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Cognition: The Sixth Sense of Safety
Integrated safety systems require an understanding of the world around the automobile and multiple sensor types.
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.
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| TRW’s Seewald says cognitive safety systems will have greater situational awareness than most drivers, and greater capability. However, though they will be capable of autonomous action, regulation and concern about liability will prevent these talents from being utilized fully. |
"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.
Getting There From Here |
| Though the technology exists to provide an integrated safety system in the 2010-2012 timeframe, it’s likely that its rollout will be limited to top-of-the-line vehicles. Unlike the early days of ABS and traction control, however, suppliers will be able to offer less ambitious systems that offer greater functionality, effectively using the driver as the second sensor, and increase the volume for the building blocks needed to produce the integrated designs and get them into volume production faster. Thus, radar-based adaptive cruise control (ACC) systems will grow in popularity as sensor prices drop—a 24 GHz unit currently runs about €1s50—and give drivers forward collision and distance warnings, activate the seatbelt pre-tensioners, prepare the braking system through pre-filling and altering the brake assist threshold, and add “follow-to-stop” functionality that will bring the vehicle to a complete stop in traffic jams. Separately, forward-facing video cameras will be used to detect and warn the driver when the vehicle drifts from its intended path in lane keeping systems. Also, cars equipped with electric power steering will use a digital torque overlay to create a “virtual road camber” that increases the farther the car drifts from the center of the lane without the driver activating the turn signal. More advanced units will combine the video image with GPS data to perform predictive path analysis, and alter the settings of the steering, suspension, and braking systems to provide optimum dynamic response with minimal loss of comfort. As more of these discrete units are purchased, Seewald believes, costs will drop to the point where OEMs can profitably combine them into high-value integrated units for volume vehicles. |
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