A radar wind measurement method and device based on multi-radar data fusion

Abstract

The application discloses a kind of radar wind measuring device based on multi-radar data fusion, including millimeter wave radar module, through millimeter wave radar module measurement wind speed data;Laser radar module, through laser radar module measurement wind speed data;Data fusion module, the data fusion module includes wind speed fusion unit;Data output module, the data output module includes wind speed output unit, for output after fusion wind speed;Compared with prior art, the device of the present application adopts double system, double framework synchronous measurement to avoid the measurement error caused by time error, improve the stability and reliability of whole system;The data fusion method of the present application adopts the idea of kalman filtering algorithm data fusion, the radial wind speed data of two kinds of radars are fused, the wind speed and wind direction information of the measured wind field are obtained;Through adaptive weight factor, the limitation brought by single operation mode measurement is overcome, and the reliability and application range of measurement data are enhanced.

Description

Technical Field

[0001] This invention relates to the field of radar wind measurement, and specifically to a radar wind measurement method and apparatus based on multi-radar data fusion. Background Technology

[0002] Lidar uses a laser to generate signal light, which is emitted into the air being measured through an optical antenna and scanning mechanism. The light is backscattered by aerosol particles and returns to the detector. Utilizing the Doppler principle, the radial wind speed is obtained by measuring the relationship between the frequency shift of the echo signal and the velocity of the aerosol particles (i.e., wind speed). By decomposing and synthesizing the same radial wind speed, wind speed and direction at a distance can be measured. Therefore, lidar is widely used to measure wind in the atmosphere, enabling research and applications in atmospheric circulation and weather forecasting. Due to its advantages such as high spatiotemporal resolution, simple installation and maintenance, and high degree of automation, lidar wind measurement radar has been widely applied in various fields, such as wind turbine wind measurement, aviation meteorology, and wind field monitoring.

[0003] Similar to lidar, millimeter-wave radar emits multiple beams and utilizes the Doppler effect generated by wind motion to measure radial wind speed and direction, used for wind power curve verification and wind turbine yaw control. Millimeter-wave radar shares these functions with lidar and anemometer towers. However, there are significant differences between millimeter-wave radar and lidar in their wind measurement principles. In clear weather, millimeter-wave radar uses Rayleigh and Mie scattering for measurement, while in rainy or foggy weather, due to the Bragg effect, millimeter-wave radar can better reflect wind field information, thus achieving better wind measurement performance.

[0004] Wind-measuring radar is typically used for wind field feedforward control and wind turbine yaw control, while lidar boasts advantages such as high efficiency, high precision, and high spatiotemporal resolution, but is significantly affected by adverse weather conditions such as rain, snow, and fog. Millimeter-wave wind-measuring radar performs well in adverse weather conditions, but its overall accuracy is relatively low. To fully utilize the advantages of both types of radar, the combination of lidar and millimeter-wave wind-measuring radar has become a development trend in practical applications.

[0005] To fully leverage the advantages of both types of radar, the combination of laser wind-measuring radar and millimeter-wave wind-measuring radar has become a development trend in practical applications. This approach reduces interference issues for laser wind-measuring radar in adverse weather conditions while also addressing the accuracy limitations of millimeter-wave wind-measuring radar. This combined approach is widely used in various fields such as wind power generation, wind farm feedforward control, and wind turbine yaw control.

[0006] The two radars are fused using different data fusion methods. Commonly used methods include the mean method and the fixed-weight method. The mean method calculates the average value of data from different sensors, resulting in uniform weights for all sensor data, which can reduce the accuracy of high-precision sensors. The fixed-weight method assigns different weights to sensors with varying levels of precision. However, this method is less adaptable to complex environments because the precision of different sensors varies with environmental factors. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of existing mean data fusion methods, which lead to a decrease in the accuracy of high-precision sensors; and fixed-weight data fusion methods, which are not suitable for complex environments. To address these shortcomings, this invention proposes a radar wind measurement method and device based on multi-radar data fusion.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A radar wind measurement device based on multi-radar data fusion includes a millimeter-wave radar module, which calculates wind speed data.

[0010] LiDAR module, used to measure wind speed data;

[0011] The data fusion module includes a wind speed fusion unit for fusing millimeter-wave radar data with lidar data;

[0012] The data output module includes a wind speed output unit for outputting the fused wind speed.

[0013] As a further preferred embodiment of the present invention, the millimeter-wave radar module includes a synthesizer for generating linear frequency modulated pulses;

[0014] A transmitter for transmitting linear frequency modulated pulses; the linear frequency modulated pulses are reflected by aerosol particles suspended in the air to form reflected linear frequency modulated pulses;

[0015] Receiver, used to receive reflected linear frequency modulated pulses;

[0016] A mixer combines the signal of a linear frequency modulated pulse with the signal of a reflected linear frequency modulated pulse to generate an intermediate frequency signal.

