Coriolis flowmeter vibration method and Coriolis flowmeter

Abstract

The present invention provides a Coriolis flowmeter vibration method and a Coriolis flowmeter. After a driving module sends a plurality of periodic composite pulse signals to drive a vibrating tube, the driving module stops driving the vibrating tube, a signal acquisition sensor acquires a vibration signal of the vibrating tube, and calculates a first frequency of the acquired signal; the driving module sends a sine wave signal with the same amplitude and frequency varying from small to large to drive the vibrating tube, the frequency variation range is, and the amplitude of each vibration signal is calculated; a sine wave signal is synthesized with the signal frequency with the largest amplitude as the starting frequency to excite the vibrating tube, and then a sine wave is synthesized with the signal frequency acquired by the signal acquisition sensor to drive the vibrating tube, and the amplitude of the synthesized sine wave signal is controlled by a PID controller; the vibration signal of the vibrating tube is acquired to determine whether the state of the fluid in the vibrating tube has changed, and if so, the vibrating tube is re-vibrated.

Description

Technical Field

[0001] The present invention belongs to the technical field of Coriolis flowmeter equipment, and in particular relates to a Coriolis flowmeter vibration method and a Coriolis flowmeter. Background Art

[0002] Coriolis flowmeters are commonly used in industrial processes, directly measuring the mass flow rate of fluids. They calculate the mass flow rate by driving a vibrating tube at its resonant frequency and measuring the phase difference. Coriolis flowmeters are commonly driven using a four-mode conversion method: square wave, zero output, positive feedback, and waveform synthesis. The oscillation startup process utilizes four mode conversions: random sequence drive mode, zero output mode, positive feedback mode, and waveform synthesis mode.

[0003] In theory, the Coriolis flowmeter should operate at the resonant frequency and calculate the mass flow rate of the fluid flowing through by measuring the phase difference between the detection sensors. However, due to changes in the fluid morphology in the measuring pipeline, it is difficult to ensure that the Coriolis flowmeter continues to operate stably at the resonant frequency. The existing technology uses a four-mode conversion driving method to enable the vibrating tube to automatically filter out the resonant frequency, but this method relies on the vibrating tube's own filtering, and it is difficult to ensure the accuracy of the resonant frequency. In addition, when the fluid flow or flow state in the vibrating tube changes, the vibrating tube will deviate from the resonant frequency. The existing technology determines whether to re-start the vibrating tube by judging the vibration amplitude. Since the vibration amplitude is not only related to whether it is the resonant frequency, but also related to the mass of the fluid in the vibrating tube, false re-starting is prone to occur, affecting the measurement of the Coriolis flowmeter. Summary of the Invention

[0004] In view of the problems existing in the prior art, the present invention provides a Coriolis flowmeter oscillation starting method and a Coriolis flowmeter to solve the problems existing in the oscillation starting process in the prior art.

[0005] The present invention provides a Coriolis flowmeter vibration method, wherein a driving module sends a driving signal to drive a vibrating tube, comprising the following steps:

[0006] Step 101: After the driving module sends multiple periodic composite pulse signals to drive the vibrating tube, the driving module stops driving the vibrating tube, and the signal acquisition sensor acquires the vibration signal of the vibrating tube and calculates the first frequency of the acquired signal. ;

[0007] Step 102: The driver module sends the same amplitude The sine wave signal with frequency varying from small to large drives the vibration tube, and the frequency variation range is ,in The frequency allowed width is used to calculate the amplitude of each vibration signal. ;

[0008] Step 103: Use the signal frequency with the largest amplitude The starting frequency is used to synthesize a sine wave signal to excite the vibration tube, and then the signal acquisition sensor collects the signal frequency to synthesize a sine wave to drive the vibration tube. The amplitude of the synthesized sine wave signal is controlled by a PID controller;

[0009] Step 104: Collect the vibration signal of the vibrating tube and determine whether the state of the fluid in the vibrating tube has changed. If so, restart the vibrating tube.

[0010] Furthermore, the composite pulse signal in step 101 is obtained by accumulating multiple pulse signals with different pulse widths and the same amplitude within the resonant frequency range of the vibrating tube.

[0011] Furthermore, the frequency allowable width in step 102 ,in is the driving signal amplitude, is the maximum vibration amplitude of the vibrating tube excited by the composite pulse signal, is the basic unit of frequency, the amplitude of the driving signal remains unchanged, and the frequency of the driving signal is successively Changes to , the change step size is ,in Adjust the coefficient and calculate the amplitude of the vibration signal at different frequencies.

