Eliminating the Forward/Backward Restriction in Vehicle Performance and Energy Use Analysis 2003-01-0223

The goal of this research was to develop and verify a computer analysis tool used for both vehicle simulation and design. Design analysis requires flexibility in setting up and solving the vehicle system of governing equations. Vehicle design analysis is fundamentally different from the structured modeling currently used in forward or backward facing vehicle simulation software. Unique numerical and equation management algorithms were developed to provide the flexibility and performance required for vehicle design analysis. These algorithms were combined into a software analysis tool called SmartDesigned Vehicles (SDV). Results from three different vehicle sizes and two different performance-based driving cycles were used to compare SDV with the Advanced Vehicle Simulator (ADVISOR) developed by the National Renewable Energy Laboratory. SDV was also validated with dynamometer test data. Results show that SDV predicts performance and energy use to within 5% of ADVISOR over most of the driving cycles. Additionally, SDV predicted vehicle performance to within 8% of dynamometer test data. SDV allows performance values as input and component size requirements as output. This result is a vehicle design tool that predicts component sizes based on performance, thereby enabling the engineer greater flexibility for design analysis.