CN120294782A

CN120294782A - Method, system and computer device for measuring wind profile using laser wind radar

Info

Publication number: CN120294782A
Application number: CN202510501261.XA
Authority: CN
Inventors: 薛媛; 刘建永; 张运刚; 于再林
Original assignee: Beijing Yanjin Optoelectronic Technology Co ltd
Current assignee: Beijing Yanjin Optoelectronic Technology Co ltd
Priority date: 2025-04-21
Filing date: 2025-04-21
Publication date: 2025-07-11

Abstract

The present application discloses a laser wind radar system and a wind profile measurement method and a computer device. By configuring at least three laser wind radars and a data server, the geographical location coordinates and the inclination angle with the horizontal plane of each laser wind radar are obtained; the measurement inclination angle, layered acquisition height and acquisition period are configured for at least three laser wind radars; the system clocks of at least three laser wind radars are synchronized, and the radial velocity of scattering particles at the same coordinate point of each layered acquisition height is collected and calculated; the radial velocity of the scattering particles is collaboratively processed using a least squares inversion algorithm in combination with the Kalman filtering technology to obtain an accurate three-dimensional wind profile; by measuring multiple wind profiles and integrating multi-dimensional real-time data, a high-precision and dynamic wind field measurement capability is provided, the limitations of traditional wind towers and single radars in applications are solved, and the needs of refined management of multiple scenarios (wind power generation, local meteorology, low-altitude flight, etc.) are met.

Description

Method, system and computer device for measuring wind profile by laser wind-finding radar

Technical Field

The disclosure relates to the field of wind measurement, in particular to a method, a system and a computer device for measuring wind profile by using a laser wind-finding radar.

Background

Existing laser wind radars have some limitations in wind profile measurement. First, when a single lidar acquires wind field data, it is generally assumed that the wind field is uniform within the scan area. In practice, however, there may be significant variations in wind farms in different areas and heights;

secondly, a single laser radar can only measure radial wind speed, cannot identify wind direction, cannot obtain accurate wind field data, cannot fully reflect the dynamic characteristics of a wind field, and is more difficult to capture the instantaneous change of the wind field;

In addition, a single laser radar can only measure radial wind speed along the laser beam direction, wind speeds in other directions such as horizontal wind speed, vertical wind speed and the like need to be obtained through multiple scans and deductions, time resolution of three-dimensional wind field measurement is lower, and calculation complexity and errors are increased.

Disclosure of Invention

In view of the above, the embodiments of the present disclosure provide a laser wind-finding radar system, a wind profile measuring method, and a computer device, which can effectively overcome the problems of low time resolution, low spatial resolution, low data refresh rate, complex computation, and insufficient precision of a single laser wind-finding radar, and meet the requirements of high-precision wind-finding.

In a first aspect, embodiments of the present disclosure provide a method for measuring wind profile by a laser wind lidar, the system comprising:

at least 3 laser wind-finding radars and a data server are configured;

obtaining the geographic position and the inclination angle between each laser wind measuring radar and a horizontal plane;

configuring measurement inclination angles, azimuth angles, layered acquisition heights and acquisition periods for the at least 3 laser wind-finding radars;

the system clocks of the at least 3 laser wind-finding radars reach time synchronization through GNSS calibration or mobile base station calibration;

the at least 3 laser wind-finding radars synchronously emit laser beams to the same coordinate point of each layered acquisition height according to azimuth angles and measurement inclination angles, and receive back scattering laser of each layered acquisition height;

the at least 3 laser wind-finding radars respectively capture the back scattering laser, the back scattering laser is compared with the emitted laser beam in frequency, the frequency change is analyzed, and the radial speed of scattering particles is calculated;

Each at least 3 laser wind measuring radars send the calculated radial velocity of the scattering particles to the data server, and the data server uses a least square inversion algorithm and combines a Kalman filtering technology to cooperatively process the radial velocity of the scattering particles sent by the at least 3 laser wind measuring radars respectively to obtain an accurate three-dimensional wind profile;

and configuring different azimuth angles for each at least 3 laser anemometer to obtain a plurality of three-dimensional wind profiles.