[0012] Furthermore, the setting method of the PID controller setting value in step 103 is:

[0013] Step 301: The driving signal amplitude is 1 / 2 of the maximum driving amplitude, driving the vibrating tube. After the vibration of the vibrating tube stabilizes, the vibration amplitude of the vibrating tube is the current setting value of the PID controller; the driving module outputs the driving signal according to the control value of the PID controller;

[0014] Step 302: When the control output of the PID controller exceeds 3 / 4 of the maximum amplitude of the drive signal or is less than 1 / 4 of the maximum amplitude, the drive signal amplitude is adjusted to 1 / 2 of the maximum drive amplitude to drive the vibration tube. After the vibration of the vibration tube stabilizes, the vibration amplitude of the vibration tube is the current setting value of the PID controller.

[0015] Furthermore, the method for determining whether the fluid state has changed in step 104 is as follows: collecting the vibration signal of the vibration tube, calculating the signal frequency and amplitude, and determining whether the signal is abnormal based on the changes in the signal frequency and amplitude. If abnormal, determining whether the signal acquisition sensor is working normally. If the signal acquisition sensor is working normally, it is considered that the fluid state has changed, and the vibration tube is restarted.

[0016] Furthermore, the method for determining abnormality in the vibration signal of the vibrating tube is that the signal of at least one signal acquisition sensor has multiple frequency components or the signal variation is greater than a first threshold.

[0017] Furthermore, the frequency component calculation method is:

[0018] Collect vibration tube signals. When the number of signals meets the quantity requirement, construct a matrix of the vibration signals of the vibration tube, and then perform singular value decomposition on the matrix to obtain the singular values ​​of the matrix. Determine the number of data in the singular values ​​that are greater than the second threshold value. If there are more than two, it is considered that the vibration tube has multiple frequency components.

[0019] Furthermore, the signal variation is calculated as follows: the sampling frequency of the acquisition signal sensor is , the vibration signal of the vibration tube is collected as , when collecting the vibration signal of the vibration tube achieve After a full cycle, count the peaks in the signal , trough value and the time of crossing zero , the signal change is:

[0020] .

[0021] Furthermore, the signal acquisition sensor fault judgment method is to calculate the first similarity of the signals collected by the two signal acquisition sensors, and the first similarity calculation method is:

[0022]

[0023] in The time when the first signal acquisition sensor collects the zero-crossing point of the vibration tube signal, The second signal acquisition sensor collects the time of the zero crossing point in the same direction of the vibration tube signal. The peak value of the first signal acquisition sensor is The first signal acquisition sensor trough value, Acquire the sensor peak value for the second signal, The valley value of the sensor is collected for the second signal. is the number of complete cycles, if the first similarity of the two signal acquisition sensors is Greater than the third threshold , determine that the signal acquisition sensor is working normally.

[0024] The present invention also provides a Coriolis flowmeter, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the above-mentioned Coriolis flowmeter vibration method is implemented.

[0025] After the present invention excites the first frequency through the driving signal, it traverses the frequency signals near the first frequency to determine the accurate resonant frequency, so the resonant frequency is more accurate. In the stage of exciting the vibration tube with the synthetic signal, it is judged whether the vibration tube is at the resonant frequency through the frequency and amplitude of the vibration signal of the vibration tube, and it is judged whether to re-oscillate, so that the vibration tube works at the resonant frequency, the vibration tube will not be excessively re-oscillated, and the resonant frequency of the vibration tube can be guaranteed to work. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a flow chart of the oscillation starting method of the present invention;

[0027] Figure 2 It is a schematic diagram of the oscillation waveform;

[0028] Figure 3 Schematic diagram of sensor installation;

[0029] Figure 4 Flowchart of PID parameter adjustment method. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and corresponding drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] like Figure 1 As shown, this embodiment provides a Coriolis flowmeter vibration method, in which a driving module sends a driving signal to drive a vibrating tube, specifically including the following steps:

[0032] Step 101: After the driving module sends multiple periodic composite pulse signals to drive the vibrating tube, the driving module stops driving the vibrating tube, and the signal acquisition sensor acquires the vibration signal of the vibrating tube and calculates the first frequency of the acquired signal. .

