CN112816972A - Water surface speed measuring radar speed sensor - Google Patents
Water surface speed measuring radar speed sensor Download PDFInfo
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- CN112816972A CN112816972A CN202011560093.5A CN202011560093A CN112816972A CN 112816972 A CN112816972 A CN 112816972A CN 202011560093 A CN202011560093 A CN 202011560093A CN 112816972 A CN112816972 A CN 112816972A
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 54
- 238000005070 sampling Methods 0.000 claims abstract description 55
- 238000012545 processing Methods 0.000 claims abstract description 35
- 238000001514 detection method Methods 0.000 claims abstract description 7
- 238000012935 Averaging Methods 0.000 claims description 18
- 238000006243 chemical reaction Methods 0.000 claims description 14
- 238000001228 spectrum Methods 0.000 claims description 6
- 238000001914 filtration Methods 0.000 claims description 4
- 238000012360 testing method Methods 0.000 claims description 4
- 230000003321 amplification Effects 0.000 claims description 3
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 3
- 238000004148 unit process Methods 0.000 claims description 2
- 238000012544 monitoring process Methods 0.000 abstract description 2
- 238000005259 measurement Methods 0.000 description 6
- 230000001133 acceleration Effects 0.000 description 2
- 230000002457 bidirectional effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000004519 grease Substances 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
- G01S13/50—Systems of measurement based on relative movement of target
- G01S13/58—Velocity or trajectory determination systems; Sense-of-movement determination systems
- G01S13/589—Velocity or trajectory determination systems; Sense-of-movement determination systems measuring the velocity vector
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Abstract
The invention discloses a water surface speed measuring radar speed sensor, and belongs to the technical field of hydrological monitoring. The device consists of a digital sampling unit, a millimeter wave radio frequency unit, a horn antenna and a signal processing unit. The water surface movement speed is calculated according to the received frequency shift quantity of the reflected wave and the transmitted wave, and is converted into the surface average flow speed through analysis and calculation, so that the measuring angle can be automatically sensed, and various water flow modes such as slow flow, splashing speed and the like are supported. The device is designed in a miniaturized, integrated and light manner, is light in weight, is mainly used for professional hydrologic, environmental-friendly and marine detection instruments, hydrologic and hydrologic regime automatic detection and reporting systems and the like, and is suitable for non-contact river flow detection and detection systems.
Description
Technical Field
The invention relates to the technical field of water surface speed measurement, in particular to a water surface speed measurement radar speed sensor.
Background
According to the statistics of the annual hydrological condition report (2015) of the Chinese hydrological grid, the current national basic hydrological stations are 3151 (mainly used for flow monitoring) and 3001 in total. A large number of adopted contact type rotor speed measuring systems observe and measure the flow velocity of rivers, lakes and seas. However, the contact type rotor speed measurement system puts the measuring device into water or is arranged on the water surface, because the measuring device is too high for the measuring environment, the measuring device cannot be normally used in many times.
Disclosure of Invention
In view of the above, the present invention provides a speed sensor for a speed measuring radar on a water surface. The sensor is not affected by temperature gradient, pressure, air density, wind or other meteorological environment conditions during working, and can stably provide service all the day long.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
a water surface speed measuring radar speed sensor comprises a digital sampling unit, a millimeter wave radio frequency unit, a horn antenna and a signal processing unit; the signal processing unit is provided with a data output port and a power input port; the signal processing unit is bidirectionally interconnected with the digital sampling unit, the horn antenna is bidirectionally interconnected with the millimeter wave radio frequency unit, and an output port of the millimeter wave radio frequency unit is connected with an input port of the digital sampling unit;
the horn antenna forms an included angle with the water surface, transmits radar signals to the water surface and receives reflected waves of the water surface; the horn antenna amplifies and outputs the microwave signal sent by the millimeter wave radio frequency unit and outputs the received water surface reflected wave to the millimeter wave radio frequency unit.
The millimeter wave radio frequency unit is used for generating a dot frequency or triangular wave linear frequency modulation signal of a Ka wave band and then sending the dot frequency or triangular wave linear frequency modulation signal to a horn antenna microwave signal; the millimeter wave radio frequency unit also receives the water surface reflected wave output of the horn antenna, and the millimeter wave radio frequency unit mixes the intermediate frequency signal to the digital sampling unit;
the digital sampling unit is used for receiving the signal from the millimeter wave radio frequency unit, amplifying the signal, performing analog-digital conversion on the signal, converting the signal into PCM data and sending the PCM data to the signal processing unit;
the signal processing unit processes the PCM data from the digital sampling unit to realize the spectrum detection of the received signal; and controlling the amplification gain of digital sampling, and obtaining the water flow rate on the surface of the river on the basis of the frequency spectrum of the received signal and the water surface included angle data.
