CN113108867B - Data processing method for sectional coaxial guided wave radar liquid level meter - Google Patents
Data processing method for sectional coaxial guided wave radar liquid level meter Download PDFInfo
- Publication number
- CN113108867B CN113108867B CN202110417184.1A CN202110417184A CN113108867B CN 113108867 B CN113108867 B CN 113108867B CN 202110417184 A CN202110417184 A CN 202110417184A CN 113108867 B CN113108867 B CN 113108867B
- Authority
- CN
- China
- Prior art keywords
- echo signal
- liquid level
- value
- initial
- predicted
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
- G01F23/22—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
- G01F23/28—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring the variations of parameters of electromagnetic or acoustic waves applied directly to the liquid or fluent solid material
- G01F23/284—Electromagnetic waves
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/35—Details of non-pulse systems
- G01S7/352—Receivers
- G01S7/354—Extracting wanted echo-signals
Abstract
The invention discloses a data processing method of a segmented guided wave radar liquid level meter. The method comprises the following steps: predicting a predicted value of the liquid level height in the target container at the next measurement according to the measured liquid level value and the liquid level change speed value of the current liquid level height in the target container; calculating a first false echo signal in the first echo signal measured next time according to the predicted value and the length of each segment of the waveguide rod; acquiring a first echo signal of a wave guide rod when liquid in a target container is positioned at the predicted liquid level height; calculating an initial measured level value of the predicted liquid level height according to the first echo signal and the first false echo signal; and performing Kalman filtering processing on the initial measurement liquid level value to obtain a measurement liquid level value of the predicted liquid level height. The present disclosure also provides a data processing system, a storage medium, and a computer program product of a segmented guided wave radar level gauge.
Description
Technical Field
The invention belongs to the technical field of FMCW radar liquid level meter signal processing, and particularly relates to a data processing method, a data processing system, a storage medium and a computer program product of a segmented guided wave radar liquid level meter.
Background
The FMCW system guided wave radar liquid level meter is a radar liquid level meter based on a frequency domain reflection principle (FDR), a frequency modulation continuous wave electromagnetic signal of the radar liquid level meter is transmitted along a guided wave rod, when the radar liquid level meter meets the surface of a measured medium, partial signals of the radar liquid level meter are reflected to form echoes and return to a signal transmitting device (receiving antenna) along the same path, the received echo signals and coupling signals of the transmitting signals are mixed to generate difference frequency signals, the transmission time is converted into frequency difference, the frequency is measured to replace direct measurement of time difference, and the liquid level height is calculated.
According to the difference of the probe structure of the guided wave rod, the commonly used guided wave radar liquid level meter comprises a coaxial type and a double-rod type. The coaxial type guided wave rod probe is the most basic and most effective probe in the guided wave radar liquid level meter, is similar to a coaxial cable in structure and is formed by coaxially installing a metal round pipe and a metal rod, electromagnetic signals are transmitted in the space between the metal rod and the metal round pipe, energy is concentrated, the electromagnetic signals cannot be diffused, high-frequency signals can be effectively transmitted, and the coaxial type guided wave rod probe is not easily influenced by the outside.
Traditional coaxial guided wave pole probe adopts the integral type structure, because rod-type structural length restriction, difficult transportation and installation, so coaxial guided wave pole is unsuitable to be applied to great range. In order to overcome the limitation, the coaxial waveguide rod can adopt a sectional structure, and all the sections are connected through threads, so that a large measuring range is realized, and the coaxial waveguide rod is convenient to transport and install.
In the process of realizing the concept of the present disclosure, the inventor finds that the characteristic impedance of the joint of each segment of the segmented coaxial waveguide rod is discontinuous with other parts, and false echoes can be generated at the joint to interfere with liquid level measurement, thereby causing a problem of large measurement error.
Disclosure of Invention
In view of this, the present disclosure provides a data processing method for a segmented coaxial guided wave radar level gauge.
One aspect of the present disclosure provides a data processing method for a segmented coaxial guided wave radar level gauge, including:
predicting a predicted value of the liquid level height in the target container at the next measurement according to the measured liquid level value and the liquid level change speed value of the current liquid level height in the target container;
calculating a first false echo signal in the first echo signal measured next time according to the predicted value and the length of each segment of the waveguide rod;
acquiring a first echo signal of the wave guide rod when the liquid in the target container is positioned at the predicted liquid level height;
calculating a measured level value for the predicted level height from the first echo signal and the first spurious echo signal;
and performing Kalman filtering processing on the liquid level value to obtain a measured liquid level value of the predicted liquid level height.
According to an embodiment of the present disclosure, the data processing method further includes:
respectively acquiring a background echo signal of the wave guide rod when no liquid exists in the target container and an initial echo signal of the wave guide rod when the liquid in the target container is positioned at an initial liquid level height;
and calculating a measurement liquid level value and a liquid level change speed value of the initial liquid level height according to the background echo signal and the initial echo signal.
According to the embodiment of the present disclosure, the obtaining the background echo signal of the waveguide rod when no liquid is in the target container and the initial echo signal of the waveguide rod when the liquid in the target container is at the initial liquid level respectively includes:
respectively collecting a second echo signal of the wave guide rod when no liquid exists in the target container and a third echo signal of the wave guide rod when the liquid in the target container is positioned at the initial liquid level height;
and respectively carrying out linear frequency modulation Z conversion on the second echo signal and the third echo signal to obtain the background echo signal and the initial echo signal.