[0033] Specifically, the driving signal in the initial stage is a composite pulse signal, which is obtained by accumulating multiple pulse signals with different pulse widths but the same amplitude within the resonance frequency range of the vibrating tube, such as Figure 2 As shown, Figure 2It is a composite signal superimposed by pulse signals with pulse widths of 10ms, 6.6ms, 5ms, and 4ms. The width between two composite pulses is 10ms. Since the pulse signal contains sinusoidal signals of various frequencies, the signal amplitude of the center frequency is the highest. In this embodiment, by using the superposition of different pulse signals, the driving signal contains multiple center signals of different frequencies, and the amplitudes of the frequency signals adjacent to different center signals are also increased. In the resonant state, the vibration tube can also achieve a larger vibration amplitude. Therefore, by vibrating at multiple different frequencies, it is easier for the vibration tube to filter out the resonant frequency.

[0034] The resonance frequency range of the vibrating tube is the resonance frequency of the vibrating tube from the empty tube state to the full tube state of the commonly used liquid. The commonly used liquid can be water or other fluids. The resonance frequency range can be obtained based on experience or calculated through simulation. This application does not impose any restrictions.

[0035] The accumulated composite pulse signal is a complete signal, and the width between the two composite pulse signals is consistent with the width of the pulse with the largest width, such as Figure 2 As shown in the figure, the width between the composite pulses is 10ms, which is the same as the width of the pulse with the largest width. The composite pulse signal drives the vibrating tube, and the vibrating tube vibrates. Figure 3 As shown, a drive sensor is installed on the vibration tube and two signal acquisition sensors, which are respectively recorded as the first signal acquisition sensor according to the flow direction of the fluid and the second signal acquisition sensor , the fluid first passes through the first signal acquisition sensor , and then pass through the second signal acquisition sensor The driving signal is sent to the driving sensor to drive the vibration tube to vibrate. The signal acquisition sensor collects the vibration signals on both sides of the vibration tube. The driving signal drives the vibration tube. The vibration tube can automatically filter out the vibration signal. The frequency of the calculated vibration signal is recorded as the first frequency. .

[0036] Step 102: The driver module sends the same amplitude The sine wave signal with frequency varying from small to large drives the vibration tube, and the frequency variation range is ,in The frequency allowed width is used to calculate the amplitude of each vibration signal. ;

[0037] Since the vibration amplitude of the vibrating tube changes little in a frequency range near the resonant frequency, the vibrating tube sometimes vibrates at a non-resonant frequency. Therefore, the first frequency is filtered out by the vibrating tube. Then, use the first frequency from small to large Allowable range of center frequency The frequency synthesized sinusoidal signal inside drives the vibrating tube.

[0038] In this embodiment, the frequency allowable width ,in is the driving signal amplitude, is the maximum vibration amplitude of the vibrating tube excited by the composite pulse signal, is the basic unit of frequency, the amplitude of the driving signal remains unchanged, and the frequency of the driving signal is successively Changes to , the change step size is ,in Adjust the coefficient and calculate the amplitude of the vibration signal at different frequencies.

[0039] The driving frequency range is , ,in is the driving signal amplitude, is the maximum amplitude calculated previously, is the basic unit of frequency, which can be 5Hz, 10HZ or other frequency values. When the mass of the fluid in the vibrating tube is light, the vibration damping of the vibrating tube is small, the vibration amplitude of the vibrating tube is large under a small driving signal, the resonant frequency of the vibrating tube is more obvious, and the vibration amplitude of the vibrating tube is small under non-resonant frequency, so the driving signal frequency can adopt a narrower range; when the mass of the fluid in the vibrating tube is heavy, the vibration damping of the vibrating tube is large, and a larger driving signal is required. The vibration amplitude of the vibrating tube is small, and the amplitude change near the resonant frequency is not obvious, so the driving signal frequency adopts a wider range. The initial step size of the excitation signal change is ,in is the adjustment coefficient, It can be adjusted according to the accuracy requirements. , or , this application does not limit it. Use the frequencies near the first frequency in sequence After the sinusoidal signal drives the vibration tube, determine the frequency at which the vibration signal amplitude is maximum , and use this frequency to synthesize a sine wave signal as the starting signal for the next step.

[0040] Step 103: Use the signal frequency with the largest amplitude The starting frequency is used to synthesize a sine wave signal to excite the vibration tube, and then the signal acquisition sensor collects the signal frequency to synthesize a sine wave to drive the vibration tube. The amplitude of the synthesized sine wave signal is controlled by a PID controller;

[0041] The vibrating tube is driven by a synthetic sinusoidal signal, the initial frequency of which is The frequency with the maximum vibration amplitude of the vibration tube within the range , followed by the frequency of the vibration signal of the vibration tube collected by the signal acquisition sensor, and the amplitude is the amplitude of the driving signal output after being controlled by the PID controller.

