ADAS Features Expand Role, V2V Looms

An array of ZF sensors can provide input that can be used by the transmission and braking systems to improve safety. (image: ZF)

Truck owners and commercial-vehicle suppliers are ramping up their safety efforts, making more advanced driver-assistance systems (ADAS) standard while looking at the potential benefits of vehicle-to-vehicle (V2V) communications. Though V2V can bring many benefits, widespread usage remains shrouded with questions.

Support for improved safety comes from some of the top executives of the largest vehicle fleets. FedEx CEO John Smith repeatedly commented on the need for improved safety during a recent Volvo Trucks-FedEx V2V demonstration. Associates detailed the push to fully equip the FedEx fleet with safety systems.

“By the end of the year, we will have collision mitigation, rollover stability control and lane-departure warnings on all our vehicles,” said FedEx communications director Michele Ehrhart. “We already have adaptive cruise control on all but the oldest vehicles.”

Truck makers are moving in lockstep, noting that it’s easy for buyers to justify the cost of safety systems. Safeguarding human lives is priceless, but protecting vehicles and cargo has a definable financial payback.

“There’s a very strong business case for improving safety,” said Kary Schaefer, general manager of strategy for Daimler Trucks North America’s Freightliner Trucks. “Every accident that safety systems prevent provides more uptime for the fleet. Active safety is one of three major areas of investment for the industry, along with propulsion and connectivity.”

As suppliers and owners move to equip more vehicles with ADAS, researchers are also exploring the potential benefits of V2V. The industry has standardized 5.9 GHz dedicated short-range communications (DSRC) to let vehicles talk to each other and communicate with roadside beacons. Many companies are testing V2V’s benefits for platooned convoys. When vehicles can tell each other when they’re braking, safety can be improved. Tightening distances between trucks can bring fuel savings up to 10%.

“The first use of V2V communication will be platooning,” said Dan Williams, director of ADAS and autonomy, commercial vehicle technologies, at ZF. “Vehicle-to-infrastructure communication could allow more cost-effective information in a restricted area environment.”

Safely shortening following distances means ensuring that trucks slow down synchronously. Volvo provides redundancy by closely linking adaptive cruise control (ACC) with V2V communications. That helps ensure that all vehicles immediately react when the lead vehicle slows.

“We’re using our standard ACC and adding a layer on top, using V2V,” said Keith Brandis, vice president for product planning at Volvo Trucks North America. “Cooperative ACC uses DSRC to let trailing vehicles know immediately when the lead truck is slowing or braking.”

Researchers feel V2V brings major financial benefits, but its usage remains in question. Platooning brings benefits even if the operating fleets are small. Greater benefits occur when more trucks can communicate, bringing broader safety improvements. It can be difficult to justify connectivity costs when only a few vehicles can talk to each other.

“In a mixed environment where sometimes this information might be available, sometimes not, it can become a source of potentially useful information, but if it is unreliable you may not want to base safety decisions on this data source,” Williams said.

The National Traffic Highway Safety Administration's (NHTSA) tardiness in mandating a rollout date has created questions around adoption. Cellular promoters say that 5G connections provide enough bandwidth to provide many of the benefits.

Platooning brings many benefits, but regulations for certifying V2V remain elusive. (image: Volvo Trucks)

Called C-V2V, it is gaining some interest from automakers who feel they can eliminate the cost of a DSRC link by using cellular modems that are likely to be on most cars in a few years. Given the lack of usage in cars and trucks, some groups have discussed selling some of the 5.9-GHz DSRC spectrum. That’s not palatable for most DSRC proponents.

“We’re working with the FCC to protect our wireless spectrum,” Brandis said. “If we get narrower bandwidth, it will restrict the amount of data we can send. That’s important for the future, when even more data will be sent.”

Having a communications infrastructure capable of handling lots of data is viewed as an important element in the drive to automate all driving. Data on road and weather conditions can help autonomous vehicles navigate safely. Vehicles could also share information about pedestrians near roadways, as well as providing real-time traffic info. V2V input is often viewed as sensor information that extends farther than on-board sensors. Increasing the volume and confidence levels of environmental data will be important as autonomous trucks move from limited applications to mainstream driving.

“Further out, we will use more sensing to identify safety issues all around the vehicle, and combine longitudinal and lateral control,” Williams said. “These associated functions will help to improve safety and efficiency of commercial vehicles, and lead to increasing levels of automation. The first automated vehicles will appear in duty cycles that are relatively easy to navigate, such as hauling from a mine pit to a railhead on a remote road, or maintaining a lane on a limited access highway.”