A method, device and equipment for determining flow velocity

Abstract

The present application provides a flow velocity determination method, apparatus, and device. The method includes: obtaining a first original time-domain signal collected by a first transducer and a second original time-domain signal collected by a second transducer; performing a frequency-domain transformation on the first original time-domain signal to obtain a first target frequency-domain signal, and performing a frequency-domain transformation on the second original time-domain signal to obtain a second target frequency-domain signal; determining a first cross-correlation frequency-domain signal based on the first target frequency-domain signal and the second target frequency-domain signal, and determining a target cross-correlation frequency-domain signal based on the first cross-correlation frequency-domain signal; performing a time-domain transformation on the target cross-correlation frequency-domain signal to obtain a cross-correlation time-domain signal, where the cross-correlation time-domain signal includes signal values at multiple positions; determining a time-of-flight difference based on a target position corresponding to a maximum signal value; and the time-of-flight difference is used to determine the flow velocity of the fluid when passing through the pipeline. Through the technical solution of the present application, the time-of-flight difference can be accurately determined, and the accuracy of the time-of-flight difference is high and the error is small.

Description

Technical Field

[0001] This application relates to the technical field of flow meters, and in particular, to a method, device, and equipment for determining flow velocity. Background Art

[0002] An ultrasonic flow meter is used to measure the flow velocity of a fluid. The ultrasonic flow meter has the advantages of non-contact, no pressure loss, fast response speed, etc., and is widely used in the flow velocity measurement of fluids such as water, gas, and oil.

[0003] An ultrasonic flow meter may include a pipeline, a first transducer, and a second transducer. The first transducer and the second transducer are installed on both sides of the pipeline. When the fluid passes through the pipeline, the first transducer sends ultrasonic waves to the second transducer, and the second transducer sends ultrasonic waves to the first transducer. Considering that the propagation speed of ultrasonic waves in the fluid will be affected by the fluid flow, the propagation speed in the downstream direction is increased, and the propagation speed in the upstream direction is decreased. Based on this, by measuring the time-of-flight difference (Time of Flight, TOF) of ultrasonic waves in the downstream direction and the upstream direction, the flow velocity of the fluid can be calculated based on the time-of-flight difference.

[0004] To determine the time-of-flight difference, it is necessary to measure the time-of-flight of sound waves from the first transducer to the second transducer and measure the time-of-flight of sound waves from the second transducer to the first transducer, and the difference between these two time-of-flights of sound waves is the time-of-flight difference. However, when measuring the time-of-flight of sound waves, the time-of-flight of sound waves cannot be accurately measured, the measurement accuracy of the time-of-flight of sound waves is low, and the error of the time-of-flight of sound waves is large. When calculating the time-of-flight difference based on the time-of-flight of sound waves, the accuracy of the time-of-flight difference is low and the error is large. Summary of the Invention

[0005] This application provides a method for determining flow velocity. A first transducer and a second transducer are respectively installed on both sides of a pipeline, and a fluid passes through the pipeline. The first transducer sends ultrasonic waves to the second transducer, and the second transducer sends ultrasonic waves to the first transducer. The method includes:

[0006] Obtain a first original time-domain signal collected by the first transducer and a second original time-domain signal collected by the second transducer; perform frequency-domain transformation on the first original time-domain signal to obtain a first target frequency-domain signal, and perform frequency-domain transformation on the second original time-domain signal to obtain a second target frequency-domain signal;

[0007] Determine a first cross-correlation frequency-domain signal based on the first target frequency-domain signal and the second target frequency-domain signal, and determine a target cross-correlation frequency-domain signal based on the first cross-correlation frequency-domain signal;

[0008] Performing a time-domain transformation on the target cross-correlation frequency-domain signal to obtain a cross-correlation time-domain signal, where the cross-correlation time-domain signal includes signal values at multiple positions; determining a time-of-flight difference based on a target position corresponding to the maximum signal value; wherein, the time-of-flight difference is the time difference between the propagation of ultrasonic waves in the downstream direction and the upstream direction; the time-of-flight difference is used to determine the flow velocity of the fluid when passing through the pipeline.

[0009] This application provides a flow velocity determination device. A first transducer and a second transducer are respectively installed on both sides of a pipeline. The fluid passes through the pipeline. The first transducer sends ultrasonic waves to the second transducer, and the second transducer sends ultrasonic waves to the first transducer. The device includes:

[0010] An acquisition module, configured to acquire a first original time-domain signal collected by the first transducer and a second original time-domain signal collected by the second transducer; performing a frequency-domain transformation on the first original time-domain signal to obtain a first target frequency-domain signal, and performing a frequency-domain transformation on the second original time-domain signal to obtain a second target frequency-domain signal;

[0011] A determination module, configured to determine a first cross-correlation frequency-domain signal based on the first target frequency-domain signal and the second target frequency-domain signal, and determine a target cross-correlation frequency-domain signal based on the first cross-correlation frequency-domain signal;

[0012] A processing module, configured to perform a time-domain transformation on the target cross-correlation frequency-domain signal to obtain a cross-correlation time-domain signal, where the cross-correlation time-domain signal includes signal values at multiple positions; determining a time-of-flight difference based on a target position corresponding to the maximum signal value; wherein, the time-of-flight difference is the time difference between the propagation of ultrasonic waves in the downstream direction and the upstream direction; the time-of-flight difference is used to determine the flow velocity of the fluid when passing through the pipeline.

[0013] This application provides an electronic device, including: a processor and a machine-readable storage medium, where the machine-readable storage medium stores machine-executable instructions that can be executed by the processor; the processor is configured to execute the machine-executable instructions to implement the flow velocity determination method in the above example.

[0014] This application provides a computer program product. The computer program product may include a computer program, and when the computer program is executed by a processor, the flow velocity determination method in the above example is implemented.

[0015] This application provides a machine-readable storage medium, where the machine-readable storage medium stores machine-executable instructions that can be executed by a processor; wherein, the processor is configured to execute the machine-executable instructions, and when the machine-executable instructions are executed, the flow velocity determination method in the above example is implemented.

[0016] As can be seen from the above technical solutions, in the embodiments of the present application, a target frequency-domain signal is obtained by performing a frequency-domain transformation on an original time-domain signal, a cross-correlation frequency-domain signal is determined based on two target frequency-domain signals, a cross-correlation time-domain signal is obtained by performing a time-domain transformation on the cross-correlation frequency-domain signal, and a time-of-flight difference is determined based on a target position corresponding to the maximum signal value in the cross-correlation time-domain signal. Thus, the time-of-flight difference is directly determined based on the original time-domain signal, without measuring the acoustic wave flight time from the first transducer to the second transducer and the acoustic wave flight time from the second transducer to the first transducer, which can avoid the low accuracy of the time-of-flight difference caused by the low measurement accuracy of the acoustic wave flight time. In this way, the time-of-flight difference can be accurately determined, the accuracy of the time-of-flight difference is relatively high, the error of the time-of-flight difference is small, the calculation accuracy of the time-of-flight difference is improved, the precise calculation of the phase difference between the upstream signal and the downstream signal of the ultrasonic wave is realized, and the anti-interference performance against noise is improved. Description of the Drawings

[0017] Figure 1 is a schematic flowchart of a flow velocity determination method in an embodiment of the present application;

[0018] Figure 2 is a schematic structural diagram of an ultrasonic flowmeter in an embodiment of the present application;

[0019] Figure 3 is a schematic flowchart of a flow velocity determination method in an embodiment of the present application;

[0020] Figure 4 is a schematic flowchart of a process for obtaining a target cross-correlation frequency-domain signal in an embodiment of the present application;

[0021] Figure 5 is a schematic structural diagram of a flow velocity determination device in an embodiment of the present application;

[0022] Figure 6 is a hardware structure diagram of an electronic device in an embodiment of the present application. Detailed Embodiments

[0023] In the embodiments of the present application, a flow velocity determination method is proposed, which is applied to an electronic device. The electronic device may be a flow velocity determination device for determining the flow velocity of a fluid. For example, the electronic device may determine the flow velocity of the fluid based on the data collected by an ultrasonic flowmeter. The ultrasonic flowmeter may include a pipeline, a first transducer, and a second transducer. The first transducer and the second transducer are respectively installed on both sides of the pipeline, and the fluid passes through the pipeline. The first transducer sends ultrasonic waves to the second transducer, and the second transducer sends ultrasonic waves to the first transducer.

[0024] See Figure 1 As shown, for the schematic flowchart of the flow velocity determination method, the method may include:

[0025] Step 101: Obtain the first original time-domain signal collected by the first transducer and the second original time-domain signal collected by the second transducer; perform a frequency-domain transformation on the first original time-domain signal to obtain a first target frequency-domain signal, and perform a frequency-domain transformation on the second original time-domain signal to obtain a second target frequency-domain signal.

[0026] Step 102: Determine a first cross-correlation frequency-domain signal based on the first target frequency-domain signal and the second target frequency-domain signal, and determine a target cross-correlation frequency-domain signal based on the first cross-correlation frequency-domain signal.

[0027] Step 103: Perform a time-domain transformation on the target cross-correlation frequency-domain signal to obtain a cross-correlation time-domain signal, where the cross-correlation time-domain signal includes signal values at multiple positions; determine a time-of-flight difference based on the target position corresponding to the maximum signal value, where the target position is the most similar position between the first original time-domain signal and the second original time-domain signal, and the time-of-flight difference represents the phase difference at the target position. Here, the time-of-flight difference is the time difference between the ultrasonic wave propagating in the downstream direction and the upstream direction; the time-of-flight difference is used to determine the flow velocity of the fluid when passing through the pipeline.

