High-stability radar flowmeter data acquisition method and radar flowmeter

Abstract

The invention discloses a high-stability radar flowmeter data acquisition method and a radar flowmeter, relates to the technical field of radar flowmeters, and solves the technical problem of unstable data acquisition results. The method comprises the steps that a radar flowmeter starts to collect an I-channel original signal and a Q-channel original signal, and frequency-selecting amplification of the signals is carried out respectively; the working temperature T of the radar flowmeter is measured, and the gain G of the programmable gain amplifier is determined; performing PGA amplification on the I channel original signal and the Q channel original signal after frequency selection amplification based on a gain selection range; the phase difference between the phase phi 1 and the phase phi 2 is converted into a voltage signal Vf through a phase frequency detector PFD, the voltage signal Vf is converted into a frequency signal F3 through a voltage-frequency converter VFC, and the phase difference delta phi = phi 1-phi 2 is obtained; and comparing the phase difference delta phi with a phase difference threshold value phi s, and judging whether phase compensation is carried out or not. The PGA amplification factor is adjusted based on the temperature, phase compensation can be carried out on the waveform, and the stability of collected data is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of radar flowmeter, and particularly relates to a high-stability radar flowmeter data acquisition method and radar flowmeter. BACKGROUND

[0002] The radar flowmeter is an online measuring instrument for measuring liquid level and flow rate simultaneously in a non-contact manner by using microwave technology and converting the flow rate into flow rate, and according to the built-in software algorithm, the instantaneous cross-sectional flow rate and cumulative flow rate are calculated and output, and the flow rate and water level can be output simultaneously, and in recent years, the radar flowmeter is widely applied to scenes such as open channels, river channels, irrigation channels and urban drainage pipe networks.

[0003] When the existing radar flowmeter acquires data, frequency leakage of low-noise operational amplifier or PGA (Programmable Gain Amplifier) occurs in an extremely low-temperature environment, and phase error of I / Q two-way signals (In-phase and Quadrature two-way signals are core data used for completely describing echo amplitude and phase in the radar flowmeter) is caused by circuit delay or external interference, so that the data acquisition result of the radar flowmeter is unstable, and a high-stability radar flowmeter data acquisition method is urgently needed.

[0004] In the process of realizing the present application, the inventors found that at least the following problems exist in the prior art: When the existing radar flowmeter acquires data, frequency leakage of low-noise operational amplifier or PGA occurs in an extremely low-temperature environment, and phase error of I / Q two-way signals is caused by circuit delay or external interference, so that the data acquisition result is unstable. SUMMARY

[0005] The present application aims to provide a high-stability radar flowmeter data acquisition method and radar flowmeter to solve the technical problem that in the prior art, when the radar flowmeter acquires data, frequency leakage of low-noise operational amplifier or PGA occurs in an extremely low-temperature environment, and phase error of I / Q two-way signals is caused by circuit delay or external interference, so that the data acquisition result is unstable. The preferred technical solutions in the technical solutions provided by the present application can produce the technical effects described below.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions: The application provides a high-stability radar flowmeter data acquisition method, which comprises the following steps: S100, a radar flowmeter starts to collect I-channel original signals and Q-channel original signals and performs frequency selection and amplification on the signals respectively; S200, the working temperature T of the radar flowmeter is measured, if the working temperature T is greater than or equal to a preset temperature T1, the gain G of a programmable gain amplifier is selected to be a full range, otherwise the gain G of the programmable gain amplifier is selected to be a preset gain range G1; S300, the I-channel original signals and the Q-channel original signals after frequency selection and amplification are amplified by PGA based on the gain selection range, and I-channel digital signals and Q-channel digital signals are obtained after ADC signal conversion, the frequency and the phase of the I-channel digital signals are F1 and φ1 respectively, and the frequency and the phase of the Q-channel digital signals are F2 and φ2 respectively; S400, the phase difference between the phase φ1 and the phase φ2 of the I-channel digital signals and the Q-channel digital signals is converted into a voltage signal Vf by a frequency and phase discriminator PFD, the voltage signal Vf is converted into a frequency signal F3 by a voltage-to-frequency converter VFC, and the phase difference |Δφ|=|φ1-φ2| of the I-channel digital signals and the Q-channel digital signals is obtained according to the relationship between the frequency signal F3 and the phase difference Δφ; S500, the phase difference |Δφ| is compared with a phase difference threshold φs to determine whether the waveforms of the I-channel digital signals or the Q-channel digital signals need to be phase compensated, if yes, phase compensation is performed and then S600 is executed, otherwise S600 is directly executed; S600, the frequencies F1 and F2 of the two signals are compared, if the frequency difference |ΔF|=|F1-F2| is within a frequency difference threshold Fs, accurate I-channel signals and accurate Q-channel signals are obtained, if the frequency difference |ΔF|=|F1-F2| is not within the frequency difference threshold Fs, the I-channel digital signals and the Q-channel digital signals are abnormal signals and the next group of signals is waited.

