Limitations of ADAS, V2V and V2X communications

At the end of 2021, Dan Loop, vice-president and general manager of Automotive Edge Processing at NXP Semiconductors, wrote an article in All About Circuits entitled, Understanding ADAS Limitations and V2X Communication Technology.

He claims that ADAS in general increase road safety for the driver. However, he finds that they are mostly isolated from their surroundings. Quite of this is because they don’t communicate with other vehicles, roadways or with other kinds of smart city infrastructure. He adds: “Overall, the main limitations of driver-assistance systems are their cost and limited availability beyond higher-end models. ADAS is costly, and so entry-level vehicles don’t tend to have it to ensure because carmakers have an eye on remaining competitive. Yet there is a need for ADAS to proliferate because ADAS and indeed V2X communication work better when there are more participants. The challenge for OEMs is to therefore develop and offer more cost-effective ADAS to the lower end of the market “to increase the safety and comfort of all road users.”

In response to some questions from TU-Automotive about the limitations of ADAS, Vehicle-to-Vehicle (V2V), and Vehicle-to-Everything (V2X) communications, Loop commented: “Today, V2X systems have limited interactions with ADAS systems.  ADAS relies on vision and radar/lidar and ultrasonics to determine obstacles and path planning, while V2X relies on messages sent from other entities, including vehicles or infrastructure.  This means the V2X system is essentially limited by a network effect that relies on the adoption of the technology to reach a critical mass in order to become useful.  ADAS is limited by the cost of implementation of the technologies in vehicles.”

Uptake of ADAS

Matthew Avery, chief research strategy Officer at Thatcham Research nevertheless comments that his organization has been very impressed with the uptake of ADAS over the last decade. “We have got to the point where it used to be a high-end option but now it’s becoming a standard, even on mass market vehicles like Fiesta’s and Clios.” He explains that this shift is being driven by Euro NCAP’s five-star requirements: “While ADAS fitment to car and vans will be mandated by the European General Safety Regulation 2 rules. The benefits of ADAS in terms of crash-avoidance and Vulnerable Road User protection are clear. However, ADAS is not without its limitations.”

These weaknesses include the fact that radars can often struggle with identifying objects. “If there is too much reflectivity, there is no recognizable radar return and the system can’t identify what it is,” he reveals.  So, for example, if a car is hidden behind a metal pillar, or if a wheelie bin is obscuring a parked car, the system will find it difficult to ‘see’ that vehicle.

He adds: “Cameras have limitations too; they can be susceptible to ‘atmospheric distortion’, in other words, if the driver can’t see clearly, nor can the system.” This issue is often caused by bad weather such as fog, snow, mist, or heavy rain. Automotive manufacturers, he says, have been finding ways to work around this issue by using sensors. So, the camera identified the object, the radar works out where that object is in order to calculate the vehicle’s path to avoid it.

Avery also points out that: “New sensors are being introduced for automated driving, such as Lidar sensors which are quite expensive, but very accurate in terms of Near Field Discrimination. At close quarters they can accurately tell where objects are.”

Resolving limitations

So, how concerning are the limitations and what is being done to resolve them? Loop comments: “Legislation in multiple regions is driving V2X adoption.  For ADAS, cost pressure and innovation are taking cost out of the systems and some OEMs are narrowing their focus to use only specific technologies for their ADAS platforms. With automation, you are going to need all three sensors and, even then, that combination of sensors can still struggle in conditions affected by snow or fog, especially when it comes to identifying white lines.”

To read the complete article, visit TU-Automotive.