According to an embodiment of the present disclosure, the background echo signal includes:
c(t)＝c0(t)+c1(t)+c2(t)+…+cQ(t)
wherein c (t) is background echo signal, c0(t) reflected signals caused by impedance mismatch at the feed port of the waveguide rod, c1(t) is a length L from the feed port of the waveguide rod1C a reflection signal generated at the junction of the first and second guided wave rods, c2(t) is a length L from the feed port of the waveguide rod2C reflected signal generated at the joint of the second and third guided wave rods, cQ(t) is a length L from the feed port of the waveguide rodQThe total reflection signal caused by the short circuit at the end of the waveguide rod in the Q section.
According to an embodiment of the present disclosure, the calculating the measurement level value and the liquid level change speed value of the initial liquid level height according to the background echo signal and the initial echo signal includes:
obtaining a second false echo signal at the feed port of the waveguide rod according to the background echo signal;
eliminating the false echo signal in the initial echo signal according to the second false echo signal to obtain a first real echo signal;
processing the first real echo signal by a peak positioning method to obtain an initial liquid level height value;
and calculating the liquid level change speed value according to the initial liquid level height value.
According to an embodiment of the present disclosure, the predicting, according to the measured level value of the current liquid level in the target container, the predicted value of the liquid level in the target container at the time of the next measurement includes:
wherein the content of the first and second substances,
in order to measure the level value of the liquid,
the liquid level change speed values of two adjacent measurements are obtained, and T is the time interval of the two adjacent measurements.
According to an embodiment of the present disclosure, the calculating a first false echo signal in the next measured first echo signal according to the predicted value and the length of each waveguide rod segment includes:
wherein
Is the first false echo signal, Ci(k) Is L from the feed port of the waveguide rodiJ is the number of segments of the waveguide rod between the predicted value and the feed port, and L is the number of segments of the waveguide rod between the predicted value and the feed portJ≤X＜LJ+1And X is a predicted value.
According to an embodiment of the present disclosure, the obtaining a first echo signal of the waveguide rod when the liquid in the target container is at the predicted liquid level includes:
collecting a fourth echo signal of the wave guide rod when the liquid in the target container is positioned at the predicted liquid level height;
and performing linear frequency modulation Z conversion on the fourth echo signal in a window taking the predicted value as the center to obtain the first echo signal.
According to an embodiment of the present disclosure, said calculating a measured level value of said predicted level height from said first echo signal and said first spurious echo signal comprises:
eliminating the false echo signal in the first echo signal according to the first false echo signal to obtain a second real echo signal;
and processing the second real echo signal by a peak positioning method to obtain an initial measurement liquid level value of the predicted liquid level height.
According to an embodiment of the present disclosure, the performing kalman filter processing on the initial measurement level value to obtain the measurement level value of the predicted liquid level height includes:
performing Kalman filtering processing on the initial measurement liquid level value to obtain a measurement liquid level value of the predicted liquid level height in the target container and the liquid level change speed value in the target container;
and outputting the measured liquid level value as a final output result.
According to the embodiment of the disclosure, the false echo signal in the echo signal of the next measurement can be calculated through the predicted value of the liquid level height in the target container during the next measurement and the lengths of the sections of the waveguide rods, and then the real echo signal of each measurement is calculated according to the false echo signal, so that the influence of the false echo on the measurement result caused by impedance discontinuity at the feed port and the connection part of each waveguide rod can be eliminated, and the measurement precision is effectively improved. Meanwhile, according to the liquid level value measuring method and device, Kalman filtering processing is carried out on the liquid level value, the influence of external interference or liquid level instantaneous jitter on measurement can be reduced, and the measurement precision is further improved.
Drawings
FIG. 1 schematically shows a flow chart of a data processing method of a segmented guided wave radar level gauge according to an embodiment of the present disclosure.
Fig. 2 schematically shows a schematic diagram of a background echo signal according to an embodiment of the present disclosure.
Fig. 3 schematically shows a schematic diagram of an initial echo signal according to an embodiment of the present disclosure.
Fig. 4 schematically shows a schematic diagram of a first real echo signal according to an embodiment of the present disclosure.
FIG. 5 schematically shows a measured value versus an actual value for a data processing method according to an embodiment of the disclosure.
Fig. 6 schematically shows an error diagram of measured values versus actual values of a data processing method according to an embodiment of the disclosure.
FIG. 7 schematically shows a block diagram of a data processing system according to an embodiment of the present disclosure.
FIG. 8 schematically shows a block diagram of a computer system suitable for implementing a data processing method according to an embodiment of the present disclosure.
Detailed Description
In order that the objects, technical solutions and advantages of the present invention will become more apparent, the present invention will be further described in detail with reference to the accompanying drawings in conjunction with the following specific embodiments.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The terms "comprises," "comprising," and the like, as used herein, specify the presence of stated features, steps, operations, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, or components.
All terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise defined. It is noted that the terms used herein should be interpreted as having a meaning that is consistent with the context of this specification and should not be interpreted in an idealized or overly formal sense.
In the process of realizing the disclosure, the inventor finds that the characteristic impedance of the joint of each section of the sectional type coaxial waveguide rod is discontinuous with other parts, false echoes can be generated at the joint, interference is caused on liquid level measurement, and the problem of large measurement error is caused.
In view of the above problems, the present disclosure provides a data processing method, a data processing system, a storage medium, and a computer program product for a segmented guided wave radar level gauge.
FIG. 1 schematically shows a flow chart of a data processing method of a segmented guided wave radar level gauge according to an embodiment of the present disclosure.
As shown in FIG. 1, the data processing method of the segmented guided wave radar level gauge provided by the embodiment of the present disclosure includes operations S101-S105.
In operation S101, a predicted value of the liquid level in the target container at the time of the next measurement is predicted based on the measured liquid level value and the liquid level variation speed value of the current liquid level in the target container.
