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EP-4565780-B1 - PDI VOLUMETRIC EFFICIENCY PASTING

EP4565780B1EP 4565780 B1EP4565780 B1EP 4565780B1EP-4565780-B1

Inventors

  • FIRSICH, NICHOLAS
  • ESKENAZI-GOLD, ALEX
  • Pedro, David R.
  • ATTARD, William P.
  • FALCON, Joseph D.

Dates

Publication Date
20260506
Application Date
20230711

Claims (15)

  1. A port and direct fuel injection (PDI) fuel delivery system for a vehicle having an engine (10) configured to selectively operate between a port fuel injection (PFI) mode, a gasoline direct injection (GDI) mode, and a PDI mode, the system comprising: a PFI system including a plurality of PFI injectors (60) configured to supply fuel to the engine (10) during the PFI mode; a GDI system including a plurality of GDI injectors (62) configured to supply fuel to the engine (10) during the GDI mode; wherein the PFI system and the GDI system are configured to provide various split-ratios of fuel mass injection to the engine (10) based on a particular engine operating condition, the split-ratios being a ratio of fuel mass injection of the PFI injectors (60) to fuel mass injection of the GDI injectors (62); characterised by a controller configured to: identify a known first long term fuel trim (LTFT) for a first split-ratio; identify a known second LTFT for a second split-ratio; generate a linear equation based on the known first and second LTFTs; and determine an unknown third LTFT for a third split-ratio by utilizing the linear equation to thereby facilitate reducing fueling errors and emissions.
  2. The PDI fuel delivery system of claim 1, wherein the linear equation is LTFT = (Slope * Split-Ratio) + Offset, wherein the Slope and the Offset are determined from the known first and second LTFTs and the first and second split-ratios.
  3. The PDI fuel delivery system of claim 1, wherein the controller includes or is configured to reference a table indexing the various split-ratios of the PDI fuel delivery system for the particular engine operating condition.
  4. The PDI fuel delivery system of claim 3, wherein the controller is configured to paste the determined third LTFT into the table as a known third LTFT at the third split-ratio.
  5. The PDI fuel delivery system of claim 3, wherein the controller is configured to determine all unknown LTFTs in the table and paste the determined LTFTs into the table in corresponding split-ratio data cells.
  6. The PDI fuel delivery system of claim 3, wherein the table includes a plurality of regions each corresponding to a particular split-ratio.
  7. The PDI fuel delivery system of claim 1, wherein the known first LTFT is a learned LTFT that is established when a sustained error from a first short term fuel trim (STFT) for the first split-ratio is transferred to the first LTFT such that the first STFT is brought back to a nominal value.
  8. The PDI fuel delivery system of claim 1, further comprising an EVAP system (68) configured to store and subsequently dispose of fuel vapor emissions, wherein the controller is configured to operate the EVAP system (68) based on the determined third LTFT.
  9. A method of controlling a port and direct fuel injection (PDI) fuel delivery system for an engine (10) having a port fuel injection (PFI) system and a gasoline direct injection (GDI) system, the engine (10) configured to selectively operate between a PFI mode, a GDI mode, and a PDI mode, characterised by the method comprising: identifying, via a vehicle controller, a known first long term fuel trim (LTFT) for a first split-ratio; identifying, via the vehicle controller, a known second LTFT for a second split-ratio; generating, via the vehicle controller, a linear equation based on the known first and second LTFTs; and determining, via the vehicle controller, an unknown third LTFT for a third split-ratio by utilizing the linear equation to thereby facilitate reducing fueling errors and emissions.
  10. The method of claim 9, wherein the linear equation is LTFT = (Slope * Split-Ratio) + Offset, wherein the Slope and the Offset are determined from the known first and second LTFTs and the first and second split-ratios.
  11. The method of claim 9, further comprising referencing, via the vehicle controller, a table indexing the various split-ratios of the PDI fuel delivery system for the particular engine operating condition.
  12. The method of claim 11, further comprising pasting, via the controller, the determined third LTFT into the table as a known third LTFT at the third split-ratio.
  13. The method of claim 11, further comprising determining, via the vehicle controller, all unknown LTFTs in the table and pasting the determined LTFTs into the table in corresponding split-ratio data cells.
  14. The method of claim 11, wherein the table includes a plurality of regions each corresponding to a particular split-ratio.
