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CN-115656933-B - Method and device for measuring water surface flow velocity under severe weather conditions

CN115656933BCN 115656933 BCN115656933 BCN 115656933BCN-115656933-B

Abstract

The invention belongs to the technical field of water flow velocity measurement, and provides a water flow velocity measurement method for severe weather conditions, which comprises a first radio frequency chip and a second radio frequency chip, wherein the first radio frequency chip transmits first electromagnetic waves to the water surface and receives echo signals of the first electromagnetic waves reflected by the water surface; the main control chip utilizes the echo signal of the second electromagnetic wave as the local oscillation signal of the first electromagnetic wave to carry out frequency mixing, and obtains Doppler frequency shift signals of the first electromagnetic wave relative to the water surface after low-pass filtering to obtain flow velocity information of the water surface. The method can improve the accuracy and reliability of flow velocity and flow information of the millimeter wave radar flowmeter under the weather conditions, reduce the influence on the flow velocity and flow measurement of the millimeter wave radar when the millimeter wave radar flowmeter blows and rains, and also designs a device according to the method, so that the real flow velocity data of water flow can be measured.

Inventors

  • WANG XING

Assignees

  • 智驰华芯(无锡)传感科技有限公司

Dates

Publication Date
20260512
Application Date
20220919

Claims (9)

  1. 1. A method for measuring the flow rate of water surface in severe weather conditions is characterized by comprising a first radio frequency chip (21) and a second radio frequency chip (22), The first radio frequency chip (21) transmits the first electromagnetic wave (3) to the water surface (6) and receives an echo signal reflected by the first electromagnetic wave (3) through the water surface (6); The second radio frequency chip (22) emits a second electromagnetic wave (4) to the unobscured sky and receives an echo signal of the second electromagnetic wave (4); The main control chip mixes the frequencies by using the echo signals of the second electromagnetic waves (4) as local oscillation signals of the first electromagnetic waves (3), and obtains Doppler frequency shift signals of the first electromagnetic waves (3) relative to the water surface (6) after low-pass filtering to obtain flow velocity information of the water surface (6); The bad weather is weather and snow.
  2. 2. The method for measuring the flow rate of the water surface in response to severe weather conditions according to claim 1, comprising an ultrasonic probe (23), wherein the ultrasonic probe (23) transmits and receives ultrasonic waves (5) in a group of two probes of opposite angles, and the main control chip calculates the wind speed by using the time difference between the transmission and the reception of the ultrasonic waves (5).
  3. 3. The method for measuring the flow rate of the water surface in response to severe weather conditions according to claim 2, wherein the mixing formula is: ; Wherein the method comprises the steps of Is an influencing factor for the surface flow rate, Is an influencing factor of wind speed.
  4. 4. The method for measuring the water surface flow rate under severe weather conditions according to claim 1, wherein the main control chip (2) converts the signal into a discrete digital form, removes the direct current component of the discrete signal, and obtains the Doppler frequency through Fourier transform calculation.
  5. 5. A method of measuring a water surface flow rate in response to severe weather conditions according to claim 3, wherein the formula of the water surface flow rate affected by the wind speed is: ; Wherein the method comprises the steps of In order to transmit the amplitude of the signal, For the water surface flow velocity doppler shift angular frequency, The additional doppler shift angular frequency generated by the wind on the water surface is represented by t, which is time, Representing the time delay of the return signal, Is the flow velocity of the water body affected by the wind speed.
  6. 6. The method for measuring the water flow rate in response to severe weather conditions according to claim 5, wherein the formula of the water flow rate for eliminating the influence of wind speed is: ; Wherein the method comprises the steps of Is the surface flow velocity obtained by the radar wave, Is the wind speed measured by ultrasonic waves, Is the water flow rate for eliminating the influence of wind speed.
  7. 7. The device according to any one of claims 1-6, comprising a radar flow meter, an ultrasonic anemometer and a main control chip, wherein the radar flow meter is internally provided with a first radio frequency chip (21) and a second radio frequency chip (22), and the ultrasonic anemometer is internally provided with an ultrasonic probe (23).
  8. 8. The device for measuring the flow rate of the water surface against severe weather conditions according to claim 7, wherein the ultrasonic probe (23) has two or more sets of a transmitting end and a receiving end.
  9. 9. A water surface flow rate measuring device against severe weather conditions according to claim 7, further comprising a mounting bracket (1) and a housing (2), wherein the housing (2) integrates a radar flow rate meter and an ultrasonic anemometer inside and is suspended at a fixed depression angle on the mounting bracket (1) on the shore.

