Phase Difference Regulation in Oscillatory Process Measurement
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Solution Overview
Problem
Existing measuring devices face challenges in optimally setting the phase difference between excitation and received signals, which is crucial for accurately monitoring process variables like density and viscosity, due to limitations in precise phase measurement.
Innovation Solution
A method and device that utilize a closed control loop to regulate the phase difference by specifying criteria for phase determination, using feedback to adjust the phase difference based on stored data and real-time signal parameters, ensuring precise phase setting and adaptation over time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If phase difference measurement is performed to enable precise monitoring of process variables, then measurement precision is improved, but reliability deteriorates due to inability to optimally set phase difference
Solution Approach 1:
The patent implements a feedback mechanism where the determined phase difference is used to automatically adjust the excitation signal phase via a phase shifter. The system continuously monitors the phase difference between excitation and received signals, and adjusts the manipulated variable (phase shift) to maintain the desired phase relationship, thereby resolving the contradiction between measurement precision and setting reliability
Solution Approach 2:
The system performs self-adjustment by automatically regulating its own phase difference setting based on real-time measurements. The control unit uses the measured phase difference to automatically modify the excitation signal phase without external intervention, enabling the system to self-optimize its measurement conditions and overcome the limitation of manual or fixed phase setting
2Adaptability or versatility
If phase difference is regulated based on real-time determination, then adaptability is improved, but device complexity increases due to additional control components
Solution Approach 1:
The control unit serves multiple functions: it determines the phase difference, evaluates measurement quality based on criteria, decides whether to regulate or control based on that evaluation, and executes the appropriate adjustment. By consolidating these diverse functions into a single multi-functional control unit, the patent achieves high adaptability while minimizing the increase in device complexity
3Measurement precision
If closed control loop is used to regulate phase difference, then measurement precision is improved, but loss of time increases due to continuous feedback processing
Solution Approach 1:
The system performs phase difference determination and regulation in periodic cycles rather than continuously. The control unit determines phase difference at discrete intervals, evaluates whether regulation is needed based on predefined criteria, and adjusts phase accordingly. This periodic operation maintains measurement precision while reducing the continuous time expenditure associated with constant feedback processing
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 reliable and precise setting of the phase difference, enhancing the accuracy of measurements for process variables like density and viscosity, and facilitates predictive maintenance by adapting control data to account for device aging and environmental changes.
Implementation Method 1
The drive/receiver unit (2), in particular piezoelectric elements, through which a conversion between mechanical vibration and electrical alternating voltage takes place
Implementation Method 2
at least one criterion for assessing the determination of the phase difference between the excitation signal and the received signal
Implementation Method 3
the setting of which a phase difference is regulated or controlled using a phase shifter (8)
Data Source
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AI summary
The invention relates to a method for determining and/or monitoring a process variable of a medium, wherein an excitation signal (SA) is applied to a unit (1) which is capable of mechanical oscillation, wherein a reception signal (SE) originating from the unit (1) which is capable of mechanical oscillation is received, wherein the excitation signal (SA) is generated in such a manner that a phase difference between the excitation signal (SA) and the reception signal (SE) is equal to a predefinable phase value. The invention provides for a criterion for assessing the determination of the phase difference between the excitation signal (SA) and the reception signal (SE) or a signal that depends on the excitation signal (SA) or on the reception signal (SE) to be predefined, for the setting of the phase difference to be regulated in the case of the criterion for assessing the determination of the phase difference being satisfied, and for the setting of the phase difference to be controlled in the alternative case. The invention also relates to a corresponding apparatus.