In operation S102, a first false echo signal in the next measured first echo signal is calculated according to the predicted value and the length of each segment of the waveguide rod.
According to the embodiment of the disclosure, since the segmented coaxial guided wave radar liquid level meter can cause false echo at the feed port and the connection position of each guided wave rod due to impedance discontinuity, and the false echo can affect the measurement result, the false echo signal in the echo signal at the next measurement needs to be calculated first.
According to the embodiment of the disclosure, for example, the predicted value of the liquid level in the target container is located in the middle of the i +1 th waveguide rod during the next measurement, at this time, before the next measurement is performed, it is necessary to predict the reflection signal generated at the connection between the i th waveguide rod and the i +1 th waveguide rod, the reflection signal generated at each connection at the upper end of the i th waveguide rod, and the reflection signal generated at the feed port by the segmented coaxial guided wave radar liquid level gauge, and calculate the false echo signal in the echo signal during the next measurement according to all the reflection signals.
In operation S103, a first echo signal of the waveguide rod when the liquid in the target container is at the predicted liquid level is obtained.
According to embodiments of the present disclosure, the predicted liquid level may be the true liquid level of the liquid within the target container at the next measurement as described above. Since the predicted liquid level height may be in error from the actual liquid level height of the liquid in the target vessel at the time of measurement, the value of the predicted liquid level height is different from the predicted value of the liquid level height in the target vessel as described above.
In operation S104, an initial measured level value of the predicted liquid level height is calculated from the first echo signal and the first spurious echo signal.
In operation S105, kalman filtering is performed on the initial measured level value to obtain a measured level value of the predicted liquid level height.
According to the embodiment of the disclosure, the false echo signal in the echo signal of the next measurement can be calculated through the predicted value of the liquid level height in the target container during the next measurement and the lengths of the sections of the waveguide rods, and then the real echo signal of each measurement is calculated according to the false echo signal, so that the influence of the false echo on the measurement result caused by impedance discontinuity at the feed port and the connection part of each waveguide rod can be eliminated, and the measurement precision is effectively improved. Meanwhile, according to the liquid level value measuring method and device, Kalman filtering processing is carried out on the liquid level value, the influence of external interference or liquid level instantaneous jitter on measurement can be reduced, and the measurement precision is further improved.
According to an embodiment of the present disclosure, the data processing method may further include:
respectively acquiring a background echo signal of the waveguide rod when no liquid exists in the target container and an initial echo signal of the waveguide rod when the liquid in the target container is positioned at the initial liquid level height; and calculating a measurement liquid level value and a liquid level change speed value of the initial liquid level height according to the background echo signal and the initial echo signal.
According to the embodiment of the present disclosure, the background echo signal may include, for example, reflected signals caused by impedance mismatch at the junction of adjacent waveguide rods, at the feed port, and at the end of the last waveguide rod.
According to an embodiment of the present disclosure, a background echo signal includes:
c(t)＝c0(t)+c1(t)+c2(t)+…+cQ(t) (1)
wherein c (t) is background echo signal, c0(t) reflected signals due to impedance mismatch at the feed port of the waveguide rod, c1(t) is a length L from the feed port of the waveguide rod1C a reflection signal generated at the junction of the first and second guided wave rods, c2(t) is a length L from the feed port of the waveguide rod2C reflected signal generated at the joint of the second and third guided wave rods, cQ(t) is a length L from the feed port of the waveguide rodQThe total reflection signal caused by the short circuit at the end of the waveguide rod in the Q section.
According to the embodiment of the disclosure, with the coaxial guided wave radar level gauge of sectional type total four sections of guided wave poles, first section guided wave pole passes through the flange and links to each other with the feed port, and length is 1.2m, and other three sections guided wave pole length are 1m for the example, then the background echo signal of guided wave pole when no liquid in the target container shows as follows:
c(t)＝c0(t)+c1(t)+c2(t)+c3(t)+c4(t) (2)
wherein, c0(t) is a reflected signal caused by impedance mismatch of the feed port of the waveguide rod, the length L of the mismatch point from the feed port1＝0，c1(t) is a length L from the feed port of the waveguide rod11.2m of a reflection signal generated at the joint of the first waveguide rod and the second waveguide rod, c2(t) is a length L from the feed port of the waveguide rod22.2m of a reflection signal generated at the joint of the second and third waveguide rods, c3(t) is the length L from the feed port of the waveguide rod33.2m of reflection generated at the joint of the third section of the waveguide rod and the fourth section of the waveguide rodSignal, c4(t) is total reflection signal caused by short circuit at end of fourth segment of waveguide rod, length L of end of waveguide rod from feed port4＝4.2m。
According to the embodiment of the present disclosure, respectively obtaining the background echo signal of the waveguide rod when no liquid is present in the target container and the initial echo signal of the waveguide rod when the liquid is located at the initial liquid level height in the target container may include:
respectively collecting a second echo signal of the wave guide rod when no liquid exists in the target container and a third echo signal of the wave guide rod when the liquid in the target container is positioned at the initial liquid level height; and respectively carrying out linear frequency modulation Z conversion on the second echo signal and the third echo signal to obtain a background echo signal and an initial echo signal.
According to an embodiment of the disclosure, the second echo signal may be, for example, raw data collected by the segmented coaxial guided wave radar level gauge when there is no liquid in the target container, and the third echo signal may be, for example, raw data collected by the segmented coaxial guided wave radar when the liquid in the target container is at an initial liquid level. And respectively obtaining a final background echo signal and an initial echo signal by carrying out linear frequency modulation Z conversion on the second echo signal and the third echo signal.
