Method and device for detecting natural frequency of coriolis flowmeter and electronic equipment

Abstract

The application provides a Coriolis flowmeter inherent frequency detection method, device and electronic equipment. The embodiment uses a sine wave sweep excitation signal with continuous frequency and phase changes to detect the inherent frequency of the Coriolis flowmeter, and eliminates problems such as poor anti-interference performance and harmonic interference caused by using equal-interval square wave signals to measure the inherent frequency of the Coriolis flowmeter. With the vibration characteristics of the flow tube in the Coriolis flowmeter derived, the frequency and phase of the sine wave sweep excitation signal used to drive the flow tube to vibrate are continuously changed, so that the interference of the external excitation signal itself on the flow tube vibration can be directly offset or reduced, the signal-to-noise ratio (SNR) is greatly improved, for example, the SNR is increased from 1db when the flow tube is excited by using equal-interval square wave signals to at least 18db by the method provided in the embodiment, the inherent frequency of the Coriolis flowmeter is accurately detected, and the anti-interference performance is enhanced.

Description

Technical Field

[0001] This application relates to fluid metering technology, and in particular to a method, apparatus and electronic equipment for detecting the natural frequency of a Coriolis flowmeter. Background Technology

[0002] Coriolis mass flowmeter (CMF) is used to directly measure the mass flow rate of fluids. Fluid mass flow rate refers to the mass of fluid flowing through a specific cross-section per unit time, expressed in units such as kilograms per second (kg / s), tons per hour (t / h), or grams per minute (g / min).

[0003] The natural frequency of a Coriolis flowmeter is characterized by the natural frequency of the flow tube within the flowmeter. Specifically, the natural frequency of the flow tube during free vibration without external excitation is determined solely by the flow tube's own physical parameters, such as mass, stiffness, and damping, and is independent of external driving forces.

[0004] The conventional method for detecting the natural frequency of a Coriolis flowmeter involves scanning the flow tube with equally spaced square wave signals. By continuously changing the frequency of the square wave signal, the method detects which frequency causes the flow tube to vibrate with the greatest amplitude, and then analyzes the natural frequency based on the frequency (resonance point) that causes the greatest vibration amplitude. However, this method has poor anti-interference capabilities; noise and gas / liquid interference can cause the vibration amplitude to fluctuate wildly, making it easy to misidentify the resonance point. Furthermore, because the square wave signal itself contains high-order harmonics, it can cause unnecessary vibrations in the flow tube, interfering with the true natural frequency. Summary of the Invention

[0005] This application provides a method, apparatus, and electronic device for detecting the natural frequency of a Coriolis flowmeter, in order to eliminate problems such as poor anti-interference and harmonic interference caused by measuring the natural frequency of a Coriolis flowmeter using equally spaced square wave signals.

[0006] This application provides a method for detecting the natural frequency of a Coriolis flowmeter, the method comprising: A sinusoidal sweep frequency excitation signal with continuously varying frequency and phase is obtained; the frequency variation range of the sinusoidal sweep frequency excitation signal covers the inherent frequency range of the flow tube in the Coriolis flowmeter. A sinusoidal sweep excitation signal with continuously varying frequency and phase is applied to the drive coil of the flow tube to cause the flow tube to vibrate, and the vibration response signal of the flow tube is acquired by a sensor; the vibration response signal includes a first vibration response of the flow tube at its natural frequency and a second vibration response of the flow tube under the sinusoidal sweep excitation signal; the first vibration response is independent of the sinusoidal sweep excitation signal, and the second vibration response refers to a forced vibration response with a frequency consistent with the frequency of the sinusoidal sweep excitation signal; under the excitation of the sinusoidal sweep excitation signal with continuously varying frequency and phase, the vibration amplitudes of the first vibration response of the flow tube are superimposed; The frequency at the maximum spectral amplitude in the vibration response signal is obtained, and the natural frequency of the Coriolis flowmeter is determined based on this frequency.