[0028] Exemplarily, determining the first cross-correlation frequency-domain signal based on the first target frequency-domain signal and the second target frequency-domain signal may include, but is not limited to: determining a first complex conjugate frequency-domain signal of the first target frequency-domain signal, and performing a convolution operation on the first complex conjugate frequency-domain signal and the second target frequency-domain signal to obtain the first cross-correlation frequency-domain signal. Or, determining a second complex conjugate frequency-domain signal of the second target frequency-domain signal, and performing a convolution operation on the first target frequency-domain signal and the second complex conjugate frequency-domain signal to obtain the first cross-correlation frequency-domain signal.

[0029] Exemplarily, determining the target cross-correlation frequency-domain signal based on the first cross-correlation frequency-domain signal may include, but is not limited to: determining the first cross-correlation frequency-domain signal as the target cross-correlation frequency-domain signal; or, moving the zero-frequency component in the first cross-correlation frequency-domain signal to the frequency center to obtain a second cross-correlation frequency-domain signal, and determining the second cross-correlation frequency-domain signal as the target cross-correlation frequency-domain signal; or, moving the zero-frequency component in the first cross-correlation frequency-domain signal to the frequency center to obtain a second cross-correlation frequency-domain signal, filtering the second cross-correlation frequency-domain signal to obtain a filtered frequency-domain signal; setting the amplitude of the frequency corresponding to the noise signal in the filtered frequency-domain signal to 0 to obtain a third cross-correlation frequency-domain signal, performing frequency-domain interpolation on the third cross-correlation frequency-domain signal to obtain a fourth cross-correlation frequency-domain signal, and determining the fourth cross-correlation frequency-domain signal as the target cross-correlation frequency-domain signal.

[0030] Exemplarily, the filtered frequency-domain signal includes the amplitudes of multiple frequencies. For each frequency, if the frequency is less than the first frequency value, or the frequency is greater than the second frequency value, where the second frequency value can be greater than the first frequency value, then the frequency is the frequency corresponding to the noise signal; wherein, the first frequency value can be determined based on the configured sampling frequency and the first coefficient, the first coefficient is greater than 0 and less than 1, and the second frequency value can be determined based on the configured sampling frequency and the second coefficient, the second coefficient is greater than 1.

[0031] Exemplarily, when performing frequency-domain interpolation on the third cross-correlation frequency-domain signal to obtain the fourth cross-correlation frequency-domain signal, the third cross-correlation frequency-domain signal includes L the amplitudes of a number of frequencies, and the fourth cross-correlation frequency-domain signal includes L1 the amplitudes of a number of frequencies, and L1 is greater than L ; wherein, for the k th frequency in the fourth cross-correlation frequency-domain signal, k takes values sequentially from 0 to L1-1 , then the following method is used to determine the target amplitude of the k th frequency:

[0032] If L takes an odd value, when , then the target amplitude is the amplitude of the k th frequency in the third cross-correlation frequency-domain signal; or, when , then the target amplitude is 0; or, when , then the target amplitude is the amplitude of the k th frequency in the third cross-correlation frequency-domain signal; or, if L takes an even value, when , then the target amplitude is the amplitude of the k th frequency in the third cross-correlation frequency-domain signal; or, when , then the target amplitude is half of the amplitude of the k th frequency in the third cross-correlation frequency-domain signal; or, when , then the target amplitude is 0; or, when , then the target amplitude is half of the amplitude of the th frequency in the third cross-correlation frequency-domain signal; or, when , then the target amplitude is the amplitude of the k th frequency in the third cross-correlation frequency-domain signal.

[0033] Exemplarily, determining the time difference of flight based on the target position corresponding to the maximum signal value may include, but is not limited to: determining the time difference of flight based on the target position corresponding to the maximum signal value, the total number of positions in the cross-correlation time-domain signal, and the target resolution of the configured time difference of flight.

[0034] Exemplarily, the time difference of flight can be determined by the following formula: ; where can represent the time difference of flight, can represent that the target position is the th position in the cross-correlation time domain signal, can represent the total number of positions, can represent the target resolution.

[0035] Exemplarily, performing a frequency domain transformation on the first original time domain signal to obtain a first target frequency domain signal may include, but is not limited to: preprocessing the first original time domain signal to obtain a first target time domain signal, and filtering the first target time domain signal to obtain a first filtered time domain signal; then, performing a frequency domain transformation on the first filtered time domain signal to obtain a first original frequency domain signal, and setting the amplitude of the frequency corresponding to the noise signal in the first original frequency domain signal to 0 to obtain the first target frequency domain signal.

[0036] Exemplarily, preprocessing the first original time domain signal to obtain a first target time domain signal may include, but is not limited to: deleting outliers in the first original time domain signal to obtain the first target time domain signal; or, removing the DC component in the first original time domain signal to obtain the first target time domain signal; or, deleting outliers in the first original time domain signal and removing the DC component in the first original time domain signal to obtain the first target time domain signal. Wherein, the first original time domain signal includes signal values at multiple positions;

[0037] For each position, select multiple signal values at this position from the first original time domain signal and the first historical time domain signal, and determine the first quartile and the second quartile based on the multiple signal values; determine whether the signal value at this position is an outlier based on the first quartile and the second quartile;

[0038] For each position, the DC component at this position is determined based on the average value of the multiple signal values at this position, or based on the average value of all signal values of the first original time domain signal, or based on the average value of all signal values of the first original time domain signal and the first historical time domain signal.

[0039] As can be seen from the above technical solutions, in the embodiments of the present application, the original time-domain signal is subjected to a frequency-domain transformation to obtain a target frequency-domain signal, a cross-correlation frequency-domain signal is determined based on two target frequency-domain signals, the cross-correlation frequency-domain signal is subjected to a time-domain transformation to obtain a cross-correlation time-domain signal, and the time difference of flight is determined based on the target position corresponding to the maximum signal value in the cross-correlation time-domain signal. Thus, the time difference of flight can be directly determined based on the original time-domain signal, without measuring the acoustic wave flight time from the first transducer to the second transducer and the acoustic wave flight time from the second transducer to the first transducer, which can avoid the low accuracy of the time difference of flight caused by the low measurement accuracy of the acoustic wave flight time. In this way, the time difference of flight can be accurately determined, the accuracy of the time difference of flight is relatively high, the error of the time difference of flight is small, the calculation accuracy of the time difference of flight is improved, the phase difference between the upstream signal and the downstream signal of the ultrasonic wave can be accurately calculated, and the anti-interference performance against noise is improved.

[0040] The above technical solutions of the embodiments of the present application will be described below in combination with specific application scenarios.

[0041] An ultrasonic flowmeter (which can also be referred to as an ultrasonic wave flowmeter, and the ultrasonic flowmeter in this embodiment can be an external clamp type ultrasonic flowmeter or other types of ultrasonic flowmeters) may include a pipeline, a first transducer, and a second transducer. Refer to Figure 2 As shown, it is a schematic structural diagram of the ultrasonic flowmeter. Transducer 1 serves as the first transducer, and transducer 2 serves as the second transducer. The first transducer and the second transducer can be installed on both sides of the pipeline. For example, the first transducer is installed on the lower side of the pipeline, and the second transducer is installed on the upper side of the pipeline.

[0042] When the fluid passes through the pipeline (such as moving from right to left), the first transducer sends ultrasonic waves to the second transducer, and the second transducer sends ultrasonic waves to the first transducer. Based on this, the acoustic wave flight time from the first transducer to the second transducer is measured, and the acoustic wave flight time from the second transducer to the first transducer is measured. The difference between these two acoustic wave flight times is the time difference of flight (Time of Flight, TOF). The time difference of flight is the time difference of flight of ultrasonic waves in the downstream direction and the upstream direction, and is used to calculate the flow velocity of the fluid.

[0043] For example, refer to Figure 2 As shown, the acoustic wave transmission length (the straight-line distance between the first transducer and the second transducer inside the pipe section) is L , the pipe section diameter (i.e., the inner vertical distance of the pipeline) is D , the angle between the acoustic wave transmission path and the pipeline (i.e., the angle between the acoustic wave transmission length direction and the pipe section diameter) is Φ , the acoustic wave flight time from the first transducer to the second transducer is T 12 , the acoustic wave flight time from the second transducer to the first transducer isT 21 , the speed of sound of ultrasonic waves in this medium (i.e., fluid) is c . Based on this, the following formula can be known from the mathematical relationship: , . Then, through the derivation of the above formula, it can be known that , . Combining the above formula, the flow velocity of the fluid can be calculated by the following formula (1). Of course, formula (1) is just an example and there is no such limitation.

[0044] Formula (1)

[0045] In formula (1), the acoustic wave transmission length L , included angle Φ are all known values. Therefore, by measuring the acoustic wave flight time from the first transducer to the second transducer, and measuring the acoustic wave flight time from the second transducer to the first transducer, the flow velocity of the fluid can be calculated. In formula (1), the flight time difference , that is, the flow velocity of the fluid can be calculated based on the flight time difference .

[0046] However, when measuring the acoustic wave flight time and the acoustic wave flight time , it is impossible to accurately measure the acoustic wave flight time and the acoustic wave flight time . The measurement accuracy of the acoustic wave flight time and the acoustic wave flight time is relatively low, and the error of the acoustic wave flight time and the acoustic wave flight time is relatively large. Thus, when calculating the flight time difference based on the acoustic wave flight time, the accuracy of the flight time difference is relatively low and the error is relatively large.

