A highly autonomous driving vehicle needs a suite of advanced technologies and a ready-to-take-control driver.
“We’re using infrared driver analyzer cameras on our next-generation highly automated driving vehicle to collect data for the development of a ‘driver model.’ The driver model would tell us if the driver is attentive. And it would predict the driver’s reaction time to resume control of the vehicle,” said Ibro Muharemovic, head of Continental’s advanced engineering in North America.
Continental’s second-generation concept was featured during a media technology preview at the supplier’s Brimley, Michigan proving grounds late last month. Muharemovic began a two-lap driving demonstration with Automotive Engineering by accelerating the vehicle to a highway speed. He then engaged the full-speed-range adaptive cruise control and activated the highly automated driving mode. The specially equipped 2014MY Chrysler 300 responded by autonomously driving at 60 mph (97 km/h), slowing to 46 mph (74 km/h) to navigate smoothly through a banked turn, then resuming highway speed through a straightaway.
Since August 2014, test engineers in the U.S. have been taking turns in the driver’s seat of the next-generation demonstrator as two in-vehicle cameras recognize and track facial movements during drive time. The accumulated data will aid in the development of a robust computer driver model.
“At this point, I only have a very early version of the driver model that indicates attentiveness when the driver is looking forward and inattentiveness when the driver is looking to the side. As for reaction time, that is a big, big undertaking. This is why we need lots and lots of raw data,” said Muharemovic.
A light bar running the length of the dashboard at the windshield’s base provides the driver a visual reminder of the current driving mode. The technology debuted on Continental’s Driver Focus Vehicle (see http://articles.sae.org/11842).
Driver assistance and full-speed adaptive cruise control engagement is indicated by a green light bar. When the light bar is blue, the vehicle is in the highly automated mode. An orange color indicates a stand-by mode, which means the driver is actively steering. “It’s important to have a straightforward, always visible way of knowing what driving mode the car is in,” Muharemovic said.
To facilitate a more human-like autonomous driving style, high-definition digital map information is being employed on the second-generation demonstrator.
“The HD map is a highly accurate representation of the road environment. It provides us with precise information, such as how many lanes there are, the exact curvatures of those lanes, and the exact location of roadway exits,” said Muharemovic, “HD map information helps us localize the vehicle on the road environment.”
Continental’s demonstrator is fitted with an array of sensing technologies.
Next-generation long-range radar looks forward 250 m (820 ft) with a 120-degree opening. That is double the field of view in the near range and an additional 50 m (165 ft) in the complete range compared to the third-generation technology used on the first-generation demonstrator. Four short-range radars look to the sides at 90 m (295 ft) with a 120-degree opening. The second-generation vehicle demonstrator also has a 360-degree surround view camera system, a feature the first-generation vehicle concept did not have.
The next-generation concept uses a windshield-mounted, forward-facing stereo camera for lane detection and to recognize pedestrians, traffic signs, oncoming high-beam headlights, and other objects.
“The stereo camera has two lane recognition algorithms that were developed by two different teams. It was done that way so we can compare the outputs of each and get added redundancy in one sensor,” said Muharemovic.
There is redundant braking and steering in case something happens with the primary units. In addition to the actuation redundancies, there is redundancy with the power supply. “As an example, the front radar is on one power supply and the stereo camera is on another power supply and communication line,” said Muharemovic.
Continental has three highly autonomous demonstration vehicles in Auburn Hills, MI. First-generation technology was showcased on a Volkswagen Passat. Two Chrysler 300s are now part of the demonstration fleet, with one car being used as a development platform for sensor fusion/sensing architecture and the other car serving as a development platform for redundant braking and steering.
“We share development globally, so whenever my colleagues in Germany or Japan make an update to a sensor or a system or a function, we are able to bring it to this region and vice-versa,” said Muharemovic. “Our partner companies are also developing technologies and as those technologies become available, we’ll make the updates.”