Description

Method and device for measuring water surface flow velocity under severe weather conditions Technical Field The invention belongs to the technical field of water flow velocity measurement, and particularly relates to a water flow velocity measurement method and device for severe weather conditions. Background The non-contact Doppler radar flow velocity meter is a flow measuring device for obtaining the liquid level flow velocity based on the Doppler principle by calculating the frequency difference value of a received echo signal and an emitted electromagnetic wave signal. The remote control device is simple in operation, can control and communicate at a remote end, is not influenced by sediment and sewage corrosion, has long service life and low maintenance cost, and has been widely applied to the fields of hydrology and water conservancy in recent years. At present, in application scenes such as a canal, a river channel and the like, a Doppler radar flow velocity meter is usually installed at a central line position, emits pulses along a water flow direction, and collects echo signals for calculation. Since the k-band radar wavelength is about 1cm, the distance below the water surface at which the radar wave can be incident is not more than one wavelength, and the measured flow velocity value can be regarded as the surface flow velocity value of the water body. The surface flow velocity of the water body often deviates from the average flow velocity of the water body under the influence of factors such as wind speed and the like, and the radar flow velocity meter cannot acquire an accurate flow velocity value at the moment. Meanwhile, due to the influence of rainfall and snowfall, the measurement of the water flow velocity is also influenced, and measurement deviation is caused. There is a need for a method and apparatus for measuring water flow rate in severe weather conditions, which removes the effects of rainfall and snowfall and wind speed, and measures real water flow rate data. Disclosure of Invention The invention aims to remove the influence of rainfall, snowfall and wind speed, measure real water flow velocity data, and mainly perform the measurement from two aspects, wherein in the first aspect, the water flow velocity measurement method for severe weather conditions comprises a first radio frequency chip 21 and a second radio frequency chip 22, wherein the first radio frequency chip 21 transmits a first electromagnetic wave 3 to a water surface 6 and receives an echo signal of the first electromagnetic wave 3 reflected by the water surface 6, the second radio frequency chip 22 transmits a second electromagnetic wave 4 to an unobstructed sky and receives an echo signal of the second electromagnetic wave 4, and a main control chip mixes by using the echo signal of the second electromagnetic wave 4 as a local oscillation signal of the first electromagnetic wave 3, and obtains Doppler frequency shift signals of the first electromagnetic wave 3 relative to the water surface 6 after low-pass filtering to obtain flow velocity information of the water surface 6. Further, the wind speed measuring device comprises an ultrasonic probe 23, wherein the ultrasonic probe 23 sends and receives ultrasonic waves 5 by using two probes at opposite angles as a group, and the main control chip calculates the wind speed by using the time difference between the sending and receiving of the ultrasonic waves 5. Further, the mixing formula is: Further, the main control chip 2 converts the signal into a discrete digital form, removes the direct current component of the discrete signal, and obtains the Doppler frequency through Fourier transform calculation. Further, the formula of the water body surface flow rate influenced by the wind speed is x (t) =acos [ (omega d+ωw) t+θ ]. Further, the water flow rate formula for eliminating the influence of wind speed is v (t) =αv 1(t)±βv2 (t). In a second aspect, a water surface flow velocity measuring device for severe weather conditions is provided, which comprises a radar flow velocity meter, an ultrasonic anemometer and a main control chip, wherein a first radio frequency chip 21 and a second radio frequency chip 22 are arranged in the radar flow velocity meter, and an ultrasonic probe 23 is arranged in the ultrasonic anemometer. Further, the ultrasonic probe 23 is provided with two or more sets of a transmitting end and a receiving end. Further, the device also comprises a mounting bracket 1 and a shell 2, wherein the radar flow rate meter and the ultrasonic anemometer are integrated inside the shell 2 and are hung on the mounting bracket 1 on the shore at a fixed depression angle. The beneficial effects are that: the method can improve the accuracy and reliability of the flow velocity and flow information of the millimeter wave radar flowmeter under the weather conditions, and reduce the influence on the flow velocity and flow measurement of the millimeter wave radar when th