[0047] In view of the above findings, an embodiment of the present application proposes a flow velocity determination method, which can determine the time of flight (TOF) of an ultrasonic flowmeter and can determine a high-precision time of flight, and then determine the fluid flow velocity based on the high-precision time of flight to obtain an accurate and reliable fluid flow velocity.

[0048] Exemplarily, the flow rate determination method can be applied to an electronic device (such as a flow rate determination device), and the electronic device can measure the fluid flow rate based on the data collected by an ultrasonic flowmeter. For example, the electronic device can be an ultrasonic flowmeter, that is, after the ultrasonic flowmeter collects data, the ultrasonic flowmeter measures the fluid flow rate based on the data. Or, the electronic device can be a management device of the ultrasonic flowmeter, that is, after the ultrasonic flowmeter collects data, the ultrasonic flowmeter sends the data to the management device, and the management device measures the fluid flow rate based on the data.

[0049] Exemplarily, the ultrasonic flowmeter can include a pipeline, a first transducer, and a second transducer. The first transducer and the second transducer are respectively installed on both sides of the pipeline. The fluid passes through the pipeline. The first transducer sends ultrasonic waves to the second transducer, and the second transducer sends ultrasonic waves to the first transducer. For example, as shown in Figure 2 As shown, transducer 1 is used as the first transducer, and transducer 2 is used as the second transducer. Transducer 1 and transducer 2 are installed on both sides of the pipeline. For example, transducer 1 is installed on the lower side of the pipeline, and transducer 2 is installed on the upper side of the pipeline.

[0050] When the first transducer sends ultrasonic waves to the second transducer, the first transducer serves as the transmitter of the ultrasonic waves, and the second transducer serves as the receiver of the ultrasonic waves. When the second transducer sends ultrasonic waves to the first transducer, the second transducer serves as the transmitter of the ultrasonic waves, and the first transducer serves as the receiver of the ultrasonic waves.

[0051] As shown in Figure 3 As shown, it is a schematic flow diagram of the flow rate determination method. The method can include:

[0052] Step 301, obtain a first original time-domain signal collected by the first transducer and a second original time-domain signal collected by the second transducer. The first original time-domain signal is the signal of the ultrasonic waves sent by the second transducer to the first transducer, and the second original time-domain signal is the signal of the ultrasonic waves sent by the first transducer to the second transducer.

[0053] Exemplarily, when the second transducer sends ultrasonic waves to the first transducer, the ultrasonic waves can be signals of a specific frequency. This signal can be a sine signal, a pulse signal, or a square wave signal. There is no limitation on this. The frequency of the ultrasonic waves can be between 20 KHz and 100 KHz. On this basis, the first transducer can collect the signal of the ultrasonic waves and call the collected signal the first original time-domain signal.

[0054] For example, the first original time-domain signal may include signal values at multiple positions. For example, the signal acquisition time interval may be divided into 100 sampling points (i.e., 100 sampling moments), and the 100 sampling points correspond to 100 positions. The first original time-domain signal may include the signal value collected at the 0th sampling point, the signal value collected at the 1st sampling point, …, the signal value collected at the 99th sampling point.

[0055] Regarding the signal value collected at the 0th sampling point, it is the signal value of the ultrasonic wave collected by the first transducer at this sampling moment. The signal value may be the amplitude of the sound wave, or it may be the voltage signal value or the numerical signal value. There is no restriction on this. The signal value collected at the 0th sampling point is used as the signal value at position 0, and so on. In this way, the first original time-domain signal may include signal values at 100 positions.

[0056] Exemplarily, when the first transducer sends ultrasonic waves to the second transducer, the second transducer may collect the signal of the ultrasonic wave, and the collected signal is called the second original time-domain signal. The second original time-domain signal may include signal values at multiple positions. For example, the second original time-domain signal includes signal values at 100 positions.

[0057] Step 302: Perform preprocessing on the first original time-domain signal to obtain the first target time-domain signal, and perform preprocessing on the second original time-domain signal to obtain the second target time-domain signal. Alternatively, use the first original time-domain signal as the first target time-domain signal, and use the second original time-domain signal as the second target time-domain signal.

[0058] Exemplarily, when performing preprocessing on the first original time-domain signal to obtain the first target time-domain signal, outliers in the first original time-domain signal may be deleted to obtain the first target time-domain signal; or, the DC component in the first original time-domain signal may be removed to obtain the first target time-domain signal; or, outliers in the first original time-domain signal may be deleted, and the DC component in the first original time-domain signal may be removed to obtain the first target time-domain signal. For example, the first target time-domain signal may be obtained by the following steps:

[0059] Step 3021: Delete the outliers in the first original time-domain signal to obtain the first intermediate time-domain signal.

[0060] Exemplarily, the first original time-domain signal includes signal values at multiple positions. For each position, if the signal value at this position is an outlier, then the signal value at this position is deleted; if the signal value at this position is not an outlier, then the signal value at this position is retained. After performing the above processing on the signal values at each position, the first intermediate time-domain signal may be obtained. Assume that the first original time-domain signal includes signal values at S1 positions, and the first intermediate time-domain signal includes signal values at S2 positions. Then S2 may be less than or equal to S1.

[0061] For example, for each position, a plurality of signal values at that position are selected from the first original time-domain signal and the first historical time-domain signal. The first historical time-domain signal is the original time-domain signal before the first original time-domain signal (collected by the first transducer, and the collection process is similar to that of the first original time-domain signal). Based on this, N signal values at that position can be selected from the first original time-domain signal and the plurality of original time-domain signals before it. The value of N can be 8, 16, 32, or 64, etc., and there is no limitation on this. For example, N signal values are randomly selected, or, N signal values are sequentially selected in the order from the latest to the earliest acquisition time, or, N signal values are selected at intervals in the order from the latest to the earliest acquisition time (such as the 1st, 3rd, 5th, 7th, etc.). Of course, the above are just a few examples, as long as N signal values at that position can be selected.

[0062] Taking the position as j as an example, the signal value at position j is selected from the first original time-domain signal, the signal value at position j is selected from the first original time-domain signal before the first original time-domain signal (the 1st original time-domain signal), the signal value at position j is selected from the second original time-domain signal before the first original time-domain signal, and so on.

[0063] For example, for each position, after obtaining a plurality of signal values at that position, the first quartile and the second quartile can be determined based on the plurality of signal values. The first quartile is the first quartile , and the second quartile is the second quartile , or, the first quartile is the first quartile , and the second quartile is the third quartile , or, the first quartile is the first quartile , and the second quartile is the fourth quartile , or, the first quartile is the second quartile , and the second quartile is the third quartile , or, the first quartile is the second quartile , and the second quartile is the fourth quartile , or, the first quartile is the third quartile , and the second quartile is the fourth quartile . For the convenience of description, it is described by taking the first quartile as the first quartile , and the second quartile as the third quartile as an example.

[0064] Based on multiple signal values at this position, the multiple signal values at this position can be sorted in ascending order. Then, the value at the 25% position among the signal values can be used as the first quartile. The value at the 75% position among the signal values can be used as the third quartile. .

[0065] For example, after obtaining the first quartile and the second quartile, it is possible to determine whether the signal value at this position is an outlier based on the first quartile and the second quartile. For example, based on the position j of the first quartile and the third quartile , the interquartile range can be calculated R . .

[0066] If the signal value j at the position satisfies the following relationship, then the signal value j at the position is an outlier. If the signal value j at the position does not satisfy the following relationship, then the signal value j at the position is not an outlier.

[0067] or

[0068] In the above relationship, represents the outlier rejection coefficient. The outlier rejection coefficient can be configured according to experience. For example, the value of the outlier rejection coefficient is between 1 and 3, and can be an integer or a decimal.

[0069] In summary, for each position in the first original time-domain signal, the above method can be used to determine whether the signal value at this position is an outlier, and then the outlier can be removed to obtain the first intermediate time-domain signal.

[0070] Step 3022: Remove the DC component from the first intermediate time-domain signal to obtain the first target time-domain signal.

[0071] Exemplarily, the first intermediate time-domain signal includes signal values at multiple positions. For each position, calculate the DC component at this position, subtract the DC component from the signal value at this position to obtain the signal value after removing the DC component at this position. After performing the above processing on the signal values at each position, the signal values after removing the DC component at each position are obtained. The first target time-domain signal includes the signal values after removing the DC component at each position.

[0072] For example, for each position, the DC component of this position is determined based on the average value of multiple signal values at this position (such as N signal values at this position that have been selected), and the average value is used as the DC component. Or, the DC component of this position is determined based on the average value of all signal values of the first original time-domain signal, and the average value is used as the DC component, that is, the same DC component corresponds to all positions. Or, the DC component of this position is determined based on the average value of all signal values of the first original time-domain signal and the first historical time-domain signal, and the average value is used as the DC component, that is, the same DC component corresponds to all positions.

[0073] For example, taking the position j as an example, assume that the DC component of the position j is , the signal value of the position j is , and the signal value after removing the DC component of the position j is , then .

[0074] In summary, the first original time-domain signal can be preprocessed to obtain the first target time-domain signal.

[0075] Exemplarily, when preprocessing the second original time-domain signal to obtain the second target time-domain signal, outliers in the second original time-domain signal can be deleted to obtain the second target time-domain signal; or, the DC component in the second original time-domain signal can be removed to obtain the second target time-domain signal; or, outliers in the second original time-domain signal can be deleted and the DC component in the second original time-domain signal can be removed to obtain the second target time-domain signal, and the implementation process can refer to the first target time-domain signal acquisition process.

