Signal Processing Circuit for Ultrasonic Flow Meter Accuracy

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Solution Overview

Problem

Ultrasonic flow meters face challenges in accuracy, which is a critical issue for precise detection of fluid flow velocity, and existing methods do not adequately address this problem.

Innovation Solution

A signal processing circuit and chip that calculate the current acoustic speed and temperature by determining delay times and distances between transducers, allowing for improved flow rate and velocity measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional ultrasonic flow meter methods are used, then the device is simple and easy to manufacture, but the measurement precision is insufficient

Engineering Contradiction:
Improveflow velocity detection accuracyVSAvoidsignal processing circuit complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The signal processing circuit is divided into multiple functional modules: a first processing module that obtains first delay time and first distance, a second processing module that obtains second delay time and second distance, a third processing module that calculates acoustic speed, and a fourth processing module that calculates flow velocity. This segmentation allows each module to perform a specific function independently, improving measurement precision while maintaining manageable system complexity through modular architecture.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The circuit performs preliminary calculations of acoustic speed and temperature compensation parameters during the measurement process. By pre-calculating the acoustic speed based on delay times and distances before final flow velocity computation, the system achieves more accurate measurements without requiring complex real-time adjustments, thus improving precision while controlling overall system complexity.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If acoustic speed is not accurately determined, then the device complexity is reduced, but the measurement precision of flow rate decreases

Engineering Contradiction:
Improveflow rate measurement accuracyVSAvoidacoustic speed calculation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The circuit uses feedback from the transducer signals to continuously refine the acoustic speed calculation. By measuring the actual delay times between signal transmission and reception, and using these feedback values to calculate acoustic speed and temperature compensation parameters, the system achieves high measurement precision. The feedback mechanism allows the system to adapt to changing acoustic conditions without requiring overly complex external calibration equipment.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts the acoustic speed parameter based on measured delay times and distances. Instead of using a fixed acoustic speed value, the circuit calculates the actual acoustic speed at the time of measurement by processing the delay time signals. This parameter change approach improves flow rate measurement accuracy by accounting for real-time acoustic conditions while keeping the calculation methodology straightforward and integrated within the signal processing circuit.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If temperature compensation is not implemented, then the device complexity is minimized, but the measurement precision is compromised

Engineering Contradiction:
Improveflow velocity detection accuracyVSAvoidtemperature compensation system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The signal processing circuit performs temperature compensation self-service by using the acoustic speed calculation itself to determine the compensation parameters. The circuit measures delay times and calculates acoustic speed, which then provides the temperature compensation information needed to correct flow velocity measurements. This self-service approach eliminates the need for separate temperature sensors and complex compensation systems, achieving improved measurement precision without significantly increasing device complexity.

Inventive Principle:
Principle #25Self-service

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

Enhances the accuracy of flow meter readings by providing a method to estimate current acoustic speed and temperature, thereby improving the precision of fluid flow detection.

Implementation Method 1

transducer receiving signal

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

acoustic path length is determined by transit times measured

Methodology Applied
Scientific EffectAcoustic wave propagation: Sound

Data Source

PatentEP3719451B1Signal processing circuit, and related chip, flowmeter and method
Publication Date: 2023.09.13 SHENZHEN GOODIX TECH CO LTD
  • EP3719451B1 patent drawingFigure 1
  • EP3719451B1 patent drawingFigure 2
  • EP3719451B1 patent drawingFigure 3

AI summary

The present application discloses a signal processing circuit (100), coupled to a first transducer (102) and a second transducer (104), wherein the first transducer and the second transducer have a distance greater than zero, and a fluid having a flow velocity flows sequentially through the first transducer and the second transducer, the signal processing circuit includes: a first transmitter (106), coupled to the first transducer; a first receiver (108), coupled to the first transducer; a second transmitter (110), coupled to the second transducer; a second receiver (112), coupled to the second transducer; and a control unit (114), coupled to the first transmitter, the first receiver, the second transmitter and the second receiver. The present application further provides a related chip, a flow meter and a method.