[0007] Preferably, in the step S500, the judgment rule of whether the waveforms of the I-channel digital signals and the Q-channel digital signals need to be phase compensated is that if the phase difference |Δφ| of the I-channel digital signals and the Q-channel digital signals is within the range of the phase difference threshold φs, the phase relationship of the two signals is correct and no phase compensation is needed, if the phase difference |Δφ| of the I-channel digital signals and the Q-channel digital signals is out of the range of the phase difference threshold φs, the phase of the I-channel digital signals or the Q-channel digital signals is abnormal, and the waveforms of the I-channel digital signals or the Q-channel digital signals are phase compensated by the phase difference |Δφ| so that the phase difference |Δφ| of the two signals is within the range of the phase difference threshold φs.

[0008] Preferably, the phase difference threshold φs is 10°.

[0009] Preferably, in step S200, when the working temperature is greater than or equal to -10℃, the gain G is full range, and when the working temperature T is less than -10℃, the preset gain range G1 is less than 50.

[0010] A high-stability radar flowmeter for implementing the high-stability radar flowmeter data acquisition method of any one of Embodiment One, comprising a power module, a main controller, a speed measurement module, a distance measurement module, a temperature sensor, a communication module, and a gyroscope; the power module is used for power supply of the radar flowmeter; the speed measurement module, the distance measurement module, the temperature sensor, the gyroscope, and the communication module are all connected with the main controller, and the main controller is of the STM32U575VI type; the speed measurement module is used for acquiring flow speed, and the distance measurement module is used for acquiring flow height; the temperature sensor is used for acquiring the working temperature of the radar flowmeter and is connected with the speed measurement module and the distance measurement module; the communication module is used for wireless or wired communication; and the gyroscope is used for auxiliary installation and positioning of the radar flowmeter.

[0011] Preferably, the communication module comprises a 4G unit, a Bluetooth unit, and an RS485 unit; the 4G unit and the RS485 unit are connected with the main controller through USART protocol, and the 4G unit is connected with the main controller through UART protocol; the 4G unit is used for receiving data acquisition instructions and uploading acquired data; the Bluetooth unit is used for wireless connection with a mobile device for debugging or parameter configuration; and the RS485 unit is used for communication debugging with external devices.

[0012] Preferably, the power module is a hybrid power supply architecture of a switching power supply and a low-dropout linear regulator; a first-stage total power supply of the power module is powered by the switching power supply, and the switching frequency of the switching power supply is mutually avoided with the measurement frequency of radar speed signals and radar distance signals; a second-stage power supply of the power module is powered by a plurality of low-dropout linear regulators, and the main controller, the speed measurement module, the distance measurement module, the gyroscope, and the temperature sensor of the radar flowmeter are respectively powered by independent low-dropout linear regulators.

[0013] Preferably, the speed measurement module comprises a speed measurement frequency selection and amplification circuit and a PGA circuit; the speed measurement frequency selection and amplification circuit performs frequency selection and amplification on I-channel original signals and Q-channel original signals; and the PGA circuit performs PGA amplification on the I-channel original signals and the Q-channel original signals after frequency selection and amplification; the speed measurement controller of the speed measurement frequency selection and amplification circuit is MS8094T, and the amplified I-channel original signals and Q-channel original signals are input into a PGA1113 chip of the PGA circuit through a capacitor C102 and a resistor R157 and a capacitor C105 and a resistor R160, respectively.

