abstract
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The goal of the initial phase of this project is to develop algorithms that assist in achieving convergence for highly couple, nonlinear equation sets for vehicle performance simulation models. The strategy is to use logic to reduce the complexity of couple sets before applying sophisticated numerical methods. To accomplish this, two algorithms that were developed previously, the DeCouple and the SmartSwapper, will be refined. The second goal is to identify and implement these methods into transportation applications. This integration will include the implementation of the algorithms into the first version of the composite software program and implementation into the RDT (Rail Design Tool) software.
The two areas of focus for the third phase of the vehicle performance simulation project are the development and validation of an alternative fuel vehicle design and simulation software tool, SmartHEV and the testing and optimization of the FutureTruck Suburban.
A linear and nonlinear equation solving software tool called SmartSolve was recently upgraded as part of the UTC Vehicle Simulation Project Phase I objectives. The upgrading involved extensive rewriting of the logic and mathematics algorithms to make the computer code more efficient and modular. Using the new structure of SmartSolve, SmartHEV will be created. SmartHEV will be a versatile vehicle software model that simulates steady-state operation. A new graphical user interface (GUI) will be designed, however much of the underlying code will transfer directly. SmartHEV will give the user tremendous flexibility in setting up a vehicle simulation in that the design variables are not restricted to being known or unknown. This enables variables that are typically performance parameters, or unknown variables, to be specified as known. A design can begin with a performance goal and work towards the necessary vehicle component sizes. The program will also include a parametric study routine that will graphically output to the screen as well as to data tables.
Once SmartHEV is finished it will be further refined in order to use it to help predict the optimum operating point of UI’s FutureTruck. This includes integrating SmartHEV with the Clean Vehicle Energy Management (CVEM) simulator in order to predict vehicle performance through a standard driving cycle. Also, further work needs to be completed in integrating the onboard GPS system with an inclinometer to develop local driving cycles that include on-road elevation data.
Once the two programs are integrated, the resulting program will be validated with FutureTruck data. The FutureTruck is already setup with an extensive data acquisition system. Downloading this data and reducing it for analysis and comparison with SmartHEV will be essential in order to use the software to determine an optimized energy control strategy.
Once SmartHEV is integrated with CVEM and validated against the FutureTruck, it can be used to make component design and operation decisions. Optimization and parametric studies can be developed in order to determine the best operating points for the vehicle components and to better understand vehicle performance. The results can then be used to develop a comprehensive energy management control strategy that minimizes tailpipe emissions and maximizes fuel economy.
Finally, with the GPS and inclinometer system, a driving cycle can be developed and analyzed before having to drive the vehicle. SmartHEV can then be used to develop an optimized control strategy for that particular driving cycle.
The SmartHEV technology is an innovative software design tool that could improve vehicle research and development. Its unique algorithms provide valuable insight into vehicle operation and component relationships. Greater understanding of vehicle parameters will result in improved component configurations and better overall vehicle designs. These improvements result in a vehicle with fewer problems that is designed in a shorter amount of time. Transferring SmartHEV technology to other vehicle software applications will add value to the alternative fueled vehicle R&D industry.