[0076] Step 303: Filter the first target time-domain signal to obtain the first filtered time-domain signal, and filter the second target time-domain signal to obtain the second filtered time-domain signal. Or, use the first target time-domain signal as the first filtered time-domain signal and the second target time-domain signal as the second filtered time-domain signal.

[0077] Exemplarily, when filtering the first target time-domain signal to obtain the first filtered time-domain signal, the first target time-domain signal can be subjected to mean filtering to obtain the first filtered time-domain signal; or, the first target time-domain signal can be subjected to band-pass filtering to obtain the first filtered time-domain signal; or, the first target time-domain signal can be subjected to mean filtering and band-pass filtering to obtain the first filtered time-domain signal.

[0078] For example, the first filtered time-domain signal can be obtained by the following steps:

[0079] Step 3031: Perform mean filtering on the first target time-domain signal to obtain the mean-filtered time-domain signal.

[0080] Exemplarily, the first target time-domain signal includes signal values at multiple positions. For each position, multiple signal values at this position are selected from the first target time-domain signal and the first historical time-domain signal. Taking N signal values as an example, the value of N can be 8, 16, 32, or 64, etc., and there is no limitation on this. The first historical time-domain signal is the target time-domain signal before the first target time-domain signal (the acquisition process is similar to that of the first target time-domain signal). Taking this position as j an example, then the signal value at position j is selected from the first target time-domain signal, and the signal value at position j is selected from the first target time-domain signal at the first target time-domain signal before the first target time-domain signal, and the signal value at position j is selected from the second target time-domain signal before the first target time-domain signal, and so on.

[0081] Based on the N signal values at position j , the signal value at position j can be mean-filtered to obtain the mean-filtered signal value. For example, the following formula (2) can be used for mean filtering.

[0082] Formula (2)

[0083] In formula (2), can represent the mean-filtered signal value at position j . When i = 1, can represent the first signal value corresponding to position j . When i = 2, can represent the second signal value corresponding to position j . And so on. When i = N, can represent the Nth signal value corresponding to position j .

[0084] Obviously, for each position of the first target time-domain signal, the mean-filtered signal value at this position can be obtained, and the mean-filtered time-domain signal includes the mean-filtered signal values at each position.

[0085] Step 3032: Perform band-pass filtering on the mean-filtered time-domain signal to obtain the first filtered time-domain signal.

[0086] Exemplarily, after obtaining the time-domain signal after mean filtering, a band-pass filter can be used to perform band-pass filtering on the time-domain signal after mean filtering to obtain the time-domain signal after band-pass filtering. The time-domain signal after band-pass filtering can be referred to as the first filtered time-domain signal, and no limitation is imposed on this band-pass filtering process.

[0087] For example, the time-domain signal after mean filtering includes signal values at multiple positions. For each position, taking this position as position j as an example, the following formula (3) can be used for band-pass filtering.

[0088] Formula (3)

[0089] In formula (3), can represent the signal value after band-pass filtering at position j , that is, the signal value at position j in the first filtered time-domain signal. can represent the signal value after band-pass filtering at position ( ). can represent the filter coefficient, which can be a configured constant. can be the order of the filter.

[0090] can represent the signal value after mean filtering at position ( ), that is, the signal value at position ( ) in the time-domain signal after mean filtering. can represent the filter coefficient, which can be a configured constant.

[0091] Taking the band-pass filter as an IIR (Infinite Impulse Response) second-order filter as an example, if the sampling frequency is 80 MHz and the band-pass frequency range of the band-pass filter is 0.3 MHz to 4 MHz, then: .

[0092] In summary, the first target time-domain signal can be filtered to obtain the first filtered time-domain signal.

[0093] Exemplarily, when filtering the second target time-domain signal to obtain the second filtered time-domain signal, the second target time-domain signal can be subjected to mean filtering to obtain the second filtered time-domain signal; or, the second target time-domain signal can be subjected to band-pass filtering to obtain the second filtered time-domain signal; or, the second target time-domain signal can be subjected to mean filtering and band-pass filtering to obtain the second filtered time-domain signal.

[0094] Step 304: Perform a frequency-domain transformation on the first filtered time-domain signal to obtain a first original frequency-domain signal, and perform a frequency-domain transformation on the second filtered time-domain signal to obtain a second original frequency-domain signal.

[0095] Exemplarily, the first filtered time-domain signal is a time-domain signal, and the first original frequency-domain signal is a frequency-domain signal. Therefore, by performing a conversion operation from the time-domain signal to the frequency-domain signal (i.e., frequency-domain transformation) on the first filtered time-domain signal, the first original frequency-domain signal can be obtained. For example, the following formula (4) can be used to perform a frequency-domain transformation on the first filtered time-domain signal to obtain the first original frequency-domain signal.

[0096] Formula (4)

[0097] In formula (4), assuming that the first filtered time-domain signal includes signal values at L positions, the first original frequency-domain signal includes amplitudes at L frequencies. represents the signal value at the j th position in the first filtered time-domain signal, and . represents the amplitude at the k th frequency in the first original frequency-domain signal, and . Obviously, when k is 0, the amplitude of the first frequency in the first original frequency-domain signal is calculated through formula (4). When k is 1, the amplitude of the second frequency in the first original frequency-domain signal is calculated through formula (4), and so on. A total of L amplitudes of frequencies can be obtained.

[0098] In summary, a frequency-domain transformation can be performed on the first filtered time-domain signal to obtain the first original frequency-domain signal, and the first original frequency-domain signal includes amplitudes at multiple frequencies, such as amplitudes at L frequencies.

[0099] Similarly, a frequency-domain transformation can be performed on the second filtered time-domain signal to obtain the second original frequency-domain signal, and the second original frequency-domain signal includes amplitudes at multiple frequencies, such as amplitudes at L frequencies.

[0100] Step 305: Set the amplitudes of the frequencies corresponding to the noise signals in the first original frequency-domain signal to 0 (the process of setting the amplitudes to 0 is frequency-domain filtering) to obtain a first target frequency-domain signal, and set the amplitudes of the frequencies corresponding to the noise signals in the second original frequency-domain signal to 0 to obtain a second target frequency-domain signal. Or, use the first original frequency-domain signal as the first target frequency-domain signal and the second original frequency-domain signal as the second target frequency-domain signal.

[0101] Exemplarily, the first original frequency-domain signal includes the amplitudes of multiple frequencies (the amplitudes of L frequencies). For each frequency (i.e., the frequency spectrum), if the frequency is less than the third frequency value, or the frequency is greater than the fourth frequency value, then the frequency is the frequency corresponding to the noise signal, and the amplitude of this frequency in the first original frequency-domain signal is set to 0. If the frequency is not less than the third frequency value and not greater than the fourth frequency value, then the frequency is not the frequency corresponding to the noise signal, and the amplitude of this frequency in the first original frequency-domain signal remains unchanged.

[0102] The third frequency value can be determined based on the configured sampling frequency and the third coefficient, and the fourth frequency value can be determined based on the configured sampling frequency and the fourth coefficient. For example, the third coefficient and the fourth coefficient can be configured according to experience, as long as the fourth coefficient is greater than the third coefficient, and the values of the third coefficient and the fourth coefficient are not restricted in this regard. For example, the third coefficient can be greater than 0 and less than 1, and the fourth coefficient can be greater than 1. For example, the third coefficient can be 0.3, 0.4, etc., and the fourth coefficient can be 3, 4, etc.

[0103] For example, the sampling frequency can be configured according to experience, which represents the sampling frequency used to distinguish noise signals. For example, when the sampling frequency is 20 MHz, if the third coefficient is 0.3 and the fourth coefficient is 3, then 6 MHz (20 MHz * 0.3) is used as the third frequency value, and the clutter below the third frequency value is regarded as a noise signal, and 60 MHz (20 MHz * 3) is used as the fourth frequency value, and the clutter above the fourth frequency value is regarded as a noise signal.

[0104] In summary, for each frequency, if the frequency is less than 6 MHz, or the frequency is greater than 60 MHz, then the frequency is the frequency corresponding to the noise signal, and the amplitude of this frequency in the first original frequency-domain signal is set to 0.

[0105] Exemplarily, the second original frequency-domain signal includes the amplitudes of multiple frequencies. For each frequency, if the frequency is less than the third frequency value or greater than the fourth frequency value, then the frequency is the frequency corresponding to the noise signal, and the amplitude of this frequency in the second original frequency-domain signal is set to 0. If the frequency is not less than the third frequency value and not greater than the fourth frequency value, then the frequency is not the frequency corresponding to the noise signal, and the amplitude of this frequency remains unchanged.

[0106] Step 306: Determine the first cross-correlation frequency-domain signal based on the first target frequency-domain signal and the second target frequency-domain signal. The first cross-correlation frequency-domain signal can reflect the correlation between the first target frequency-domain signal and the second target frequency-domain signal, and is the correlation signal between the first target frequency-domain signal and the second target frequency-domain signal.

[0107] Exemplarily, the first complex conjugate frequency domain signal of the first target frequency domain signal can be determined, and the first cross-correlation frequency domain signal is obtained by performing a convolution operation on the first complex conjugate frequency domain signal and the second target frequency domain signal. Alternatively, the second complex conjugate frequency domain signal of the second target frequency domain signal can be determined, and the first cross-correlation frequency domain signal is obtained by performing a convolution operation on the first target frequency domain signal and the second complex conjugate frequency domain signal.