[0014] Preferably, after the speed measurement frequency selective amplifier circuit is powered on, the flow velocity data is acquired with a delay based on the capacitance values ​​of capacitors C102 and C105.

[0015] Preferably, the PGA1113 chip is connected to the main controller via the SPI protocol.

[0016] Implementing one of the above-described technical solutions of the present invention has the following advantages or beneficial effects: This invention measures the operating temperature T of a radar flow meter and adjusts the amplification factor of a low-noise operational amplifier or PGA by adjusting the temperature. This solves the problem of equipment instability caused by frequency leakage of the low-noise operational amplifier or PGA in extreme low-temperature environments. At the same time, it can also perform phase compensation on the waveform of the I-channel digital signal or the Q-channel digital signal, thereby improving the stability of the acquired data. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 This is a flowchart of a high-stability radar flowmeter data acquisition method according to Embodiment 1 of the present invention; Figure 2 This is the noise floor spectrum of the device when the operating temperature is -20 degrees and the programmable gain amplifier gain is 20 times in a high-stability radar flow meter data acquisition method according to Embodiment 1 of the present invention. Figure 3 This is the noise floor spectrum of the device when the operating temperature is -20 degrees and the programmable gain amplifier gain is 50 times in a high-stability radar flowmeter data acquisition method according to Embodiment 1 of the present invention. Figure 4 This is a circuit block diagram of a high-stability radar flow meter according to Embodiment 2 of the present invention; Figure 5 This is a schematic diagram of the power supply module of a high-stability radar flowmeter according to Embodiment 2 of the present invention; Figure 6 This is a circuit diagram of the speed measurement frequency selective amplifier circuit of the speed measurement module in a high-stability radar flowmeter according to Embodiment 2 of the present invention; Figure 7 This is the PGA circuit of the velocity measurement module in a high-stability radar flowmeter according to Embodiment 2 of the present invention. Figure 1 ; Figure 8 This is the PGA circuit of the velocity measurement module in a high-stability radar flowmeter according to Embodiment 2 of the present invention. Figure 2 ; Figure 9 is a data floor noise chart of a first frame and a second frame of data collected after power-on of a high-stability radar flowmeter according to Embodiment Two of the present application. DETAILED DESCRIPTION

[0018] In order to make the objects, technical solutions and advantages of the present application clearer, the various exemplary embodiments to be described below will be described with reference to the corresponding drawings, which form part of the exemplary embodiments, and various exemplary embodiments that can be used to implement the present application are described. Unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. It should be understood that they are only examples of processes, methods and devices, etc. consistent with some aspects of the present disclosure as detailed in the appended claims, and other embodiments can be used, or structural and functional modifications can be made to the embodiments listed herein, without departing from the scope and spirit of the present application.

[0019] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the elements referred to must have a particular orientation, be constructed and operated in a particular orientation. The terms "first", "second" and the like are only for descriptive purposes and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. The term "a plurality of" means two or more. The terms "connected", "connected" should be interpreted broadly, for example, it can be fixed connection, detachable connection, integral connection, mechanical connection, electrical connection, communication connection, direct connection, indirect connection through intermediate medium, internal communication of two elements or interaction relationship between two elements. The term "and / or" includes any and all combinations of one or more related listed items. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0020] In order to illustrate the technical solutions described in the present application, the following will be described by specific embodiments, only showing the parts related to the embodiments of the present application.