[0007] A device for detecting the natural frequency of a Coriolis flowmeter, the device comprising: The acquisition unit is used to acquire a sinusoidal sweep frequency excitation signal with continuously changing frequency and phase; the frequency variation range of the sinusoidal sweep frequency excitation signal covers the inherent frequency range of the flow tube in the Coriolis flowmeter. A control unit is configured to apply a continuously varying sinusoidal sweep excitation signal with both frequency and phase to the drive coil of the flow tube to cause the flow tube to vibrate, and to acquire the vibration response signal of the flow tube via a sensor; the vibration response signal includes a first vibration response of the flow tube at its natural frequency and a second vibration response of the flow tube under the sinusoidal sweep excitation signal; the first vibration response is independent of the sinusoidal sweep excitation signal, and the second vibration response refers to a forced vibration response with a frequency consistent with the frequency of the sinusoidal sweep excitation signal; under the excitation of the continuously varying sinusoidal sweep excitation signal with both frequency and phase, the vibration amplitudes of the first vibration response of the flow tube are superimposed; The detection unit is used to obtain the frequency at the maximum spectral amplitude in the vibration response signal, so as to determine the natural frequency of the Coriolis flowmeter based on the frequency.

[0008] An electronic device comprising: a processor and a machine-readable storage medium; The machine-readable storage medium stores machine-executable instructions that can be executed by the processor; The processor is used to execute machine-executable instructions to implement the steps in the above method.

[0009] As can be seen from the above technical solutions, this embodiment uses a sinusoidal sweep frequency excitation signal with continuously changing frequency and phase to detect the natural frequency of the Coriolis flowmeter. This eliminates problems such as poor anti-interference and harmonic interference caused by the existing method of measuring the natural frequency of the Coriolis flowmeter using equally spaced square wave signals.

[0010] Furthermore, this embodiment analyzes and derives the vibration characteristics of the flow tube in the Coriolis flowmeter. With the help of these vibration characteristics, this embodiment controls the continuous change of the frequency and phase of the sinusoidal sweep excitation signal that drives the vibration of the flow tube. This directly cancels or reduces the interference of the external excitation signal itself on the vibration of the flow tube, greatly improving the signal-to-noise ratio (SNR) of the signal, so as to accurately detect the natural frequency of the Coriolis flowmeter and enhance the anti-interference capability.

[0011] Furthermore, this embodiment, by controlling the continuous change in frequency and phase of the sinusoidal sweep excitation signal driving the flow tube vibration, can directly cancel or reduce the originally dominant secondary vibration response during the frequency sweep process. This method of weakening the secondary vibration response reduces the mechanical impact on the flow tube, improving its applicability; for example, it can be applied to various complex working conditions (such as gas-containing or high-viscosity fluids). Using this embodiment, even if the frequency of the sinusoidal sweep excitation signal is not perfectly aligned with the resonant frequency of the flow tube during the frequency sweep stage, the true natural frequency of the flow tube can be predicted in advance through the above general solution analysis. Attached Figure Description

[0012] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0013] Figure 1 A flowchart illustrating the method provided in this application embodiment; Figures 2 to 4 A schematic diagram of frequency sweep under a fixed frequency excitation signal; Figures 5 to 7 A schematic diagram of frequency sweep under a frequency-varying excitation signal; Figure 8 This is a schematic diagram of the device structure provided in the embodiments of this application; Figure 9 This is a structural diagram of an electronic device provided in an embodiment of this application. Detailed Implementation

[0014] This embodiment no longer simply relies on equally spaced square wave signals to find the frequency that causes the largest amplitude of flow tube vibration. Instead, it utilizes the mathematical characteristics of flow tube vibration to detect the natural frequency of the Coriolis flowmeter. To enable those skilled in the art to better understand the technical solutions provided in this application's embodiments, and to make the above-mentioned objectives, features, and advantages of this application's embodiments more apparent, the technical solutions in this application's embodiments will be further described in detail below with reference to the accompanying drawings.

[0015] In practical implementation, the mathematical characteristics of flow tube vibration can be represented by a second-order linear differential equation. This equation describes the result of the interaction of the spring, mass, and damping coefficient. The spring refers to the elasticity of the flow tube's metal. The mass refers to the metal mass of the flow tube itself and the mass of the fluid retained within it (which is the core of the vibration, propelled by the driving device). The damping system refers to the damping of the flow tube, such as viscous friction, friction between the tube body and the supporting structure, and air resistance, which ensures that the vibration of the flow tube does not continuously amplify and remains stable.

[0016] In this embodiment, the second-order linear differential equation can be expressed as: (Equation 1) Where m is the mass of the flow tube, such as the metal mass of the flow tube itself and the mass of the fluid trapped inside the flow tube, c is the damping coefficient of the flow tube, k is the stiffness coefficient of the flow tube, x(t) is the response signal of the flow tube when it vibrates, such as displacement, and F(t) is the excitation signal. Let x(t) be the first derivative. It is the second derivative, for example, representing the acceleration of the flow tube vibration.

