Method of fuel injector management based on cylinder knock detection and vehicle including the same

Patent metadata

Field	Value
Publication number	US-12577921-B1
Application number	US-202418888321-A
Country	US
Kind code	B1
Filing date	Sep 18, 2024
Priority date	Sep 18, 2024
Publication date	Mar 17, 2026
Grant date	Mar 17, 2026

Abstract

A method of fuel injector management based on cylinder knock detection includes: receiving an individual cylinder knock count from a first cylinder; determining whether a knock metric is initialized for the first cylinder, whether the knock metric deviates from an established baseline knock metric after multiple cycles when the knock metric is initialized for the first cylinder, whether the knock metric is decreasing with respect to the established baseline knock metric when the knock metric deviates from the established baseline knock metric, whether a fuel system memory indicates rich, lean or healthy when that the knock metric is decreasing with respect to the established baseline knock metric, whether a knock adaptation control indicates a reduction of knock for the first cylinder, and updating a health status of a fuel injector based on the indication of rich, lean, or healthy.

First claim

What is claimed is:

1 . A method of fuel injector management based on cylinder knock detection for an internal combustion engine having a plurality of cylinders, the method comprising:
receiving, via a controller, an individual cylinder knock count from each of the plurality of cylinders, wherein the plurality of cylinders includes at least a first cylinder and a first fuel injector associated with the first cylinder, and wherein the individual cylinder knock count for the first cylinder is received from a knock sensor during a current cycle; determining, via the controller, whether a knock metric is initialized for the first cylinder; determining, via the controller, whether the knock metric for the first cylinder deviates during the current cycle from an established baseline knock metric for the first cylinder when it is determined that the knock metric is initialized for the first cylinder; determining, via the controller, whether the knock metric for the first cylinder is decreasing with respect to the established baseline knock metric for the first cylinder when it is determined that the knock metric for the first cylinder deviates from the established baseline knock metric for the first cylinder; determining, via the controller, whether a fuel system long term memory indicates one of rich, lean or healthy when it is determined that the knock metric for the first cylinder is decreasing with respect to the established baseline knock metric for the first cylinder; determining, via the controller, whether a knock adaptation control indicates a reduction of knock for the first cylinder; identifying, via the controller, the first fuel injector as shifted rich when it is determined that the fuel system long term memory indicates rich, and the knock adaptation control indicates the reduction of knock for the first cylinder; and providing, via the controller, an alert when a rich residual metric exceeds a rich threshold metric when the first injector is identified as rich.

2 . The method as recited in claim 1 , further including:
receiving, via the controller, the individual cylinder knock count from each of the plurality of cylinders, when it is determined that the knock metric for the first cylinder does not deviate from the established baseline knock metric for the first cylinder prior to determining whether the knock metric is initialized.

3 . The method as recited in claim 1 , further including:
providing, via a controller, a first indicator when it is determined that the knock metric for the first cylinder is not decreasing with respect to the established baseline knock metric for the first cylinder.

4 . The method as recited in claim 1 , further including:
providing, via the controller, a second indicator when it is determined that the fuel system long term memory indicates healthy.

5 . The method as recited in claim 1 , further including:
determining, via the controller, whether multiple misfires have been registered for the first cylinder, when it is determined that the fuel system memory indicates lean; identifying, via the controller, the first fuel injector as shifted lean, when it is determined that the fuel system memory indicates lean, multiple misfires have been registered for the first cylinder, and the knock adaptation control indicated the reduction of knock for the first cylinder; and providing, via the controller, an alert when a lean residual metric exceeds a lean threshold metric when the first injector is identified as lean.

6 . The method as recited in claim 5 , further including:
updating, via the controller, a health status of the first fuel injector, wherein updating the health status of the first fuel injector includes:
calculating, via the controller, an allowable range of fuel injector pulse widths based on a fuel injector degradation factor and fuel injector nominal performance data when the first fuel injector is identified as shifted rich; and
calculating, via the controller, the allowable range of fuel injector pulse widths and operating pressures based on the fuel injector degradation factor and fuel nominal performance data when the first fuel injector is identified as shifted lean.

7 . The method as recited in claim 6 , wherein the fuel injector degradation factor is calculated based upon a current long term multiplier, a nominal long term multiplier, and a total number of fuel injectors identified as shifted rich and/or shifted lean.

8 . The method as recited in claim 7 , further including:
increasing, via the controller, an engine idle speed when the first fuel injector is identified as shifted rich.

9 . The method as recited in claim 7 , further including:
increasing an engine idle speed, reducing a torque, and/or reducing a maximum allowable engine speed, via the controller, when the first fuel injector is identified as shifted lean.

10 . The method as recited in claim 1 , further including:
initializing, via the controller, the knock metric for the first cylinder when it is determined that the knock metric for the first cylinder is not initialized, wherein initializing the knock metric for the first cylinder when is it determined that the knock metric for the first cylinder is not initialized includes:
determining, via the controller, whether a sum of the individual knock counts for the plurality of cylinders during the current cycle is greater than a knock threshold (T Knock );
determining, via the controller, a cylinder specific knock metric for the first cylinder for the current cycle;
establishing, via the controller, a baseline knock metric for the first cylinder for the current cycle;
determining, via the controller, a weighted average knock metric for the first cylinder based on the current cycle; and
repeating, via the controller, the initialization of the knock metric for the first cylinder for at least one more cycle until the knock metric is initialized.

11 . The method as recited in claim 10 , wherein the sum of the individual knock counts of the plurality of cylinders for the current cycle is determined based upon a formula 1, which is defined as:

∑

i
=
1

n

⁢

∑

Cyl

i
-
Knock

[
1
]

where: i=a cylinder number from 1 to n;
n=a total number of cylinders in the plurality of cylinders; and
Cyl i-Knock =a total number of knock events for cylinder i.

12 . The method as recited in claim 10 , wherein the T Knock is a calibratable value that is greater than one.

13 . The method as recited in claim 10 , wherein the cylinder specific knock count

K
i
j

is determined based on a formula 2, whi

Assignees

• Gm Global Tech Operations Llc

Inventors

• Sarwar Azeem
• Gillett Andrew B
• Ault Joseph C

Classifications

• F02D41/1497

  With detection of the mechanical response of the engine · CPC title

• F02D2200/0616

  determined by estimation · CPC title

• F02D2041/225

  Leakage detection · CPC title

• F02D41/20

  Output circuits, e.g. for controlling currents in command coils · CPC title

• F02D41/2451

  characterised by what is learned or calibrated · CPC title