Vehicle OEMs have pledged to make automatic emergency braking (AEB) a standard feature by 2022, a move that is likely to alter electronic architectures and increase collaboration between module suppliers.
Twenty automakers recently teamed up with the U.S. National Highway Traffic Safety Admin. and the Insurance Institute for Highway Safety to set voluntary programs to move emergency braking from a luxury option to mainstream vehicles over the next few years.
For that to happen, many vehicle platforms will leverage hardware and software that’s already being proven on roadways. However, these system will all have to be tweaked to provide efficient performance on hundreds of different vehicle models.
“The main effort will be to validate and test systems on new platforms, which is not an insignificant job,” said Dean McConnell, Project Management Leader at Continental Automotive Systems. “The other question mark is what the actual functional requirements are, the speed range, stopping distance and other functions that will be important differentiators.”
IIHS estimates that as many as 20% of the 5 million vehicle crashes that occur annually in the U.S. could be prevented by the technology. The advantages of AEB were recently demonstrated to Automotive Engineering's Editor-in-Chief during a winter-test session at ZF TRW's proving ground near Arvidsjaur, Sweden.
Having driven AEB-equipped prototypes from various suppliers in previous dry-surface tests, this was the editor's first experience with AEB on a low-mµ-surface frozen lake. He came away convinced of the technology's high value in avoiding crashes as well as reducing the severity of crashes that may not be avoidable, by prepping the restraint systems before impact (see https://www.youtube.com/watch?v=8RxifQ_UDoA&feature=youtu.be).
Taxing engineering capacity
For the industry, the engineering task to implement AEB will encompass a number of different modules. Sensors will have to guarantee that they’re seeing something that’s a potential threat. When a collision is imminent, several systems will have to work harmoniously to slow the vehicle without sending it into a skid.
“There’s generally a combination of sensors like cameras and radar, along with controllers, software and algorithms,” said Frank Sgambati, Director of Innovation, Chassis Systems Control, at Robert Bosch. “They all have to work with vehicle braking systems and electronic stability control, all operating in concert.”
Outfitting all these vehicles with AEB in just six years will require a lot of design and development effort. Modules will often come from multiple suppliers, which is likely to foster closer working agreements between suppliers as well as OEMs.
“The main challenge to meeting this goal is engineering capacity — the amount of work needed to add AEB technology to several hundred vehicle models,” noted Aaron Jefferson, Director, Product Planning for ZF TRW Global Electronics. “This further enhances the need for multiple suppliers to work together efficiently.”
More powerful controllers needed?
Shifting from option to standard function may also alter electronic architectures. Distributed computing is currently quite common, with microprocessors deployed in both sensors and controllers. When all cars have more generic types of emergency braking system, the need to use modules that can be added as options can disappear, opening the door for integration.
“The need to design for options is part of why the strategy has gone towards separate controllers for different functions,” McConnell said. “The redundancy of separate modules may go away once it’s a standard feature. Some redundancy will still be required because it’s a safety function.”
That could alter requirements for semiconductors. Advanced driver assistance programs now rely on intelligent sensors that make some decisions before data is transferred to control modules. AEB could reduce the usage of this type of distributed computing, putting more focus on more powerful controllers.
“ADAS today is decentralized; the sensors all have brains,” said John Buszek, Segment Marketing Manager for ADAS Solution at Renesas Electronics America. “OEMs may decide to remove some of those brains and centralize intelligence, which will probably mean using more powerful controllers.”
Boosting computing power and memory size might not be the only change for chipmakers. Over the past several years, semiconductor makers have been providing more software. The standardization of AEB is likely to broaden the role of AUTOSAR, a standard that helps OEMs employ modules from multiple suppliers.
“The big thing for many OEMs will be time to market,” Buszek explained. “One way to move faster is to use standards — they provide a common base so work can proceed quickly. AUTOSAR already has momentum, I think there will be more of push behind it, so silicon vendors will probably be asked to create that software.”
Though the AEB agreement may impact a number of aspects of vehicle and subsystems engineering development, most observers feel that it won’t cause the type of scrambling seen in some efforts to meet tighter fuel economy regulations mandated by the U.S. The voluntary pact relies on existing technology to improve safety.
“AEB will greatly help reduce the number of accidents,” Jefferson said. “The AEB agreement is based upon the foundation that these systems are in the market today, performing well and providing safety benefits, but on a relatively small scale."