The oil film Parameters Identification in Gasoline Engine Transient Conditions Based on Recursive Finite Memory Auxiliary Variable Method

In order to identify the engine inlet oil film parameters more accurately, the oil film identification equation based on oil film model is built under the consideration of random error which is consisted by model error and measurement error. For the purpose of eliminating the influence of random error to the identification results, Recursive Auxiliary Variable (RAV) is put forward. At the same time, as the growth of the sample data, the recursion method will appear data saturation phenomenon which may lead the recursion method lose correcting capability slowly. Thus, the finite memory item is introduced to the RAV. Finally, a engine model is set up using EN-DYNA. Parameter identification applying Recursive finite memory auxiliary variable(RFMAV), Least Squares(LS) and recursive auxiliary variable are conducted and compared respectively at 1500-3000r/min and the throttle opening from 10%-80% based on the calibration value. The results indicate that the RFMAV has a better identification outcome than LS and RAV.