[0017] make , Then, equation 1 above can be transformed into equation 2 as follows: (Equation 2) If the excitation signal F(t) currently applied to the drive coil of the flow tube is a sinusoidal sweep frequency excitation signal: ,in This is the current scanning frequency. By deriving Equation 2 above (for example, by first setting F(t) = 0, and then calculating...), Let again ,calculate ), ultimately we can obtain: The reason for using a sine wave frequency sweep excitation signal here is that, compared to a square wave signal, a sine wave is purer and does not contain the high-order harmonic interference found in a square wave signal.

[0018] in, This represents the general solution, used to describe the first vibration response of the flow tube at its natural frequency, which is equivalent to natural vibration. This represents a particular solution used to describe the forced vibration response of a flow tube under the frequency of a sinusoidal sweep excitation signal, which is equivalent to forced vibration.

[0019] By analyzing the above equation 2, It can be represented as: .

[0020] Where A represents the amplitude of the flow tube at its natural frequency. , It decays exponentially over time, directly reflecting the inherent frequency of the flow tube. Indicates phase.

[0021] By analyzing the above equation 2, It can be represented as: Where B represents the amplitude of the flow tube at the frequency of the sinusoidal sweep excitation signal. Indicates phase. B is less than or equal to A.

[0022] Through analysis and The vibration characteristics of the flow tube in the Coriolis flowmeter were discovered. Under the premise that the frequency and phase of the external sinusoidal sweep excitation signal are constantly changing, the transient response of the flow tube caused by each excitation change (i.e., the general solution mentioned above, the first vibration response) remains fixed at its natural frequency (e.g., 100Hz). However, because the frequency of the sinusoidal sweep excitation signal is dispersed, for example, across a wide frequency band of 50Hz to 150Hz, the energy density of the flow tube's particular solution, the second vibration response, is relatively low at any single frequency point, forming a low-amplitude and flat "noise floor plateau." In other words, the aforementioned particular solution is frequency- and phase-locked with the sinusoidal sweep excitation signal. The vibration amplitudes of the flow tube's second vibration response are dispersed, and through the inverted sinusoidal sweep excitation signal or weighted subtraction processing, the second vibration response of the flow tube under inverted excitation is partially canceled out.

[0023] Based on the above analysis, the embodiments of this application provide the following: Figure 1 The process is shown below. This method can be applied to electronic devices.

[0024] like Figure 1 As shown, the process may include the following steps: Step 101: Obtain a sinusoidal sweep excitation signal with continuously changing frequency and phase.

[0025] Based on the vibration characteristics of the flow tube in the Coriolis flowmeter described above, this embodiment can generate a series of sinusoidal sweep excitation signals with different frequencies and phases using a digital signal processor (DSP) or FPGA. The frequency range of this sinusoidal sweep excitation signal covers the inherent frequency range of the flow tube in the Coriolis flowmeter. For example, generally, the inherent frequency range of the flow tube in a Coriolis flowmeter is around 100 Hz, so the frequency range of the sinusoidal sweep excitation signal could be, for example, 40 Hz to 700 Hz, or 50 Hz to 100 Hz.

[0026] Step 102: Apply the aforementioned sinusoidal sweep frequency excitation signal with continuously changing frequency and phase to the drive coil of the flow tube to make the flow tube vibrate, and collect the vibration response signal of the flow tube through a sensor.

[0027] In this embodiment, the vibration response signal includes the first vibration response of the flow tube at its natural frequency and the second vibration response of the flow tube under a sinusoidal sweep frequency excitation signal. Based on the above vibration characteristics, it can be seen that the first vibration response is independent of the sinusoidal sweep frequency excitation signal, while the second vibration response refers to the forced vibration response with a frequency consistent with the sinusoidal sweep frequency excitation signal. Under the excitation of a sinusoidal sweep frequency excitation signal whose frequency and phase both change continuously, the vibration amplitudes of the first vibration response of the flow tube are superimposed, while the vibration amplitudes of the second vibration response of the flow tube are dispersed, and the second vibration response of the flow tube under anti-phase excitation partially cancels each other out. Under this premise, step 103 can be performed based on this characteristic to detect the natural frequency of the flow tube in the Coriolis flowmeter (also called the natural frequency of the Coriolis flowmeter).

