Model-Based Fuel Economy Technology Assessment

Many leading companies in the automotive industry have been putting tremendous amount of efforts into developing new designs and technologies to make their products more energy efficient. It is straightforward to evaluate the fuel economy benefit of an individual technology in specific systems and components. However, when multiple technologies are combined and integrated into a whole vehicle, estimating the impact without building and testing an actual vehicle becomes very complex, because the efficiency gains from individual components do not simply add up. In an early concept phase, a projection of fuel efficiency benefits from new technologies will be extremely useful; but in many cases, the outlook has to rely on engineer’s insight since it is impractical to run tests for all possible technology combinations. This paper demonstrates a model-based framework to support new vehicle concept development by providing a full vehicle-level analysis of fuel economy, performance, and product cost via mixing and matching of available technologies and vehicle components. The simulation tool automatically assembles vehicle models from a user-definable component library and technology decision tree and analyzes the feasibility of the combination through its vehicle sizing/matching algorithm. The tool also applies an appropriate control strategy to a particular system configuration and runs vehicle simulations using a U.S. Environmental Protection Agency (EPA) five-cycle test procedure to assess the fuel consumption of each technology package. The production costs of component/technology combinations are estimated based on actual cost data, and on valid assumptions gathered from reliable sources. Ultimately, the framework provides visualization and analysis modules that enable users to identify the new system configuration candidates that meet their production cost and fuel economy requirements.