  15. The method of claim 9, wherein the known first LTFT is a learned LTFT that is established when a sustained error from a first short term fuel trim (STFT) for the first split-ratio is transferred to the first LTFT such that the first STFT is brought back to a nominal value, and the engine (10) includes an EVAP system (68) configured to store and subsequently dispose of fuel vapor emissions, wherein the vehicle controller is configured to operate the EVAP system (68) based on the determined third LTFT.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S) This application claims the benefit of United States Application Serial Number 17/881,071, filed on August 4, 2022. FIELD The present application relates generally to internal combustion engines and, more particularly, to systems and methods for predicting long term fuel trim of an engine having a port and direct fuel injection system. BACKGROUND Internal combustion engines have traditionally utilized port fuel injection (PFI) fuel delivery technology. PFI engines mix fuel and air in an intake port before the mixture is drawn into the engine cylinders for combustion. This mixing is performed to optimize the combustion and improve engine performance. More recently, gasoline direct injection (GDI) fuel delivery technology has been introduced to provide improved fuel economy. GDI engines draw air into the cylinder during the intake stroke, and fuel is injected directly into the cylinders during the intake or compression stroke to mix with the air. This type of mixing potentially provides improved fuel economy and engine performance under various load conditions. However, both PFI and GDI engines have their own unique advantages and disadvantages when compared to each other. In an attempt to utilize the advantages of both systems, some engines as known e.g. from US 2006/207559 Al, US 2018/328306 Al or US 2016/377019 A1, include both port and direct fuel injection (PDI) fuel delivery systems. Conventional fuel adaption strategies have been utilized to minimize fueling errors. However, when utilizing a PDI system, errors learned while running in one fueling mode (PFI or GDI) may not be anywhere near the error for the other mode. This can potentially lead to inaccurate long term fuel trims, which can potentially negatively impact emissions, particularly while trying to run purge. Thus, while such systems work well for their intended purpose, it is desirable to provide continuous improvement in the relevant art. SUMMARY According to one example aspect of the invention, a port and direct fuel injection (PDI) fuel delivery system for a vehicle having an engine configured to selectively operate between a port fuel injection (PFI) mode, a gasoline direct injection (GDI) mode, and a PDI mode is provided. In one exemplary implementation, the PDI fuel delivery system includes a PFI system including plurality of PFI injectors configured to supply fuel to the engine during the PFI mode, and a GDI system including a plurality of GDI injectors configured to supply fuel to the engine during the GDI mode. The PFI system and the GDI system are configured to provide various split-ratios of fuel mass injection to the engine based on a particular engine operating condition, the split-ratio being a ratio of fuel mass injection of the PFI injectors to fuel mass injection of the GDI injectors. A controller is programmed to identify a known first long term fuel trim (LTFT) for a first split-ratio, identify a known second LTFT for a second split-ratio, generate a linear equation based on the known first and second LTFTs, and determine an unknown third LTFT for a third split-ratio by utilizing the linear equation to thereby facilitate reducing fueling errors and emissions. In addition to the foregoing, the described system may include one or more of the following features: wherein the linear equation is LTFT = (Slope * Split-Ratio) + Offset, wherein the Slope and Offset are determined from the known first and second LTFTs and first and second split-ratios; wherein the controller includes or is configured to reference a table indexing the various split-ratios of the PDI fuel delivery system for the particular engine operating condition; wherein the controller is configured to paste the determined third LTFT into the table as a known third LTFT at the third split-ratio; and wherein the controller is configured to determine all unknown LTFTs in the table and paste the determined LTFTs into the table in corresponding split-ratio data cells. In addition to the foregoing, the described system may include one or more of the following features: wherein the table includes a plurality of regions each corresponding to a particular split-ratio; wherein the known first LTFT is a learned LTFT that is established when the sustained error from a first short term fuel trim (STFT) for the first split-ratio is transferred to the first LTFT such that the first STFT is brought back to a nominal value; and an EVAP system configured to store and subsequently dispose of fuel vapor emissions, wherein the controller is configured to operate the EVAP system based on the determined third LTFT. According to another example aspect of the invention, a method of controlling a port and direct fuel injection (PDI) fuel delivery system for an engine having a port fuel injection (PFI) system and a gasoline direct injection (GDI) system, the engine configured to selectively operate between a PFI mode, a GDI mode, and a PDI mode is p