Using Simulation to Optimize Driving Routes and Vehicle Emissions

Written by Phil Mireault

September 16, 2022
How Simulation Can Create Real Driving Routes and Predict Vehicle Emissions

Setting Up An Integrated Vehicle and Aftertreatment Simulation

Ever wondered what kind of emissions your car produces when driving to work or your favorite restaurant? With GT-SUITE and a few hours of hard work, you can have your answer! Learn how do set-up such a simulation using our software as detailed in our paper published on SAE entitled, A Study Examining the Effects of Driver Profile and Route Characteristics on Vehicle Performance and Tailpipe Emissions under Virtual Real Driving Scenarios, which is summarized in this blog. 

Thanks to the fact that GT-SUITE is a versatile multi-physics simulation platform, an integrated vehicle model can be set-up containing the vehicle, powertrain and aftertreatment system. We used this capability to create a model of a turbo diesel passenger car with an entire aftertreatment system as shown below. This allowed us to simulate the final emissions that the vehicle produces, often referred to as ‘tail-pipe out’. 

 tail pipe out setup simulation

Tailpipe out setup via GT-SUITE

Next, we needed to create the real driving routes. While we couldn’t agree on who’s favorite restaurant to simulate driving to, we did decide that long cruise around the Los Angeles area was a great choice (see below) along with a cost to coast drive. The two routes were then created using GT-RealDrive, a built-in application tool within GT-SUITE to create real driving routes. It works nearly identical to navigation apps like Google Maps, the only difference is that instead of physically driving the route, we’re just doing it virtually. It considers the live traffic conditions, stop lights, and elevation, all of which have an impact on the vehicle’s emissions. 

Los Angeles virtual driving route simulation

Los Angeles driving routes created with GT-RealDrive

Lastly, we realized that who was driving the car would impact the emissions. Rather than pick only 1 driver, we decided that we’d set up two different drivers to represent a range of conservative to aggressive, to represent how we all drive slightly differently. With our model and routes set-up, the simulations were run and produced a variety of results, some of which will be highlighted below. 

Results of Simulation: Tailpipe Emissions

As expected, the more conservative driver generated less emissions than the aggressive driver and was generally more fuel efficient. During the cruise around Los Angeles, the aggressive driver used 6% more fuel and produced nearly twice the amount of nitrogen oxides (NOx) a pollutant linked to smog and acid rain.  

tailpipe out emissions simulation results

Los Angeles tailpipe out emissions results

However, for the coast-to-coast route, this difference was quite small as both drivers used cruise control for the majority of the 2,817-mile drive which minimized the impact of their behavior. As a result, the fuel economy and emissions were similar for the two drivers. When normalized on a distance basis, the New York to California route produced less emissions and was more fuel efficient than the Los Angeles cruise. 

Further results and more in-depth details such as the impacts of traffic light duration, the start-stop system, and effects of sulfur poisoning and platinum oxidation on the emissions are available in the paper. 

Learn More About Generating Real Driving Routes and Predicting Emissions

Be it for regulatory compliance assessment, initial design, robustness or simply curiosity, GT-SUITE can simulate the emissions produced by vehicles while driving real routes. This is further simplified by GT-RealDrive by generating the routes virtually rather than having to use recorded GPS data.  

For further information about this paper or information on emissions simulations in GT-SUITE, please contact us at here.