[0028] By utilizing the frequency and phase lock-in characteristic of the particular solution, namely the second vibration response, with the sinusoidal sweep excitation signal in step 102, the second vibration responses of the flow tube can be mutually canceled out by either the presence of an inverted sinusoidal sweep excitation signal or by weighted subtraction processing of the vibration response signal. At the end of one scan cycle, the vibration response signal may consist mostly of the first vibration response of the flow tube.

[0029] Step 103: Obtain the frequency at the maximum spectral amplitude in the vibration response signal, and determine the natural frequency of the Coriolis flowmeter based on this frequency.

[0030] For example, by filtering out low-energy noise interference through frequency spectrum analysis (FFT), zero-crossing detection, or adaptive filters, the frequency at the maximum spectral amplitude in the vibration response signal can be obtained. Optionally, in this embodiment, this frequency can be used as the natural frequency of the Coriolis flowmeter. This natural frequency can then be used as the frequency of the drive signal, enabling the Coriolis flowmeter to quickly enter and maintain a stable resonant operating state.

[0031] This concludes the process. Figure 1 The process is shown below.

[0032] pass Figure 1 As can be seen from the flowchart, this embodiment uses a sinusoidal sweep excitation signal with continuously changing frequency and phase to detect the natural frequency of the Coriolis flowmeter. This eliminates problems such as poor anti-interference and harmonic interference caused by the existing method of measuring the natural frequency of the Coriolis flowmeter using equally spaced square wave signals.

[0033] Furthermore, this embodiment analyzes and derives the vibration characteristics of the flow tube in the Coriolis flowmeter. With the help of these vibration characteristics, this embodiment controls the continuous change of the frequency and phase of the sinusoidal sweep excitation signal that drives the vibration of the flow tube. This directly cancels or reduces the interference of the external excitation signal itself on the vibration of the flow tube, greatly improving the signal-to-noise ratio (SNR) of the signal, so as to accurately detect the natural frequency of the Coriolis flowmeter and enhance the anti-interference capability.

[0034] Furthermore, this embodiment, by controlling the continuous change in frequency and phase of the sinusoidal sweep excitation signal driving the flow tube vibration, can directly cancel or reduce the originally dominant secondary vibration response during the frequency sweep process. This method of weakening the secondary vibration response reduces the mechanical impact on the flow tube, improving its applicability; for example, it can be applied to various complex working conditions (such as gas-containing or high-viscosity fluids). Using this embodiment, even if the frequency of the sinusoidal sweep excitation signal is not perfectly aligned with the resonant frequency of the flow tube during the frequency sweep stage, the true natural frequency of the flow tube can be predicted in advance through the above general solution analysis.

[0035] In this embodiment, the sinusoidal sweep excitation signal refers to a sinusoidal signal whose frequency and phase change linearly with time; the frequency changing linearly with time means changing from small to large or from large to small with time; the phase changing linearly with time means changing from small to large or from large to small with time.

[0036] Optionally, linear frequency change with time means that the frequency changes from small to large over time with increasingly smaller frequency change intervals; or, linear frequency change with time means that the frequency changes from large to small over time with increasingly larger frequency change intervals. Here, the frequency change interval refers to the frequency difference between the frequencies of the sinusoidal sweep excitation signal at two adjacent moments.

[0037] A linear phase change over time means that the phase changes from small to large over time with decreasing intervals, or conversely, a linear phase change over time means that the phase changes from large to small over time with increasing intervals. Here, the phase change interval refers to the phase difference between the sinusoidal sweep excitation signals at two adjacent moments.

[0038] Optionally, the frequency variation range is 40Hz to 700Hz.

[0039] To make the effects achieved by the method provided in this application embodiment more intuitive, the following analogy is made in this embodiment: Taking a sinusoidal frequency sweep excitation signal as an example, such as Figure 2 This shows the time-domain waveform of the excitation signal at a fixed frequency (e.g., 80Hz). From Figure 2It can be seen that the energy of the excitation source is continuously output in the time domain, and highly concentrated at a single frequency point, namely 80Hz, in the frequency domain.

