Software cuts car design time in half

In the mid-1990s, it took car makers, on average, four years to bring a new car model to market. Since then, cars have become even more complex with more variation. But thanks to new award-winning software developed at Argonne, manufacturers can now bring more gas-efficient, environmentally friendly vehicles to market in half that time.

The software is PSAT, the Powertrain System Analysis Toolkit, and it allows car designers to create models of different powertrains and realistically represent their characteristics. A powertrain is the group of components used to transmit engine power to the driving wheels. By testing these models on a computer, engineers can predict each design's fuel economy, emissions and performance, and only send to production the blueprints of the most efficient and high-performance designs.

The PSAT software is even more beneficial in the development of hybrid cars, vehicles that draw energy from more than one source, such as from an engine, fuel cell and battery. The more variables that designers have to consider, the more complex the design process becomes.

"With conventional vehicles, there are only a few options: manual or automatic, two- or four-wheel drive, said Aymeric Rousseau, research engineer at Argonne. "But with hybrids there are hundreds, thousands of variations: one or two electric motors? Use just electric energy to propel the vehicle, or use mechanical energy too? Use a battery or a fuel cell? Use a starter and alternator or a full hybrid?

"We wanted to make sure the software was easy for the engineers to use, Rousseau said. "Our main rule was that users shouldn't need a computer science degree to use our program — they should only have to click buttons. The computer interface is an intuitive graphical interface that features standard drag-and-drop functionality. Users choose the configurations they want to model, then select the characteristics they want to test. Depending on the complexity of the model created and the detail desired, the program takes anywhere from 20 seconds to 20 hours to run.

Based on the user's specifications, PSAT then predicts fuel economy and vehicle performance for that design. The predictions have proven to be close to results measured in the lab. For example, predicted values for conventional and mild-hybrid vehicles have been within two percent of actual values.

The software was originally designed for the Big Three automakers in the U.S., but since Argonne's goal was to help as many car makers as possible, any car maker can license the software. Within the first 18 months, said Rousseau, PSAT became the most profitable software in Argonne's history.

Rousseau said customers have not had the software long enough to quantify its benefits, but users are already praising PSAT's capabilities.

David Wenzhong Gao, assistant research professor at Mississippi State University's Center for Advanced Vehicular Systems, said, "There is a rich collection of models, both at the component and vehicle levels, for advanced powertrains in PSAT. These will certainly accelerate our research.

Dennis Assanis, president of Assanis & Associates, agreed, saying, "PSAT provides a critical link in the assessment of various control strategies and their impact on the fuel economy.

Rousseau said his team's next steps include increasing the product's distribution, driving it toward becoming the standard in the industry for vehicle modeling. Licensed PSAT users to date include major automotive suppliers, energy companies, research institutions and universities. Ultimately, though, the real winners are consumers.

" The software helps engineers choose which technology to use before even touching any hardware, said Rousseau. "They make decisions faster, which allows the technology to get to market faster. So consumers have a lower cost of vehicle ownership — they get cars that get better gas mileage, and they benefit from the fact that car makers have lower development costs.