Method of controlling fuel to be injected within a combustion engine

Patent metadata

Field	Value
Publication number	US-9879632-B2
Application number	US-201314404277-A
Country	US
Kind code	B2
Filing date	Jun 20, 2013
Priority date	Jun 27, 2012
Publication date	Jan 30, 2018
Grant date	Jan 30, 2018

Abstract

A method of controlling the injection of fuel into cylinders of an internal combustion engine provides a method of distributing injection of fuel among cylinders of the engine so as to inject a quantity of fuel which is reliable and accurate, even when the quantity of fuel for each cylinder is close to the minimum quantity which can reliably and accurately be injected. The method may be applicable to injection of fuel for combustion in the engine or injection of fuel which is timed to be injected so as to pass through the cylinder without combusting.

First claim

The invention claimed is:

1. A method of controlling injection of a volume of fuel to be injected per time period within a combustion engine having a plurality of cylinders, each cylinder having an associated fuel injector, each fuel injector able to deliver a first injectable fuel volume, wherein each time period comprises a number of possible injection windows, and each possible injection window is associated with one of the plurality of cylinders, wherein each possible injection window is associated with an integer count value, x, between 1 and mp, wherein each of m and p is an integer and wherein x increments by 1 for each possible injection window and wherein mp to is a multiple of 1, the method involving use of a matrix having p columns and mp rows wherein each row of the matrix is associated with one of the integer count values from 1 to mp, each column of the matrix is associated with a fraction value, and each column of the matrix comprises an injection sequence associated with its fraction value, the method comprising:
determining whether it is true or false that the volume of fuel to be injected per time period is an exact multiple of a product of the number of possible injection windows per time period and the first injectable fuel volume; and
when it is determined to be false, identifying a column of the matrix associated with a fraction value which is close to a remainder value obtained by dividing the volume of fuel to be injected per time period by the product of the number of possible injection windows per time period and the first injectable fuel volume, and using the injection sequence of said column to determine in which of a next mp possible injection windows to inject the first injectable fuel volume.

2. The method of claim 1 wherein each position in the matrix is populated by one of a pair of binary values, wherein a first of the pair of binary values comprises an instruction to inject fuel and a second of the pair of binary values comprises either:
an instruction not to inject fuel; or
the absence of an instruction to inject fuel.

3. The method of claim 1 wherein the integer multiple m is 1 such that the matrix is a p×p matrix.

4. The method of claim 1 wherein p is greater than the number of cylinders.

5. The method of claim 1 wherein p is not an exact multiple of the number of cylinders.

6. The method of claim 1 wherein p is a prime number.

7. The method of claim 2 wherein, for each injection sequence, the first of the pair of binary instruction values are distributed evenly among the second of the pair of binary instruction values in accordance with a desired fractional of the first pair of binary instruction values to the second pair of binary instruction values in the particular injection sequence.

8. The method of claim 1 wherein the fraction values are either:

1
p

,

2
p

,

3
p

⁢

⁢
⋯
⁢

⁢

p
-
1

p

,

p
p

;
or

2
⁢

x
1

-
1

2
⁢
p

,

2
⁢

x
2

-
1

2
⁢
p

,

2
⁢

x
3

-
1

2
⁢
p

⁢

⁢
⋯
⁢

⁢

2
⁢

x

p
-
1

-
1

2
⁢
p

,

2
⁢

x
p

-
1

2
⁢
p

wherein x 1 , x 2 , x 3 . . . x p−1 , x p represent each of the integer count values, 1 to p.

9. The method of claim 2 wherein the injection sequence associated with a smallest fraction comprises exactly one of the first of the pair of binary values, and for each increasing fraction of the fraction values the associated injection sequence comprises an additional one of the first of the pair of binary values such that the injection sequence associated with a largest fraction comprises exclusively the first of the pair of binary values.

10. The method of claim 2 wherein the injection sequence associated with a smallest fraction comprises exclusively the second of the pair of binary values, and for each increasing fraction of the fraction values the associated injection sequence comprises an additional one of the first of the pair of binary values such that the injection sequence associated with a largest fraction comprises exactly one of the second pair of binary values.

11. The method of claim 1 wherein the first injectable fuel volume is a minimum injectable fuel volume which can reliably be injected by each injector.

12. The method of claim 1 wherein each fuel injector is able to deliver a secondary injectable fuel volume which represents a greater volume than the first injectable fuel volume.

13. The method of claim 12 wherein the secondary inje

Assignees

• Perkins Engines Co Ltd

Inventors

• Smith Michael

Classifications

• F02D41/008 Primary

  Controlling each cylinder individually · CPC title

• F02D41/34 Primary

  with means for controlling injection timing or duration · CPC title

• F02D41/30

  Controlling fuel injection {(F02D41/182, F02D41/24 take precedence)} · CPC title

• F02D41/405

  with post injections · CPC title

• F02D41/1402 Primary

  Adaptive control · CPC title