Metal Powder Quantity Determination in Particulate Filters

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Solution Overview

Problem

Existing methods for determining the quantity of metal powders accumulated in a particulate filter for internal combustion engines are not reliable, leading to potential underestimation or overestimation, which can cause negative effects on the filter's performance and regeneration processes.

Innovation Solution

A method that uses an electronic control unit with an estimation model and a measure model to accurately determine the quantity of metal powders by integrating physical quantities such as engine speed, fuel quality, and exhaust gas flow rates, ensuring precise calculation of pressure drops and volume flow rates to differentiate between particulate and metal powder contributions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If existing methods are used to determine the quantity of metal powders, then the determination process is simple, but the reliability and precision of the measurement are insufficient

Engineering Contradiction:
Improvedetermination precision of metal powder quantityVSAvoidcomplexity of determination method
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The determination method is segmented into two distinct models: an estimation model that uses operating parameters to calculate expected metal powder accumulation, and a measurement model that uses pressure drop data to calculate actual metal powder accumulation. This segmentation allows each model to be optimized for its specific function while maintaining overall system reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by using the estimation model only during accumulation phases when particulate is being trapped, and switching to the measurement model during regeneration phases or when high precision is required. This selective application of different determination approaches optimizes both precision and computational resources.

Inventive Principle:
Principle #16Partial or excessive action

2Productivity

If the quantity of metal powders is not accurately determined, then the system operation remains simple, but the regeneration process becomes inefficient and filter performance deteriorates

Engineering Contradiction:
Improveregeneration process efficiencyVSAvoidaccuracy of metal powder quantity determination
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent implements feedback by continuously monitoring pressure drop across the particulate filter and using this information to update both the estimation and measurement models. The differential pressure sensor provides real-time feedback on filter loading conditions, allowing the system to adjust regeneration timing and duration based on actual metal powder accumulation rather than relying solely on predetermined schedules.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The estimation model performs preliminary determination of metal powder quantity based on engine operating parameters before actual regeneration is needed. This preliminary assessment allows the system to prepare for upcoming regeneration events and plan maintenance activities in advance, improving overall system productivity.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If additional sensors are added to improve measurement accuracy, then the measurement precision increases, but the device complexity and cost increase

Engineering Contradiction:
Improveprecision of metal powder quantity measurementVSAvoidnumber of sensors and components
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system uses existing sensors (differential pressure sensor, temperature sensors, air flow meter) to determine metal powder quantity without requiring additional specialized sensors. The estimation model leverages data already being collected for other control functions, making the existing sensor network serve dual purposes: standard engine control and metal powder determination.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent introduces a computational intermediary (the dual-model determination system) that processes data from existing sensors to extract metal powder quantity information. Rather than adding sensors, the system adds an intermediate layer of data processing that transforms readily available sensor data into precise metal powder measurements.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 method provides a reliable and efficient means to determine the actual quantity of metal powders, preventing under or overestimation, thus ensuring proper regeneration phases and maintaining filter efficiency without requiring additional expensive components or sensors.

Implementation Method 1

a differential pressure sensor having a first and a second input connected to the inlet and to the outlet, respectively, of the particulate filter, as well as an output providing an electrical signal indicating the pressure drop at the ends of said particulate filter

Methodology Applied
Scientific EffectPressure drop measurement: Pressure Drop

Implementation Method 2

a temperature sensor arranged at the outlet of the particulate filter and providing an electrical signal indicating the temperature of the exhaust gases flowing out of the particulate filter; a temperature sensor arranged at the inlet of the particulate filter and providing an electrical signal indicating the temperature of the exhaust gases flowing into the particulate filter

Methodology Applied
Scientific EffectTemperature sensing:

Implementation Method 3

a catalytic converter, which is also arranged along the exhaust duct, upstream of the particulate filter

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 4

The particulate filter, indeed, acts like a mechanical barrier for the passage of the particulate and usually consists of channels parallel to porous walls and alternatively obstructed. The obstructions force the exhaust gases to flow through the side walls of the channels, so that the unburned particles making up the particulate, at first, are held back in the porosities of the side walls

Methodology Applied
Scientific EffectMechanical filtration: Filter (physical)

Data Source

PatentEP3521597B1Method to determine the quantity of metal powders accumulated in a particulate filter for an internal combustion engine
Publication Date: 2021.03.10 FAB ITAL MAGNETI MARELLI SPA
  • EP3521597B1 patent drawingFigure 1~2
  • EP3521597B1 patent drawingFigure 3
  • EP3521597B1 patent drawing

AI summary

A method to determine the actual quantity (ṁASH) of metal powders or ashes trapped in a particulate filter (10), which involves determining an estimated value of the quantity (ṁASH_EST) of metal powders trapped in the particulate filter (10) based on an estimation model (20, 21, 22, 23); determining a measured value of the quantity (ṁASH_M) of metal powders trapped in the particulate filter (10); updating the estimated value of the quantity (ṁASH_EST) of metal powders trapped in the particulate filter (10) as a function of the measured value; and determining the actual quantity (ṁASH) of metal powders or ashes trapped in a particulate filter (10) as a function of the update of the estimated value of the quantity (ṁASH_EST) of metal powders trapped in the particulate filter (10).