Particle Sensor Signal Valuation Using Exhaust Gas Flow
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Solution Overview
Problem
Existing particle sensors, especially integrating particle sensors, face cross-sensitivity issues due to changes in combustion process conditions, affecting their accuracy in measuring particle concentration in exhaust gases.
Innovation Solution
The method involves adjusting the sensor sensitivity by considering the exhaust gas stream, specifically by modifying the threshold value based on the exhaust gas flow, which includes air and fuel signals, to compensate for decreased sensitivity at higher gas flows, thereby enhancing measuring accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the exhaust gas stream flow increases, then the particle deposition on sensor surface decreases, but the sensor sensitivity decreases
Solution Approach 1:
The patent adjusts the threshold value parameter dynamically based on exhaust gas stream conditions. When exhaust gas flow increases and reduces particle deposition, the threshold value is lowered to maintain sensor sensitivity. This parameter adaptation resolves the contradiction by compensating for the reduced deposition effect through threshold adjustment, ensuring consistent measurement precision across varying flow conditions.
2Measurement precision
If the threshold value is lowered to compensate for decreased sensitivity at high gas flows, then measurement accuracy is maintained, but the complexity of signal valuation increases
Solution Approach 1:
The patent implements a feedback mechanism where the exhaust gas stream measurement is continuously monitored and used to dynamically adjust the threshold value. This closed-loop approach automates the compensation process, maintaining measurement accuracy without requiring complex manual signal valuation. The feedback system automatically adapts the threshold based on current flow conditions, resolving the contradiction between accuracy and complexity.
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 increases the accuracy of particle concentration measurements by accounting for the influence of exhaust gas streams on sensor signals, ensuring reliable monitoring and control of combustion processes.
Implementation Method 1
particles, especially soot particles, arrive in the collecting chamber and deposit in the hollow space between the two electrodes
Implementation Method 2
The at least slightly conductive particles bridge the intervening space between the two electrodes, so that there is a change in the impedance of the particle sensor
Data Source
AI summary
A method for operating a sensor for recording particles in an exhaust gas flow and a device for carrying out the method are provided, in which at least one measure of the exhaust gas flow is ascertained and in which the measure of the exhaust gas flow is taken into consideration in the valuation of the particle sensor signal made available by the particle sensor. The procedure is based on the knowledge that the exhaust gas flow, for instance, the exhaust gas volume flow, has an influence on the particle sensor signal made available by the particle sensor, especially when the measuring effect is based on the depositing of particles on a sensor surface. Using the procedure, a possibly present cross sensitivity of the particle sensor with respect to different exhaust gas flows is taken into consideration, so that the measuring accuracy is increased.