[0021] Embodiment One: As Figure 1As shown, this invention provides a high-stability radar flowmeter data acquisition method, including the following steps: S100: The radar flowmeter begins to acquire the raw signals of the I channel and the Q channel, and performs frequency-selective amplification of the signals respectively; S200: The operating temperature T of the radar flowmeter is measured. If it is greater than or equal to the preset temperature T1, the gain G of the programmable gain amplifier is selected to be in the full range; otherwise, the gain G of the programmable gain amplifier is selected to be in the preset gain range G1. The amplification factor of the low-noise operational amplifier or PGA is adjusted by temperature, thereby solving the problem of unstable equipment testing caused by frequency leakage of the low-noise operational amplifier or PGA in extreme low-temperature environments. S300: Based on the gain selection range, the original I-channel and Q-channel signals after frequency selection amplification are amplified by PGA, and then converted by ADC signal to obtain the I-channel digital signal and Q-channel digital signal. The frequency and phase of the I-channel digital signal are F1 and φ1, respectively, and the frequency and phase of the Q-channel digital signal are F2 and φ2, respectively. S400: The phase difference between phases φ1 and φ2 of the I-channel and Q-channel digital signals is converted into a voltage signal Vf by a frequency and phase detector (PFD). The voltage signal Vf is then converted into a frequency signal F3 by a voltage-to-frequency converter (VFC). The phase difference |Δφ| between the I-channel and Q-channel digital signals is obtained according to the relationship between the frequency signal F3 and the phase difference Δφ. Due to the differences between the two acquisition links of the I-channel and Q-channel on the PCB board and external abnormal interference, the phase difference Δφ between the two may deviate from 90°. This deviation needs to be compensated to improve the stability and reliability of data acquisition. S500: Compare the phase difference |Δφ| with the phase difference threshold φs to determine whether phase compensation is needed for the waveforms of the I-channel or Q-channel digital signals. If so, perform phase compensation and then execute S600; otherwise, execute S600 directly. S600: Compare the frequencies F1 and F2 of the two signals. If the frequency difference |ΔF| = |F1 - F2| is within the frequency difference threshold Fs (where Fs is a safe threshold and does not affect the correct acquisition of the I-channel and Q-channel signals, it can be set as needed to obtain accurate I-channel and Q-channel signals), then the I-channel and Q-channel digital signals are abnormal signals, and the system waits for the next set of signals. This invention measures the operating temperature T of a radar flow meter and adjusts the amplification factor of a low-noise operational amplifier or PGA by adjusting the temperature. This solves the problem of equipment instability caused by frequency leakage of the low-noise operational amplifier or PGA in extreme low-temperature environments. At the same time, it can also perform phase compensation on the waveform of the I-channel digital signal or the Q-channel digital signal, thereby improving the stability of the acquired data.

[0022] As an optional implementation, in step S500, the rule for determining whether phase compensation is needed for the waveforms of the I-channel digital signal and the Q-channel digital signal is as follows: if the phase difference |Δφ| between the I-channel digital signal and the Q-channel digital signal is within the range of the phase difference threshold φs, then the phase relationship between the two signals is correct and phase compensation is not required; if the phase difference |Δφ| between the I-channel digital signal and the Q-channel digital signal is outside the range of the phase difference threshold φs, it is determined that the phase of the I-channel digital signal and the Q-channel digital signal is abnormal, and phase compensation is performed on the waveforms of the I-channel digital signal or the Q-channel digital signal using the phase difference |Δφ|, so that the phase difference |Δφ| between the two signals is within the range of the phase difference threshold φs.

[0023] As an optional implementation, the phase difference threshold φs is 10°. When the phase difference between the I-channel digital signal and the Q-channel digital signal is within 10°, the acquired signal itself achieves high stability and high reliability. Therefore, phase compensation of the waveforms of the I-channel and Q-channel digital signals is unnecessary. Of course, in actual operation, the phase difference threshold φs can be finely adjusted from 10° according to the usage scenario to achieve more stable and reliable data acquisition.

