Fuel Injection Diagnosis via Oxygen Sensor Signal Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for diagnosing fuel supply system failures in internal combustion engines with spark ignition and fuel injection struggle to accurately detect faults due to the complex interactions between parameters, leading to false detections and unreliable reliability analysis, as they monitor GAIN and ALPHACL independently without considering their linked effects on injection time and exhaust gas richness.
Innovation Solution
A method that calculates the effective injection time using the oxygen sensor signal, incorporating factors like OFFSET, ALPHACL_MOYEN, GAIN, and Mair, and evaluates the diagnostic criterion CRITERION by integrating differences between theoretical and actual system characteristics, comparing it to predetermined thresholds to diagnose faulty states, ensuring reliable and representative analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If GAIN and ALPHACL are monitored independently to detect fuel supply system failures, then the monitoring can be simplified, but false detections occur and reliability analysis becomes inaccurate
Solution Approach 1:
The patent combines the monitoring of GAIN and ALPHACL parameters into a single integrated diagnostic criterion that evaluates their joint effect on injection time. Instead of independently monitoring each parameter against separate thresholds, the invention creates a unified monitoring approach that assesses the combined impact of both parameters on the effective injection time, thereby reducing false detections while maintaining diagnostic accuracy.
Solution Approach 2:
The patent implements a feedback mechanism where the diagnostic criterion continuously evaluates the actual injection time against the theoretical injection time, and uses this feedback to adjust the monitoring thresholds and detect deviations. The system learns from operational data and adapts the diagnostic criteria to account for normal variations in hydraulic characteristics while maintaining sensitivity to actual failures.
2Adaptability or versatility
If GAIN is adjusted to compensate for hydraulic drift, then the system adapts to aging, but ALPHACL remains nominal causing false negative detections
Solution Approach 1:
The patent merges the monitoring of GAIN compensation with ALPHACL regulation into a single diagnostic framework. The integrated criterion evaluates whether changes in GAIN are appropriately reflected in ALPHACL adjustments, detecting cases where GAIN compensates for hydraulic drift without corresponding ALPHACL changes that would indicate actual fuel supply failures.
Solution Approach 2:
The patent changes the diagnostic approach from monitoring individual parameter values to monitoring the relationship and interaction between parameters. The diagnostic criterion transforms the monitoring focus from static parameter thresholds to dynamic parameter relationships, evaluating how GAIN and ALPHACL interact to produce the effective injection time.
3Ease of operation
If separate monitoring windows are used for GAIN and ALPHACL, then each parameter can be monitored independently, but the diagnostic criterion cannot serve as a reliability criterion
Solution Approach 1:
The patent merges separate monitoring windows for GAIN and ALPHACL into a single integrated diagnostic criterion that evaluates both parameters simultaneously. This unified criterion provides a comprehensive assessment of fuel supply system health while maintaining ease of implementation through a structured monitoring approach.
Solution Approach 2:
The patent adds a new dimension to parameter monitoring by evaluating the interaction between GAIN and ALPHACL rather than their individual values. The diagnostic criterion operates in a combined parameter space that captures the joint effect of both parameters on injection time, providing more precise failure detection.
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 allows for rapid detection of fuel supply system failures by accounting for parameter interactions, reducing false detections and improving reliability, ensuring accurate diagnosis of faulty states without additional specific means, and providing a criterion that reflects the system's static behavior effectively.
Implementation Method 1
a lambda probe 8 located upstream of the catalyst 8, said lambda probe 8 making it possible to determine the richness of the exhaust gases at the outlet of the engine
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a method for diagnosing the condition of a system for supplying fuel to a fuel injected controlled-ignition internal combustion engine (1), of the type comprising an electric control device (6) that makes use of an oxygen probe (8) for closed-loop regulation of the value of the air/fuel ratio admitted to the combustion chambers of said engine (1), and according to which the signal delivered by said oxygen probe (8) is analyzed, characterized in that it consists in a) deducing from said signal, the change in the effective injection time making it possible to regulate the richness of the exhaust gases leaving the engine; b) calculating CRITERION = ?(CRITERIONl + CRITERION2 + CRITERION3); c) comparing CRITERION against predetermined minimum and maximum threshold values THRESHOLD_MIN and THRESHOLD_MAX; d) diagnosing a defective condition when CRITERION is outside of the window contained between THRESHOLD_MIN and THRESHOLD_MAX.