According to an embodiment of the present disclosure, performing a chirp-Z-transform on the second echo signal and the third echo signal includes:
wherein N is the number of collected points of echo data, M is the total number of frequency spectrum analysis points, Ci(k) As an echo signal Ci(n) spectrum of frequencies; where M is determined by the distance measurement accuracy requirement.
Fig. 2 schematically shows a schematic diagram of a background echo signal according to an embodiment of the present disclosure.
According to an embodiment of the present disclosure, as shown in fig. 2, the abscissa is distance and the ordinate is amplitude. The sectional type coaxial guided wave radar liquid level meter has four sections of guided wave rods, and the first section of guided wave rod is connected with the feed through a flangeThe electric ports are connected, the length is 1.2m, and the lengths of the rest three waveguide rods are all 1m as an example. The total number of spectrum sampling points M is 131072. C of the background echo signal0(k) Is a waveform between-50 cm and 100cm, C1(k) Is a wave form of between 100cm and 140cm, C2(k) Is a waveform between 200cm and 240cm, C3(k) The waveform is between 310cm and 330 cm.
Fig. 3 schematically shows a schematic diagram of an initial echo signal according to an embodiment of the present disclosure.
According to the embodiment of the disclosure, the sectional type coaxial guided wave radar liquid level meter has four sections of guided wave rods, the first section of guided wave rod is connected with the feed port through a flange, the length of the first section of guided wave rod is 1.2m, and the lengths of the rest three sections of guided wave rods are all 1 m. And (3) the total number M of the frequency spectrum samples is 131072. The real initial echo signal with an initial liquid level height value of 40.4cm is shown in fig. 3, in which the abscissa is distance and the ordinate is amplitude. As can be seen from fig. 3, the measurement error is large because the first real echo signal is mixed with the reflected signal generated at the feeding port.
According to an embodiment of the present disclosure, calculating a measurement level value and a level change velocity value of an initial level height from a background echo signal and an initial echo signal may include:
obtaining a second false echo signal at the feed port of the waveguide rod according to the background echo signal; eliminating the false echo signal in the initial echo signal according to the second false echo signal to obtain a first real echo signal; processing the first real echo signal by a peak positioning method to obtain an initial liquid level height value; and calculating the liquid level change speed value according to the initial liquid level height value.
According to the embodiment of the disclosure, processing the first real echo signal by a peak positioning method to obtain an initial liquid level height value comprises:
wherein the content of the first and second substances,
is an initial liquid level height value, S0(k)-C0(k) Is the first true echo signal, S0(k) As initial echo signals, C0(k) Is the second false echo signal, T is the sweep time width, B is the sweep bandwidth, c is the electromagnetic wave propagation speed in vacuum, fsTo receive the sampling frequency, M is the total number of spectral samples.
Fig. 4 schematically shows a schematic diagram of a first real echo signal according to an embodiment of the present disclosure.
As shown in fig. 4, the abscissa is distance and the ordinate is amplitude. The sectional type coaxial guided wave radar liquid level meter is provided with four sections of guided wave rods, the first section of guided wave rod is connected with the feed port through a flange, the length of the first section of guided wave rod is 1.2m, and the lengths of the rest three sections of guided wave rods are 1 m. The total number of spectrum sampling points M is 131072. And the real initial liquid level height value is 40.4cm, and the first real echo signal is processed according to a peak positioning method to obtain the initial liquid level height value of 40.38 cm.
According to the embodiment of the present disclosure, predicting the predicted value of the liquid level in the target container at the next measurement according to the measured liquid level value of the current liquid level in the target container comprises:
wherein the content of the first and second substances,
in order to measure the level value of the liquid,
the liquid level change speed values of two adjacent measurements are obtained, and T is the time interval of the two adjacent measurements.
According to the embodiment of the disclosure, calculating the first false echo signal in the first echo signal measured next time according to the predicted value and the length of each segment of the waveguide rod comprises the following steps:
wherein the content of the first and second substances,
is the first false echo signal, Ci(k) Is L from the feed port of the waveguide rodiJ is the number of segments of the waveguide rod between the predicted value and the feed port, LJ≤X＜LJ+1And X is a predicted value.
According to an embodiment of the present disclosure, acquiring a first echo signal of a waveguide rod when a liquid in a target container is located at a predicted liquid level may include:
collecting a fourth echo signal of the wave guide rod when the liquid in the target container is positioned at the predicted liquid level height; and performing linear frequency modulation Z conversion on the fourth echo signal in a window taking the predicted value as the center to obtain a first echo signal.
According to an embodiment of the present disclosure, in order to reduce the amount of computation, a spectrum may be computed in the range of k, where:
where w is the spectral computation window.
According to the embodiments of the present disclosure, the width of w may include, for example, 20cm, 25cm, etc., according to the implementation requirement, and may be other widths.
According to an embodiment of the present disclosure, calculating an initial measured level value of the predicted liquid level height from the first echo signal and the first spurious echo signal may comprise:
eliminating the false echo signal in the first echo signal according to the first false echo signal to obtain a second real echo signal; and processing the second real echo signal by a peak positioning method to obtain an initial measurement liquid level value of the predicted liquid level height.
According to the embodiment of the disclosure, processing the second real echo signal by a peak positioning method to obtain the measured liquid level value of the predicted liquid level height includes:
wherein, ykFor the initial measured level value of the liquid level to be predicted,
is the second real echo signal, S (k) is the first echo signal,
is the first false echo signal, T is the sweep time width, B is the sweep bandwidth, c is the electromagnetic wave propagation speed in vacuum, fsTo receive the sampling frequency, M is the total number of spectral samples.