[0108] For example, the first cross-correlation frequency domain signal can be calculated using the following formula (5):

[0109] Formula (5)

[0110] In formula (5), represents the first cross-correlation frequency domain signal, represents the first target frequency domain signal, represents the second target frequency domain signal, represents the second complex conjugate frequency domain signal of the second target frequency domain signal. The first target frequency domain signal includes the amplitudes of L frequencies, the second target frequency domain signal includes the amplitudes of L frequencies, and the first cross-correlation frequency domain signal includes the amplitudes of L frequencies.

[0111] Step 307: Determine the target cross-correlation frequency domain signal based on the first cross-correlation frequency domain signal, and the target cross-correlation frequency domain signal can reflect the correlation between the first target frequency domain signal and the second target frequency domain signal.

[0112] Exemplarily, after obtaining the first cross-correlation frequency domain signal, the first cross-correlation frequency domain signal is determined as the target cross-correlation frequency domain signal. Alternatively, the zero-frequency component in the first cross-correlation frequency domain signal is moved to the frequency center to obtain the second cross-correlation frequency domain signal, and the second cross-correlation frequency domain signal is determined as the target cross-correlation frequency domain signal. Alternatively, the zero-frequency component in the first cross-correlation frequency domain signal is moved to the frequency center to obtain the second cross-correlation frequency domain signal, and the second cross-correlation frequency domain signal is adjusted to obtain the target cross-correlation frequency domain signal. Of course, the above are only a few examples, and the acquisition method of the target cross-correlation frequency domain signal is not limited.

[0113] In a possible implementation manner, referring to Figure 4 shown, which is a schematic flowchart for obtaining the target cross-correlation frequency domain signal, the target cross-correlation frequency domain signal can be obtained by the following steps:

[0114] Step 401: Move the zero-frequency component in the first cross-correlation frequency domain signal to the frequency center to obtain the second cross-correlation frequency domain signal, that is, the zero-frequency component in the second cross-correlation frequency domain signal is located at the frequency center. Alternatively, the first cross-correlation frequency domain signal can be directly used as the second cross-correlation frequency domain signal.

[0115] Exemplarily, after obtaining the first cross-correlation frequency domain signal it is possible to determine the zero-frequency component in the first cross-correlation frequency domain signal For example, if the first cross-correlation frequency domain signal includes the amplitudes of L frequencies, and if the amplitude of a certain frequency is 0, then this amplitude is the zero-frequency component. Move the zero-frequency component (i.e., the amplitude 0) to the frequency center (i.e., the central region of the L frequencies). After moving the zero-frequency component to the frequency center, the amplitudes of each frequency in the first cross-correlation frequency domain signal can be re-ordered, and the re-ordered first cross-correlation frequency domain signal is used as the second cross-correlation frequency domain signal, denoted as the second cross-correlation frequency domain signal .

[0116] When re-ordering the amplitudes of each frequency, if the amplitude 0 of the first frequency on the left side of the frequency center is moved to the frequency center, then the amplitudes of each frequency between the frequency center and the first frequency move to the left side

[0117] When re-ordering the amplitudes of each frequency, if the amplitude 0 of the second frequency on the right side of the frequency center is moved to the frequency center, then the amplitudes of each frequency between the frequency center and the second frequency move to the right side

[0118] Assume that the first cross-correlation frequency domain signal includes the amplitude 1 of frequency a1, the amplitude 0 of frequency a2, the amplitude 2 of frequency a3, the amplitude 3 of frequency a4, the amplitude 4 of frequency a5, the amplitude 5 of frequency a6, and the amplitude 3 of frequency a7. Then, the amplitude 0 of frequency a2 is the zero-frequency component, frequency a4 is the frequency center. Move the zero-frequency component to frequency a4, re-order the amplitudes of each frequency, and obtain the second cross-correlation frequency domain signal , and the second cross-correlation frequency domain signal includes the amplitude 1 of frequency a1, the amplitude 2 of frequency a2 (i.e., the amplitude of frequency a3 is moved to frequency a2), the amplitude 3 of frequency a3 (i.e., the amplitude of frequency a4 is moved to frequency a2), the amplitude 0 of frequency a4, the amplitude 4 of frequency a5, the amplitude 5 of frequency a6, and the amplitude 3 of frequency a7

[0119] Step 402: Filter the second cross-correlation frequency domain signal to obtain the filtered frequency domain signal. Alternatively, the second cross-correlation frequency domain signal can also be directly used as the filtered frequency domain signal

[0120] For example, at least one of a low-pass filter, a high-pass filter, a band-pass filter, and a band-stop filter can be used to filter the second cross-correlation frequency domain signal, and there is no limitation on this filtering process

[0121] Step 403: Set the amplitude of the frequency corresponding to the noise signal in the filtered frequency-domain signal to 0 to obtain the third cross-correlation frequency-domain signal. Alternatively, the filtered frequency-domain signal can also be used as the third cross-correlation frequency-domain signal.

[0122] Exemplarily, the filtered frequency-domain signal includes amplitudes of multiple frequencies (amplitudes of L frequencies). For each frequency, if the frequency is less than the first frequency value, or the frequency is greater than the second frequency value, and the second frequency value is greater than the first frequency value, then the frequency is the frequency corresponding to the noise signal, and set the amplitude of this frequency in the filtered frequency-domain signal to 0. If the frequency is not less than the first frequency value and not greater than the second frequency value, then the frequency is not the frequency corresponding to the noise signal, and keep the amplitude of this frequency in the filtered frequency-domain signal unchanged.

[0123] The first frequency value can be determined based on the configured sampling frequency and the first coefficient, and the second frequency value can be determined based on the configured sampling frequency and the second coefficient. For example, the first coefficient and the second coefficient can be configured according to experience, as long as the second coefficient is greater than the first coefficient, and the values of the first coefficient and the second coefficient are not restricted in this regard. For example, the first coefficient can be greater than 0 and less than 1, and the second coefficient can be greater than 1. For example, the first coefficient can be 0.5, 0.6, etc., and the second coefficient can be 2, 3, etc.

[0124] For example, the sampling frequency can be configured according to experience, which represents the sampling frequency used to distinguish noise signals. For example, when the sampling frequency is 20 MHZ, if the first coefficient is 0.5 and the second coefficient is 2, then take 10 MHZ (20 MHZ * 0.5) as the first frequency value, and consider the clutter below the first frequency value as noise signals, take 40 MHZ (20 MHZ * 2) as the second frequency value, and consider the clutter above the second frequency value as noise signals.

[0125] In summary, for each frequency, if the frequency is less than 10 MHZ, or the frequency is greater than 40 MHZ, then the frequency is the frequency corresponding to the noise signal, and set the amplitude of this frequency in the filtered frequency-domain signal to 0.

[0126] Step 404: Perform frequency-domain interpolation on the third cross-correlation frequency-domain signal to obtain the fourth cross-correlation frequency-domain signal. Alternatively, the third cross-correlation frequency-domain signal can also be directly used as the fourth cross-correlation frequency-domain signal.

[0127] Exemplarily, when performing frequency-domain interpolation on the third cross-correlation frequency-domain signal to obtain the fourth cross-correlation frequency-domain signal, the third cross-correlation frequency-domain signal includes L amplitudes of frequencies, the fourth cross-correlation frequency-domain signal includes L1 amplitudes of frequencies, and L1 is greater than L , that is, increase ( L1 -L The amplitude of () frequencies.

[0128] Regarding the value of the number of frequencies L1 The value can be configured according to experience, L1 or an algorithm can be used to calculate the number of frequencies. L1 There is no restriction on this, as long as L1 is greater than L That's all.

[0129] For example, based on the time resolution, the target resolution of the configured time difference of flight, and the number of frequencies in the third cross-correlation frequency domain signal L to determine the number of frequencies in the fourth cross-correlation frequency domain signal L1 . For example, the following formula can be used to determine the number of frequencies L1 : .

[0130] In the above formula, represents the time resolution, that is, the time resolution corresponding to the sampling frequency. Assuming the frequency range of the third cross-correlation frequency domain signal (fourth cross-correlation frequency domain signal) is 80 MHz, the time resolution is 12500 ps. represents the target resolution, that is, the desired resolution of the time difference of flight is , such as the target resolution is 10 ps. Based on this, the above formula can be equivalent to: .

[0131] Exemplarily, for the k th frequency in the fourth cross-correlation frequency domain signal, since the fourth cross-correlation frequency domain signal includes L1 the amplitudes of () frequencies, therefore, k the values of L1-1 are from 0 to L . Based on this, if the number of frequencies k in the third cross-correlation frequency domain signal takes an odd value, the formula (6) can be used to determine the target amplitude of the k th frequency in the fourth cross-correlation frequency domain signal. Of course, formula (6) is just an example, and there is no restriction on the determination method of this target amplitude, as long as the target amplitude of the

[0132] Formula (6)

[0133] In formula (6), represents the target amplitude of the k th frequency in the fourth cross-correlation frequency domain signal, represents the kThe amplitude of a frequency. It can be seen from formula (6) that when , the target amplitude is the amplitude of the k th frequency in the third cross-correlation frequency domain signal; when , the target amplitude is 0; when , the target amplitude is the amplitude of the k th frequency in the third cross-correlation frequency domain signal.

[0134] If the number of frequencies L in the third cross-correlation frequency domain signal takes an even value, formula (7) can be used to determine the target amplitude of the k th frequency in the fourth cross-correlation frequency domain signal. Of course, formula (7) is just an example, and there is no limit to the method of determining this target amplitude, as long as it can determine the target amplitude of the k th frequency.

