Active safety systems rely on input from a number of onboard sensors to monitor driving conditions and watch for situations that may cause accidents. A number of design teams are beginning to consider external inputs as a way to augment or even replace these sensors.
Instead of relying solely on vehicle sensors like cameras and radars, some engineers are considering ways to expand the level of knowledge by combining data sent from GPS satellites with data from the vehicle’s navigation system.
More companies are studying vehicle-to-vehicle and vehicle-to-infrastructure communications, jointly abbreviated V2X. This communication technology uses dedicated short range communications to provide data that usually can’t be collected by onboard sensors.
Though V2X isn’t yet near production, major on-highway tests are now finishing up in the U.S. Regulators will use data from these road tests when they determine whether to set some sort of mandate for putting V2X equipment on vehicles. Many companies feel that the promise for improved safety and better traffic flow is great enough that they are considering adopting this technology.
“Along with cameras, LIDAR, and radar, there’s a piece that’s not there yet, V2X communications,” said Doug Patton, Senior Vice President of Engineering for Denso International America Inc. “V2X gives you non-line-of-site information. No other sensor does that for you.”
Getting braking information or other data from unseen vehicles far ahead will let cars slow down well before drivers or onboard sensors can see that a potential problem is arising. This not only can enhance safety but also help improve fuel economy and reduce traffic slowdowns.
“V2X can extend the range of radar and camera sensors on vehicles today, allowing vehicles to share traffic and road information in real time with each other and the network, further expanding the 'cocoon of safety' around the vehicle,” said Jeff Owens, Delphi’s Chief Technology Officer. “Looking even further, these systems will enable highway platooning and fully autonomous driving.”
One roadblock for V2X is that there must be a fair number of nodes on roadways so there is a critical mass of vehicles that can communicate with each other. A mandate would ensure that numbers will rise, but some feel the benefits are great enough that truckers and other fleets may employ the technology even without a mandate.
Strategists are now working on the technology so they’re ready if either of these reasons spark growth. Some are even looking into the long term, when V2X may even let system designers replace some sensors now used for advanced driver assistance systems (ADAS).
“V2X can provide a lower cost system than traditional ADAS,” said Brian Daugherty, Associate Director of Advanced Development at Visteon. “V2X will complement ADAS on many vehicles but could be offered as an alternative to ADAS on lower cost vehicles. ADAS provides an excellent but relatively short-range solution, whereas V2X increases the detection range. It also provides additional functionality such as intersection cross-traffic warnings, slippery road ahead warnings, and emergency electronic brake light, which allows vehicles to ‘see’ braking cars that are blocked from view by the car immediately ahead.”
While some engineers consider the trade-offs for adding sensors or V2X communications, others are determining how GPS and mapping data can be used to augment sensors. Knowing whether the vehicle’s going around a curve or up a hill can be helpful information for a safety system.
“You can use navigation and GPS input in a matrix with radar and cameras to help confirm that you’re on the right track,” said Alois Seewald, Global Director, Research and Development and Cognitive Safety Integration, at TRW Automotive. “Maps and GPS data can tell you you’re going around a curve so the vehicle that’s turning in front of you is not switching into your lane, it’s just going around a curve.”
However, today’s map data are not usually thought to be precise enough for safety. Still, it can provide useful input. Over time, map data will continue to improve, with better coverage and more accurate information regarding road curvature, but it will always be subject to change.
“Maps will be used as an additional sensor, but data will be regarded as inaccurate. Systems won’t rely on it alone,” said Martin Schleicher, Vice President of Strategic Development at Elektrobit Automotive. “Map data will be reviewed in conjunction with other sensors when there is a conflict. Map data can never be perfect; things can change for construction or other factors.”