Furthermore, the signal processing unit comprises a low-pass filter, a random access memory, a fast Fourier transform module, an averaging module, a maximum value calculating module, an operation module, an automatic gain control module, a storage module and an inclination angle measuring module; the data output port is connected with the operation module;
the low-pass filter, the random access memory module, the fast Fourier transform module, the averaging module, the maximum value solving module and the operation module are sequentially connected; the averaging module, the inclination angle measuring module, the automatic gain control module and the storage module are also connected with the operation module, wherein the storage module and the operation module are bidirectionally interconnected; the low-pass filter and the automatic gain control module are respectively connected with the digital sampling unit, wherein the automatic gain control module and the digital sampling unit are bidirectionally interconnected;
the low-pass filter finishes low-pass filtering on PCM data from the digital sampling unit and then stores the PCM data in the random access memory, the fast Fourier transform module reads the data in the random access memory and carries out fast Fourier transform, the averaging module averages the PCM data according to set time, the maximum value module finds out the maximum value of the averaged value, the inclination angle measuring module tests the inclination angle of the horn antenna, the operation module operates the output data of the averaging module, the maximum value calculating module and the inclination angle measuring module to obtain water flow speed, and the operation module stores the water flow speed in the storage module, reads the water flow speed from the storage module and sends the water flow speed to the data output port; the operation module also sends the gain control signal of the digital sampling unit to the automatic gain control module, and the automatic gain control module obtains the digital sampling gain and outputs the digital sampling gain to the digital sampling unit.
Furthermore, the signal processing unit further comprises a power supply conversion module; the power supply input port is connected with the power supply conversion module, and the power supply conversion module outputs current to the digital sampling unit and the millimeter wave radio frequency unit respectively.
The invention adopts the technical scheme to produce the beneficial effects that:
1. the millimeter wave radio frequency unit adopts a Ka frequency band, and has the advantages of narrow beam, high angular resolution and low background noise.
2. When the device is used, the device is far away from the water surface, the speed measuring environment is relatively stable, the speed measuring efficiency is high, and the device can be adapted to different water flows (slow flow, torrent, splash, wave and the like).
Drawings
FIG. 1 is an electrical schematic block diagram of an embodiment of the present invention.
Fig. 2 is an electrical schematic diagram of a signal processing unit of an embodiment of the present invention.
Detailed Description
The present invention will be further described with reference to the accompanying drawings and specific embodiments.
Referring to fig. 1: a water surface speed measuring radar speed sensor comprises a digital sampling unit, a millimeter wave radio frequency unit, a horn antenna and a signal processing unit. The first output port of the signal processing unit is connected with a data port A1, the second input port of the signal processing unit is connected with a power port A2, the third input port of the digital sampling unit and the second input port of the millimeter wave radio frequency unit are connected with the third output port of the signal processing unit respectively, the fourth output port of the signal processing unit is connected with the second input port of the digital sampling unit, and the fifth input port of the signal processing unit is connected with the first output port of the digital sampling unit; the fourth input port of the digital sampling unit is connected with the first output port of the millimeter wave radio frequency unit; and a third input port of the millimeter wave radio frequency unit is connected with a second output port of the horn antenna, and a fourth output port of the millimeter wave radio frequency unit is connected with a first input port of the horn antenna.
Referring to fig. 2: the signal processing unit comprises a low-pass filter, a random access memory, a fast Fourier transform module, an averaging module, a maximum value calculating module, an operation module, an automatic gain control module, a storage module, an inclination angle measuring module and a power supply conversion module. The first input port of the low-pass filter is connected with the first output port of the digital sampling unit, and the second output port of the low-pass filter is connected with the first input port of the random access memory; a second output port of the random access memory is connected with a first input port of the fast Fourier transform module; the second output port of the fast Fourier transform module is connected with the first input port of the averaging module; the second output port of the averaging module is connected with the first input port of the maximum value calculating module and the second input port of the operation module; the second output port of the maximum value calculating module is connected with the first input port of the operation module; a third input port of the operation module is connected with a first output port of the inclination angle measurement module, a fourth output port of the operation module is connected with a first input port of the automatic gain control module, a fifth bidirectional port of the operation module is connected with a first bidirectional port of the storage module, and a sixth output port of the operation module is connected with a data end A1; the first input port of the power supply conversion module is connected with a power supply A2, the first output port is connected with the second input port of the millimeter wave radio frequency unit, the second output port is connected with the third input port of the digital sampling unit, and the + V voltage output end is connected in parallel with the corresponding power supply end of each device of the signal processing unit.