[0017] The processing unit includes a digital-to-analog converter for converting intermediate frequency signals into wind speed information.

[0018] As a further preferred embodiment of the present invention, the lidar module includes an all-fiber laser for generating pulsed laser signals;

[0019] A telescope used to emit pulsed laser signals and receive pulsed laser signals reflected by aerosols in the air;

[0020] A coherent detector is used to combine the emitted and reflected pulsed laser signals to generate an intermediate frequency signal.

[0021] A circulator is used to decompose the pulsed laser signal, with one path being emitted through a telescope and the other entering a coherent detector.

[0022] The processing unit includes a digital-to-analog converter for converting intermediate frequency signals into wind speed information.

[0023] A wind measurement method based on a radar wind measurement device using multi-radar data fusion.

[0024] The process includes the following steps:

[0025] S1. At the same time and altitude, wind is measured using millimeter-wave radar and lidar respectively, and the wind measurement data from the millimeter-wave radar and lidar are sent to the data fusion module; the wind measurement data is radial wind speed.

[0026] S2. The wind measurement data from millimeter-wave radar and lidar are fused using the data fusion module.

[0027] As a further preferred embodiment of the present invention, the wind measurement data is radial wind speed;

[0028] pass Calculate the radial wind speed of the laser. ,in, The Doppler frequency shift of radial wind speed, λ is the wavelength of the laser.

[0029] As a further preferred embodiment of the present invention, step S2 includes the following specific steps:

[0030] S21. Perform wind speed inversion on the wind measurement data of millimeter-wave radar and lidar to obtain the horizontal wind speed of millimeter-wave radar and lidar.

[0031] S22. Based on the Kalman filter concept, the horizontal wind speed of the millimeter-wave radar and the horizontal wind speed of the lidar are fused to obtain the final wind measurement data.

[0032] As a further preferred embodiment of the present invention, the wind speed inversion process in step S21, which involves analyzing the wind measurement data from the millimeter-wave radar and the lidar, includes the following specific steps:

[0033] Four laser beams along The axes, in a positive direction and counterclockwise, are LOS1, LOS2, LOS3, and LOS4, respectively.

[0034] Using the X-axis as the boundary, the four laser beams are divided into an upper plane and a lower plane. Lasers LOS1 and LOS2 are located on the upper plane, and lasers LOS3 and LOS4 are located on the lower plane.

[0035] pass ,

[0036] The horizontal wind speed was calculated. and wind direction ;

[0037] in, When calculating the horizontal wind speed on the upper plane, , For the radial wind velocities of laser LOS1 and LOS2, when calculating the horizontal wind velocity on the lower plane, , The radial wind speeds for laser LOS3 and LOS4 are given. , The angle formed by the planes containing lasers LOS1 and LOS2 and the planes containing lasers LOS3 and LOS4. The angle formed by the plane containing lasers LOS1 and LOS4 and the plane containing lasers LOS2 and LOS3;

[0038] When wind speed is inverted from lidar wind measurement data, the horizontal wind speed output by the lidar is obtained. Or wind direction ;

[0039] When wind speed is retrieved from millimeter-wave radar wind data, the horizontal wind speed output by the millimeter-wave radar is obtained. Or wind direction .

[0040] As a further preferred embodiment of the present invention, step S22 includes the following specific steps:

[0041] The horizontal wind speed obtained from the lidar output in step S21 Or wind direction Horizontal wind speed output by millimeter-wave radar Or wind direction Calculate the average wind speed within time window t. Average wind direction Data variance and millimeter-wave radar average wind speed Average wind direction Data variance ;

[0042] pass ,

[0043] in The horizontal wind speed after fusion was calculated. ;

[0044] pass ,

[0045] in, The horizontal wind direction after fusion was calculated. .

[0046] The advantages of this invention are:

[0047] 1. The device of the present invention adopts a dual-system, dual-architecture synchronous measurement to avoid measurement errors caused by time errors, thereby improving the stability and reliability of the entire system;

[0048] 2. The data fusion method of the present invention adopts the idea of ​​Kalman filter algorithm data fusion to fuse the radial wind speed data of two radars to obtain the wind speed and wind direction information of the wind field being measured.