[0135] Formula (7)

[0136] In formula (7), represents the target amplitude of the k th frequency in the fourth cross-correlation frequency domain signal, and represents the amplitude of the k th frequency in the third cross-correlation frequency domain signal. It can be seen from formula (7) that when , the target amplitude is the amplitude of the k th frequency in the third cross-correlation frequency domain signal; when , the target amplitude is half of the amplitude of the k th frequency in the third cross-correlation frequency domain signal (i.e., ); when , the target amplitude is 0; when , the target amplitude is half of the amplitude of the th frequency in the third cross-correlation frequency domain signal (i.e., ); when , the target amplitude is the amplitude of the k th frequency in the third cross-correlation frequency domain signal.

[0137] In summary, the target amplitude of the k th frequency in the fourth cross-correlation frequency domain signal can be obtained. When the values of k are successively from 0 to L1-1 , the target amplitudes of L1 frequencies can be obtained, and the target amplitudes of L1 frequencies form the fourth cross-correlation frequency domain signal, thus obtaining the fourth cross-correlation frequency domain signal.

[0138] Step 405: Determine the target cross-correlation frequency-domain signal based on the fourth cross-correlation frequency-domain signal. For example, the fourth cross-correlation frequency-domain signal can be determined as the target cross-correlation frequency-domain signal, or the fourth cross-correlation frequency-domain signal can be optimized, and the optimized frequency-domain signal can be used as the target cross-correlation frequency-domain signal.

[0139] So far, step 307 is completed, and the target cross-correlation frequency-domain signal can be obtained.

[0140] Step 308: Perform a time-domain transformation based on the target cross-correlation frequency-domain signal to obtain the cross-correlation time-domain signal.

[0141] Exemplarily, the target cross-correlation frequency-domain signal can be a frequency-domain signal, and the cross-correlation time-domain signal can be a time-domain signal. Therefore, by performing a conversion operation from the frequency-domain signal to the time-domain signal (i.e., time-domain transformation) on the target cross-correlation frequency-domain signal, the cross-correlation time-domain signal can be obtained. For example, the following formula (8) can be used to perform a time-domain transformation on the target cross-correlation frequency-domain signal to obtain the cross-correlation time-domain signal.

[0142] Formula (8)

[0143] In formula (8), assume that the target cross-correlation frequency-domain signal includes L1 amplitudes (target amplitudes) of L1 frequencies, then the cross-correlation time-domain signal includes signal values at k positions. . represents the amplitude of the k th frequency in the target cross-correlation frequency-domain signal, and . represents the signal value at the n th position in the cross-correlation time-domain signal, and . Obviously, when is 0, the signal value at the first position in the cross-correlation time-domain signal is calculated through formula (8), and when is 1, the signal value at the second position in the cross-correlation time-domain signal is calculated through formula (8), and so on. A total of L1 signal values can be obtained, and these L1 signal values can form the cross-correlation time-domain signal.

[0144] Step 309: The cross-correlation time-domain signal includes signal values at multiple positions. Determine the time difference of flight based on the target position corresponding to the maximum signal value. The target position can be the most similar position between the first original time-domain signal and the second original time-domain signal. The time difference of flight can represent the phase difference of the target position.

[0145] Exemplarily, based on the signal values at each position in the cross-correlation time-domain signal, the maximum signal value can be selected from these signal values, and the position corresponding to the maximum signal value is called the target position, denoted as , which can indicate that the target position is the th position in the cross-correlation time-domain signal. For example, if is 3, it means that the signal value at the 3rd position in the cross-correlation time-domain signal is the maximum signal value.

[0146] Exemplarily, based on the target position corresponding to the maximum signal value, the total number of positions in the cross-correlation time-domain signal, and the target resolution of the configured time difference of flight, the time difference of flight can be determined.

[0147] For example, the time difference of flight can be determined using the following formula (9). Of course, formula (9) is just an example, and there is no limitation on this determination method as long as the time difference of flight is related to the target position.

[0148] Formula (9)

[0149] In formula (9), can represent the time difference of flight, which can be the time difference between the propagation times of ultrasonic waves in the downstream direction and the upstream direction. For example, the acoustic flight time from the first transducer to the second transducer and the acoustic flight time from the second transducer to the first transducer The difference between them.

[0150] In formula (9), can represent the total number of positions. For example, if the cross-correlation time-domain signal includes L1 signal values at positions, then the total number of positions in the cross-correlation time-domain signal is L1 . represents the target resolution, that is, it is desired to make the resolution of the time difference of flight be , such as the target resolution is 10 ps.

[0151] Exemplarily, when the signal value at the target position is the maximum signal value, it indicates that the first original time-domain signal and the second original time-domain signal are most similar at the target position. Thus, the phase difference at the target position can be used as the time difference of flight between the first original time-domain signal and the second original time-domain signal. Regarding how to determine the phase difference at the target position, reference can be made to formula (9) shown, that is, this phase difference is used as the time difference of flight. For example, for the phase difference at the target position, this phase difference can refer to the difference between the signal value at this target position in the first original time-domain signal and the signal value at this target position in the second original time-domain signal.

[0152] In a possible implementation, the cross-correlation function Rxy ( τ ) is defined as the inner product of signal x ( t ) and signal y ( t ) at different time delays τ . The physical meaning of cross-correlation is to measure the similarity between two signals at different time offsets. When signal y ( t ) is delayed to a certain value τ , the cross-correlation signal Rxy ( τ ) will reach a maximum value. This maximum value indicates that the shapes of the two signals are closest at this time, that is, the two signals are best aligned in time.

[0153] Based on the above principle, in this embodiment, the position corresponding to the maximum value in the cross-correlation time-domain signal (i.e., the target position) is the phase difference (i.e., the time difference) between the two signals (the first original time-domain signal and the second original time-domain signal), and this phase difference is the time-of-flight difference , .

[0154] In this embodiment, , is a discretized representation. Signal y ( t ) moves backward corresponding to being negative, and signal y ( t ) moves forward corresponding to being positive. The length of the cross-correlation time-domain signal is L1 . Signal y ( t ) moves backward by , moves forward by , plus one point that does not move itself. Since n this sequence number starts from 0, so subtract , that is, the formula (9) is obtained.

[0155] Exemplarily, after obtaining the time-of-flight difference, it is also possible to determine whether the time-of-flight difference is an outlier. If the time-of-flight difference is an outlier, then the time-of-flight difference is excluded, and the flow rate of the fluid passing through the pipeline is not determined based on this time-of-flight difference. If the time-of-flight difference is not an outlier, then the time-of-flight difference is retained, and the flow rate of the fluid passing through the pipeline can be determined based on this time-of-flight difference.

[0156] For example, based on this time-of-flight difference and historical time-of-flight differences (i.e., time-of-flight differences obtained in the past, and the number of historical time-of-flight differences can be multiple), the mean value of these time-of-flight differences can be calculated and standard deviation . Based on the mean and standard deviation to determine whether the time difference of flight is an outlier. For example, if the time difference of flight satisfies or , then the time difference of flight is an outlier. If the time difference of flight does not satisfy or , then the time difference of flight is not an outlier. In the above relationship, can represent the time difference of flight, can represent the configured constant, can have a value range of 0.5 to 2, and there is no restriction on this.

[0157] Exemplarily, after obtaining the time difference of flight, the flow velocity of the fluid passing through the pipeline can be determined based on the time difference of flight. For example, the flow velocity of the fluid can be determined using the following formula (10).

[0158] * c 2 * / 2D Formula (10)

[0159] represents the time difference of flight, c represents the sound velocity of ultrasonic waves in the medium (i.e., the fluid), represents the flow velocity of the fluid passing through the pipeline. Refer to Figure 2 shown, Φ represents the angle between the sound wave transmission path and the pipeline (the angle between the sound wave transmission length direction and the pipe diameter), D represents the pipe diameter (the inner vertical distance of the pipeline).

[0160] As can be seen from the above technical solutions, in the embodiments of the present application, it is not necessary to measure the sound wave flight time from the first transducer to the second transducer and the sound wave flight time from the second transducer to the first transducer, which can avoid the low accuracy of the sound wave flight time measurement resulting in the low accuracy of the time difference of flight, can accurately obtain the time difference of flight, the accuracy of the time difference of flight is relatively high, the error of the time difference of flight is small, improve the calculation accuracy of the time difference of flight, realize the accurate calculation of the phase difference between the upstream signal and the downstream signal of the ultrasonic wave, and improve the anti-interference performance against noise. By using the frequency domain interpolation method, the information of signals of any length can be used, and the invalid noise can be filtered, improving the anti-interference performance against noise, and the influence of signal noise and signal asymmetry on the calculation accuracy can be eliminated, thereby greatly improving the time resolution and interpolation accuracy, and improving the calculation accuracy of the time difference of flight.

[0161] Based on the same application concept as the above method, in an embodiment of the present application, a flow velocity determination device is proposed. A first transducer and a second transducer are respectively installed on both sides of a pipeline. A fluid passes through the pipeline. The first transducer sends ultrasonic waves to the second transducer, and the second transducer sends ultrasonic waves to the first transducer. Refer to Figure 5 As shown in

[0162] An acquisition module 51, configured to acquire a first original time-domain signal collected by the first transducer and a second original time-domain signal collected by the second transducer; perform frequency-domain transformation on the first original time-domain signal to obtain a first target frequency-domain signal, and perform frequency-domain transformation on the second original time-domain signal to obtain a second target frequency-domain signal; a determination module 52, configured to determine a first cross-correlation frequency-domain signal based on the first target frequency-domain signal and the second target frequency-domain signal, and determine a target cross-correlation frequency-domain signal based on the first cross-correlation frequency-domain signal; a processing module 53, configured to perform time-domain transformation on the target cross-correlation frequency-domain signal to obtain a cross-correlation time-domain signal, where the cross-correlation time-domain signal includes signal values at multiple positions; determine a time-of-flight difference based on a target position corresponding to a maximum signal value; where the time-of-flight difference is the time difference between the ultrasonic waves propagating in the downstream direction and the upstream direction; the time-of-flight difference is used to determine the flow velocity of the fluid when passing through the pipeline.