The signal processing unit of the invention is used for processing PCM data from the digital sampling unit, controlling the amplification gain of the digital sampling unit and supplying power to the digital sampling unit and the millimeter wave radio frequency unit.
The signal processing unit consists of a low-pass filter, a Random Access Memory (RAM), a Fast Fourier Transform (FFT) module, an averaging module, a maximum value calculating module, an operation module, an Automatic Gain Control (AGC) module, a storage module (flash), an inclination angle measuring module and a power supply conversion module.
The low pass filter performs low pass filtering of the PCM data from the digital sampling unit, and then stores in a random access memory, the fast Fourier transform module reads data in the random memory and carries out Fast Fourier Transform (FFT), the averaging module averages PCM data according to set time, the maximum value module finds out the maximum value of the averaged value, the inclination angle measuring module tests the inclination angle of the horn antenna, the operation module calculates output data of the averaging module, the maximum value module and the inclination angle measuring module to obtain water flow velocity, the water flow velocity is stored in the storage module, and the gain control signal is read from the storage module and sent to a data terminal A1, the gain control signal of the digital sampling unit is sent to the automatic gain control module, and the automatic gain control module obtains the gain of the digital sampling unit and outputs the gain to the digital sampling unit. The first input port of the power supply conversion module is connected with a power supply A2, and the power supply voltage is converted and output to each device of the digital sampling unit, the millimeter wave radio frequency unit and the signal processing unit.
The formula of the operation module is as follows: v. ofwater＝fd×c/(f×cosθ)
Wherein f isdTo find the value of the output in the maximum module, vwaterThe water speed, c is the electromagnetic wave propagation speed constant, theta is the inclination angle of the sensor towards the water surface water-coming direction (upstream), and f is the value output in the averaging module.
V is calculated by the above formulawaterThe measurement of theta is obtained by a three-dimensional acceleration sensor mounted on the board, from which the maximum value f is found by means of 2048-point FFT processingdIs measured.
In practical use, multiple tests show that the horn antenna can measure the water body obliquely downwards at an angle of 60-90 degrees with the incoming water direction, and the effect is best.
The low-pass filter, the random access memory, the fast fourier transform module, the averaging module, the maximum value module, the operation module and the automatic gain control module in the signal processing unit are manufactured by adopting a Cyclone series digital field programmable chip EP3C55F484I7 manufactured by Alterna, USA, the inclination angle measurement module is manufactured by adopting a node control acceleration sensor ADXL345BCCZ manufactured by ADI, USA, the storage module is manufactured by adopting an electrically erasable programmable read-only memory (EEPROM AT93C66-10 SI-2.7) manufactured by ATMEL, USA, and the power supply conversion module is manufactured by adopting a voltage module LMZ14203HTZ/NOPB-adj manufactured by Tex instruments.
The digital sampling unit of the invention is used for receiving the signal from the millimeter wave radio frequency unit, amplifying the signal and carrying out analog-digital conversion, and the digital sampling unit of the embodiment is manufactured by a preamplifier PGA2505 and an AD converter PCM4202 produced by Texas instruments.
The millimeter wave radio frequency unit of the invention is used for generating a dot frequency or triangular wave linear frequency modulation signal of Ka wave band, amplifying and outputting the microwave signal, and mixing the signal received by the antenna with the frequency comprehensive signal to obtain an intermediate frequency signal and sending the intermediate frequency signal to the digital sampling unit. The millimeter wave radio frequency unit is manufactured by adopting a front end YXSFKa-ZJ of a Ka waveband Doppler radar produced by Shijiazhuangyuan electronic Limited company.
The horn antenna is used for transmitting radar signals to the water surface along the water surface at a certain included angle and receiving reflected waves of the water surface. The horn antenna is manufactured by the university of electronic technology of west ampere.