[0024] As an optional implementation, in step S200, when the operating temperature is greater than or equal to -10℃, the gain G is in the full range; when the operating temperature T is less than -10℃, the preset gain range G1 < 50. If the operating temperature T collected by the temperature sensor is greater than or equal to (T1 = -10℃), the gain G of the PGA in the full range {in the PGA1113 chip, PGA=7 (G1 = 200 times), PGA=6 (G1 = 100 times), PGA=5 (G1 = 50 times), PGA=4 (G1 = 20 times), PGA=3 (G1 = 10 times), PGA=2 (G1 = 5 times), PGA=1 (G1 = 2 times), PGA=0 (G1 = 1 times)} will not cause a sudden increase in the noise of the device itself (noise is normal). If the operating temperature T collected by the temperature sensor is less than or equal to -10℃ (e.g., T1 = -20℃), the noise floor increases with the amplification of the PGA gain. Specifically, the noise floor is normal when PGA = 4 (G1 = 20 times), PGA = 3 (G1 = 10 times), PGA = 2 (G1 = 5 times), PGA = 1 (G1 = 2 times), and PGA = 0 (G1 = 1 times). However, when PGA = 5 (G1 = 50 times), the noise floor becomes significantly abnormal. Figure 2 , Figure 3 As shown, under the condition of T1=-20℃, in order to ensure normal noise floor, PGA<5 (gain factor less than 50) needs to be set.

[0025] The embodiment is merely a specific example and does not indicate that this is the only way to implement the present invention.

[0026] Example 2: A high-stability radar flow meter is used to operate the high-stability radar flow meter data acquisition method described in Embodiment 1, such as... Figure 4 As shown, the system includes a power supply module, a main controller, a speed measurement module, a distance measurement module, a temperature sensor, a communication module, and a gyroscope. The power supply module provides power to the radar flow meter. The speed measurement module, distance measurement module, temperature sensor, gyroscope, and communication module are all connected to the main controller, which is an STM32U575VI. The speed measurement module is used to collect flow rate data, and the distance measurement module is used to collect flow height data. The temperature sensor is used to collect the operating temperature of the radar flow meter and is connected to the speed measurement module and distance measurement module. The communication module is used for wireless or wired communication, and the gyroscope is used for auxiliary installation and positioning of the radar flow meter.

[0027] As an optional implementation, the communication module includes a 4G unit, a Bluetooth unit, and an RS485 unit. The 4G unit and the RS485 unit are both connected to the main controller via the USART protocol, and the 4G unit is connected to the main controller via the UART protocol. The 4G unit is used to receive data acquisition commands and upload acquired data, the Bluetooth unit is used to wirelessly connect to mobile devices for debugging or parameter configuration, and the RS485 unit is used for communication debugging with external devices.

[0028] As an optional implementation method, radar measurement belongs to the field of precision measurement. The echo signals from radar ranging and velocity measurement are weak signals, and the background noise of the equipment's hardware system can significantly affect the measurement. A higher signal-to-noise ratio (SNR) of the radar measurement signal to its background noise is more conducive to stable and effective radar signal measurement. Therefore, if... Figure 5 As shown, the power supply module of this invention employs a hybrid power supply architecture combining a switching power supply and a low-dropout linear regulator. The first-stage main power supply of the power module is provided by a switching power supply. The switching frequency of the switching power supply avoids interference with the measurement frequencies of the radar speed and ranging signals, thus preventing the switching power supply from affecting radar measurements. For example, the radar speed signal measurement frequency range is 0~500kHz, and the switching frequency of the switching power supply can be selected to be above 1MHz. The second-stage power supply of the power module is provided by multiple low-dropout linear regulators. The main controller of the radar flowmeter, the speed measurement module, the ranging module, the gyroscope, and the temperature sensor are each powered by an independent low-dropout linear regulator, thereby preventing excessive power consumption in any single module from causing power fluctuations and affecting radar measurements.