According to the embodiment of the present disclosure, performing kalman filtering processing on the initial measurement level value to obtain the measurement level value of the predicted liquid level height may include:
performing Kalman filtering processing on the initial measurement liquid level value to obtain a measurement liquid level value of the predicted liquid level height in the target container and a liquid level change speed value in the target container; and outputting the measured liquid level value as a final output result.
According to the embodiment of the disclosure, the kalman filtering processing is performed on the initial measured liquid level value to obtain the measured liquid level value of the predicted liquid level height in the target container and the liquid level change speed value in the target container, and the method comprises the following steps:
wherein x is the measured liquid level value, v is the liquid level change speed value measured twice adjacently, and T is the liquid level change speed value measured twice adjacentlyTime interval of measurement, process noise omegamFor a white noise vector with a two-dimensional mean of zero, the noise v is measuredmIs a white noise signal with a mean value of zero, ymThe measured liquid level value is processed by Kalman filtering.
FIG. 5 schematically shows a measured value versus an actual value for a data processing method according to an embodiment of the disclosure.
Fig. 6 schematically shows an error diagram of measured values versus actual values of a data processing method according to an embodiment of the disclosure.
According to the embodiment of the disclosure, as shown in fig. 5 and fig. 6, the segmented coaxial guided-wave radar level gauge has four segments of guided-wave rods, the first segment of guided-wave rod is connected with the feed port through a flange, the length of the first segment of guided-wave rod is 1.2m, the lengths of the remaining three segments of guided-wave rods are all 1m, and the total number of frequency spectrum sampling points is 131072. In the whole measuring range, the error between the liquid level measured value and the true value can be kept within +/-1 cm, so that the data processing method can effectively process data of the segmented coaxial guided wave radar liquid level meter.
FIG. 7 schematically shows a block diagram of a data processing system 700 according to an embodiment of the present disclosure.
As shown in fig. 7, a data processing system 700 provided by the embodiment of the present disclosure may include a prediction module 701, a first calculation module 702, a first acquisition module 703, a second calculation module 704, and a processing module 705.
The predicting module 701 is configured to predict a predicted value of the liquid level height in the target container at the next measurement according to the measurement level value and the liquid level change speed value of the current liquid level height in the target container.
And a first calculating module 702, configured to calculate a first false echo signal in the first echo signal measured next time according to the predicted value and the lengths of the waveguide rods.
The first obtaining module 703 is configured to obtain a first echo signal of the waveguide rod when the liquid in the target container is located at the predicted liquid level.
And the second calculation module 704 calculates an initial measurement level value of the predicted liquid level according to the first echo signal and the first false echo signal.
The processing module 705 is configured to perform kalman filtering processing on the initial measured liquid level value to obtain a measured liquid level value of the predicted liquid level height.
According to the embodiment of the disclosure, the false echo signal in the echo signal of the next measurement can be calculated through the predicted value of the liquid level height in the target container during the next measurement and the lengths of the sections of the waveguide rods, and then the real echo signal of each measurement is calculated according to the false echo signal, so that the influence of the false echo on the measurement result caused by impedance discontinuity at the feed port and the connection part of each waveguide rod can be eliminated, and the measurement precision is effectively improved. Meanwhile, according to the liquid level value measuring method and device, Kalman filtering processing is carried out on the liquid level value, the influence of external interference or liquid level instantaneous jitter on measurement can be reduced, and the measurement precision is further improved.
The data processing system 700 may also include a second acquisition module and a third computation module according to embodiments of the present disclosure.
And the second acquisition module is used for respectively acquiring the background echo signal of the waveguide rod when no liquid exists in the target container and the initial echo signal of the waveguide rod when the liquid in the target container is positioned at the initial liquid level height.
And the third calculation module is used for calculating a measurement liquid level value and a liquid level change speed value of the initial liquid level height according to the background echo signal and the initial echo signal.
According to an embodiment of the present disclosure, the second obtaining module may include a first acquiring unit and a first transforming unit.
And the first acquisition unit is used for respectively acquiring a second echo signal of the guided wave rod when no liquid exists in the target container and a third echo signal of the guided wave rod when the liquid in the target container is positioned at the initial liquid level height.
And the first transformation unit is used for respectively carrying out linear frequency modulation Z transformation on the second echo signal and the third echo signal to obtain a background echo signal and an initial echo signal.
According to an embodiment of the present disclosure, the third calculation module may include a first calculation unit, a first elimination unit, a first positioning unit, and a second calculation unit.
And the first computing unit is used for obtaining a second false echo signal at the feed port of the waveguide rod according to the background echo signal.
And the first eliminating unit is used for eliminating the false echo signal in the initial echo signal according to the second false echo signal to obtain a first real echo signal.
And the first positioning unit is used for processing the first real echo signal by a peak positioning method to obtain an initial liquid level height value.
And the second calculating unit is used for calculating the liquid level change speed value according to the initial liquid level height value.
According to an embodiment of the present disclosure, the first obtaining module 703 may include a second acquiring unit and a second transforming unit.
And the second acquisition unit is used for acquiring a fourth echo signal of the waveguide rod when the liquid in the target container is positioned at the predicted liquid level height.
And the second transformation unit is used for carrying out linear frequency modulation Z transformation on the fourth echo signal in a window taking the predicted value as the center to obtain a first echo signal.
According to an embodiment of the present disclosure, the second calculation module 704 may include a second elimination unit and a second positioning unit.
And the second eliminating unit is used for eliminating the false echo signal in the first echo signal according to the first false echo signal to obtain a second real echo signal.
And the second positioning unit is used for processing the second real echo signal by a peak positioning method to obtain an initial measurement liquid level value of the predicted liquid level height.