[0163] Exemplarily, when the determination module 52 determines the first cross-correlation frequency-domain signal based on the first target frequency-domain signal and the second target frequency-domain signal, it is specifically configured to: determine a first complex conjugate frequency-domain signal corresponding to the first target frequency-domain signal, and perform a convolution operation on the first complex conjugate frequency-domain signal and the second target frequency-domain signal to obtain the first cross-correlation frequency-domain signal; or, determine a second complex conjugate frequency-domain signal corresponding to the second target frequency-domain signal, and perform a convolution operation on the first target frequency-domain signal and the second complex conjugate frequency-domain signal to obtain the first cross-correlation frequency-domain signal.

[0164] Exemplarily, when determining the target cross-correlation frequency-domain signal based on the first cross-correlation frequency-domain signal, the determining module 52 is specifically configured to: determine the first cross-correlation frequency-domain signal as the target cross-correlation frequency-domain signal; or, move the zero-frequency component in the first cross-correlation frequency-domain signal to the frequency center to obtain a second cross-correlation frequency-domain signal, and determine the second cross-correlation frequency-domain signal as the target cross-correlation frequency-domain signal; or, move the zero-frequency component in the first cross-correlation frequency-domain signal to the frequency center to obtain a second cross-correlation frequency-domain signal, filter the second cross-correlation frequency-domain signal to obtain a filtered frequency-domain signal; set the amplitude of the frequency corresponding to the noise signal in the filtered frequency-domain signal to 0 to obtain a third cross-correlation frequency-domain signal, perform frequency-domain interpolation on the third cross-correlation frequency-domain signal to obtain a fourth cross-correlation frequency-domain signal, and determine the fourth cross-correlation frequency-domain signal as the target cross-correlation frequency-domain signal.

[0165] Exemplarily, the filtered frequency-domain signal includes amplitudes of multiple frequencies. For each frequency, if the frequency is less than a first frequency value, or the frequency is greater than a second frequency value, then the frequency is the frequency corresponding to the noise signal; wherein, the first frequency value is determined based on the configured sampling frequency and a first coefficient, the first coefficient is greater than 0 and less than 1, and the second frequency value is determined based on the configured sampling frequency and a second coefficient, the second coefficient is greater than 1.

[0166] Exemplarily, when performing frequency-domain interpolation on the third cross-correlation frequency-domain signal to obtain the fourth cross-correlation frequency-domain signal, the third cross-correlation frequency-domain signal includes L amplitudes of frequencies, the fourth cross-correlation frequency-domain signal includes L1 amplitudes of frequencies, and L1 is greater than L ; wherein, for the k th frequency in the fourth cross-correlation frequency-domain signal, k takes values sequentially from 0 to L1-1 , and the determining module 52 determines the target amplitude of the k th frequency in the following manner: if L takes an odd value, when , then the target amplitude is the amplitude of the k th frequency in the third cross-correlation frequency-domain signal; or, when , then the target amplitude is 0; or, when , then the target amplitude is the amplitude of the k th frequency in the third cross-correlation frequency-domain signal; or,

[0167] if L takes an even value, when When, the target amplitude is the amplitude of the k th frequency in the third cross-correlation frequency domain signal; or, when When, the target amplitude is half of the amplitude of the k th frequency in the third cross-correlation frequency domain signal; or, when When, the target amplitude is 0; or, when When, the target amplitude is half of the amplitude of the th frequency in the third cross-correlation frequency domain signal; or, when When, the target amplitude is the amplitude of the k th frequency in the third cross-correlation frequency domain signal.

[0168] Exemplarily, when the processing module 53 determines the time difference of flight based on the target position corresponding to the maximum signal value, it is specifically configured to: determine the time difference of flight based on the target position corresponding to the maximum signal value, the total number of positions in the cross-correlation time domain signal, and the target resolution of the configured time difference of flight; wherein, the processing module 53 uses the following formula to determine the time difference of flight: ;

[0169] Wherein, represents the time difference of flight, represents that the target position is the th position in the cross-correlation time domain signal, represents the total number of positions, represents the target resolution.

[0170] Exemplarily, when the acquisition module 51 performs a frequency domain transformation on the first original time domain signal to obtain a first target frequency domain signal, it is specifically configured to: perform preprocessing on the first original time domain signal to obtain a first target time domain signal, and perform filtering on the first target time domain signal to obtain a first filtered time domain signal; perform a frequency domain transformation on the first filtered time domain signal to obtain a first original frequency domain signal, and set the amplitude of the frequency corresponding to the noise signal in the first original frequency domain signal to 0 to obtain a first target frequency domain signal.

[0171] Exemplarily, when the obtaining module 51 preprocesses the first original time-domain signal to obtain the first target time-domain signal, it specifically is used for: deleting the outliers in the first original time-domain signal to obtain the first target time-domain signal; or, removing the DC component in the first original time-domain signal to obtain the first target time-domain signal; or, deleting the outliers in the first original time-domain signal and removing the DC component in the first original time-domain signal to obtain the first target time-domain signal; wherein, the first original time-domain signal includes signal values at multiple positions; for each position, multiple signal values at this position are selected from the first original time-domain signal and the first historical time-domain signal, and the first quartile and the second quartile are determined based on the multiple signal values; based on the first quartile and the second quartile, it is determined whether the signal value at this position is an outlier; for each position, the DC component at this position is determined based on the average value of the multiple signal values at this position, or based on the average value of all the signal values of the first original time-domain signal, or based on the average value of all the signal values of the first original time-domain signal and the first historical time-domain signal.

[0172] Based on the same application concept as the above method, an electronic device is proposed in an embodiment of the present application. Refer to Figure 6 As shown, the electronic device includes: a processor 61 and a machine-readable storage medium 62, and the machine-readable storage medium 62 stores machine-executable instructions that can be executed by the processor 61; the processor 61 is used to execute the machine-executable instructions to implement the flow rate determination method disclosed in the above example of the present application.

[0173] Based on the same application concept as the above method, an embodiment of the present application further provides a machine-readable storage medium, and a number of computer instructions are stored on the machine-readable storage medium. When the computer instructions are executed by a processor, the flow rate determination method disclosed in the above example of the present application can be implemented.

[0174] Among them, the above-mentioned machine-readable storage medium can be any electronic, magnetic, optical or other physical storage device, and can contain or store information, such as executable instructions, data, etc. For example, the machine-readable storage medium can be: RAM (Random Access Memory, random access memory), volatile memory, non-volatile memory, flash memory, storage drive (such as a hard disk drive), solid-state drive, any type of storage disk (such as an optical disc, DVD, etc.), or a similar storage medium, or a combination thereof.

[0175] Based on the same application concept as the above method, an embodiment of the present application further provides a computer program product, and the computer program product may include a computer program. When the computer program is executed by a processor, the flow rate determination method disclosed in the above example can be implemented.

[0176] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the embodiments of the present 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.

[0177] The above are only the embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. A method for determining flow velocity, characterized in that: A first transducer and a second transducer are respectively installed on both sides of a pipeline, and fluid passes through the pipeline, the first transducer sends an ultrasonic wave to the second transducer, and the second transducer sends an ultrasonic wave to the first transducer. The method includes: Acquire a first original time domain signal acquired by the first transducer and a second original time domain signal acquired by the second transducer; perform frequency domain transformation based on the first original time domain signal to obtain a first target frequency domain signal, and perform frequency domain transformation based on the second original time domain signal to obtain a second target frequency domain signal; Determine a first mutual correlation frequency domain signal based on the first target frequency domain signal and the second target frequency domain signal, and determine a target mutual correlation frequency domain signal based on the first mutual correlation frequency domain signal; Performing a time domain transformation based on the target cross-correlation frequency domain signal to obtain a cross-correlation time domain signal, wherein the cross-correlation time domain signal includes signal values ​​at multiple positions; determining a flight time difference based on the target position corresponding to the maximum signal value; wherein the flight time difference is the time difference of ultrasonic wave propagation in the downstream direction and the upstream direction; wherein the flight time difference is used to determine the flow velocity of the fluid when it passes through the pipeline; The determining of the target cross-correlation frequency domain signal based on the first cross-correlation frequency domain signal includes: The zero-frequency component in the first mutually correlated frequency domain signal is moved to the frequency center to obtain a second mutually correlated frequency domain signal, and the second mutually correlated frequency domain signal is filtered to obtain a filtered frequency domain signal; the amplitude of the frequency corresponding to the noise signal in the filtered frequency domain signal is set to 0 to obtain a third mutually correlated frequency domain signal, the third mutually correlated frequency domain signal is interpolated in the frequency domain to obtain a fourth mutually correlated frequency domain signal, and the fourth mutually correlated frequency domain signal is determined as the target mutually correlated frequency domain signal.

