Parametric Vehicle Dynamics and Emissions Analysis of a Crossover SUV

Abstract

A team of students and faculty from Embry Riddle are participating in the DOE and GM sponsored EcoCAR Challenge. As part of this three year program, the Embry Riddle EcoEagles team, will design and build a power-split extended-range electric vehicle. This paper chronicles the first year of development, which includes a parametric study of each vehicle component and configuration, hardware-in-the-loop simulations and well-to-wheel emissions analysis and compliments works by other team members [1,2]. Key vehicle parameters that were evaluated included; fuel stock, driveline configuration, engine size, motor size, energy storage system size and control strategy. The team used a range of design tools to evaluate available components within space, time and financial constraints. Per the sponsor’s guidelines, the base vehicle was a Saturn Vue and the crush zones of the vehicle could not be modified. Using Siemens NX, a packaging analysis was conducted to determine which driveline configurations were viable options for this vehicle. Once the viable design space was established, each configuration was modeled using Argonne National Laboratory’s Powertrain System Analysis Toolkit and Matlab to determine predicted fuel economies. The Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model was used to predict emissions for each configuration. Based on this analysis, an electric four-wheel-drive configuration was selected. On the front wheels, the vehicle is propelled in a compound hybrid configuration using a 1.3 liter diesel engine operating on B20 biodiesel and a 50kW electric motor. The rear wheels are propelled by a 55kW electric motor that is connected through the road to the engine. The combined electric power of 105kW and 320Volt, 11kW Battery Pack allows an all-electric operating range of approximately 20 miles. This configuration substantially reduces petroleum energy usage and improves fuel economy when compared to the stock vehicle. The predicted improvements are a 50% reduction in petroleum usage and a similar improvement in fuel economy.