Vibratory Sensor Hybrid Drive for Rapid Viscosity Measurement

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Solution Overview

Problem

Existing vibratory sensors face limitations in measuring rapid changes in fluid viscosity due to their closed-loop drive systems, which require significant time to achieve target phase differences and cannot efficiently handle fluid properties that vary rapidly.

Innovation Solution

The proposed solution involves a vibratory sensor that employs a combination of closed-loop and open-loop drive systems to rapidly determine the frequency points ω1 and ω2, allowing for discontinuous transitions to previously determined frequencies, thereby enabling faster measurement of fluid viscosity changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a closed-loop drive system is used to achieve target phase differences, then measurement stability is improved, but response time increases significantly

Engineering Contradiction:
Improvemeasurement stabilityVSAvoidresponse time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies dynamics by making the drive system adaptable - it operates in closed-loop mode during stable conditions to ensure measurement stability, and switches to open-loop mode during rapid changes to reduce response time. This dynamic switching between control modes resolves the contradiction between stability and speed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the control parameter from purely closed-loop to a hybrid mode that incorporates open-loop operation. By modifying the operational parameters of the drive system to include both closed-loop and open-loop modes, the patent achieves both measurement stability and fast response to viscosity changes.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If closed-loop drive is used to determine frequency points, then phase difference accuracy is improved, but measurement speed decreases

Engineering Contradiction:
Improvephase difference accuracyVSAvoidmeasurement speed
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent uses periodic switching between closed-loop and open-loop modes. During rapid viscosity changes, it periodically uses open-loop mode for fast frequency point determination, then switches back to closed-loop mode for accurate phase difference measurement, achieving both speed and precision through periodic action.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent applies preliminary action by using open-loop mode to quickly approximate frequency points before refining them with closed-loop mode. This preliminary fast estimation followed by precise refinement resolves the contradiction between measurement speed and accuracy.

Inventive Principle:
Principle #10Preliminary action

3Stability of the object's composition

If incremental frequency changes are used in closed-loop mode, then phase difference stability is improved, but ability to track rapid viscosity changes deteriorates

Engineering Contradiction:
Improvephase difference stabilityVSAvoidability to track rapid changes
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The patent makes the system adaptive by dynamically switching between incremental closed-loop operation (for stability) and direct open-loop frequency transitions (for tracking rapid changes). This dynamic behavior allows the system to maintain stability during normal operation while adapting quickly to viscosity changes.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent uses feedback intelligently - it employs closed-loop feedback for stability during normal conditions, but switches to open-loop operation when rapid changes are detected, using feedback only to trigger the mode switch. This selective use of feedback resolves the contradiction between stability and adaptability.

Inventive Principle:
Principle #23Feedback

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 the sensor to react to rapid changes in fluid viscosity by using open-loop operations, significantly reducing the time required to achieve target phase differences and improving the measurement of fluid properties.

Implementation Method 1

Vibratory sensors, such as vibratory densitometers and vibratory viscometers, operate by detecting motion of a vibrating element that vibrates in the presence of a fluid to be characterized

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 2

The vibration of the vibrating element is generally affected by the combined mass, stiffness and damping characteristics of the vibrating element in combination with the fluid

Methodology Applied
Scientific EffectDamping: Damping

Implementation Method 3

Vibratory sensors, such as vibratory densitometers and vibratory viscometers, operate by detecting motion of a vibrating element that vibrates in the presence of a fluid to be characterized. The vibration of the vibrating element is generally affected by the combined mass, stiffness and damping characteristics of the vibrating element in combination with the fluid

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP2989439B1Vibratory sensor and method of varying vibration in a vibratory sensor
Publication Date: 2021.10.20 MICRO MOTION INC
  • EP2989439B1 patent drawingFigure 1
  • EP2989439B1 patent drawingFigure 2
  • EP2989439B1 patent drawingFigure 3

AI summary

A vibratory sensor (5) includes a vibratory element (104), a receiver circuit (134) that receives a vibration signal from the vibratory element (104), and a drive circuit (138) that generates a drive signal. The drive circuit (138) includes a closed-loop drive (143) and an open-loop drive (147). The meter electronics (20) vibrates the vibratory element (104) commencing at a commanded first frequency and in an open-loop manner to achieve a first target phase difference Φ1 for a fluid being characterized and determines a corresponding first frequency point ω1, vibrates the vibratory element (104) commencing at a commanded second frequency and in the open-loop manner to achieve a second target phase difference Φ2 and determines a corresponding second frequency point ω2, and determines a viscosity of the fluid being characterized using the first frequency point ω1 and the second frequency point ω2.