Engine knock detection method and engine pre-ignition detection method

A detection method and engine technology, applied in the directions of engine ignition, engine components, machines/engines, etc., to achieve the effects of perfect knock detection function, suppression of misjudgment, and improvement of knock detection threshold

Active Publication Date: 2017-05-31
UNITED AUTOMOTIVE ELECTRONICS SYST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] The technical problem to be solved by the present invention is to reduce the misjudgment of engine knock or early ignition caused by the noise of intake valve closing

Method used

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  • Engine knock detection method and engine pre-ignition detection method
  • Engine knock detection method and engine pre-ignition detection method

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Experimental program
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Effect test

Embodiment 1

[0049] engine knock detection methods such as figure 1 shown, including the following steps:

[0050] 1. Calculate the crankshaft phase corresponding to the intake valve closing period of each cylinder of the engine under the current working condition in real time, calibrate the crankshaft phase of the knock recognition window of each cylinder of the engine, and calibrate the default background noise Srkr and the first knock threshold , the second knocking threshold, the first knocking threshold is greater than the second knocking threshold;

[0051] 2. Comparing the knock recognition window of the current combustion cylinder with the crankshaft phase of the intake valve closing period of the next combustion cylinder;

[0052] 3. If the intake valve closing period of the next combustion cylinder overlaps with the crankshaft phase of the knock identification window of the current combustion cylinder, it is judged that the intake valve closing noise enters the knock identificat...

Embodiment 2

[0061] Based on the engine knock detection method of Embodiment 1, in step 2, compare the knock recognition window of the current combustion cylinder with the crankshaft phase of the intake valve closing period of the next combustion cylinder; and compare the current ignition cycle with the previous ignition cycle , the change rate of the crankshaft phase during the intake valve closing period of the next combustion cylinder;

[0062] In step 3, if the intake valve closing period of the next combustion cylinder overlaps with the crankshaft phase of the knock identification window of the current combustion cylinder, and the change rate of the crankshaft phase of the intake valve closing period of the next combustion cylinder is greater than the set limit value, it is judged that the intake valve closing noise enters the knock identification window of the current combustion cylinder, and proceed to step 4; if the intake valve closing period of the next combustion cylinder is the ...

Embodiment 3

[0063] The engine knock detection method of the third embodiment optimizes the knock identification, and further judges the next combustion cylinder when the intake valve closing period of the next combustion cylinder overlaps with the crankshaft phase of the knock identification window of the current combustion cylinder. Whether the rate of change of the crankshaft phase during the closing period of the intake valve is fast enough, if the rate of change is high, a higher knock threshold is used for knock identification, and if the rate of change is low, a lower knock threshold is used for knock identification.

[0064] Embodiment three

[0065] Based on the engine knock detection method of Embodiment 1, in step 1, the first angle and the second angle are also calibrated, and the first angle is smaller than the second angle;

[0066] In step five, if it is detected that knocking occurs in the current combustion cylinder, the ignition angle of the current combustion cylinder is...

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PUM

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Abstract

The invention discloses an engine knock detection method. A knock recognition window of a current combustion cylinder and the crankshaft phase position of the closing time period of an air inlet valve of a next combustion cylinder are compared, whether the closing noise of the air inlet valve enters the knock recognition window of the current combustion cylinder or not is judged, if the closing noise of the air inlet valve enters the knock recognition window of the current combustion cylinder, when the knock recognition window of the current combustion cylinder comes, the overlapping knock strength Cvirkr of the current combustion cylinder is calculated through the default background noise Srkr, Cvirkr=ikr/Srkr, ikr is a knock sensor signal integration variable of the knock recognition window of the current combustion cylinder, and because the default background noise is larger than the knock sensor signal integration variable of the knock recognition window of an internal combustion cylinder under the normal condition, and a knock detection threshold is improved, the engine knock misjudgment caused when the closing noise of the air inlet valve enters the knock recognition window of the current combustion cylinder can be reduced. The invention further discloses an engine pre-ignition detection method.

Description

technical field [0001] The invention relates to engine control technology, in particular to an engine knock detection method and an engine pre-ignition detection method. Background technique [0002] The knock sensor is an acceleration sensor that can detect the vibration and sound waves of objects. If the engine has abnormal knock combustion or early combustion, the vibration and sound waves will be detected by the knock sensor and converted into electrical signals and input to the electronic control unit. When the electronic control unit detects the occurrence of knocking combustion, the electronic control unit will adjust the ignition to avoid the occurrence of continuous knocking combustion; Measures such as restricting the throttle valve protect the engine. Usually, a knock sensor is installed on the 4-cylinder in-line engine, which monitors the combustion of the engine in the corresponding detection window, and determines which cylinder has knock combustion or pre-ign...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): F02P5/15F02P5/152
CPCF02P5/15F02P5/152
Inventor 姚辉蔡建张力华於仕达
Owner UNITED AUTOMOTIVE ELECTRONICS SYST
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