[0042] The amplitude of the synthetic signal in step 103 is calculated by the PID controller according to the set value. Since the vibration amplitude of the vibrating tube is greatly affected by the mass and state of the fluid in the tube, in the case of low mass, the vibration amplitude of the vibrating tube is large, and a smaller driving signal can make the vibrating tube vibrate stably at the set value. When the mass of the fluid in the vibrating tube is heavy, in order to ensure the driving ability of the driving signal, the set value of the PID controller can be adjusted to stabilize the vibration amplitude of the vibrating tube. The method for adjusting the set value of the PID controller is as follows: Figure 4 As shown, including:

[0043] Step 301: The driving signal amplitude is 1 / 2 of the maximum driving amplitude, driving the vibration tube. After the vibration of the vibration tube stabilizes, the vibration amplitude of the vibration tube is the current setting value of the PID controller; the driving module outputs the driving signal according to the control value of the PID controller.

[0044] Step 302: When the control output of the PID controller exceeds 3 / 4 of the maximum amplitude of the drive signal or is less than 1 / 4 of the maximum amplitude, the drive signal amplitude is adjusted to 1 / 2 of the maximum drive amplitude to drive the vibration tube. After the vibration of the vibration tube stabilizes, the vibration amplitude of the vibration tube is the current setting value of the PID controller.

[0045] The vibrating tube of a Coriolis flowmeter needs to vibrate stably at its resonant frequency. A PID controller is typically used to stabilize its vibration amplitude at a set value. However, due to the wide range of the vibrating tube's resonance amplitude, a single set value can result in insufficient driving capability or underutilization of the driver module's driving capability. Therefore, a method for dynamically adjusting the PID controller's set value is employed. The PID controller's set value is adjusted in a timely manner based on the vibrating tube's vibration amplitude and the driver module's drive signal amplitude. When the PID controller's control result, i.e., the drive signal amplitude, is about to exceed the driver module's driving capability, the driver module's amplitude is adjusted to 1 / 2 of the maximum drive amplitude. This set value is used as the vibrating tube's vibration amplitude at that point. This allows the driver module to maintain a stable set value even when the fluid mass within the vibrating tube changes. Similarly, when the PID controller's control result, i.e., the drive signal amplitude, is too small and underutilizes the driver module's driving capability, the driver module's amplitude is adjusted to 1 / 2 of the maximum drive amplitude. This set value is used as the vibrating tube's vibration amplitude at that point. This allows the driver module to maintain a stable set value even when the fluid mass within the vibrating tube changes.

[0046] Step 104: Collect the vibration signal of the vibrating tube and determine whether the state of the fluid in the vibrating tube has changed. If so, restart the vibrating tube.

[0047] The method for determining whether the state of the fluid in the vibration tube has changed is as follows: collecting the vibration signal of the vibration tube, calculating the signal frequency and amplitude, and determining whether the signal is abnormal based on the changes in the signal frequency and amplitude. If abnormal, determining whether the signal acquisition sensor is working normally. If the signal acquisition sensor is working normally, it is determined that the fluid state has changed, and the vibration tube is restarted.

[0048] In this embodiment, the method for determining whether the vibration tube signal is abnormal is:

[0049] If the signal of at least one signal acquisition sensor has multiple frequency components or the signal change is greater than a first threshold, it is considered that the vibration tube acquisition signal is abnormal.

[0050] When the fluid in the vibration tube undergoes large changes, including changes in the fluid state, changes in the fluid quality, etc., it will affect the vibration of the vibration tube, destroy the stable vibration state of the vibration tube, and cause the vibration waveform of the vibration tube to change or the amplitude of the vibration wave to suddenly change. Therefore, it is determined whether the stable vibration state of the vibration tube is interrupted by judging whether there are multiple frequency components in the signal or the change in the vibration signal is greater than the first threshold. If it is interrupted, it is restarted.

[0051] The method for determining whether the vibration signal of the vibrating tube has multiple frequency components is as follows:

[0052] Collect the vibration tube signal. When the number of signals meets the quantity requirement, the vibration signal of the vibration tube is collected to form a matrix. Then, the matrix is ​​subjected to singular value decomposition to obtain the singular value of the matrix. The number of data in the singular value that is greater than the second threshold is determined. If there are more than two, it is considered that the vibration tube has multiple frequency components, and then the vibration tube signal is collected again.