The brief working principle of the sensor is as follows:
the sensor is arranged above water bodies such as rivers and channels and forms a certain included angle with the water surface, a millimeter wave radio frequency unit generates a dot frequency or triangular wave linear frequency modulation signal and converts the frequency to a Ka waveband, a horn antenna amplifies and outputs a microwave signal sent by the millimeter wave radio frequency unit and outputs a received water surface reflected wave to the millimeter wave radio frequency unit, the millimeter wave radio frequency unit mixes the frequency to output an intermediate frequency signal to a digital sampling unit, the digital sampling unit amplifies and AD converts the intermediate frequency signal, PCM data is output to a signal processing unit, filtering, FFT and average value and maximum value processing are carried out on the input PCM data, and spectrum detection of the received signal is achieved. And obtaining the water flow rate on the surface of the river on the basis of the frequency spectrum of the received signal and the water surface included angle data.
The mounting structure of the present embodiment is as follows:
the signal processing unit, the digital sampling unit and the millimeter wave radio frequency unit are respectively arranged on three printed boards, and the millimeter wave radio frequency unit is tightly attached to the horn antenna; the dimensions of each printed board (length × width × height) are as follows:
a signal processing unit: 64mm by 10 mm;
a digital sampling unit: 64mm by 10 mm;
millimeter wave radio frequency unit: 68mm by 12 mm;
the aperture of the horn antenna is 88mm, and the length of the horn antenna is 75 mm;
then three printed boards are arranged in a housing with the length of 108mm, the width of 88mm and the height of 88mm, a horn antenna is arranged on the front opening of the housing, and a socket adopting IP68 protection grade is arranged on the rear panel, thus the invention is assembled. The whole sensor shell adopts an integrally formed seamless design, and each part is sealed by a rubber ring and silicone grease.
Claims (3)
1. A water surface speed measuring radar speed sensor comprises a digital sampling unit, a millimeter wave radio frequency unit and a horn antenna, and is characterized by also comprising a signal processing unit; the signal processing unit is provided with a data output port and a power input port; the signal processing unit is bidirectionally interconnected with the digital sampling unit, the horn antenna is bidirectionally interconnected with the millimeter wave radio frequency unit, and an output port of the millimeter wave radio frequency unit is connected with an input port of the digital sampling unit;
the horn antenna forms an included angle with the water surface, transmits radar signals to the water surface and receives reflected waves of the water surface; the horn antenna amplifies and outputs the microwave signal sent by the millimeter wave radio frequency unit and outputs the received water surface reflected wave to the millimeter wave radio frequency unit;
the millimeter wave radio frequency unit is used for generating a dot frequency or triangular wave linear frequency modulation signal of a Ka wave band and then sending the dot frequency or triangular wave linear frequency modulation signal to a horn antenna microwave signal; the millimeter wave radio frequency unit also receives the water surface reflected wave output of the horn antenna, and the millimeter wave radio frequency unit mixes the intermediate frequency signal to the digital sampling unit;
the digital sampling unit is used for receiving the signal from the millimeter wave radio frequency unit, amplifying the signal, performing analog-digital conversion on the signal, converting the signal into PCM data and sending the PCM data to the signal processing unit; the digital sampling unit also receives a digital sampling gain from the signal processing unit;
the signal processing unit processes the PCM data from the digital sampling unit to realize the spectrum detection of the received signal; transmitting the amplification gain of the digital samples; and obtaining the water flow rate on the surface of the river on the basis of the received signal frequency spectrum and the water surface included angle data.
2. The sensor of claim 1, wherein the signal processing unit comprises a low pass filter, a random access memory, a fast fourier transform module, an averaging module, a maximum value module, an arithmetic module, an automatic gain control module, a storage module and an inclination measuring module; the data output port is connected with the operation module;
the low-pass filter, the random access memory module, the fast Fourier transform module, the averaging module, the maximum value solving module and the operation module are sequentially connected; the averaging module, the inclination angle measuring module, the automatic gain control module and the storage module are also connected with the operation module, wherein the storage module and the operation module are bidirectionally interconnected; the low-pass filter and the automatic gain control module are respectively connected with the digital sampling unit, wherein the automatic gain control module and the digital sampling unit are bidirectionally interconnected;
the low-pass filter finishes low-pass filtering of PCM data from the digital sampling unit and then stores the PCM data in the random access memory, the fast Fourier transform module reads the data in the random access memory and carries out fast Fourier transform, the averaging module averages the PCM data according to set time, the maximum value module finds out the maximum value of the averaged value, the inclination angle measuring module tests the inclination angle of the horn antenna, the operation module operates the output data of the averaging module, the maximum value calculating module and the inclination angle measuring module to obtain the water flow speed and a gain control signal of the digital sampling unit, and the operation module stores the water flow speed in the storage module, reads the water flow speed from the storage module and sends the water flow speed to a data output port; the operation module sends the gain control signal of the digital sampling unit to the automatic gain control module, and the automatic gain control module obtains the digital sampling gain and outputs the digital sampling gain to the digital sampling unit.
