Knock Determination Value Correction for Ignition Timing Control

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Solution Overview

Problem

Existing knock control devices for internal combustion engines suffer from precision deterioration due to noise components, leading to inaccurate determination of knocking, which affects ignition timing control.

Innovation Solution

A device that uses a knock sensor to detect vibration magnitude and an operation unit to calculate knock magnitude, compare it with a predetermined determination value, and correct the determination value based on knocking occurrence frequency, thereby improving ignition timing control by adjusting the determination value dynamically.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If knock determination is performed using statistical processing and waveform shape independently, then knocking detection can be performed, but precision deteriorates due to noise components

Engineering Contradiction:

Improveknocking determination precisionVSAvoidnoise components

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent merges statistical processing results with waveform shape analysis by integrating their findings into a unified knock determination process. The operation unit combines the knock magnitude from statistical processing with waveform characteristics to make a final determination, thereby improving precision while maintaining robustness against noise components that might affect either method independently.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The system implements feedback by continuously monitoring knock determination results and using them to adjust the determination value dynamically. The operation unit corrects the determination value based on the knocking occurrence state, creating a closed-loop system that adapts to changing engine conditions and reduces the impact of noise over time through iterative refinement.

Inventive Principle:

Principle #23Feedback

2Measurement precision

If the determination value is corrected based on knocking occurrence frequency, then ignition timing control precision is improved, but device complexity increases

Engineering Contradiction:

Improveignition timing control precisionVSAvoidcontrol system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The determination value is made dynamic rather than fixed, allowing it to be corrected based on knocking occurrence frequency. This dynamic adjustment mechanism enables the system to adapt to varying engine conditions and sensor degradation without requiring complex hardware modifications, achieving improved precision through software-based adaptability.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system performs self-correction by automatically adjusting the determination value based on its own operational data and knocking occurrence patterns. The operation unit uses feedback from the engine's actual performance to refine the determination value, eliminating the need for external calibration or manual intervention while maintaining high precision.

Inventive Principle:

Principle #25Self-service

3Ease of operation

If knock magnitude is calculated based on vibration magnitude, then knocking detection is enabled, but accuracy decreases due to sensor output variation and degradation

Engineering Contradiction:

Improveknocking detection capabilityVSAvoidknock magnitude accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The system changes the parameter used for knock determination from a fixed threshold to a dynamically corrected determination value. By adjusting this parameter based on knocking occurrence frequency and sensor performance characteristics, the system compensates for sensor degradation and output variation, maintaining accurate knock detection throughout the sensor's operational life.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The operation unit performs preliminary correction of the determination value based on knocking occurrence patterns before using it for ignition timing control. This preliminary adjustment ensures that the determination value accounts for sensor characteristics and environmental conditions, improving the accuracy of subsequent knock magnitude comparisons.

Inventive Principle:

Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enhances the precision of knocking determination and ignition timing control, ensuring appropriate ignition timing by setting the determination value for each ignition cycle, even in varying engine states and sensor degradation conditions.

Implementation Method 1

a knock sensor detecting a magnitude value related to magnitude of vibration occurring in the internal combustion engine

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentUS7653477B2Method and device for control ignition timing through knock control in an internal combustion engine

Publication Date: 2010.01.26 TOYOTA JIDOSHA KK

AI summary

An engine ECU executes a program including: determining whether or not a condition for stopping knocking determination is satisfied; setting a flag of stopping correction of a determination value to “ON”; calculating a knock determination level based on the extracted magnitude value; and when the correction stop flag is not “ON”, decreasing or increasing the determination value in accordance with a knock proportion KC that is a proportion of magnitude values greater than the knock determination level. The knock determination level is calculated even when the correction stop flag is “ON”.