Particle Filter Mass Estimation via Differential Pressure and Flow

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Solution Overview

Problem

Current methods for estimating the mass of particles in a motor vehicle particulate filter are not precise enough to meet current anti-pollution standards, are costly due to the use of multiple sensors, and result in fuel overconsumption and engine performance reduction, necessitating a more accurate and cost-effective solution.

Innovation Solution

A system and method that estimates the mass of particles by measuring differential pressure and flow rate at the particulate filter terminals, using a variable coefficient to correct estimates, and incorporating measurements of gas flow, oxygen, and nitrogen oxide concentrations to provide precise mass estimation with a minimal number of sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple sensors (two oxygen sensors) are used to estimate particle mass, then measurement precision improves, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improveparticle mass estimation precisionVSAvoidsensor quantity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts and utilizes parameters that are already being measured by existing sensors in the exhaust system (oxygen concentration, nitrogen oxide concentration, temperature, flow rates) rather than adding dedicated sensors for particle mass measurement. This approach achieves accurate particle mass estimation without increasing sensor quantity, directly resolving the contradiction between measurement precision and device complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a microprocessor-based calculation system that acts as an intermediary, computing particle mass from measurements of other parameters (oxygen concentration difference, nitrogen oxide concentration, temperature, flow rates) rather than directly measuring particle mass. This intermediary calculation approach achieves precise estimation without requiring additional expensive sensors.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If post-treatment systems are implemented to meet emission standards, then nitrogen oxide and particle emission levels improve, but fuel consumption increases and engine performance decreases

Engineering Contradiction:
Improveemission levelsVSAvoidfuel consumption
Core Design Contradiction:
Object-affected harmful factorsVSUse of energy by moving object

Solution Approach 1:

The patent implements a feedback mechanism where particle mass is continuously estimated in real-time, and this information feeds back to the control system to optimize regeneration timing and injection strategies. This feedback enables precise control of the post-treatment system, ensuring emissions are met while minimizing unnecessary fuel injection and regeneration events, thus reducing overall fuel consumption.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent performs preliminary estimation of particle mass accumulation to predict when regeneration will be needed, allowing the system to plan and execute regeneration events at optimal moments. This preliminary action prevents premature or excessive regeneration, reducing unnecessary fuel consumption while ensuring emissions standards are consistently met.

Inventive Principle:
Principle #10Preliminary action

3Object-affected harmful factors

If frequent regeneration is performed to maintain low particle emissions, then emission levels improve, but fuel consumption increases

Engineering Contradiction:
Improveparticle emission levelsVSAvoidfuel consumption
Core Design Contradiction:
Object-affected harmful factorsVSUse of energy by moving object

Solution Approach 1:

The patent employs dynamic estimation of particle mass that adapts to varying operating conditions (engine load, temperature, flow rates) rather than using fixed thresholds. This dynamic approach allows the system to accurately determine when regeneration is truly necessary, preventing premature regeneration events that would waste fuel while ensuring emissions standards are met under all operating conditions.

Inventive Principle:
Principle #15Dynamics

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 allows for real-time, precise estimation of particle mass, reducing fuel consumption and manufacturing costs while meeting anti-pollution standards, and is applicable across various engine operating modes.

Implementation Method 1

comprising means for measuring a differential pressure at the particle filter terminals

Methodology Applied
Scientific EffectDifferential pressure measurement: Pressure Drop

Implementation Method 2

means for measuring a gas flow upstream of the particulate filter

Methodology Applied
Scientific EffectGas flow measurement:

Implementation Method 3

means for measuring the temperature of the particulate filter

Methodology Applied
Scientific EffectTemperature measurement:

Implementation Method 4

means for measuring the temperature of the particulate filter, oxygen and nitrogen oxide concentrations downstream of the particulate filter

Methodology Applied
Scientific EffectGas concentration measurement:

Implementation Method 5

the filter is regenerated by combustion of the particles which it contains using in particular a catalyst to raise the temperature within the particle filter

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP2507491B1System and method for estimating the mass of particles stored in a particle filter of a motor vehicle
Publication Date: 2016.05.11 RENAULT SA
  • EP2507491B1 patent drawingFigure 1
  • EP2507491B1 patent drawingFigure 2
  • EP2507491B1 patent drawing

AI summary

The invention relates to a system for estimating the mass of particles stored in a particle filter (2) mounted in the exhaust line (6) of an internal combustion engine (3) of a motor vehicle, including a means (7, 8, 15) for measuring a differential pressure across the terminals of the particle filter, a first estimation means (15) for estimating a differential particle flow across the terminals of the particle filter, a second estimation means (15) for estimating a differential pressure across the terminals of the particle filter, and a third estimation means (17) for estimating the mass of particles stored in the particle filter (2) according to the sum of the differential particle flow and a deviation calculated between the estimation and the measurement of the differential pressure.