[0029] As an optional implementation method, such as Figure 6-8As shown, the speed measurement module includes a speed measurement frequency selective amplifier circuit and a PGA circuit. The speed measurement frequency selective amplifier circuit performs frequency selective amplification on the original I-channel and Q-channel signals, and the PGA circuit performs PGA amplification on the frequency-selectively amplified original I-channel and Q-channel signals. The preferred speed controller for the speed measurement frequency selective amplifier circuit is the MS8094T. The MS8094T is a 350MHz rail-to-rail operational amplifier, an easy-to-use and low-cost rail-to-rail output voltage feedback amplifier. The speed controller inputs the amplified original I-channel and Q-channel signals to the PGA1113 chip of the PGA circuit through capacitor C102 and resistor R157, and capacitor C105 and resistor R160, respectively. For some application scenarios, the radar speed measurement module is required to measure extremely low flow velocities (as low as 0.03m / s). The frequency corresponding to a flow velocity of 0m / s is 0Hz. To meet the requirement of extremely low flow velocities (as low as 0.03m / s), the frequency range of the radar flow velocity acquisition signal should be as close to 0Hz as possible. In this invention, the initial measurement frequency of the radar flow velocity is determined by (C102, R157) and (C105, R160). According to the formula f=1 / (2πRC), the initial measurement frequency f=1 / (2πxC102xR157)=3.61Hz, which satisfies the requirement for low flow velocity measurement. However, the values ​​of C102 and C105 are 22µF, which will cause the radar flow velocity module acquisition circuit to charge C102 and C105 (on the order of milliseconds) every time it is powered on and off. Figure 9 As shown in the left-hand diagram, this causes a sudden increase in the noise floor of the first frame of data after power-on, affecting the stability of data measurement at low flow rates. In most applications, to achieve low power consumption (extending battery life to extend the device's lifespan), various acquisition modules need to be controlled. Modules are powered on when data acquisition is needed, and then the corresponding number of data frames are acquired; when not acquiring data, the modules are powered off. Therefore, to ensure the stability of data measurement at low flow rates, this invention, after powering on the radar flow rate acquisition link, delays the acquisition of flow rate data for a corresponding time (charge / discharge time). Specifically, after the speed measurement frequency selection amplifier circuit is powered on, the flow rate data is acquired with a delay based on the capacitance values ​​of capacitors C102 and C105 (when the circuit operating voltage is constant, the capacitance value determines the specific charge / discharge time). This avoids the impact of capacitor charging / discharging on the stability of data measurement at low flow rates.

[0030] As an optional implementation, the PGA1113 chip is connected to the main controller via the SPI protocol. The SPI protocol is a high-speed, full-duplex, synchronous serial communication protocol with advantages such as low power consumption, uninterrupted transmission, and reliable communication. Specifically, in this invention, the PGA1113 chip is connected to the main controller via the CS pin, DIO pin, and SCLK pin.

[0031] The above description is merely a preferred embodiment of the present invention. Those skilled in the art will understand that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the present invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. A high-stability radar flowmeter data acquisition method, characterized in that, Includes the following steps: S100: The radar flow meter begins to acquire the raw signals from the I channel and the Q channel, and performs frequency-selective amplification on the signals respectively; S200: Measure the operating temperature T of the radar flow meter. If it is greater than or equal to the preset temperature T1, select the full range of the gain G of the programmable gain amplifier; otherwise, select the preset gain range G1 of the gain G of the programmable gain amplifier. S300: Based on the gain selection range, the original I-channel signal and the original Q-channel signal after frequency selection amplification are respectively amplified by PGA, and after ADC signal conversion, the I-channel digital signal and the Q-channel digital signal are obtained. The frequency and phase of the I-channel digital signal are F1 and φ1, respectively, and the frequency and phase of the Q-channel digital signal are F2 and φ2, respectively. S400: The phase difference between phases φ1 and φ2 of the I-channel digital signal and the Q-channel digital signal is converted into a voltage signal Vf by the phase detector PFD. The voltage signal Vf is then converted into a frequency signal F3 by the voltage-to-frequency converter VFC. The phase difference between the I-channel digital signal and the Q-channel digital signal is obtained by the relationship between the frequency signal F3 and the phase difference Δφ: |Δφ|=|φ1-φ2|. S500: Compare the phase difference |Δφ| with the phase difference threshold φs to determine whether phase compensation is needed for the waveform of the I-channel digital signal or the Q-channel digital signal. If so, perform phase compensation and then execute S600; otherwise, execute S600 directly. S600: Compare the frequencies F1 and F2 of the two signals. If the frequency difference |ΔF|=|F1-F2| is within the frequency difference threshold Fs, the accurate I-channel signal and the accurate Q-channel signal are obtained. If the frequency difference |ΔF|=|F1-F2| is within the frequency difference threshold Fs, the I-channel digital signal and the Q-channel digital signal of this group are abnormal signals, and the system waits for the next group of signals.