[0049] 3. The weights in the data fusion method of this invention are adaptive. Therefore, in clear weather, the weight ratio of measurements taken by laser wind radar will increase, making full use of its high precision and high spatial resolution. Conversely, in adverse weather conditions such as rain, snow, and fog, the weight ratio of measurements taken by millimeter-wave wind radar will increase, resulting in more accurate measurement data. This strategy of performing detailed measurements of the wind field through a multi-sensor inversion method overcomes the limitations of single-operation mode measurements and enhances the reliability and applicability of the measurement data. Attached Figure Description

[0050] Figure 1 This is a flowchart illustrating the present invention;

[0051] Figure 2 This is a schematic diagram of the beam azimuth angle;

[0052] Figure 3 This is a schematic diagram of the radar wind measurement device of the present invention. Detailed Implementation

[0053] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0054] This invention relates to the fields of lidar and millimeter-wave radar wind measurement, specifically to achieving high-precision and stable wind speed measurement under any weather conditions based on lidar and millimeter-wave wind speed measurement results. Particularly useful for cabin wind measurement in complex climatic environments, it improves measurement accuracy while maintaining high efficiency.

[0055] Example 1:

[0056] Combination Figure 3 A radar wind measurement device based on multi-radar data fusion includes a millimeter-wave radar module for calculating wind speed data; a lidar module for calculating wind speed data; a data fusion module, which includes a wind speed fusion unit for fusing millimeter-wave radar data and lidar data; and a data output module, which includes a wind speed output unit for outputting the fused wind speed.

[0057] The millimeter-wave radar module includes a synthesizer for generating linear frequency modulated (LFM) pulses; a transmitter for transmitting LFM pulses via a transmitting antenna (Tx); when the LFM pulses propagate in the air, they are reflected by aerosol particles suspended in the air, generating reflected LFM pulses; a receiver (Rx) for receiving the reflected LFM pulses; a mixer for combining the signals from the transmitting antenna (Tx) and the receiving antenna (RX) to generate an intermediate frequency (IF) signal; and a processing unit, which includes a digital-to-analog converter (DAC) to convert the IF signal into wind speed information.

[0058] The lidar module includes an all-fiber laser for generating pulsed laser signals; a telescope that transmits the generated pulsed laser signals and receives pulsed laser signals reflected back from aerosols in the air; a coherent detector that combines the transmitted and reflected pulsed laser signals to generate an intermediate frequency signal; a circulator that splits the pulsed laser signal into two paths, one of which is transmitted through the telescope and the other is input to the coherent detector module; and a processing unit that includes a digital-to-analog converter, which converts the intermediate frequency signal into wind speed information.

[0059] Example 2:

[0060] Combination Figure 1 A wind measurement method based on a radar wind measurement device using multi-radar data fusion, comprising the following steps:

[0061] S1. At the same time and altitude, wind measurements are taken using millimeter-wave radar and lidar respectively, and the wind measurement data from millimeter-wave radar and lidar are sent to the data fusion module.

[0062] The wind measurement data is radial wind speed;

[0063] pass Calculate the radial wind speed of the four laser beams. ,in, The Doppler frequency shift of radial wind speed, λ is the wavelength of the laser.

[0064] Combination Figure 2 S2. The wind measurement data from the millimeter-wave radar and the wind measurement data from the lidar are fused through the data fusion module to obtain the final wind measurement data.

[0065] S21. Perform wind speed inversion on the wind measurement data from the millimeter-wave radar and the lidar to obtain the horizontal wind speed from the millimeter-wave radar and the lidar.

[0066] Four laser beams along The axes, in a positive direction and counterclockwise, are LOS1, LOS2, LOS3, and LOS4, respectively.

[0067] Using the X-axis as the boundary, the four laser beams are divided into an upper plane and a lower plane. Lasers LOS1 and LOS2 are located on the upper plane, while lasers LOS3 and LOS4 are located on the lower plane.

[0068] pass ,

[0069] The horizontal wind speed was calculated. and wind direction ;

[0070] in, When calculating the horizontal wind speed on the upper plane, , For the radial wind velocities of laser LOS1 and LOS2, when calculating the horizontal wind velocity on the lower plane, , The radial wind speeds for laser LOS3 and LOS4 are calculated using the formula in S1. , The angle formed by the planes containing lasers LOS1 and LOS2 and the planes containing lasers LOS3 and LOS4. The angle formed by the plane containing lasers LOS1 and LOS4 and the plane containing lasers LOS2 and LOS3.

[0071] When wind speed is inverted from lidar wind measurement data, the horizontal wind speed output by the lidar is obtained. Or wind direction .

[0072] When wind speed is retrieved from millimeter-wave radar wind data, the horizontal wind speed output by the millimeter-wave radar is obtained. Or wind direction .

[0073] S22. Based on the Kalman filter concept, the horizontal wind speed of millimeter-wave radar and the horizontal wind speed of lidar are fused.

[0074] The horizontal wind speed obtained from the lidar output in step S21 Or wind direction Horizontal wind speed output by millimeter-wave radar Or wind direction Calculate the average wind speed within time window t. Average wind direction Data variance and millimeter-wave radar average wind speed Average wind direction Data variance ;

[0075] pass ,

[0076] in The horizontal wind speed after fusion was calculated. ;

[0077] pass ,

[0078] in, The horizontal wind direction after fusion was calculated. .

