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Development and Testing of an Automatic Transmission Shift Schedule Algorithm for Vehicle Simulation (SAE Paper 2015-01-1142)
Citation:
NEWMAN, K. Development and Testing of an Automatic Transmission Shift Schedule Algorithm for Vehicle Simulation (SAE Paper 2015-01-1142). In Proceedings, 2015 SAE World Congress, Detroit, MI, April 21 - 23, 2015. SAE International, Warrendale, PA, SAE #2015-01-1142, (2015).
Impact/Purpose:
This paper presents ALPHA’s shift logic algorithm and compares its predicted shift points to data from a mid-size light-duty vehicle and to the shift points predicted using a static table-based shift logic as calibrated to the same vehicle during benchmark testing. An explanation of, and a process for tuning, the user defined parameters is presented and an example application of the algorithm in a transmission gear ratio sensitivity study is described.
Description:
The Advanced Light-Duty Powertrain and Hybrid Analysis (ALPHA) modeling tool was created by EPA to estimate greenhouse gas (GHG) emissions of light-duty vehicles. ALPHA is a physics-based, forward-looking, full vehicle computer simulation capable of analyzing various vehicle types combined with different powertrain technologies. In order to model the behavior of current and future vehicles, an algorithm was developed to dynamically generate transmission shift logic from a set of user defined parameters, a cost function (e.g., engine fuel consumption) and vehicle performance during simulation.