2. The high-stability radar flowmeter data acquisition method according to claim 1, characterized in that, In step S500, the rule for determining whether phase compensation is needed for the waveforms of the I-channel digital signal and the Q-channel digital signal is as follows: If the phase difference |Δφ| between the I-channel digital signal and the Q-channel digital signal is within the range of the phase difference threshold φs, then the phase relationship between the two signals is correct and no phase compensation is required. If the phase difference |Δφ| between the I-channel digital signal and the Q-channel digital signal is outside the phase difference threshold φs, it is determined that the phase of the I-channel digital signal and the Q-channel digital signal is abnormal. Phase compensation is performed on the waveform of the I-channel digital signal or the Q-channel digital signal by using the phase difference |Δφ|, so that the phase difference |Δφ| between the two signals is within the phase difference threshold φs.

3. The high-stability radar flowmeter data acquisition method according to claim 2, characterized in that, The phase difference threshold φs is 10°.

4. The high-stability radar flowmeter data acquisition method according to claim 1, characterized in that, In step S200, when the operating temperature is greater than or equal to -10℃, the gain G is in the full range; when the operating temperature T is less than -10℃, the preset gain range G1 < 50.

5. A high-stability radar flow meter, characterized in that, A high-stability radar flowmeter data acquisition method according to any one of claims 1-4 includes a power module, a main controller, a speed measurement module, a distance measurement module, a temperature sensor, a communication module, and a gyroscope; the power module is used to supply power to the radar flowmeter; the speed measurement module, distance measurement module, temperature sensor, gyroscope, and communication module are all connected to the main controller, the main controller being an STM32U575VI; the speed measurement module is used to acquire flow rate, the distance measurement module is used to acquire flow height; the temperature sensor is used to acquire the operating temperature of the radar flowmeter and is connected to the speed measurement module and the distance measurement module; the communication module is used for wireless or wired communication; and the gyroscope is used for auxiliary installation and positioning of the radar flowmeter.

6. A high-stability radar flowmeter according to claim 5, characterized in that, The communication module includes a 4G unit, a Bluetooth unit, and an RS485 unit. The 4G unit and the RS485 unit are both connected to the main controller via the USART protocol, and the 4G unit is connected to the main controller via the UART protocol. The 4G unit is used to receive data acquisition commands and upload acquired data. The Bluetooth unit is used to wirelessly connect to mobile devices for debugging or parameter configuration. The RS485 unit is used for communication debugging with external devices.

7. A high-stability radar flowmeter according to claim 5, characterized in that, The power supply module is a hybrid power supply architecture consisting of a switching power supply and a low-dropout linear regulator. The first-stage main power supply of the power supply module is supplied through the switching power supply, and the switching frequency of the switching power supply avoids the measurement frequencies of the radar speed measurement signal and the radar ranging signal. The second-stage power supply of the power supply module is supplied through multiple low-dropout linear regulators. The main controller, speed measurement module, ranging module, gyroscope, and temperature sensor of the radar flow meter are each supplied through an independent low-dropout linear regulator.

8. A high-stability radar flowmeter according to claim 5, characterized in that, The speed measurement module includes a speed measurement frequency selective amplifier circuit and a PGA circuit. The speed measurement frequency selective amplifier circuit performs frequency selective amplification on the original I-channel signal and the original Q-channel signal. The PGA circuit performs PGA amplification on the frequency selectively amplified original I-channel signal and the original Q-channel signal. The speed controller of the speed measurement frequency selective amplifier circuit is an MS8094T. The amplified original I-channel signal and the original Q-channel signal are input to the PGA1113 chip of the PGA circuit through capacitor C102 and resistor R157 and capacitor C105 and resistor R160, respectively.

9. A high-stability radar flowmeter according to claim 8, characterized in that, After the speed measurement frequency selective amplifier circuit is powered on, it performs delayed acquisition of flow velocity data based on the capacitance values ​​of capacitors C102 and C105.

10. A high-stability radar flowmeter according to claim 8, characterized in that, The PGA1113 chip is connected to the main controller via the SPI protocol.

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