[0079] Through weight As can be seen from the calculation method, its value is adaptively changing, thus adapting to different weather and environmental conditions.

[0080] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the above embodiments do not limit the present invention in any way, and all technical solutions obtained by equivalent substitution or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A radar wind measurement method based on multi-radar data fusion, characterized in that, Includes the following steps: S1. At the same time and altitude, wind is measured using millimeter-wave radar and lidar respectively, and the wind measurement data from the millimeter-wave radar and lidar are sent to the data fusion module; the wind measurement data is radial wind speed. S2. The wind measurement data from millimeter-wave radar and lidar are fused using a data fusion module to obtain the final wind measurement data; specifically including: S21. Perform wind speed inversion on the wind measurement data of millimeter-wave radar and lidar to obtain the horizontal wind speed and direction of millimeter-wave radar and lidar. S22. Based on the Kalman filter concept, the horizontal wind speed of millimeter-wave radar and the horizontal wind speed of lidar are fused. The horizontal wind speed obtained from the lidar output in step S21 Or wind direction Horizontal wind speed output by millimeter-wave radar Or wind direction Calculate the average wind speed within time window t. Average wind direction Data variance and millimeter-wave radar average wind speed Average wind direction Data variance ; pass ; in The horizontal wind speed after fusion was calculated. ; pass , in The horizontal wind direction after fusion was calculated. .

2. The radar wind measurement method based on multi-radar data fusion according to claim 1, characterized in that, pass Calculate the radial wind speed of the laser. ,in, The Doppler frequency shift of radial wind speed, λ is the wavelength of the laser.

3. The radar wind measurement method based on multi-radar data fusion according to claim 2, characterized in that, The wind speed inversion process in step S21, which involves analyzing wind data from millimeter-wave radar and lidar, includes the following specific steps: Four laser beams along The axes, in a positive direction and counterclockwise, are LOS1, LOS2, LOS3, and LOS4, respectively. Using the X-axis as the boundary, the four laser beams are divided into an upper plane and a lower plane. Lasers LOS1 and LOS2 are located on the upper plane, and lasers LOS3 and LOS4 are located on the lower plane. pass , The horizontal wind speed was calculated. and wind direction ; in, When calculating the horizontal wind speed on the upper plane, , For the radial wind velocities of laser LOS1 and LOS2, when calculating the horizontal wind velocity on the lower plane, , The radial wind speeds for laser LOS3 and LOS4 are given. , The angle formed by the planes containing lasers LOS1 and LOS2 and the planes containing lasers LOS3 and LOS4. The angle formed by the plane containing lasers LOS1 and LOS4 and the plane containing lasers LOS2 and LOS3; When wind speed is inverted from lidar wind measurement data, the horizontal wind speed output by the lidar is obtained. Or wind direction ; When wind speed is retrieved from millimeter-wave radar wind data, the horizontal wind speed output by the millimeter-wave radar is obtained. Or wind direction .

4. An apparatus employing the radar wind measurement method based on multi-radar data fusion as described in any one of claims 1-3, characterized in that, Includes a millimeter-wave radar module, which is used to measure wind speed data; LiDAR module, used to measure wind speed data; The data fusion module includes a wind speed fusion unit for fusing millimeter-wave radar data with lidar data; The data output module includes a wind speed output unit for outputting the fused wind speed.

5. A radar wind measurement device based on multi-radar data fusion according to claim 4, characterized in that, The millimeter-wave radar module includes a synthesizer for generating linear frequency modulated pulses; A transmitter for transmitting linear frequency modulated pulses; the linear frequency modulated pulses are reflected by aerosol particles suspended in the air to form reflected linear frequency modulated pulses; Receiver, used to receive reflected linear frequency modulated pulses; A mixer combines the signal of a linear frequency modulated pulse with the signal of a reflected linear frequency modulated pulse to generate an intermediate frequency signal. The processing unit includes a digital-to-analog converter for converting intermediate frequency signals into wind speed information.

6. A radar wind measurement device based on multi-radar data fusion according to claim 4, characterized in that, The lidar module includes an all-fiber laser for generating pulsed laser signals; A telescope used to emit pulsed laser signals and receive pulsed laser signals reflected by aerosols in the air; A coherent detector is used to combine the emitted pulsed laser signal and the reflected pulsed laser signal to generate an intermediate frequency signal; A circulator is used to decompose the pulsed laser signal, with one path being emitted through a telescope and the other entering a coherent detector. The processing unit includes a digital-to-analog converter for converting intermediate frequency signals into wind speed information.

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