The processing module 705 may include a processing unit and an output unit according to an embodiment of the present disclosure.
And the processing unit is used for carrying out Kalman filtering processing on the initial measurement liquid level value to obtain a measurement liquid level value of the predicted liquid level height in the target container and a liquid level change speed value in the target container.
And the output unit is used for outputting the measured liquid level value as a final output result.
Any number of modules, sub-modules, units, sub-units, or at least part of the functionality of any number thereof according to embodiments of the present disclosure may be implemented in one module. Any one or more of the modules, sub-modules, units, and sub-units according to the embodiments of the present disclosure may be implemented by being split into a plurality of modules. Any one or more of the modules, sub-modules, units, sub-units according to embodiments of the present disclosure may be implemented at least in part as a hardware circuit, such as a Field Programmable Gate Array (FPGA), a Programmable Logic Array (PLA), a system on a chip, a system on a substrate, a system on a package, an Application Specific Integrated Circuit (ASIC), or may be implemented in any other reasonable manner of hardware or firmware by integrating or packaging a circuit, or in any one of or a suitable combination of software, hardware, and firmware implementations. Alternatively, one or more of the modules, sub-modules, units, sub-units according to embodiments of the disclosure may be at least partially implemented as a computer program module, which when executed may perform the corresponding functions.
For example, any plurality of the prediction module 701, the first calculation module 702, the first obtaining module 703, the second calculation module 704 and the processing module 705 may be combined and implemented in one module/unit/sub-unit, or any one of the modules/units/sub-units may be split into a plurality of modules/units/sub-units. Alternatively, at least part of the functionality of one or more of these modules/units/sub-units may be combined with at least part of the functionality of other modules/units/sub-units and implemented in one module/unit/sub-unit. According to an embodiment of the present disclosure, at least one of the prediction module 701, the first calculation module 702, the first obtaining module 703, the second calculation module 704, and the processing module 705 may be implemented at least partially as a hardware circuit, such as a Field Programmable Gate Array (FPGA), a Programmable Logic Array (PLA), a system on a chip, a system on a substrate, a system on a package, an Application Specific Integrated Circuit (ASIC), or may be implemented by hardware or firmware in any other reasonable manner of integrating or packaging a circuit, or implemented by any one of three implementations of software, hardware, and firmware, or an appropriate combination of any several of them. Alternatively, at least one of the prediction module 701, the first calculation module 702, the first obtaining module 703, the second calculation module 704 and the processing module 705 may be at least partially implemented as a computer program module, which when executed may perform a corresponding function.
It should be noted that, the data processing system 700 portion in the embodiment of the present disclosure corresponds to the data processing method portion in the embodiment of the present disclosure, and the description of the data processing system 700 portion specifically refers to the data processing method portion, and is not described herein again.
FIG. 8 schematically illustrates a block diagram of a computer system suitable for implementing the above-described method, according to an embodiment of the present disclosure. The computer system illustrated in FIG. 8 is only one example and should not impose any limitations on the scope of use or functionality of embodiments of the disclosure.
As shown in fig. 8, a computer system 800 according to an embodiment of the present disclosure includes a processor 801 that can perform various appropriate actions and processes according to a program stored in a Read Only Memory (ROM)802 or a program loaded from a storage section 808 into a Random Access Memory (RAM) 803. The processor 801 may include, for example, a general purpose microprocessor (e.g., a CPU), an instruction set processor and/or associated chipset, and/or a special purpose microprocessor (e.g., an Application Specific Integrated Circuit (ASIC)), among others. The processor 801 may also include onboard memory for caching purposes. The processor 801 may include a single processing unit or multiple processing units for performing different actions of the method flows according to embodiments of the present disclosure.
In the RAM 803, various programs and data necessary for the operation of the system 800 are stored. The processor 801, the ROM 802, and the RAM 803 are connected to each other by a bus 804. The processor 801 performs various operations of the method flows according to the embodiments of the present disclosure by executing programs in the ROM 802 and/or RAM 803. Note that the programs may also be stored in one or more memories other than the ROM 802 and RAM 803. The processor 801 may also perform various operations of method flows according to embodiments of the present disclosure by executing programs stored in the one or more memories.
According to embodiments of the present disclosure, method flows according to embodiments of the present disclosure may be implemented as computer software programs. For example, embodiments of the present disclosure include a computer program product comprising a computer program embodied on a computer readable storage medium, the computer program containing program code for performing the method illustrated by the flow chart. In such an embodiment, the computer program can be downloaded and installed from a network through the communication section 809 and/or installed from the removable medium 811. The computer program, when executed by the processor 801, performs the above-described functions defined in the system of the embodiments of the present disclosure. The systems, devices, apparatuses, modules, units, etc. described above may be implemented by computer program modules according to embodiments of the present disclosure.
The present disclosure also provides a computer-readable storage medium, which may be contained in the apparatus/device/system described in the above embodiments; or may exist separately and not be assembled into the device/apparatus/system. The computer-readable storage medium carries one or more programs which, when executed, implement the method according to an embodiment of the disclosure.
According to an embodiment of the present disclosure, the computer-readable storage medium may be a non-volatile computer-readable storage medium. Examples may include, but are not limited to: a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the present disclosure, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
For example, according to embodiments of the present disclosure, a computer-readable storage medium may include the ROM 802 and/or RAM 803 described above and/or one or more memories other than the ROM 802 and RAM 803.
Embodiments of the present disclosure also include a computer program product comprising a computer program containing program code for performing the method provided by the embodiments of the present disclosure, when the computer program product is run on an electronic device, the program code being adapted to cause the electronic device to carry out the data processing method provided by the embodiments of the present disclosure.