[0040] Figure 3 The vibration response signal (also known as the time-domain waveform of the vibration pickup signal) of the flow tube under fixed frequency excitation is shown. Since the frequency of the excitation signal (80Hz) is inconsistent with the natural frequency of the flow tube (100Hz), under the premise that the frequency of the excitation signal (80Hz) is fixed, the vibration response signal of the flow tube mainly exhibits forced vibration (the second vibration response mentioned above). It can also be seen that the frequency of the vibration response signal completely follows the frequency of the excitation signal, and the waveform is stable.

[0041] Figure 4 The spectrum of the vibration response signal of the flow tube at a fixed excitation signal frequency (80Hz) is shown. It can be seen from this spectrum that almost all the signal energy is concentrated at the excitation signal frequency (80Hz), forming an extremely high energy peak. That is, the second vibration response dominates, and the first vibration response is completely submerged. The signal-to-noise ratio (SNR) is very low, making it impossible to identify the natural frequency of the flow tube in the spectrum. This demonstrates that using a fixed-frequency excitation signal at non-resonance points cannot detect the natural frequency of the flow tube, and may even lead to the excitation signal frequency (80Hz) being incorrectly taken as the natural frequency of the flow tube.

[0042] The method provided in this application embodiment uses a sinusoidal sweep frequency excitation signal with a frequency that changes linearly from 50Hz to 150Hz. Figure 5 As shown, the signal amplitude remains constant, but the frequency changes linearly with time. Figure 2 In contrast, the total energy of the excitation source is uniform along the time axis, but is stretched along the frequency dimension.

[0043] Figure 6 The vibration response signal of the flow tube acquired by the sensor during the frequency sweep process is shown. This vibration response signal contains two components: a forced vibration component that follows the excitation signal (particular solution, i.e., the second vibration response), and a natural vibration component of the flow tube (general solution, i.e., the first vibration response). Figure 7 The signal spectrum diagram of the vibration response signal is shown, illustrating the energy spectral density distribution of the vibration response signal.

[0044] pass Figure 6 and Figure 7 It can be seen that, because the sinusoidal sweep excitation signal disperses the energy over a wide frequency range of 50Hz-150Hz, the energy density at any single frequency point of the second vibration response is significantly reduced, forming a low-amplitude and flat "noise floor plateau". Figure 7The excitation energy shown is dispersed over a wide bandwidth. For the first vibration response, although the frequency of the sinusoidal sweep excitation signal changes continuously, the frequency of the first vibration response remains fixed at its natural frequency (100Hz), as shown below. Figure 7 The spike shown signifies a "frequency superposition" effect at the inherent frequency of the flow tube.

[0045] It can be seen that throughout the entire scanning cycle, the spectral amplitude (also known as the energy value) of the second vibration response is spread out evenly, while the spectral amplitude (also known as the energy value) of the first vibration response is always "superimposed" and accumulated at the frequency of 100Hz.

[0046] By comparison Figure 4 and Figure 7 As can be seen, this embodiment disperses the energy of the second vibration response, making the spectral amplitude of the flow tube at its natural frequency stand out above the diluted energy of the second vibration response without the need for resonant amplification. This results in an extremely high signal-to-noise ratio, facilitating the algorithm's accurate locking of the flow tube's natural frequency. Under conditions containing random noise, the frequency identification error of existing traditional peak methods may be ±0.5Hz, while this embodiment, by removing the interference of the excitation signal and analyzing only natural vibration, can reduce the error to below ±0.01Hz. Using a certain model of Coriolis flowmeter (flow tube natural frequency of 100Hz), the experimental conditions included normal operation, gas-containing operation (gas content 10% ~ 30%), and high viscosity operation (viscosity 100mPa·s ~ 500mPa·s). The experimental results are as follows: the detection error of the traditional method is ±0.5Hz ~ ±1.0Hz, and the signal-to-noise ratio (SNR) is 20dB ~ 30dB; the method provided in this embodiment has a detection error of less than ±0.01Hz, and the signal-to-noise ratio (SNR) is improved to more than 60dB, with significantly better anti-interference ability than the traditional method.

[0047] It should be noted that in this embodiment, the amplitude of the sinusoidal sweep excitation signal is 5V ~ 10V, the frequency variation range is 40Hz ~ 700Hz, the sweep time is 10s ~ 30s, the step interval of the linear frequency change can be adjusted according to actual needs (the step interval is 0.1Hz ~ 1Hz when the change is uniform, and the interval gradually decreases from 0.5Hz to 0.1Hz when the change is non-uniform), the phase change range is 0 ~ 2π, and the phase change rate can be synchronized with the frequency change rate.

