Vehicle Probe Clogging Diagnosis via Resistance Monitoring

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Solution Overview

Problem

The oxygen probe in heat engine vehicles can become clogged due to soot deposition, leading to incorrect fuel injection measurements and unnecessary replacement costs, as the distinction between temporary clogging and permanent malfunction is challenging to determine.

Innovation Solution

A computer system that communicates with oxygen probes before and after the depollution system, calculates air coefficients, and diagnoses clogging by monitoring parameter variations over defined intervals, allowing for differentiation between temporary clogging and permanent malfunctions, and triggering unclogging operations when necessary.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the engine control unit replaces the oxygen probe upon detecting clogging, then the measurement accuracy is restored, but unnecessary replacement costs and time are incurred due to temporary clogging that can resolve itself

Engineering Contradiction:

Improvemeasurement accuracyVSAvoidreplacement time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary diagnostic actions by monitoring probe resistance variations and comparing them against stored reference values before triggering a replacement. This preliminary monitoring phase allows the system to distinguish between temporary clogging (where resistance varies but remains within acceptable ranges) and permanent malfunction (where resistance exceeds thresholds), preventing unnecessary replacements while maintaining measurement reliability.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors the probe's electrical resistance and provides feedback to the control unit, which compares real-time measurements against stored reference profiles. This feedback mechanism enables the system to detect clogging conditions and determine whether they are temporary or permanent, allowing for intelligent decision-making about probe replacement versus continued operation.

Inventive Principle:

Principle #23Feedback

2Measurement precision

If the engine control unit advises probe replacement upon detecting clogging, then the fuel injection accuracy is maintained, but unnecessary costs are incurred for replacing probes that can be unclogged through high-speed operation

Engineering Contradiction:

Improvefuel injection accuracyVSAvoidreplacement cost

Core Design Contradiction:

Measurement precisionVSLoss of substance

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system enables the probe to self-diagnose and self-cure by monitoring its own electrical resistance and triggering high-speed operation sequences that burn off soot accumulation. The probe's performance is continuously self-monitored, and when clogging is detected, the system automatically initiates unclogging operations without requiring external intervention or replacement.

Inventive Principle:

Principle #25Self-service

3Reliability

If the system monitors probe resistance continuously, then temporary clogging can be distinguished from permanent malfunction, but the device complexity increases due to additional monitoring circuits and processing requirements

Engineering Contradiction:

Improveclogging detection accuracyVSAvoidmonitoring system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The monitoring system performs multiple functions using a single integrated approach: it measures probe resistance, compares against reference values, detects clogging conditions, determines whether clogging is temporary or permanent, and triggers appropriate responses. By consolidating these functions into a unified monitoring and diagnostic system, the complexity is managed more efficiently than if separate systems were used for each function.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system monitors changes in the probe's electrical resistance parameter over time and compares these variations against stored reference profiles. By tracking parameter changes rather than relying on absolute values, the system can detect clogging conditions and distinguish between temporary and permanent states, maintaining diagnostic accuracy while using relatively simple monitoring hardware.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS12146430B2Computer for diagnosing clogging of a probe for a vehicle

Publication Date: 2024.11.19 SCHAEFFLER TECHNOLOGIES AG & CO KG

AI summary

A computer for a vehicle, the vehicle including a heat engine, a depollution system configured to depollute the exhaust gases originating from the engine, a first probe placed between the outlet of the heat engine and the inlet of the depollution system and configured to measure a first parameter relating to the oxygen level in the exhaust gases exiting the heat engine, a second probe placed at the outlet of the depollution system and configured to measure a second parameter relating to the oxygen level in the exhaust gases exiting the depollution system. The computer being configured to receive the values measured by the first probe and by the second probe over a predefined measurement time interval and to diagnose clogging of the first probe.