Snow has long posed a hazard for drivers, causing wheels to spin, windows to grow opaque with frost and, in some cases, engines to gasp behind snow-obstructed air filters.
Automotive engineers have developed technologies to combat many of these hazards over the years. But as the vehicles they design become increasingly complex, they’re facing an evolving set of new hazards unique to semi-autonomous and modern vehicle technologies.
Dr. Hossein Sojoudi, an associate professor and interim chair of the Department of Mechanical, Industrial and Manufacturing Engineering, leads research using a walk-in freezer connected to a wind tunnel in the College of Engineering.
The University of Toledo’s Dr. Hossein Sojoudi addresses this conundrum in a new review article in the peer-reviewed journal Powder Technology. It analyzes methods to model snow accumulation on vehicles and explores what research and development advancements are needed to ensure that advanced driver assistance systems ranging from backup cameras to adaptive cruise control can continue to operate as designed under inclement weather.
“It’s happened to me multiple times,” said Sojoudi, an associate professor and interim chair of the Department of Mechanical, Industrial and Manufacturing Engineering. “You’re driving in snowy conditions, and you see a message indicating that your adaptive cruise control or lane departure warning system is no longer available. It’s because snow has accumulated on the sensors that operate this technology.”
Sojoudi is well suited to study this problem and the hazards it creates as an expert in the multifaceted science of how snow and ice interact with surfaces.
Working out of indoor and outdoor laboratories at the College of Engineering, including a walk-in freezer that hits temperatures as low as -20 Celsius connected to a small wind tunnel that hits speeds as high as 45 mph, he and his student researchers explore active and passive strategies to mitigate issues related to ice, snow and frost accumulation.
Since Sojoudi joined the UToledo College of Engineering in 2016, his research has yielded one patent and more than 40 journal publications related to snow and ice accumulation.
“Ice and snow accumulation can result in increased operational costs, reduced efficiency and significant safety hazards,” Sojoudi said. “In order to develop strategies to mitigate these risks, we need to first understand snow dynamics. What are the factors that influence accumulation? From the composition of the particles to their trajectory and velocity to the characteristics of the surface that they’re striking.”
Sojoudi analyzed the uses and limitations of several models that engineers use to predict snow accumulation in the recent article in Powder Technology, noting the importance of these calculations in light of advancements in semi-autonomous and modern vehicle technologies.
Semi-autonomous vehicle technology utilizes a collection of sensor technologies like cameras, radar and LiDAR to allow the vehicle to perceive and respond to its surroundings — breaking when the vehicle advances too closely on another, for example, or alerting when a vehicle edges too close to traffic lines separating lanes.
When snow accumulation covers these sensors, the system may receive erroneous data leading to system malfunctions or, in a worst-case scenario, a traffic accident.
Sojoudi also proposes expanded research on the microscale interactions between snow and surfaces and new models to account for the complex, irregular shapes of flakes.
“Nearly a quarter of weather-related automobile collisions occur on snowy, slushy or ice pavement,” Sojoudi, citing data from the U.S. Department of Transportation. “These are the conditions where advanced driver assistance systems are especially needed and where they’re least likely to be available to drivers. We want our research on the dynamics of snow accumulation to inform practical solutions to enhance vehicle safety and performance in the winter weather that many of us regularly navigate.”