Optionally, the step of obtaining the geographic position and the inclination angle with the horizontal plane of each laser wind-finding radar comprises the steps that the laser wind-finding radar determines the three-dimensional coordinate of the position of the laser wind-finding radar through a positioning system;

the laser wind-finding radar monitors the inclination state of the laser wind-finding radar through an inclinometer and an angle encoder, and the inclination state is used for carrying out posture adjustment on the laser wind-finding radar or carrying out corresponding correction on a measurement result during data processing.

Optionally, the measurement dip angle is used for determining a beam vertical direction of the laser wind-finding radar;

The layered acquisition height is used for setting the range and interval of wind profile data acquisition of the laser wind-finding radar on different height layers;

and the acquisition period is used for determining the time interval of wind field data acquisition by the laser wind-finding radar.

Optionally, the at least 3 lidars synchronously transmit laser beams to the same coordinate point of each layered acquisition height, and receive backscattered laser light of each layered acquisition height, including:

Before observation, presetting equal-height layered acquisition heights and corresponding coordinate points, wherein the corresponding coordinate points are the common measurement target points of the at least 3 laser wind-finding radars, and the corresponding coordinate points have the same geographic coordinates in space and are distributed on different layered acquisition heights;

The at least 3 laser wind-finding radars can adjust the emission direction according to the common measurement target point of each layered acquisition height, so that the emission laser beam accurately points to the common measurement target point;

When the emitted laser beams reach the common measurement target point, the emitted laser beams interact with particles in the atmosphere to generate backward scattering laser, the at least 3 laser wind-finding radars receive the backward scattering laser, and each at least 3 laser wind-finding radars are configured with different azimuth angles to obtain a plurality of three-dimensional wind profiles.

Optionally, the at least 3 lidars respectively receive the backscattered laser, compare the frequencies of the backscattered laser and the emitted laser beam, analyze the frequency variation, and calculate the radial velocity of the scattering particles, including:

The at least 3 laser wind radars calculate the movement speed of particles in the atmosphere by measuring the frequency offset of the back scattering laser relative to the emitted laser beam by utilizing the Doppler effect principle, and then the radial speed of the scattering particles is obtained, and the specific formula is as follows:

Δf=fr-ft=λ2vcosθ,

Wherein Δf is the frequency offset of the back-scattered laser relative to the emitted laser beam, fr is the frequency of the emitted laser beam, ft is the frequency of the back-scattered laser, λ is the wavelength of the emitted laser beam, v is the radial velocity of the scattered particles, and θ is the angle between the emitted laser beam and the wind direction.

Optionally, each of the at least 3 lidars sends the calculated radial velocity of the scattering particle to the data server, and the data server uses a least square inversion algorithm and combines a kalman filtering technology to cooperatively process the radial velocity of the scattering particle sent by the at least 3 lidars, so as to obtain an accurate three-dimensional wind profile, and the method includes:

the at least 3 laser wind radars send the radial velocity information of the scattering particles obtained by calculation to the data server, wherein the radial velocity information comprises radar identifications, acquisition time, layering heights, acquisition point space coordinates and radial velocities of the scattering particles;

the data server fuses the radial speeds of the scattering particles collected by the at least 3 laser anemometers at the same layering height and the same time, and a wind speed vector is formed through a trigonometric function relation;

The data server calculates the horizontal wind speed and the vertical wind speed of each height layer through the wind speed vector by using a least square inversion algorithm, and the data server carries out smoothing processing on the horizontal wind speed and the vertical wind speed data of each height layer by using a Kalman filtering technology to obtain the accurate three-dimensional wind profile.