2. The method according to claim 1, characterized in that The determining a first mutually correlated frequency domain signal based on the first target frequency domain signal and the second target frequency domain signal comprises: determining a first complex conjugate frequency domain signal of the first target frequency domain signal, and performing a convolution operation on the first complex conjugate frequency domain signal and the second target frequency domain signal to obtain a first cross-correlation frequency domain signal; or, A second complex conjugate frequency domain signal of the second target frequency domain signal is determined, and a convolution operation is performed on the first target frequency domain signal and the second complex conjugate frequency domain signal to obtain a first cross-correlation frequency domain signal.

3. The method according to claim 1, characterized in that The filtered frequency domain signal includes amplitudes of multiple frequencies, and for each frequency, if the frequency is less than a first frequency value, or the frequency is greater than a second frequency value, then the frequency is a frequency corresponding to the noise signal; wherein the first frequency value is determined based on a configured sampling frequency and a first coefficient, the first coefficient is greater than 0 and less than 1, and the second frequency value is determined based on the configured sampling frequency and the second coefficient, the second coefficient is greater than 1; When frequency domain interpolation is performed on the third mutually correlated frequency domain signal to obtain a fourth mutually correlated frequency domain signal, the third mutually correlated frequency domain signal includes L The fourth cross-correlation frequency domain signal includes L1 The amplitude of the frequency, and L1 Greater than L ; Wherein, for the first k frequency, k The values ​​are from 0 to L1-1 , then the following method is used to determine the k Target amplitude for each frequency: like L The value of is an odd number. When , the target amplitude is the first k The amplitude of a frequency; or, When , the target amplitude is 0; or When , the target amplitude is the first k the amplitude of a frequency; or, like L The value of is an even number. When , the target amplitude is the first k The amplitude of a frequency; or, When , the target amplitude is the first k half the amplitude of the frequency; or, When , the target amplitude is 0; or When , the target amplitude is the first half the amplitude of the frequency; or, When , the target amplitude is the first k The amplitude of a frequency.

4. The method according to claim 1, characterized in that: The determining of the flight time difference based on the target position corresponding to the maximum signal value includes: determining the time of flight difference based on the target position corresponding to the maximum signal value, the total number of positions in the cross-correlated time domain signal, and a configured target resolution of the time of flight difference; The flight time difference is determined by the following formula: ; in, represents the flight time difference, Indicates that the target position is the first Locations, represents the total number of positions, Indicates the target resolution.

5. The method according to any one of claims 1 to 4, characterized in that: The performing frequency domain transformation based on the first original time domain signal to obtain a first target frequency domain signal includes: Preprocessing the first original time domain signal to obtain a first target time domain signal; Filtering the first target time domain signal to obtain a first filtered time domain signal; Performing frequency domain transformation on the first filtered time domain signal to obtain a first original frequency domain signal, and setting the amplitude of the frequency corresponding to the noise signal in the first original frequency domain signal to 0 to obtain a first target frequency domain signal.

6. The method according to claim 5, characterized in that The preprocessing of the first original time domain signal to obtain the first target time domain signal includes: deleting abnormal values ​​in the first original time domain signal to obtain the first target time domain signal; or removing a DC component in the first original time domain signal to obtain the first target time domain signal; or deleting abnormal values ​​in the first original time domain signal and removing a DC component in the first original time domain signal to obtain the first target time domain signal; Wherein, the first original time domain signal includes signal values ​​at multiple positions; For each position, select multiple signal values ​​of the position from the first original time domain signal and the first historical time domain signal, determine a first quartile and a second quartile based on the multiple signal values; determine whether the signal value of the position is an abnormal value based on the first quartile and the second quartile; For each position, the DC component of the position is determined based on the average value of multiple signal values ​​of the position, or based on the average value of all signal values ​​of the first original time domain signal, or based on the average value of all signal values ​​of the first original time domain signal and the first historical time domain signal.

7. A flow rate determination device, characterized in that: A first transducer and a second transducer are respectively installed on both sides of the pipeline. When the fluid passes through the pipeline, the first transducer sends ultrasonic waves to the second transducer, and the second transducer sends ultrasonic waves to the first transducer. The device includes: An acquisition module, configured to acquire a first original time domain signal acquired by a first transducer and a second original time domain signal acquired by a second transducer; perform a frequency domain transformation based on the first original time domain signal to obtain a first target frequency domain signal, and perform a frequency domain transformation based on the second original time domain signal to obtain a second target frequency domain signal; a determination module, configured to determine a first mutual correlation frequency domain signal based on the first target frequency domain signal and the second target frequency domain signal, and determine a target mutual correlation frequency domain signal based on the first mutual correlation frequency domain signal; A processing module, configured to perform a time domain transformation based on the target cross-correlation frequency domain signal to obtain a cross-correlation time domain signal, wherein the cross-correlation time domain signal includes signal values ​​at multiple positions; determine a flight time difference based on the target position corresponding to the maximum signal value; wherein the flight time difference is a time difference between the propagation of the ultrasonic wave in the downstream direction and the upstream direction; and the flight time difference is used to determine the flow velocity of the fluid when it passes through the pipeline; Among them, when the determination module determines the target mutual correlation frequency domain signal based on the first mutual correlation frequency domain signal, it is specifically used to: move the zero-frequency component in the first mutual correlation frequency domain signal to the frequency center to obtain the second mutual correlation frequency domain signal, and filter the second mutual correlation frequency domain signal to obtain the filtered frequency domain signal; set the amplitude of the frequency corresponding to the noise signal in the filtered frequency domain signal to 0 to obtain the third mutual correlation frequency domain signal, perform frequency domain interpolation on the third mutual correlation frequency domain signal to obtain the fourth mutual correlation frequency domain signal, and determine the fourth mutual correlation frequency domain signal as the target mutual correlation frequency domain signal.

8. The device according to claim 7, characterized in that in, When the determination module determines the first mutually correlated frequency domain signal based on the first target frequency domain signal and the second target frequency domain signal, it is specifically used to: determine the first complex conjugate frequency domain signal of the first target frequency domain signal, and perform a convolution operation on the first complex conjugate frequency domain signal and the second target frequency domain signal to obtain the first mutually correlated frequency domain signal; or determine the second complex conjugate frequency domain signal of the second target frequency domain signal, and perform a convolution operation on the first target frequency domain signal and the second complex conjugate frequency domain signal to obtain the first mutually correlated frequency domain signal; The filtered frequency domain signal includes amplitudes of multiple frequencies, and for each frequency, if the frequency is less than a first frequency value, or the frequency is greater than a second frequency value, then the frequency is a frequency corresponding to the noise signal; wherein the first frequency value is determined based on a configured sampling frequency and a first coefficient, the first coefficient is greater than 0 and the first coefficient is less than 1, and the second frequency value is determined based on the configured sampling frequency and the second coefficient, and the second coefficient is greater than 1; When the third mutually correlated frequency domain signal is subjected to frequency domain interpolation to obtain a fourth mutually correlated frequency domain signal, the third mutually correlated frequency domain signal includes L The fourth cross-correlation frequency domain signal includes L1 The amplitude of the frequency, and L1 Greater than L ; Wherein, for the first k frequency, k The values ​​are from 0 to L1-1 The determination module determines the first k The target amplitude of the frequency: L The value of is an odd number. When , the target amplitude is the first k The amplitude of a frequency; or, When , the target amplitude is 0; or When , the target amplitude is the first k the amplitude of a frequency; or, like L The value of is an even number. When , the target amplitude is the first k The amplitude of a frequency; or, When , the target amplitude is the first k half the amplitude of the frequency; or, When , the target amplitude is 0; or When , the target amplitude is the first half the amplitude of the frequency; or, When , the target amplitude is the first k The amplitude of a frequency; Wherein, when the processing module determines the flight time difference based on the target position corresponding to the maximum signal value, it is specifically used to: determine the flight time difference based on the target position corresponding to the maximum signal value, the total number of positions in the cross-correlated time domain signal and the configured target resolution of the flight time difference; wherein, the processing module determines the flight time difference using the following formula: ; in, represents the flight time difference, Indicates that the target position is the first Locations, represents the total number of positions, represents the target resolution; Wherein, when the acquisition module performs frequency domain transformation based on the first original time domain signal to obtain the first target frequency domain signal, it is specifically used to: preprocess the first original time domain signal to obtain the first target time domain signal, filter the first target time domain signal to obtain the first filtered time domain signal; perform frequency domain transformation on the first filtered time domain signal to obtain the first original frequency domain signal, and set the amplitude of the frequency corresponding to the noise signal in the first original frequency domain signal to 0 to obtain the first target frequency domain signal; Wherein, when the acquisition module preprocesses the first original time domain signal to obtain the first target time domain signal, it is specifically used to: delete the abnormal values ​​in the first original time domain signal to obtain the first target time domain signal; or, remove the DC component in the first original time domain signal to obtain the first target time domain signal; or, delete the abnormal values ​​in the first original time domain signal, and remove the DC component in the first original time domain signal to obtain the first target time domain signal; wherein, the first original time domain signal includes signal values ​​at multiple positions; for each position, multiple signal values ​​at the position are selected from the first original time domain signal and the first historical time domain signal, and a first quartile and a second quartile are determined based on the multiple signal values; based on the first quartile and the second quartile, determine whether the signal value at the position is an abnormal value; For each position, the DC component of the position is determined based on the average value of multiple signal values ​​of the position, or based on the average value of all signal values ​​of the first original time domain signal, or based on the average value of all signal values ​​of the first original time domain signal and the first historical time domain signal.

9. An electronic device, characterized in that: include: a processor and a machine-readable storage medium storing machine-executable instructions executable by the processor; The processor is used to execute machine executable instructions to implement the method described in any one of claims 1-6.

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