[0048] The methods provided in the embodiments of this application have been described above. The apparatus provided in the embodiments of this application is described below: See Figure 8 , Figure 8 This is a structural diagram of the device provided in an embodiment of this application. Figure 8 As shown, the device includes: The acquisition unit is used to acquire a sinusoidal sweep frequency excitation signal with continuously changing frequency and phase based on the vibration characteristics of the flow tube in the Coriolis flowmeter; the frequency variation range of the sinusoidal sweep frequency excitation signal covers the inherent frequency range of the flow tube in the Coriolis flowmeter. A control unit is configured to apply a continuously varying sinusoidal sweep excitation signal with both frequency and phase to the drive coil of the flow tube to cause the flow tube to vibrate, and to acquire the vibration response signal of the flow tube via a sensor; the vibration response signal includes a first vibration response of the flow tube at its natural frequency and a second vibration response of the flow tube under the sinusoidal sweep excitation signal; the first vibration response is independent of the sinusoidal sweep excitation signal, and the second vibration response refers to a forced vibration response with a frequency consistent with the frequency of the sinusoidal sweep excitation signal; under the excitation of the continuously varying sinusoidal sweep excitation signal with both frequency and phase, the vibration amplitudes of the first vibration response of the flow tube are superimposed, the vibration amplitudes of the second vibration response of the flow tube are dispersed, and the second vibration response of the flow tube under anti-phase excitation partially cancels out; The detection unit is used to obtain the frequency at the maximum spectral amplitude in the vibration response signal, so as to determine the natural frequency of the Coriolis flowmeter based on the frequency.

[0049] Optionally, the sinusoidal sweep excitation signal refers to a sinusoidal signal whose frequency and phase change linearly with time. The frequency changing linearly with time refers to a change that increases or decreases with time. The linear change of phase over time refers to a change from small to large or from large to small over time.

[0050] Optionally, the sinusoidal sweep excitation signal refers to a sinusoidal signal whose frequency and phase change linearly with time. The frequency changing linearly with time means that it changes from small to large over time and the intervals between frequency changes become smaller and smaller; or, the frequency changing linearly with time means that it changes from large to small over time and the intervals between frequency changes become larger and larger. The linear change of phase over time means that the phase changes from small to large over time with the intervals between phase changes becoming smaller and smaller, or the linear change of phase over time means that the phase changes from large to small over time with the intervals between phase changes becoming larger and larger.

[0051] Optionally, the frequency variation range is 40Hz to 700Hz.

[0052] Optionally, determining the inherent frequency of the Coriolis flowmeter based on this frequency includes: This frequency is taken as the inherent frequency of the Coriolis flowmeter.

[0053] Optionally, the vibration characteristics of the flow tube in the Coriolis flowmeter are characterized by analyzing x(t) obtained from the second-order linear differential equation describing the vibration of the flow tube, where x(t) represents the response of the flow tube during vibration. , This represents the general solution, used to describe the first vibration response of the flow tube at its natural frequency. The frequency is the inherent frequency of the flow tube; This represents a particular solution used to describe the second vibrational response of the flow tube forced under the frequency of a sinusoidal sweep excitation signal. The frequency is the frequency of the sinusoidal sweep excitation signal; The and stated This characterizes the superposition of the vibration amplitudes of the first vibration response of the flow tube under the excitation of a sinusoidal sweep frequency excitation signal with continuously changing frequency and phase, the dispersion of the vibration amplitudes of the second vibration response of the flow tube, and the partial cancellation of the second vibration response of the flow tube under the opposite phase excitation.

[0054] Optionally, the second-order linear differential equation is: ; in, Where m is the mass of the flow tube, c is the damping coefficient of the flow tube, and k is the stiffness coefficient of the flow tube. , k is the stiffness coefficient corresponding to the flow tube, and F(t) is the sinusoidal sweep frequency excitation signal.

[0055] The apparatus provided in the embodiments of this application has been described above.

[0056] This application also provides embodiments that... Figure 8 A description of the hardware structure of the device shown. (e.g.) Figure 9 As shown, the electronic device may include a processor and a machine-readable storage medium; the machine-readable storage medium stores machine-executable instructions that can be executed by the processor; the processor is used to execute the machine-executable instructions to implement the methods disclosed in the above examples of this application.

