Engine Octane Adaptation via Knock Counter Ignition Control

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Solution Overview

Problem

Current engine settings for spark-ignition engines are not adequately adaptable to different octane numbers of fuels, leading to unsatisfactory operation, including knocking phenomena that can damage the combustion chamber, especially when the engine is optimized for a higher octane number than the fuel used or vice versa.

Innovation Solution

A method that increments the learned octane number by adjusting the ignition advance based on detected knocking events, using a counter system to switch between reference settings corresponding to different octane numbers, with a fast and slow correction loop to optimize engine performance across various engine operating zones.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the engine is optimized for a higher octane number than the fuel used, then the engine setting can be adjusted for optimal performance, but knocking phenomena occur that can damage the combustion chamber

Engineering Contradiction:
Improveengine performanceVSAvoidknocking phenomenon
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent implements dynamic adaptation of ignition advance settings by continuously monitoring knocking signals and adjusting the ignition timing in real-time. The system transitions from static pre-defined ignition maps to dynamic adjustment based on actual fuel characteristics and engine operating conditions, allowing the engine to adapt to different octane numbers while maintaining optimal performance and preventing knocking damage

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs feedback mechanisms by using knock sensors to detect knocking phenomena and feeding this information back to the control unit. The control unit then adjusts the ignition advance accordingly, creating a closed-loop control system that continuously optimizes ignition timing based on actual engine response, thereby preventing knocking while maximizing performance

Inventive Principle:
Principle #23Feedback

2Reliability

If the engine setting is adjusted to prevent knocking, then the combustion chamber is protected from damage, but engine performance and capacity are not optimized

Engineering Contradiction:
Improvecombustion chamber protectionVSAvoidengine capacity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system dynamically adjusts ignition timing based on real-time knocking detection rather than using conservative fixed settings. This allows the engine to operate at optimal performance levels when knock-free conditions are achieved, while automatically retarding timing only when necessary to prevent knocking, thus balancing performance and protection

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the ignition advance parameter dynamically based on detected knocking characteristics and fuel octane number. By continuously adjusting this critical parameter rather than maintaining fixed conservative settings, the system achieves both protection against knocking and optimization of engine capacity and performance

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If a fixed ignition advance setting is used for a determined octane number, then the engine setting is simple to manage, but the engine cannot adapt when fuel octane number changes

Engineering Contradiction:
Improveengine setting managementVSAvoidadaptation to fuel octane number
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The system performs self-adjustment by automatically detecting fuel octane number through knock sensor monitoring and autonomously adapting ignition timing settings without requiring manual intervention. The control unit learns the specific fuel characteristics and optimizes ignition maps accordingly, enabling the engine to adapt to different fuels while maintaining simple operation for the user

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent implements preliminary adaptation during engine operation by continuously monitoring knocking signals and pre-adjusting ignition timing before significant performance degradation or knocking damage occurs. The system proactively learns fuel characteristics and modifies ignition settings in advance, ensuring optimal performance across different octane numbers

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2425117B1Method of adaptation of a motor to a fuel index by incrementing the learned octane number of the fuel
Publication Date: 2017.11.15 RENAULT SA
  • EP2425117B1 patent drawingFigure 1
  • EP2425117B1 patent drawingFigure 2
  • EP2425117B1 patent drawingFigure 3

AI summary

The invention relates to a method for adapting an engine to the octane number of the fuel by incrementing the initial octane number. Starting with a reference setting of the spark advance in an engine operating range (10) for a given octane number, the engine operating range (10) being divided into a plurality of zones (1 to 16), each including an anti-pinking corrective value of the spark advance of the reference setting, the engine is switched to a reference setting that corresponds to a higher octane number: when a top dead centre counter (TDC_CTR), incremented if the advance correction in the current zone is lower than a predetermined threshold (S l_l to S 16_l), exceeds a predetermined threshold (S4), or when a counter of the number of zones, in which the advance correction loop is lower than another threshold value (Sl_2 to S 16_2), exceeds a multi-zone threshold (S3).