[0053] The specific method is: the sampling frequency of the acquisition signal sensor is , the vibration signal of the vibration tube is collected as , when collecting the vibration signal of the vibration tube Reach quantity Afterwards, Split into matrices:

[0054]

[0055] right Perform singular value decomposition and get the matrix The singular values ​​of , judge the number of singular values ​​greater than the second threshold, if the number is greater than 2, it is considered that there are multiple frequency components in the signal and it is necessary to re-oscillate. Then the vibration signal Clear and re-collect.

[0056] The calculation method of signal variation is: the sampling frequency of the signal sensor is , the vibration signal of the vibration tube is collected as , when collecting the vibration signal of the vibration tube achieve After a full cycle, count the peaks in the signal , trough value and the time of crossing zero , the signal change is:

[0057]

[0058] in Indicates the change in the time difference between two adjacent zero-crossing points, that is, the change in frequency. The amplitude of the vibration signal is affected by the amplitude of the drive signal, the fluid in the vibrating tube, and whether the vibration is operating at the resonant frequency. Therefore, a sudden change in the vibration signal indicates a change in the fluid state in the vibrating tube, requiring the tube to be re-vibrated.

[0059] However, signal abnormality may also be caused by a fault in the signal acquisition sensor, such as poor sensor contact. Therefore, in the case of a signal abnormality, it is necessary to determine whether it is caused by the signal acquisition sensor. If the signal acquisition sensor fails, the fault location must be determined and an alarm must be processed. If it is caused by a change in the state of the fluid in the vibration tube, the vibration tube must be restarted. Therefore, after detecting the waveform abnormality, the two signal acquisition sensors are automatically fault detected. By intercepting the abnormal signal, the similarity of the two signals is calculated to determine whether the sensor is abnormal. If the two sensor signal fluctuations are consistent, it is considered that the signal acquisition sensor is working normally. If they are inconsistent, it is considered that the signal acquisition sensor is faulty. The similarity calculation method can calculate the similarity by calculating the correlation coefficient of the two signals. When the correlation coefficient is greater than the threshold, there is no sensor fault; when it is less than or equal to the threshold, there is a fault. However, the correlation coefficient can only determine whether the signal trends are similar, and ignores the similarity of the signal details. Therefore, a similarity calculation method is provided in another embodiment, which is as follows: Calculate the first similarity of the two signal acquisition sensor signals. :

[0060]

[0061] in The time when the first signal acquisition sensor collects the zero-crossing point of the vibration tube signal, The second signal acquisition sensor collects the time of the zero crossing point in the same direction of the vibration tube signal. The peak value of the first signal acquisition sensor is The first signal acquisition sensor trough value, Acquire the sensor peak value for the second signal, The valley value of the sensor is collected for the second signal. is the number of complete cycles, if the first similarity of the two signal acquisition sensors is Greater than the third threshold , determine that the signal acquisition sensor is working normally.

[0062] in Indicates a timing anomaly between the first and second signal acquisition sensors. This is because there is a phase difference between the first and second signal acquisition sensors due to the Coriolis force, but their vibration periods should be the same. If they are different, the probability of a fault in the signal acquisition sensor is increased. It indicates the abnormality in the amplitude of the first signal acquisition sensor and the second signal acquisition sensor. The combination of time and amplitude indicates whether the two sensor signals are similar. The greater the similarity, the more similar the signals are, and the sensors are working properly.

[0063] In another embodiment, a method combining correlation coefficient and similarity is used to calculate the second similarity by combining the trend and details of the waveform. , making the judgment more accurate.

[0064] The second similarity is calculated as follows:

[0065]

[0066] in is the correlation coefficient between the first signal acquisition sensor and the second signal acquisition sensor, is the first similarity, is the third threshold. If the second similarity is greater than the fourth threshold If yes, the sensor is judged to be working normally, otherwise it is judged to be faulty.

[0067] In another embodiment of the present invention, a technical solution for a Coriolis flowmeter is provided. The Coriolis flowmeter includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements a Coriolis flowmeter vibration method as described in the previous embodiment. The Coriolis flowmeter vibration method is the same as that in the previous embodiment and will not be described in detail in this embodiment.

