PM Filter Crack Detection via Exhaust Gas Conversion Efficiency

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional diagnostic systems for cracked particulate matter (PM) filters in vehicle exhaust systems are expensive due to the use of PM or particulate number (PN) sensors, necessitating a cost-effective alternative for detecting filter damage.

Innovation Solution

A diagnostic system utilizing existing gas and pressure sensors to measure exhaust gas components and calculate conversion efficiency, comparing it to predetermined thresholds to determine if the PM filter is cracked or damaged, without requiring a PM sensor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a PM sensor is used to detect cracked PM filters, then diagnostic accuracy is improved, but vehicle cost increases

Engineering Contradiction:

Improvediagnostic accuracyVSAvoidvehicle cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent uses gas concentration measurements as a substitute (copy) for direct PM particle counting. By measuring gas components like CO, HC, and NOx upstream and downstream of the PM filter, the system infers filter performance without requiring expensive PM sensors. This copying approach maintains diagnostic capability while using cheaper, more readily available sensor technology.

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent replaces the mechanical/optical PM sensing system with a chemical sensing system. Instead of directly detecting particulate matter physically, the system uses gas sensors to detect chemical composition changes in the exhaust gas, which indirectly indicate PM filter performance. This substitution eliminates the need for costly PM sensors while maintaining diagnostic functionality.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of manufacture

If existing gas sensors are used instead of PM sensors, then vehicle cost is reduced, but diagnostic capability may be compromised

Engineering Contradiction:

Improvevehicle costVSAvoiddiagnostic capability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent introduces gas concentration measurements as an intermediary indicator for PM filter performance. Rather than directly measuring PM, the system uses gas component concentrations (CO, HC, NOx) as proxy indicators. The conversion efficiency calculation serves as the intermediary metric that links gas sensor data to filter health assessment, maintaining diagnostic reliability through indirect measurement.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the measurement parameter from direct PM mass/concentration to gas component conversion efficiency. By monitoring how effectively the exhaust gas treatment system converts harmful gases (CO to CO2, HC to CO2+H2O, NOx to N2), the system derives filter performance information. This parameter transformation allows existing gas sensors to provide meaningful diagnostic data about PM filter condition.

Inventive Principle:

Principle #35Parameter changes

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

Enables cost-effective detection of PM filter damage by using existing sensors, reducing vehicle costs and improving exhaust system performance by accurately distinguishing between functional and cracked PM filters based on conversion efficiency and pressure drop analysis.

Implementation Method 1

at least one gas sensor configured to measure a gas component of exhaust gas flowing through the exhaust system and the PM filter

Methodology Applied

Scientific EffectGas sensing:

Implementation Method 2

Catalysts chemically convert portions of the exhaust gas

Methodology Applied

Scientific EffectCatalysis: Catalysis

Implementation Method 3

at least one pressure sensor configured to measure an exhaust gas pressure drop across the PM filter

Methodology Applied

Scientific EffectPressure measurement:

Implementation Method 4

PM filters trap PM in the exhaust gas

Methodology Applied

Scientific EffectPhysical filtration: Filter (physical)

Implementation Method 5

it is regenerated by burning the trapped PM at a high temperature

Methodology Applied

Scientific EffectCombustion: Combustion

Data Source

PatentUS9739761B2Particulate matter filter diagnostic techniques based on exhaust gas analysis

Publication Date: 2017.08.22 FCA US LLC

AI summary

A diagnostic system and method for diagnosing the performance of a particulate matter (PM) filter of an exhaust system each involve receiving, by a controller from at least one sensor, a gas component measurement of exhaust gas flowing through the exhaust system and the PM filter. The controller calculates a conversion efficiency of the gas component by the PM filter and compares the calculated conversion efficiency to a predetermined conversion efficiency threshold indicative of an expected conversion efficiency of a flow-through catalyst. The controller then determines whether the PM filter is cracked or damaged based on the comparison between the calculated conversion efficiency and the predetermined conversion efficiency threshold.