Ultrasonic Flowmeter Interleaving Measurement and Estimation Sequences

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Solution Overview

Problem

Ultrasonic flowmeters face challenges in achieving precise flowrate measurements with low power consumption due to the need for substantial data processing to infer the speed of sound, which is temperature-dependent, leading to increased power consumption and potential inaccuracies.

Innovation Solution

An ultrasonic flowmeter that employs a combination of flow measurement and estimation sequences, where flow estimation sequences determine changes in fluid conditions by comparing transit times of co- and counter-propagating ultrasonic wave packets, reducing the need for full flow measurements and thus minimizing power consumption, and using a learning algorithm to adjust the frequency and duration of these sequences based on fluid conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If full flow measurement sequences are continuously performed to maintain measurement precision, then measurement precision is improved, but power consumption increases

Engineering Contradiction:
Improveflowrate measurement precisionVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic flow measurement sequences interspersed with flow estimation sequences. The control circuit alternates between performing complete flow measurements (which consume more power but provide accurate data) and performing only flow estimations (which consume less power). This periodic alternation allows the system to maintain acceptable measurement precision while significantly reducing average power consumption compared to continuous full measurements.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent applies partial action by implementing flow estimation sequences that perform only partial measurements - specifically measuring only the transit time of ultrasonic signals in one direction or using simplified calculation methods. These partial measurements provide sufficient information for estimating flow conditions between full measurements, reducing the computational burden and power consumption while maintaining adequate measurement precision for the application.

Inventive Principle:
Principle #16Partial or excessive action

2Measurement precision

If flow measurement sequences are performed frequently to track fluid condition changes, then measurement accuracy is improved, but power consumption increases

Engineering Contradiction:
Improvefluid condition monitoring accuracyVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent implements a feedback mechanism where the control circuit analyzes results from flow estimation sequences to determine whether fluid conditions have changed significantly. Based on this feedback, the system dynamically decides whether to perform a complete flow measurement or continue with estimation sequences. This feedback-driven approach ensures accurate tracking of fluid condition changes while minimizing unnecessary full measurements that would consume excessive power.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If substantial data processing is performed to infer speed of sound for accurate flowrate measurement, then measurement precision is improved, but power consumption increases

Engineering Contradiction:
Improveflowrate measurement precisionVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent extracts only the essential information needed for flow measurement by using flow estimation sequences that determine whether fluid conditions have changed without performing complete speed of sound inference calculations. By taking out only the critical measurement components and omitting substantial data processing during estimation phases, the system maintains measurement precision when needed while dramatically reducing power consumption during routine monitoring.

Inventive Principle:
Principle #2Taking out (Extraction)

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 accurate flowrate measurement with reduced power consumption by interleaving flow measurement sequences with flow estimation sequences, adapting to changes in fluid conditions, and maintaining overall meter accuracy over longer periods, thereby extending battery life and improving efficiency.

Implementation Method 1

two or more ultrasonic transducers arranged at the flow tube for transmitting and receiving the ultrasonic wave packets through the fluid

Methodology Applied
Scientific EffectUltrasonic wave propagation: Ultrasound

Implementation Method 2

the transit time is considered to be the time an ultrasonic wave front takes to traverse the fluid from transmitting transducer to the receiving transducer

Methodology Applied
Scientific EffectTime of flight: Time of Flight

Implementation Method 3

A measure for the transit time is the phase difference, Δφ between two oscillations making up the wave packets

Methodology Applied
Scientific EffectPhase difference:

Data Source

PatentEP3516348B1Ultrasonic flowmeter and method using partial flow measurements
Publication Date: 2020.11.04 KAMSTRUP
  • EP3516348B1 patent drawingFigure 1~2
  • EP3516348B1 patent drawingFigure 3~4
  • EP3516348B1 patent drawing

AI summary

Ultrasonic flowmeter for measuring the flowrate of a fluid based on transit times of opposite propagating ultrasonic wave packets, including two ultrasonic transducers arranged at a flow tube for transmitting and receiving the ultrasonic wave packets through a fluid; a control circuit configured for operating the ultrasonic transducers to transmit and receive co-propagating and counter-propagating ultrasonic wave packets, and to determine transit times between transmission and reception of the ultrasonic wave packets; wherein the control circuit is further configured to continuously determine the flowrate of the fluid based on sequential application of separate flow measurement sequences and flow estimation sequences, the flow measurement sequence including transmitting and receiving a co-propagating wave packet and a counter-propagating wave packet, determining a transit time difference between the co-propagating and the counter-propagating wave packets, determining the speed of sound in the fluid, and calculating the flowrate based on the transit time difference and the speed of sound; and the flow estimation sequence including transmitting and receiving a co-propagating wave packet and/or a counter-propagating wave packet, and based on the co-propagating or the counter-propagating wave packet, determining whether a fluid condition of the fluid has changed since the previous flow measurement.