Pump Speed Determination via Pressure Signal Edge Counting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for determining the speed of pumps used in SCR catalytic converters for reducing NOx emissions are computationally intensive and costly, requiring complex Fourier analysis of pressure signals.
Innovation Solution
A method that determines the rotational speed of a pump by analyzing fluctuations in the pressure signal directly in the time domain, eliminating the need for frequency domain analysis, by counting rising and falling sections or edges of the pressure signal within a predetermined time interval, and calculating the speed with minimal computational effort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If Fourier analysis is used to determine pump speed from pressure signals, then measurement precision is improved, but device complexity and computational cost increase
Solution Approach 1:
The patent extracts only the essential information needed for speed determination from the pressure signal by counting rising and falling edges, eliminating the need for complex Fourier analysis. This extracts the core speed-related features while discarding unnecessary computational complexity.
Solution Approach 2:
The invention replaces expensive, computationally intensive Fourier analysis with a simple, low-cost edge-counting method. This disposable approach uses minimal computational resources while achieving sufficient measurement precision for pump speed monitoring.
2Measurement precision
If Fourier analysis is used to determine pump speed, then measurement precision is improved, but processing time increases
Solution Approach 1:
The patent skips the time-consuming Fourier transform process and directly counts pressure signal edges to determine pump speed. This rushing through the essential measurement step achieves rapid results without sacrificing necessary accuracy.
Solution Approach 2:
The method extracts only the critical speed information from pressure signals by counting edges, eliminating unnecessary computational steps and reducing processing time while maintaining measurement precision.
3Measurement precision
If complex frequency analysis is performed on pressure signals, then measurement precision is improved, but ease of operation deteriorates
Solution Approach 1:
The invention replaces complex frequency analysis with a simple, easily implementable edge-counting method. This approach is computationally cheap and operationally simple, making pump speed determination accessible without specialized processing capabilities.
Solution Approach 2:
The method extracts the essential speed information through simple edge counting, removing the complexity of frequency analysis while maintaining sufficient measurement precision for practical applications.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a method for determining the speed of a pump. In particular, the invention relates to a method for determining the speed of a pump by means of which the fluid pressure of a fluid (e.g., a reducing agent for exhaust aftertreatment) is regulated to a target fluid pressure ptarget. The method comprises the step of providing (S1) a pressure signal at a predetermined time interval, wherein the pressure signal indicates a fluid pressure of the fluid and/or is a quantity from which the fluid pressure of the fluid can be derived. Furthermore, the method comprises the step of determining (S2) the speed from temporal fluctuations of the pressure signal at the predetermined time interval. In addition to the method itself, the invention also relates to a device designed to carry out the method and to a motor vehicle with a corresponding device.