3. The sensor of claim 2, wherein the signal processing unit further comprises a power conversion module; the power supply input port is connected with the power supply conversion module, and the power supply conversion module outputs current to the digital sampling unit and the millimeter wave radio frequency unit respectively.
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| CN202011560093.5A CN112816972A (en) | 2020-12-25 | 2020-12-25 | Water surface speed measuring radar speed sensor |
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201252555Y (en) * | 2008-08-27 | 2009-06-03 | 中国电子科技集团公司第五十四研究所 | Speed self-adaptive scatter communication modem |
| WO2014192528A1 (en) * | 2013-05-31 | 2014-12-04 | 古野電気株式会社 | Surface tidal-current estimation device, radar device, surface tidal-current estimation method and surface tidal-current estimation program |
| CN104502910A (en) * | 2015-01-13 | 2015-04-08 | 上海航征测控系统有限公司 | Handheld radar for measuring surface velocity of river-way |
| CN104849491A (en) * | 2015-04-28 | 2015-08-19 | 奇瑞汽车股份有限公司 | Water flow velocity detection method and system |
| CN109001723A (en) * | 2018-06-29 | 2018-12-14 | 薛志勇 | Radar current meter |
| US20190041494A1 (en) * | 2017-08-04 | 2019-02-07 | Infineon Technologies Ag | Distributed radar sensor system |
| CN109557531A (en) * | 2018-11-21 | 2019-04-02 | 南京微麦科斯电子科技有限责任公司 | A kind of high-resolution river radar installations based on phased-array technique |
| CN110618291A (en) * | 2019-09-30 | 2019-12-27 | 河南安宏信息科技有限公司 | Microwave surface flow velocity measuring method for eliminating wind and rain interference by utilizing quadrature mixing phase |
-
2020
- 2020-12-25 CN CN202011560093.5A patent/CN112816972A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201252555Y (en) * | 2008-08-27 | 2009-06-03 | 中国电子科技集团公司第五十四研究所 | Speed self-adaptive scatter communication modem |
| WO2014192528A1 (en) * | 2013-05-31 | 2014-12-04 | 古野電気株式会社 | Surface tidal-current estimation device, radar device, surface tidal-current estimation method and surface tidal-current estimation program |
| CN104502910A (en) * | 2015-01-13 | 2015-04-08 | 上海航征测控系统有限公司 | Handheld radar for measuring surface velocity of river-way |
| CN104849491A (en) * | 2015-04-28 | 2015-08-19 | 奇瑞汽车股份有限公司 | Water flow velocity detection method and system |
| US20190041494A1 (en) * | 2017-08-04 | 2019-02-07 | Infineon Technologies Ag | Distributed radar sensor system |
| CN109001723A (en) * | 2018-06-29 | 2018-12-14 | 薛志勇 | Radar current meter |
| CN109557531A (en) * | 2018-11-21 | 2019-04-02 | 南京微麦科斯电子科技有限责任公司 | A kind of high-resolution river radar installations based on phased-array technique |
| CN110618291A (en) * | 2019-09-30 | 2019-12-27 | 河南安宏信息科技有限公司 | Microwave surface flow velocity measuring method for eliminating wind and rain interference by utilizing quadrature mixing phase |
Non-Patent Citations (3)
| Title |
|---|
| 安然等: "基于AR模型的水流速雷达信号处理方法", 《电子测量技术》 * |
| 李小波 等: "《雷达波测速探头在水文缆道测验中的开发应用》", 《水利水电快报》 * |
| 温宗周等: "电波流速仪信号处理技术研究", 《电子测量技术》 * |
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Application publication date: 20210518 |