Vibratory Sensor Phase Difference Lookup Table Calibration
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Solution Overview
Problem
Existing vibratory sensors face delays in determining vibration response parameters due to the need for incremental approaches to reach specific phase differences, which is time-consuming and inefficient in measuring fluid properties like viscosity and density.
Innovation Solution
The method involves vibrating a vibratory element at two frequencies to measure phase differences between drive and vibration signals, allowing for the calculation of half-power or 3dB frequencies, which correspond to resonant and off-resonant frequencies, using linear approximations and interpolations to determine fluid properties accurately and quickly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a closed-loop circuit is used to incrementally adjust the drive frequency to reach target phase differences, then the measurement accuracy of fluid properties is improved, but the measurement time is significantly increased
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing the relationship between drive frequencies and corresponding phase differences in a lookup table during system initialization or calibration. When a measurement is needed, the system directly queries the lookup table to obtain the required drive frequency for the target phase difference (45° or 135°), eliminating the need for incremental frequency adjustments during actual measurement. This transforms a time-consuming iterative process into an instantaneous lookup operation, significantly reducing measurement time while maintaining measurement accuracy.
2Measurement precision
If incremental frequency adjustment is performed to achieve precise phase differences, then the determination of vibration response parameters becomes more accurate, but the productivity of the measurement system decreases
Solution Approach 1:
The system performs the computationally intensive frequency-phase relationship calibration in advance and stores the results in a lookup table. During production measurements, the system simply retrieves pre-computed frequency values from the lookup table based on required phase differences, enabling rapid determination of vibration response parameters without sacrificing accuracy. This separates the accuracy-critical calibration phase from the productivity-critical measurement phase.
Solution Approach 2:
The patent creates a simplified model (lookup table) that copies the essential relationship between drive frequency and phase difference without requiring the complex iterative closed-loop control process during actual measurements. The lookup table serves as a pre-computed representation of the system's frequency-response characteristics, allowing rapid parameter determination that maintains accuracy while dramatically improving throughput.
3Measurement precision
If the closed-loop feedback system is used to monitor and adjust drive frequency, then the phase difference control precision is improved, but the system complexity increases
Solution Approach 1:
The patent eliminates the need for complex real-time feedback control by pre-determining and storing the optimal drive frequency for each target phase difference in a lookup table. The control system simply reads the appropriate frequency from the lookup table and applies it directly, replacing the complex iterative feedback mechanism with a simple lookup and set operation. This maintains phase difference control precision while dramatically simplifying the control system architecture.
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 enables faster and more accurate determination of vibration response parameters, reducing the time required to measure fluid properties such as viscosity and density by directly calculating phase differences and frequencies corresponding to half-power or 3dB frequencies.
Implementation Method 1
vibrating the vibratory element at a first frequency with a first drive signal, receiving a first vibration signal from the vibratory element vibrated at the first frequency
Implementation Method 2
The vibratory element has a vibration response that may have a vibration response parameter such as a resonant frequency or quality factor Q
Implementation Method 3
The piezoelectric element is coupled to the second tine and the receiver circuit. The piezoelectric element converts the vibration of the second tine to an electrical signal.
Data Source
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AI summary
A method (900, 1000) of determining a vibration response parameter of a vibratory element (104) is provided. The method (900, 1000) includes vibrating the vibratory element (104) at a first frequency with a first drive signal, receiving a first vibration signal from the vibratory element (104) vibrated at the first frequency, measuring a first phase difference, the first phase difference being a phase difference between the first drive signal and the first vibration signal. The method (900, 1000) also includes vibrating the vibratory element (104) at a second frequency with a second drive signal, receiving a second vibration signal from the vibratory element (104) vibrated at the second frequency, measuring a second phase difference, the second phase difference being a phase difference between the second drive signal and the second vibration signal. The method (900, 1000) further includes using the first phase difference and the second phase difference to determine at least one of a phase difference, and a frequency of the vibratory element (104).