Engineering news
The scandal, which broke in 2015, affected millions of diesel cars built during a six-year period between 2009 and 2015, and cost the German automaker billions of dollars in fines and refitting costs.
A team of international researchers led by Kirill Levchenko, a computer scientist at the University of California San Diego, has conducted a year-long investigation into the software used in the cars. The researchers found copies of the illegal code on the company’s own maintenance website, and on forums run by car enthusiasts.
Current emissions tests involve equipping vehicles with a dynamometer, which measures the power output of the engine. The car is then run in a laboratory setting, at a precisely defined set of speeds which attempts to mimic real driving on an urban route.
But, because the conditions of the test are public knowledge, and they’re the same every time, Volkswagen were able to game the system.
The researchers found lines of code which allowed the car’s on-board computer to check for conditions associated with the test, such as distance, speed and the position of the wheel, and then activate a lower emissions mode when those criteria were met.
When that system wasn’t running, the cars released up to 40 times more nitrogen oxide than permitted under US regulations. A recent report found that nitrogen oxide emissions from diesel vehicles contributed to more than 38,000 premature deaths in 2015.
“We were able to find the smoking gun,” said Levchenko, whose team will present their findings at the 38th IEEE Symposium on Security and Privacy this week. “We found the system and how it was used.”
The scandal first came to light because of discrepancies between the emissions found in laboratory testing, and other tests done in the real world. Sam Akehurst, a lecturer at the Centre for Low Emission Vehicle Research in Bath, told Professional Engineering that new testing regulations based on similar real driving emissions (RDE) tests will help. They’re being brought in for new cars sold from September onwards.
“The RDE emissions legislation has been in development with the European Union for some time and they are speeding up the deployment of that testing to prevent things like that happening again,” he said.
The new testing protocol will compare emissions in the standard laboratory test with readings taken during real world driving by a compact device which attaches to the exhaust pipe of a car and sits in the boot. There is still some debate over how much discrepancy will be permitted between the laboratory and real world testing.
With software set to play a much bigger role in vehicles in the future, some are calling for tighter regulation. "Regulators and the research community will need to rethink how we make sure that vehicles, and other devices subject to regulatory oversight, are compliant," Levchenko told The Register.
However, Akehurst told PE that because the software is so complicated, it may be difficult to find independent experts. “Who would have the capability to do that, and who would be independent enough not to effectively potentially share that code between competitor companies?” he said. “There's an IP protection issue.”