System and method for determining engine knock

Patent metadata

Field	Value
Publication number	US-10107217-B2
Application number	US-201715428407-A
Country	US
Kind code	B2
Filing date	Feb 9, 2017
Priority date	Jun 9, 2016
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

Systems and methods for detecting and controlling knock in an engine are presented. In one example, engine knock sensors are selected based on whether or not certain cylinders are activated and combusting air and fuel or deactivated and not combusting air and fuel. Output of selected knock sensors is the basis for adjusting engine spark timing.

First claim

The invention claimed is:

1. A method for operating an engine, comprising:
generating a first knock reference value from a knock sensor output provided to a controller during a first cycle of a cylinder when a cylinder's valves are active and combustion occurs in the cylinder;
generating a second knock reference value from the knock sensor output provided to the controller during a second cycle of the cylinder when the cylinder's valves are not active and combustion does not occur in the cylinder;
judging a presence or absence of knock based on the first knock reference value during a first condition;
judging the presence or absence of knock based on the second knock reference value during a second condition; and
adjusting engine spark timing via the controller based on the presence or absence of knock.

2. The method of claim 1 , further comprising generating a third knock reference value from the knock sensor output provided to the controller during a third cycle of the cylinder when at least one of the cylinder's valves are active and combustion does not occur in the cylinder, and judging the presence or absence of knock based on the third knock reference value during a third condition.

3. The method of claim 2 , where the first condition is combustion in all cylinders of the engine.

4. The method of claim 3 , where the second condition is the first knock reference value being greater than a threshold.

5. The method of claim 2 , where the third condition is the first knock reference value being greater than a threshold.

6. The method of claim 2 , further comprising integrating the knock sensor output and dividing the integrated knock sensor output by the first knock reference value, the second knock reference value, or the third knock reference value.

7. The method of claim 2 , further comprising integrating the knock sensor output and dividing the integrated knock sensor output by the first knock reference value, the second knock reference value, or the third knock reference value based on mapped expected knock reference values.

8. The method of claim 7 , where the presence of knock is determined via comparing a knock intensity to a threshold value.

Assignees

• Ford Global Tech Llc

Inventors

• Glugla Chris Paul

Classifications

• F02D41/0087 Primary

  Selective cylinder activation, i.e. partial cylinder operation (deceleration cut-off F02D41/123) · CPC title

• F02P5/152

  dependent on pinking (detecting or indicating knocks in internal-combustion engines G01L23/22) · CPC title

• F02D13/06

  Cutting-out cylinders · CPC title

• F02P5/1522 Primary

  with particular means concerning an individual cylinder · CPC title

• F02D37/02

  one of the functions being ignition · CPC title