Flow Meter Signal Processing for EGR Intake Modes

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Solution Overview

Problem

Current methods for processing signals from flow meters in internal combustion engines are inadequate for accurately measuring air flow under different intake modes, such as those involving EGR exhaust gas recirculation, leading to measurement errors beyond acceptable limits, especially when the engine operates in mode B.

Innovation Solution

A method that processes signals from flow meters using distinct logic for each intake mode, converting electrical characteristics into instantaneous flow values and applying corrections based on engine parameters like load and rotational speed, with separate linearization and correction steps for each mode to achieve precise flow rate measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a single processing logic is used for all intake modes, then the device complexity is reduced, but the measurement precision deteriorates significantly in mode B (error exceeds ±3%)

Engineering Contradiction:
Improveair flow measurement precisionVSAvoidprocessing logic complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements dynamic adaptation of processing logic based on detected intake modes. The system automatically switches between first processing logic (for mode A) and second processing logic (for mode B) depending on the current operating conditions, allowing optimal measurement precision for each mode without requiring a permanently complex multi-logic system.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes processing parameters (filtering coefficients, correction factors, calculation methods) based on the detected intake mode. By adjusting these parameters dynamically, the system achieves high measurement precision for both mode A and mode B while maintaining a unified processing framework that doesn't permanently increase device complexity.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If distinct processing logic is implemented for each intake mode, then the measurement precision is maintained within ±3% across all modes, but the device complexity increases

Engineering Contradiction:
Improveair flow measurement precisionVSAvoidsystem configuration ease
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The system performs self-configuration by automatically detecting the current intake mode and selecting the appropriate processing logic without requiring manual intervention. The control unit autonomously adapts the processing parameters based on operating conditions, eliminating the need for complex manual configuration procedures while maintaining high measurement precision.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system uses feedback from mode detection mechanisms to automatically adjust processing logic selection. By continuously monitoring intake mode conditions and adjusting processing parameters accordingly, the system maintains optimal measurement precision across different modes while simplifying operation through automatic adaptation rather than manual configuration.

Inventive Principle:
Principle #23Feedback

3Reliability

If conventional filtering and map correction are used, then the processing simplicity is maintained, but the measurement accuracy becomes insufficient for future anti-pollution standards under varying intake modes

Engineering Contradiction:
Improvemeasurement reliability for emission standardsVSAvoidprocessing chain complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent enhances conventional processing by dynamically adapting filtering and correction parameters based on detected intake modes. The system maintains the basic structure of conventional processing (filtering + map correction) but adds dynamic parameter adjustment that improves reliability for emission standards without requiring a complete redesign of the processing chain.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent modifies processing parameters (filter coefficients, map selection, correction factors) based on intake mode detection. This parameter adaptation allows the conventional processing framework to achieve the measurement accuracy required for future anti-pollution standards while avoiding the need for fundamentally more complex processing architectures.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2404047B1Method for processing a signal from a flow meter for measuring a gas flow in an internal combustion engine
Publication Date: 2017.01.25 RENAULT SA
  • EP2404047B1 patent drawingFigure 1
  • EP2404047B1 patent drawingFigure 2
  • EP2404047B1 patent drawingFigure 3~4

AI summary

The invention relates to a method for processing a signal from a flow meter for measuring a gas flow in an internal combustion engine, characterised in that the method comprises processing the signal according to a first logic when the engine operates in a first intake mode and processing the signal according to a second logic when the engine operates in a second intake mode. The first intake mode is characterised by the activation of a high-pressure EGR valve. The second intake mode is characterised by the activation of a low-pressure EGR valve.