The first year of the EcoCAR 3 competition series stresses the application of the Vehicle Development Process, math-based modeling tools and architecture selection for the Chevrolet Camaro. Energy flow through the components of a hybrid electric vehicle can be arranged and configured in various ways. The arrangement of these components will define the architecture of the vehicle.
To select the best architecture the team needs to have a solid understanding of the strengths and weaknesses of various powertrains. To uncover these attributes, the team will need to evaluate multiple powertrain components and subsystems as part of a total vehicle system. After final evaluations, the team will select or reject the specific components (e.g., engines, motors, batteries, transmissions, subsystems) for their proposed vehicle architecture.
The entire process of evaluating each component that best fits the needs for the team and competition is tedious. The Ohio State EcoCAR team developed a tool within MATLAB and Simulink, called EcoSIM, which provides assistance in evaluating an overall vehicle’s performance.
EcoSIM utilizes mathematical equations, performance maps of powertrain components, vehicle physical properties and a control strategy to evaluate a vehicle’s performance within Simulink. Also, sub-tools were developed that help in generating fuel consumption maps for different engine sizes and efficiency maps for different electric machine sizes. The maps are then implemented within EcoSIM. Maps generated by these tools can then be utilized to test how varying engine and electric machine sizes can affect the overall performance of different vehicle architectures.
This will allow the EcoCAR 3 team to make an informed decision on what size engine and electric machine could be used in different architectures. Evaluation of several architectures will help the team to select the architecture that best fits competition and consumer needs. Results of modeling and simulation testing weigh heavily on the selection of Ohio State EcoCAR’s future vehicle architecture. This is a choice that will set the team’s course of action for the rest of the competition.