The computer program, when executed by the processor 801, performs the above-described functions defined in the system/apparatus of the embodiments of the present disclosure. The systems, apparatuses, modules, units, etc. described above may be implemented by computer program modules according to embodiments of the present disclosure.
In one embodiment, the computer program may be hosted on a tangible storage medium such as an optical storage device, a magnetic storage device, and the like. In another embodiment, the computer program may also be transmitted in the form of a signal on a network medium, distributed, downloaded and installed via communication section 809, and/or installed from removable media 811. The computer program containing program code may be transmitted using any suitable network medium, including but not limited to: wireless, wired, etc., or any suitable combination of the foregoing.
In accordance with embodiments of the present disclosure, program code for executing computer programs provided by embodiments of the present disclosure may be written in any combination of one or more programming languages, and in particular, these computer programs may be implemented using high level procedural and/or object oriented programming languages, and/or assembly/machine languages. The programming language includes, but is not limited to, programming languages such as Java, C + +, python, the "C" language, or the like. The program code may execute entirely on the user computing device, partly on the user device, partly on a remote computing device, or entirely on the remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user computing device through any kind of network, including a Local Area Network (LAN) or a Wide Area Network (WAN), or may be connected to an external computing device (e.g., through the internet using an internet service provider).
The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams or flowchart illustration, and combinations of blocks in the block diagrams or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions. Those skilled in the art will appreciate that various combinations and/or combinations of features recited in the various embodiments and/or claims of the present disclosure can be made, even if such combinations or combinations are not expressly recited in the present disclosure. In particular, various combinations and/or combinations of the features recited in the various embodiments and/or claims of the present disclosure may be made without departing from the spirit or teaching of the present disclosure. All such combinations and/or associations are within the scope of the present disclosure.
The embodiments of the present disclosure have been described above. However, these examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Although the embodiments are described separately above, this does not mean that the measures in the embodiments cannot be used in advantageous combination. The scope of the disclosure is defined by the appended claims and equivalents thereof. Various alternatives and modifications can be devised by those skilled in the art without departing from the scope of the present disclosure, and such alternatives and modifications are intended to be within the scope of the present disclosure.
Claims (10)
1. A data processing method of a segmented guided wave radar liquid level meter comprises the following steps:
predicting a predicted value of the liquid level height in the target container at the next measurement according to the measured liquid level value and the liquid level change speed value of the current liquid level height in the target container;
calculating a first false echo signal in the first echo signal measured next time according to the predicted value and the length of each segment of the waveguide rod;
acquiring a first echo signal of the wave guide rod when the liquid in the target container is positioned at the predicted liquid level height;
calculating an initial measured level value for the predicted level height from the first echo signal and the first spurious echo signal;
and performing Kalman filtering processing on the initial measurement liquid level value to obtain the measurement liquid level value of the predicted liquid level height.
2. The method of claim 1, further comprising:
respectively acquiring a background echo signal of the wave guide rod when no liquid exists in the target container and an initial echo signal of the wave guide rod when the liquid in the target container is positioned at an initial liquid level height;
and calculating a measurement liquid level value and a liquid level change speed value of the initial liquid level height according to the background echo signal and the initial echo signal.
3. The method of claim 2, wherein the separately obtaining the background echo signal of the waveguide rod when no liquid is in the target vessel and the initial echo signal of the waveguide rod when the liquid in the target vessel is at an initial liquid level comprises:
respectively collecting a second echo signal of the wave guide rod when no liquid exists in the target container and a third echo signal of the wave guide rod when the liquid in the target container is positioned at the initial liquid level height;
and respectively carrying out linear frequency modulation Z conversion on the second echo signal and the third echo signal to obtain the background echo signal and the initial echo signal.
4. The method of claim 2, wherein the background echo signal comprises:
c(t)＝c0(t)+c1(t)+c2(t)+…+cQ(t)
wherein c (t) is background echo signal, c0(t) reflected signals due to impedance mismatch at the feed port of the waveguide rod, c1(t) is a length L from the feed port of the waveguide rod1C a reflection signal generated at the junction of the first and second guided wave rods, c2(t) is a length L from the feed port of the waveguide rod2C reflected signal generated at the joint of the second and third guided wave rods, cQ(t) is a length L from the feed port of the waveguide rodQThe total reflection signal caused by the short circuit of the tail end of the waveguide rod in the Q section.
5. The method of claim 4, wherein said calculating a measured level value and a level change velocity value for said initial liquid level height from said background echo signal and said initial echo signal comprises:
obtaining a second false echo signal at the feed port of the waveguide rod according to the background echo signal;
eliminating the false echo signal in the initial echo signal according to the second false echo signal to obtain a first real echo signal;
processing the first real echo signal by a peak positioning method to obtain an initial liquid level height value;
and calculating the liquid level change speed value according to the initial liquid level height value.
6. The method of claim 1, wherein predicting a predicted value of the liquid level in the target container at the next measurement based on the measured liquid level value of the current liquid level in the target container comprises:
wherein the content of the first and second substances,
in order to measure the level value of the liquid,
the liquid level change speed values of two adjacent measurements are obtained, and T is the time interval of the two adjacent measurements.
7. The method of claim 1, wherein said calculating a first false echo signal in said next measured first echo signal based on said predicted values and waveguide rod segment lengths comprises:
wherein the content of the first and second substances,
is the first false echo signal, Ci(k) Is L from the feed port of the waveguide rodiJ is the number of segments of the waveguide rod between the predicted value and the feed port, LJ≤X＜LJ+1And X is a predicted value.