Claims

1. A Coriolis flowmeter vibration method, wherein a driving module sends a driving signal to drive a vibrating tube, characterized in that The following steps are involved: Step 101: After the driving module sends multiple periodic composite pulse signals to drive the vibrating tube, the driving module stops driving the vibrating tube, and the signal acquisition sensor acquires the vibration signal of the vibrating tube and calculates the first frequency of the acquired signal. ; Step 102: The driver module sends the same amplitude The sine wave signal with frequency varying from small to large drives the vibration tube, and the frequency variation range is ,in The frequency allowed width is used to calculate the amplitude of each vibration signal. ; Step 103: Use the signal frequency with the largest amplitude The starting frequency is used to synthesize a sine wave signal to excite the vibration tube, and then the signal acquisition sensor collects the signal frequency to synthesize a sine wave to drive the vibration tube. The amplitude of the synthesized sine wave signal is controlled by a PID controller; Step 104: Collect the vibration signal of the vibrating tube and determine whether the state of the fluid in the vibrating tube has changed. If so, restart the vibrating tube.

2. A Coriolis flowmeter vibration method according to claim 1, characterized in that The composite pulse signal in step 101 is obtained by accumulating multiple pulse signals with different pulse widths but the same amplitude within the resonant frequency range of the vibrating tube.

3. A Coriolis flowmeter vibration method according to claim 1, characterized in that The frequency allowable width in step 102 ,in is the driving signal amplitude, is the maximum vibration amplitude of the vibrating tube excited by the composite pulse signal, is the basic unit of frequency, the amplitude of the driving signal remains unchanged, and the frequency of the driving signal is successively Changes to , the change step size is ,in Adjust the coefficient and calculate the amplitude of the vibration signal at different frequencies.

4. A Coriolis flowmeter vibration method according to claim 1, characterized in that The method for setting the PID controller setting value in step 103 is: Step 301: The driving signal amplitude is 1 / 2 of the maximum driving amplitude, driving the vibrating tube. After the vibration of the vibrating tube stabilizes, the vibration amplitude of the vibrating tube is the current setting value of the PID controller; the driving module outputs the driving signal according to the control value of the PID controller; Step 302: When the control output of the PID controller exceeds 3 / 4 of the maximum amplitude of the drive signal or is less than 1 / 4 of the maximum amplitude, the drive signal amplitude is adjusted to 1 / 2 of the maximum drive amplitude to drive the vibration tube. After the vibration of the vibration tube stabilizes, the vibration amplitude of the vibration tube is the current setting value of the PID controller.

5. A Coriolis flowmeter vibration method according to claim 1, characterized in that The method for determining whether the fluid state has changed in step 104 is: collecting the vibration signal of the vibration tube, calculating the signal frequency and amplitude, and judging whether the signal is abnormal based on the changes in the signal frequency and amplitude. If it is abnormal, judging whether the signal acquisition sensor is working normally. If the signal acquisition sensor is working normally, it is considered that the fluid state has changed, and the vibration tube is restarted.

6. A Coriolis flowmeter vibration method according to claim 5, characterized in that The method for judging abnormality of the vibration signal of the vibration tube is that the signal of at least one signal acquisition sensor has multiple frequency components or the signal change is greater than a first threshold.

7. A Coriolis flowmeter vibration method according to claim 6, characterized in that The frequency component calculation method is: Collect vibration tube signals. When the number of signals meets the quantity requirement, construct a matrix of the vibration signals of the vibration tube, and then perform singular value decomposition on the matrix to obtain the singular values ​​of the matrix. Determine the number of data in the singular values ​​that are greater than the second threshold value. If there are more than two, it is considered that the vibration tube has multiple frequency components.

8. A flow meter vibration method according to claim 6, characterized in that The calculation method of the signal variation is: the sampling frequency of the acquisition signal sensor is , the vibration signal of the vibration tube is collected as , when collecting the vibration signal of the vibration tube achieve After a full cycle, count the peaks in the signal , trough value and the time of zero crossing , the signal change is: 。 9. A Coriolis flowmeter vibration method according to claim 6, characterized in that The signal acquisition sensor fault judgment method is to calculate the first similarity of the signals collected by the two signal acquisition sensors. The first similarity calculation method is: in The time when the first signal acquisition sensor collects the zero-crossing point of the vibration tube signal, The second signal acquisition sensor collects the time of the zero crossing point in the same direction of the vibration tube signal. The peak value of the first signal acquisition sensor is The valley value of the first signal acquisition sensor, Acquire the sensor peak value for the second signal, Acquire the trough value of the sensor for the second signal, is the number of complete cycles, if the first similarity of the two signal acquisition sensors is Greater than the third threshold , determine that the signal acquisition sensor is working normally.

10. A Coriolis flowmeter, characterized in that The method comprises a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, a Coriolis flowmeter vibration method according to any one of claims 1 to 9 is implemented.

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