Liquid Flow Measurement Using Stereometric Imaging

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Solution Overview

Problem

Existing methods for determining the flow rate and cross-sectional area of liquids in open-top channels, such as wastewater channels, are complex and require multiple optical measurements and image recognition processes, which can be cumbersome and inefficient.

Innovation Solution

The method involves simultaneously capturing stereometric images from multiple optical imaging devices positioned around the channel to determine local surface velocities and vertical heights of floating structures, using trigonometric functions and digital image recognition to calculate three-dimensional distances, and then applying these data to a flow model to calculate mean flow velocity and volume flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple separate optical measurements are taken to determine flow rate and cross-sectional area, then measurement accuracy is improved, but device complexity and measurement time increase

Engineering Contradiction:
Improveflow rate measurement accuracyVSAvoidapparatus structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines multiple optical imaging devices into a single integrated measurement system that simultaneously captures both surface flow velocity and liquid level data. The control evaluation device integrates multiple measurement functions (velocity calculation, level detection, cross-sectional area computation) into one unified system, eliminating the need for separate measurement apparatuses and reducing overall device complexity while maintaining measurement accuracy.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent transitions from separate one-dimensional measurements (velocity and level) to a unified three-dimensional stereometric imaging approach. By capturing images from multiple angles and processing them to extract 3D position information, the system simultaneously determines both horizontal velocity and vertical level data from a single integrated measurement process, reducing the number of required optical measurements.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If multiple separate optical measurements are taken to determine flow rate and cross-sectional area, then measurement accuracy is improved, but measurement time increases

Engineering Contradiction:
Improvecross-sectional area measurement accuracyVSAvoidmeasurement process time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent implements continuous simultaneous measurement by synchronizing multiple optical imaging devices to capture images at the same moment. The control evaluation device continuously processes these synchronized images to calculate both velocity and level data in real-time, eliminating the sequential measurement approach and reducing total measurement time while maintaining accuracy through continuous data acquisition.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

By using stereometric imaging from multiple angles, the system extracts both horizontal and vertical position information simultaneously from the same set of images. This dimensional approach allows concurrent determination of flow velocity and liquid level without requiring separate measurement passes, significantly reducing measurement time while preserving accuracy.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Measurement precision

If stereometric images are evaluated using trigonometric functions and digital image recognition, then measurement precision is improved, but computational complexity increases

Engineering Contradiction:
Improvethree-dimensional distance accuracyVSAvoidimage evaluation process
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex manual or mechanical measurement methods with automated digital image recognition and trigonometric calculations. The control evaluation device uses software-based image processing to automatically extract position information from stereometric images, eliminating the need for physical measurement instruments and reducing operational complexity despite increased computational requirements.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 simplifies the apparatus structure and measurement process, allowing for accurate and efficient determination of flow rates and cross-sectional areas by reducing the need for multiple optical measurements and enhancing the precision of volume flow calculations.

Implementation Method 1

images of the surface of the flowing liquid are made at defined time intervals

Methodology Applied
Scientific EffectOptical imaging: Photography

Implementation Method 2

a three-dimensional distance between the floating structure and a stationary reference point can be determined for each set of images

Methodology Applied
Scientific EffectStereometry: Photogrammetry

Data Source

PatentEP2589936B1Method for measuring the volume flow of a liquid flowing in a channel, and device for carrying out the same
Publication Date: 2018.08.08 SEBA HYDROMETRIE GMBH & CO
  • EP2589936B1 patent drawingFigure 1~2
  • EP2589936B1 patent drawingFigure 3~4

AI summary

The flow rate of liquid (2) is determined at defined time intervals by creating the images of the surface (3) of flowing liquid, to determine the displacement on the surface of the liquid floating structures (4,4'). The vertical position (h) of the surface of the liquid is evaluated by determining the cross-sectional area of the liquid. The flow velocity of liquid and the vertical position of the surface of liquid are determined using several images simultaneously captured from different positions of the liquid surface. An independent claim is included for a device for detecting flow rate of liquid flowing through channel.