8. The method of claim 1, wherein the obtaining a first echo signal of the waveguide rod when the liquid in the target vessel is at the predicted liquid level comprises:
collecting a fourth echo signal of the wave guide rod when the liquid in the target container is positioned at the predicted liquid level height;
and performing linear frequency modulation Z conversion on the fourth echo signal in a window taking the predicted value as the center to obtain the first echo signal.
9. The method of claim 1, wherein said calculating an initial measured level value of said predicted level from said first echo signal and said first spurious echo signal comprises:
eliminating the false echo signal in the first echo signal according to the first false echo signal to obtain a second real echo signal;
and processing the second real echo signal by a peak positioning method to obtain an initial measurement liquid level value of the predicted liquid level height.
10. The method of claim 1, wherein the kalman filtering the initial measured level value to obtain the measured level value of the predicted liquid level height comprises:
performing Kalman filtering processing on the initial measurement level value to obtain a measurement level value of the predicted liquid level height in the target container and the liquid level change speed value in the target container;
and outputting the measured liquid level value as a final output result.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110417184.1A CN113108867B (en) | 2021-04-20 | 2021-04-20 | Data processing method for sectional coaxial guided wave radar liquid level meter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110417184.1A CN113108867B (en) | 2021-04-20 | 2021-04-20 | Data processing method for sectional coaxial guided wave radar liquid level meter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113108867A CN113108867A (en) | 2021-07-13 |
| CN113108867B true CN113108867B (en) | 2022-05-24 |
Family
ID=76718238
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110417184.1A Active CN113108867B (en) | 2021-04-20 | 2021-04-20 | Data processing method for sectional coaxial guided wave radar liquid level meter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113108867B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114634007B (en) * | 2022-02-11 | 2024-03-22 | 国能黄骅港务有限责任公司 | Feeding system of dumper and low material level detection method and device thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102661773A (en) * | 2012-05-15 | 2012-09-12 | 合肥工业大学 | System and method for processing echo signal of guided wave type radar level meter |
| CN104132713A (en) * | 2014-05-22 | 2014-11-05 | 深圳万讯自控股份有限公司 | Method and device for processing echo signals of guided wave radar liquid level meter |
| CN106643979A (en) * | 2016-12-23 | 2017-05-10 | 重庆川仪自动化股份有限公司 | Automatic compensation method and device for guided wave radar level meter measured value |
| CN109357729A (en) * | 2018-11-13 | 2019-02-19 | 中国科学院沈阳自动化研究所 | A method of based on guide wave radar liquid level gauge measurement liquid circle position |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE0403165D0 (en) * | 2004-12-23 | 2004-12-23 | Saab Rosemount Tank Radar Ab | A radar level gauge system |
-
2021
- 2021-04-20 CN CN202110417184.1A patent/CN113108867B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102661773A (en) * | 2012-05-15 | 2012-09-12 | 合肥工业大学 | System and method for processing echo signal of guided wave type radar level meter |
| CN104132713A (en) * | 2014-05-22 | 2014-11-05 | 深圳万讯自控股份有限公司 | Method and device for processing echo signals of guided wave radar liquid level meter |
| CN106643979A (en) * | 2016-12-23 | 2017-05-10 | 重庆川仪自动化股份有限公司 | Automatic compensation method and device for guided wave radar level meter measured value |
| CN109357729A (en) * | 2018-11-13 | 2019-02-19 | 中国科学院沈阳自动化研究所 | A method of based on guide wave radar liquid level gauge measurement liquid circle position |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113108867A (en) | 2021-07-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9958310B2 (en) | Fill level measurement with improved distance determination | |
| CN105556332B (en) | The dispersion correction of fmcw radar in pipeline or pipe | |
| US9645003B2 (en) | Efficient dispersion correction for FMCW-radar in a pipe | |
| CN107907878A (en) | The method that high accuracy obtains fmcw radar distance measure | |
| CN103823215A (en) | Linear frequency modulation continuous wave radar distance measuring method | |
| CN113108867B (en) | Data processing method for sectional coaxial guided wave radar liquid level meter | |
| CN109613503B (en) | Calibration method and device for radar echo signals | |
| US20140266863A1 (en) | Radar level gauge with signal division | |
| US10816385B2 (en) | Radar level gauge | |
| CN116087908B (en) | Radar high-precision level meter measuring method based on cooperative operation | |
| CN107346022A (en) | High accuracy based on microwave interferometer surveys ship radar and speed-measuring method | |
| CN203177928U (en) | Echo sampling unit and pulse type radar material level meter with the same | |
| CN113805166A (en) | Target tracking and ranging method and system of radar level meter | |
| Chaudhari et al. | Frequency estimator to improve short range accuracy in FMCW radar | |
| Vogt et al. | An optimized radar system for tank level measurement in dispersive bypass pipes | |
| CN108072868A (en) | A kind of precision distance measurement method based on the refinement of fmcw radar signal frequency | |
| US6529794B1 (en) | Method and device for measuring distance and speed | |
| CN110488272A (en) | A kind of test the speed distance measuring method and device based on frequency modulated continuous wave radar | |
| RU2434242C1 (en) | Method of measuring distance and radio range finder with frequency modulation of probing radio waves (versions) | |
| WO2018121470A1 (en) | Fmcw radar frequency-time waveform modulation method, apparatus and electronic device | |
| CN112461306B (en) | Non-invasive flow measurement method and device | |
| Chang et al. | A practical FMCW radar signal processing method and its system implementation | |
| CN110441746B (en) | Time domain gate transformation method and device | |
| RU2655746C1 (en) | Method of level measurement and radio range station with frequency modulation | |
| EP2789996B1 (en) | Echo curve determination with different resolution in different areas |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |