Engine Knock Control Filter Coefficient Correction

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Solution Overview

Problem

Existing internal combustion engine knock controlling apparatuses face issues with inappropriate correction periods and response characteristics when calculating transition correction factors, leading to ineffective knock detection, especially in transitional operation states.

Innovation Solution

An internal combustion engine knock controlling apparatus that adjusts the correction period and response characteristics by using a previous value of the filter coefficient for calculating the transition correction factor, ensuring equal processing periods for filtering processes, thereby improving knock detection performance without requiring comprehensive matching.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the filter coefficient is corrected using a transition correction factor calculated with a different process period, then the response characteristics of the knock signal filtering is improved, but the correction period becomes inappropriate and knock detection accuracy deteriorates

Engineering Contradiction:

Improveresponse characteristicsVSAvoidknock detection accuracy

Core Design Contradiction:

SpeedVSMeasurement precision

Solution Approach 1:

The patent applies dynamics by making the filter coefficient correction period adaptive to the engine's operational state. The correction period is dynamically adjusted based on whether the engine is in a steady state or transitional state, ensuring that the correction factor is applied at the appropriate time. This resolves the contradiction by synchronizing the correction period with the actual operational conditions rather than using a fixed mismatched period.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent implements feedback by continuously monitoring the engine's operational state and using this information to adjust the filter coefficient correction timing. The system feeds back the operational state information to the correction mechanism, ensuring that corrections are applied only when appropriate. This feedback loop ensures both improved response characteristics and maintained knock detection accuracy.

Inventive Principle:

Principle #23Feedback

2Productivity

If the filter coefficient is corrected to improve response characteristics in transitional operation state, then tracking capability is improved, but erroneous knock detection occurs due to inappropriate correction period

Engineering Contradiction:

Improvetracking capabilityVSAvoidknock detection reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The system dynamically adjusts the correction application based on the engine's operational state. During transitional states, the correction factor is calculated and applied with appropriate timing, while during steady states, the correction is suspended or modified. This dynamic adaptation ensures high tracking capability during transitions while maintaining reliable knock detection during steady operation.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent applies local quality by treating different operational states differently. Instead of applying a uniform correction approach, the system applies correction factors selectively based on the local operational conditions. Transitional states receive correction to improve tracking, while steady states maintain original filtering characteristics to ensure reliable knock detection.

Inventive Principle:

Principle #3Local quality

3Measurement precision

If comprehensive matching is performed for calculating correction factor, then accuracy is improved, but device complexity increases

Engineering Contradiction:

Improvecorrection factor accuracyVSAvoidcalculation process complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the correction factor calculation into distinct components: a base filter coefficient and a separate transition correction factor. This segmentation allows each component to be calculated and applied independently, simplifying the overall process while maintaining accuracy. The correction factor is not calculated as a single complex value but as coordinated separate elements.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent extracts the transition correction factor as a separate element from the main filter coefficient. By taking out the correction component, the system can apply it selectively based on operational state without complicating the base filtering process. This extraction simplifies the calculation by separating the correction logic from the primary signal processing.

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS9164012B2Internal combustion engine knock controlling apparatus

Publication Date: 2015.10.20 MITSUBISHI ELECTRIC MOBILITY CORP

AI summary

An internal combustion engine knock controlling apparatus is obtained that improves knock detection performance by making a correction period appropriate without performing matching, when calculating a transition correction factor for correcting a filter coefficient used for calculating a mean value and a standard deviation of a knock signal in a transitional operation state. A previous value of a filter coefficient for calculating a knock determination threshold value that has been corrected by a transition correction factor is used for a filter coefficient for calculating the transition correction factor so that the response characteristics are made equal between a filtering process used for calculating a transition correction factor for correcting a knock determination threshold value and a filtering process used for calculating the knock determination threshold value in a transition operation period.