Diesel Particulate Filter Regeneration Control via Weighted Parameter Averaging

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Solution Overview

Problem

Current diesel particulate filter systems face challenges in efficiently determining the optimal time for regeneration, as existing control methods rely on discrete boolean responses, which may overlook various factors and are susceptible to sensor faults, leading to inefficient or unsafe regeneration processes.

Innovation Solution

A diesel particulate filtering system that includes a regeneration device and a controller capable of evaluating a weighted average of normalized parameter values to initiate regeneration, considering multiple factors such as soot loading, backpressure, time since last regeneration, favorable conditions, and engine signals, allowing for adaptive weighting to account for sensor accuracy and operational conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If discrete boolean control methods are used to determine regeneration timing, then the control system is simple, but the regeneration efficiency is poor and sensor faults are not detected

Engineering Contradiction:
Improvecontrol system complexityVSAvoidregeneration efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The system transforms discrete boolean sensor readings into continuous normalized parameter values (0-1 range), enabling more granular assessment of regeneration conditions. Multiple parameters (soot loading, backpressure, time since regeneration, favorable conditions, engine signals) are converted from binary states to continuous scales, allowing for more precise determination of optimal regeneration timing.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

A weighted average calculation serves as an intermediary between raw sensor data and regeneration control decisions. The controller computes a composite score by combining multiple normalized parameters with assigned weights, creating a single decision metric that balances various factors. This intermediary processing layer enables more reliable regeneration timing determination compared to direct boolean control.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If multiple parameters are evaluated for regeneration timing, then the accuracy of regeneration control is improved, but the computational complexity increases

Engineering Contradiction:
Improveregeneration timing accuracyVSAvoidcontrol algorithm complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The control algorithm is segmented into distinct processing stages: (1) reading individual sensor parameters, (2) normalizing each parameter to a 0-1 scale, (3) applying pre-determined weights to normalized values, (4) calculating the weighted average, and (5) comparing against a threshold. This segmentation makes the complex multi-parameter evaluation more manageable and implementable in embedded controllers.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system replaces complex mechanical or hardware-based decision-making with computational algorithms. Instead of using multiple separate hardware switches or mechanical indicators for each parameter, the invention uses software-based normalization and weighted averaging to process multiple sensor inputs, reducing hardware complexity while maintaining high measurement precision.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Loss of energy

If regeneration is delayed to maintain engine efficiency, then fuel economy is improved, but the risk of uncontrolled soot ignition increases

Engineering Contradiction:
Improvefuel economyVSAvoidsafety of regeneration process
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The system performs preliminary assessment of multiple parameters before initiating regeneration, including evaluating favorable conditions and engine signals in advance. By normalizing and weighting parameters such as time since last regeneration and current operating conditions, the system predicts the optimal regeneration timing beforehand, allowing regeneration to be scheduled at the most efficient moment while preventing dangerous delays that could lead to uncontrolled soot ignition.

Inventive Principle:
Principle #10Preliminary action

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 enables more efficient and controlled regeneration by considering a range of parameters, reducing the risk of uncontrolled soot ignition and maintaining engine efficiency, while compensating for potential sensor inaccuracies and varying operational conditions.

Implementation Method 1

a regeneration device configured to heat exhaust gases from the diesel engine prior to the exhaust gases reaching the filter

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

The DOC converts the excess hydrocarbon fuel into heat by means of the catalytic reaction of the catalyst

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 3

The DOC converts the excess hydrocarbon fuel into heat by means of the catalytic reaction of the catalyst, thus increasing the exhaust gas temperature

Methodology Applied
Scientific EffectExothermic Reaction: Exothermic Reaction

Implementation Method 4

Supplemental heat may also be generated in the exhaust flow by use of an auxiliary electrical heater

Methodology Applied
Scientific EffectJoule Heating: Joule Heating

Implementation Method 5

Supplemental heat may also be generated in the exhaust flow by use of an auxiliary electrical heater, or a microwave heater

Methodology Applied
Scientific EffectMicrowave Radiation: Microwave Radiation

Implementation Method 6

another method of filter regeneration uses a fuel-fired burner to heat the exhaust gas prior to the DPF

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 7

The DPF is configured so that the soot particles in the exhaust gas are deposited in the filter substrate of the DPF

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Data Source

PatentUS8136351B2System and method for filtering diesel engine exhaust particulates
Publication Date: 2012.03.20 WOODWARD INC
  • US8136351B2 patent drawing
  • US8136351B2 patent drawing
  • US8136351B2 patent drawing

AI summary

A diesel particulate filtering system that includes a filter configured to capture exhaust particulates from a diesel engine, a regeneration device configured to heat exhaust gases from the diesel engine prior to the exhaust gases reaching the filter, and a controller configured to control operation of the regeneration device, wherein the controller is further configured to turn the regeneration device on when a weighted average of a plurality of normalized parameter values exceeds a threshold value.