[0057] Based on the same application concept as the above method, this application embodiment also provides a machine-readable storage medium storing a plurality of computer instructions, which, when executed by a processor, can implement the method disclosed in the above examples of this application.

[0058] For example, the aforementioned machine-readable storage medium can be any electronic, magnetic, optical, or other physical storage device that can contain or store information such as executable instructions, data, etc. For instance, machine-readable storage media can be: RAM (Random Access Memory), volatile memory, non-volatile memory, flash memory, storage drives (such as hard disk drives), solid-state drives, any type of storage disk (such as optical discs, DVDs, etc.), or similar storage media, or combinations thereof.

[0059] The systems, devices, modules, or units described in the above embodiments can be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer, which can take the form of a personal computer, laptop computer, cellular phone, camera phone, smartphone, personal digital assistant, media player, navigation device, email sending and receiving device, game console, tablet computer, wearable device, or any combination of these devices.

[0060] For ease of description, the above devices are described separately by function as various units. Of course, in implementing this application, the functions of each unit can be implemented in one or more software and / or hardware.

[0061] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, embodiments of this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0062] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0063] Furthermore, these computer program instructions can also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in the process. Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0064] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0065] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for detecting the natural frequency of a Coriolis flowmeter, characterized in that, The method includes: A sinusoidal sweep frequency excitation signal with continuously varying frequency and phase is obtained; the frequency variation range of the sinusoidal sweep frequency excitation signal covers the inherent frequency range of the flow tube in the Coriolis flowmeter. A sinusoidal sweep excitation signal with continuously varying frequency and phase is applied to the drive coil of the flow tube to cause the flow tube to vibrate, and the vibration response signal of the flow tube is acquired by a sensor; the vibration response signal includes a first vibration response of the flow tube at its natural frequency and a second vibration response of the flow tube under the sinusoidal sweep excitation signal; the first vibration response is independent of the sinusoidal sweep excitation signal, and the second vibration response refers to a forced vibration response with a frequency consistent with the frequency of the sinusoidal sweep excitation signal; under the excitation of the sinusoidal sweep excitation signal with continuously varying frequency and phase, the vibration amplitudes of the first vibration response of the flow tube are superimposed; The frequency at the maximum spectral amplitude in the vibration response signal is obtained, and the natural frequency of the Coriolis flowmeter is determined based on this frequency.

2. The method according to claim 1, characterized in that, The sinusoidal sweep excitation signal refers to a sinusoidal signal whose frequency and phase change linearly with time. The frequency changing linearly with time refers to a change that increases or decreases with time. The linear change of phase over time refers to a change from small to large or from large to small over time.

3. The method according to claim 1, characterized in that, The sinusoidal sweep excitation signal refers to a sinusoidal signal whose frequency and phase change linearly with time. The frequency changing linearly with time means that it changes from small to large over time and the intervals between frequency changes become smaller and smaller; or, the frequency changing linearly with time means that it changes from large to small over time and the intervals between frequency changes become larger and larger. The linear change of phase over time means that the phase changes from small to large over time with the intervals between phase changes becoming smaller and smaller, or the linear change of phase over time means that the phase changes from large to small over time with the intervals between phase changes becoming larger and larger.

4. The method according to claim 2 or 3, characterized in that, The frequency variation range is 40Hz to 700Hz.

5. The method according to claim 1, characterized in that, Determining the inherent frequency of the Coriolis flowmeter based on this frequency includes: This frequency is taken as the inherent frequency of the Coriolis flowmeter.

6. The method according to claim 1, characterized in that, The sinusoidal sweep frequency excitation signal matches the vibration characteristics of the flow tube in the Coriolis flowmeter; the vibration characteristics of the flow tube in the Coriolis flowmeter are characterized by x(t) obtained by analyzing the second-order linear differential equation used to describe the vibration of the flow tube, where x(t) represents the response of the flow tube during vibration. , This represents the general solution, used to describe the first vibration response of the flow tube at its natural frequency. The frequency is the inherent frequency of the flow tube; This represents a particular solution used to describe the second vibrational response of the flow tube forced under the frequency of a sinusoidal sweep excitation signal. The frequency is the frequency of the sinusoidal sweep excitation signal; The The first vibration response of the flow tube is characterized to be independent of the frequency of the sinusoidal sweep excitation signal, such that under the excitation of a sinusoidal sweep excitation signal with continuously changing frequency and phase, the vibration amplitudes of the first vibration response of the flow tube are superimposed; The second vibration response of the flow tube was characterized as being related to the frequency of the sinusoidal sweep excitation signal.

