Adjusting Soot Loading Model for Diesel Particulate Filter

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Solution Overview

Problem

Current methods for estimating soot loading in diesel particulate filters (DPFs) are inaccurate due to uncertainties such as sensor drift, DPF variations, ash loading, and non-uniform soot distribution, leading to potential damage or premature wear of the filters.

Innovation Solution

A method that adjusts the soot loading model by using a factor to align pressure drop and volume flow measurements of the subject DPF with those of a nominal DPF, incorporating an offset value and adjusting model parameters to minimize errors, ensuring accurate soot loading estimation for timely regeneration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If pressure drop data is used to estimate soot loading through a nominal DPF model, then soot loading estimation can be performed, but accuracy deteriorates due to DPF-to-DPF variations, ash loading, non-uniform soot loading, and sensor uncertainties

Engineering Contradiction:
Improvesoot loading estimation accuracyVSAvoidmodel accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system continuously monitors actual pressure drop measurements from the subject DPF and compares them against the nominal DPF model predictions. When deviations exceed predetermined thresholds, the system triggers regeneration operations or adjusts the model parameters to account for DPF-to-DPF variations and aging effects, thereby maintaining estimation accuracy over time

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The model dynamically adjusts parameters such as the nominal DPF pressure drop curve and soot loading thresholds based on accumulated operational data. The system modifies model inputs to compensate for ash loading, catalyst sintering, and other aging factors that cause deviations from nominal behavior, ensuring continued accurate soot loading estimation

Inventive Principle:
Principle #35Parameter changes

2Reliability

If soot loading is not accurately estimated, then DPF damage may result, but implementing more complex measurement systems increases device complexity

Engineering Contradiction:
ImproveDPF performanceVSAvoidmeasurement system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The DPF system uses its own operational data (pressure drop measurements, temperature, flow rate) to self-diagnose soot loading conditions and trigger appropriate responses. The system performs self-regeneration based on estimated soot levels without requiring external intervention or complex external monitoring systems

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The controller acts as an intermediary that processes pressure drop signals, compares them against nominal models, and translates them into soot loading estimates. This intermediate processing layer simplifies the overall system by consolidating measurement and estimation functions in a single control unit rather than requiring multiple sensors and complex measurement infrastructure

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If estimated soot loading is too low, then the DPF may be overloaded with soot before regeneration, but if estimated soot loading is too high, then excessive regeneration operations can shorten DPF useful life

Engineering Contradiction:
Improveregeneration timing accuracyVSAvoidDPF useful life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The system uses feedback from continuous pressure drop monitoring to dynamically adjust regeneration timing. When the estimated soot loading approaches thresholds that would cause overload, regeneration is triggered. The system learns from actual DPF performance and regeneration outcomes to refine its estimation algorithm, preventing both premature and delayed regeneration while extending DPF service life

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary estimation of soot loading using pressure drop data before initiating regeneration operations. This advance assessment allows the system to prepare appropriate regeneration parameters and timing, ensuring that regeneration occurs at the optimal moment to burn off soot without subjecting the DPF to unnecessary thermal stress from excessive or premature regeneration cycles

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2321504B1Method for estimating soot loading in a diesel particulate filter, and engine and aftertreatment system
Publication Date: 2018.11.07 MACK TRUCKS INC
  • EP2321504B1 patent drawingFigure 1~2
  • EP2321504B1 patent drawingFigure 3
  • EP2321504B1 patent drawing

AI summary

A method for estimating soot loading of a diesel particulate filter includes establishing a soot loading model for estimating soot loading of a nominal diesel particulate filter, adjusting the soot loading model for a subject filter to account for differences between the nominal filter and the subject filter, and estimating soot loading of the subject filter using the adjusted soot loading model. An engine with a diesel particulate filter is also provided.