete occupant protection system by analyzing data from the crash sensors to determine the severity of the accident, and then deploying the appropriate restrain systems. “Networking these controllers with the active safety systems,” says Dr. Michael Strugala, development chief of the Occupant Safety Business Unit, “allows us to use a much shorter plausibility check before the occupant protection systems are employed.” Thus, a vehicle whose stability control system indicates it has surpassed the adhesion limit can use this information to alert the airbag controller. This Early Pole Crash Detection (EPCD) greatly minimizes the amount of time it takes the seatbelt pre-tensioners and side-impact airbags to deploy. This increases survivability in an area where physical protection—the space between the occupant and the side of the vehicle—is limited. “The system also works in reverse,” says Strugala. Once a collision has occurred, the airbag controller signals the stability control system to automatically implement a full-ABS emergency stop to eliminate or reduce the impact of a secondary collision. Like the other systems, the driver can override this function, but a real-world demonstration of this system—the steering wheel was jerked to one side and crash sounds were fed into the cabin once the vehicle reached a pre-determined speed—indicated that an average driver would be unlikely to do so.

“Our goal is to provide technologies for these exigencies,” says Bohr, “but it requires a long-term partnership between suppliers and OEMs that doesn’t postpone payback for the development costs into the distant future.” Introducing these technologies on premium vehicles reduces the time before investment in them yields a profit, brings them to the volume end of the market sooner, and, says Bohr, makes it easier to keep up with the pace of innovation.