7. The method according to claim 6, characterized in that, The second-order linear differential equation is: ； in, Where m is the mass of the flow tube, c is the damping coefficient of the flow tube, and k is the stiffness coefficient of the flow tube. , k is the stiffness coefficient corresponding to the flow tube, and F(t) is the sinusoidal sweep frequency excitation signal.

8. A device for detecting the natural frequency of a Coriolis flowmeter, characterized in that, The device includes: The acquisition unit is used to acquire a sinusoidal sweep frequency excitation signal with continuously changing frequency and phase; the frequency variation range of the sinusoidal sweep frequency excitation signal covers the inherent frequency range of the flow tube in the Coriolis flowmeter. A control unit is configured to apply a continuously varying sinusoidal sweep excitation signal with both frequency and phase to the drive coil of the flow tube to cause the flow tube to vibrate, and to acquire the vibration response signal of the flow tube via a sensor; the vibration response signal includes a first vibration response of the flow tube at its natural frequency and a second vibration response of the flow tube under the sinusoidal sweep excitation signal; the first vibration response is independent of the sinusoidal sweep excitation signal, and the second vibration response refers to a forced vibration response with a frequency consistent with the frequency of the sinusoidal sweep excitation signal; under the excitation of the continuously varying sinusoidal sweep excitation signal with both frequency and phase, the vibration amplitudes of the first vibration response of the flow tube are superimposed; The detection unit is used to obtain the frequency at the maximum spectral amplitude in the vibration response signal, so as to determine the natural frequency of the Coriolis flowmeter based on the frequency.

9. The apparatus according to claim 8, characterized in that, The sinusoidal sweep excitation signal refers to a sinusoidal signal whose frequency and phase change linearly with time. The frequency changing linearly with time refers to a change that increases or decreases with time. The linear change of phase over time refers to a change that increases or decreases over time. And / or, the sinusoidal sweep excitation signal refers to a sinusoidal signal whose frequency and phase change linearly with time; the linear change of frequency with time means that it changes from small to large with time and the frequency change interval becomes smaller and smaller; or, the linear change of frequency with time means that it changes from large to small with time and the frequency change interval becomes larger and larger. The linear change of phase over time means that the phase changes from small to large over time and the interval between phase changes becomes smaller and smaller; or, the linear change of phase over time means that the phase changes from large to small over time and the interval between phase changes becomes larger and larger. And / or, the frequency variation range is 40Hz~700Hz; And / or, determining the inherent frequency of the Coriolis flowmeter based on this frequency includes: This frequency is taken as the inherent frequency of the Coriolis flowmeter; And / or, the sinusoidal sweep frequency excitation signal matches the vibration characteristics of the flow tube in the Coriolis flowmeter; the vibration characteristics of the flow tube in the Coriolis flowmeter are characterized by x(t) obtained by analyzing the second-order linear differential equation used to describe the vibration of the flow tube, wherein x(t) represents the response of the flow tube during vibration: , This represents the general solution, used to describe the first vibration response of the flow tube at its natural frequency. The frequency is the inherent frequency of the flow tube; This represents a particular solution used to describe the second vibrational response of the flow tube forced under the frequency of a sinusoidal sweep excitation signal. The frequency is the frequency of the sinusoidal sweep excitation signal; The and stated It is characterized that under the excitation of a sinusoidal sweep frequency excitation signal with continuously changing frequency and phase, the vibration amplitudes of the first vibration response of the flow tube are superimposed, the vibration amplitudes of the second vibration response of the flow tube are dispersed, and the second vibration response of the flow tube under the reverse phase excitation is partially canceled. And / or, the second-order linear differential equation is: ； in, Where m is the mass of the flow tube, c is the damping coefficient of the flow tube, and k is the stiffness coefficient of the flow tube. , k is the stiffness coefficient corresponding to the flow tube, and F(t) is the sinusoidal sweep frequency excitation signal.

10. An electronic device, characterized in that, The electronic device includes: a processor and a machine-readable storage medium; The machine-readable storage medium stores machine-executable instructions that can be executed by the processor; The processor is configured to execute machine-executable instructions to implement the method steps of any one of claims 1-8.

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