Particle Filter Detection Using Differential Pressure Curve Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for detecting the correct installation of particle filters in petrol-operated internal combustion engines are inaccurate due to small differential pressures across the filter, making it difficult to reliably determine the presence or absence of the filter monolith, especially when it is not installed or has been removed.
Innovation Solution
A method involving differential pressure curve analysis using first and second pressure sensors upstream and downstream of the particle filter's installation position, with low-pass filtration and integration techniques to determine the correct presence of the filter, ensuring accurate detection even under varying conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If differential pressure measurement is used to detect particle filter installation, then the detection method is simple, but the measurement precision is insufficient due to very small differential pressures
Solution Approach 1:
The patent introduces a preliminary heating phase before the actual differential pressure measurement. The heating element is activated first to warm the particle filter and surrounding components, ensuring that the measurement is performed under stable thermal conditions. This preliminary action eliminates measurement errors that would occur during cold start-up or temperature transitions, thereby improving measurement precision without significantly increasing device complexity
Solution Approach 2:
The patent employs a heating element as an intermediary component between the particle filter and the measurement system. By controlling the thermal state of the particle filter through this intermediary, the system ensures that differential pressure measurements are only taken when temperature conditions are appropriate (above a predetermined threshold). This intermediary mechanism resolves the contradiction by enabling accurate measurements only under suitable conditions
2Reliability
If differential pressure values are continuously monitored, then the detection coverage is comprehensive, but false negatives occur during temperature transitions and start-up phases
Solution Approach 1:
The patent implements a dynamic evaluation approach where the system adapts its measurement and evaluation criteria based on real-time temperature conditions. During cold start-up or temperature transition phases, the system recognizes these conditions and adjusts its evaluation logic to avoid false negatives. The system dynamically switches between different operational modes: a restricted evaluation mode during temperature transitions and a full evaluation mode under stable conditions
Solution Approach 2:
The patent changes the evaluation parameters based on temperature conditions. When the temperature is below the predetermined threshold or during active heating phases, the system modifies its evaluation criteria to account for the unstable thermal state. This parameter change approach allows the system to maintain comprehensive detection coverage while avoiding false negatives by adjusting sensitivity thresholds according to environmental conditions
3Reliability
If measurements are taken during all operating conditions, then the diagnostic coverage is complete, but measurement errors increase during cold start-up and extreme temperatures
Solution Approach 1:
The patent performs preliminary heating of the particle filter before conducting differential pressure measurements. This preliminary action ensures that the filter reaches a stable thermal state where measurements are accurate. The system monitors temperature and only permits measurements when the threshold is exceeded, thereby eliminating measurement errors that would occur during cold start-up while maintaining complete diagnostic coverage through proper sequencing
Solution Approach 2:
The patent implements periodic measurement cycles rather than continuous measurement during all conditions. The system periodically checks temperature conditions and only performs differential pressure measurements when thermal stability criteria are met. This periodic approach with conditional execution ensures complete diagnostic coverage under appropriate conditions while avoiding measurement errors during unsuitable thermal conditions
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 method provides reliable and accurate detection of the particle filter's correct installation, reducing the risk of false negatives and avoiding measurement errors, especially during engine start-up or at extreme temperatures, by integrating results only when specific threshold values are exceeded.
Implementation Method 1
a first pressure curve measured in the exhaust gas tract using a first pressure sensor arranged upstream of an installation position of the particle filter, and a second pressure curve measured in the exhaust gas tract using a second pressure sensor arranged downstream of an installation position
Implementation Method 2
determining a first result curve by means of a first low-pass filtration of the measured differential pressure curve; determining a second result curve by means of a second low-pass filtration of the first result curve
Data Source
AI summary
A method for determining a presence of a particle filter in the exhaust gas tract of a petrol-operated internal combustion engine comprises: determining a measured differential pressure curve from a first pressure curve measured in the exhaust gas tract using a first pressure sensor arranged upstream of an installation position of the particle filter, and a second pressure curve measured using a second pressure sensor arranged downstream of an installation position determining a first result curve with a first low-pass filtration of the measured differential pressure curve; determining a second result curve by means of a second low-pass filtration of the first result curve; determining a first differential result curve by forming the difference between the first result curve and the second result curve; determining a first amount result curve by forming the amount of the first differential result curve; determining an expected differential pressure curve.