The laser radar wind measuring system is provided with 3 laser wind measuring radars, different azimuth angles are configured, and a plurality of vertical wind profiles can be observed;

In a second aspect, embodiments of the present disclosure also provide a laser wind lidar system, the system comprising:

at least 3 laser wind-finding radars and a data server are configured;

each laser wind-finding radar obtains a geographic position through a positioning system, and obtains the dip angle of the laser wind-finding radar and a horizontal plane through a dip angle meter and an encoder;

configuring a measurement dip angle, a layered acquisition height and an acquisition period for the at least 3 laser wind radars;

The at least 3 laser wind-finding radars synchronously emit laser beams to the same coordinate point of each layered acquisition height and receive the back scattering laser of each layered acquisition height;

And each at least 3 laser wind measuring radars send the calculated radial velocity of the scattering particles to the data server, and the data server uses a least square inversion algorithm and combines a Kalman filtering technology to cooperatively process the radial velocity of the scattering particles sent by the at least 3 laser wind measuring radars respectively so as to obtain an accurate three-dimensional wind profile.

In a third aspect, embodiments of the present disclosure further provide a computer apparatus, wherein the computer apparatus includes:

at least one processor, and

A memory communicatively coupled to the at least one processor, wherein,

The memory stores instructions executable by the at least one processor to enable the at least one processor to perform any one of the lidar wind profile measurement methods described above.

In a fourth aspect, an embodiment of the present disclosure further provides a computer readable storage medium, where the computer readable storage medium stores computer instructions for causing a computer to perform any one of the above laser wind lidar measurement wind profile methods.

In a fifth aspect, embodiments of the present disclosure also provide a computer program product comprising computer instructions, characterized in that the computer instructions, when executed by a processor, implement the steps of the method of any one of the above.

The application discloses a laser wind-finding radar system, a wind profile measuring method and a computer device, wherein at least 3 laser wind-finding radars and a data server are configured to obtain the geographic position and the inclination angle with a horizontal plane of each laser wind-finding radar, the at least 3 laser wind-finding radars are configured to measure the inclination angle, the layered collecting height and the collecting period, the system clocks of the at least 3 laser wind-finding radars are synchronized, the radial speeds of scattering particles at the same coordinate point of each layered collecting height are collected and calculated, and a least square inversion algorithm is used to combine a Kalman filtering technology to carry out cooperative processing on the radial speeds of the scattering particles sent by the at least 3 laser wind-finding radars respectively so as to obtain an accurate three-dimensional wind profile, so that a cooperative observation system consisting of a plurality of laser wind-finding radars is realized. The collaborative observation system provides high-precision and dynamic wind resource measurement capability by integrating multidimensional real-time wind field data, solves the limitation of the traditional wind measuring tower and Shan Bulei in application, and meets the requirement of fine management of multiple scenes (wind power, weather and low-altitude flight).

And the cooperative observation system (more than 3 laser wind measuring radars are selected according to the terrain and meteorological conditions of the site) forms a set of laser radar wind station system, and the wind fields in the same area are subjected to fine measurement in a cooperative observation mode. The system utilizes the intersection of laser beams to generate a vertical wind profile, and realizes the high-precision and real-time acquisition of parameters such as wind speed, wind direction and the like. Compared with the traditional wind measuring tower, the laser radar wind measuring station has the advantages that besides wind profile data can be accurately measured, the wind measuring position can be flexibly selected, the wind measuring height, the wind measuring azimuth and the wind measuring vertical resolution are adjustable, and the dynamic wind measuring requirement can be effectively met.

The foregoing description is only an overview of the disclosed technology, and may be implemented in accordance with the disclosure of the present disclosure, so that the above-mentioned and other objects, features and advantages of the present disclosure can be more clearly understood, and the following detailed description of the preferred embodiments is given with reference to the accompanying drawings.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present disclosure, and other drawings may be obtained according to these drawings without inventive effort to a person of ordinary skill in the art.

Fig. 1 is a schematic structural diagram of a laser wind-finding radar system according to an embodiment of the disclosure.

Fig. 2 is a schematic flow chart of a laser wind-finding radar measuring wind profile according to an embodiment of the disclosure.

Fig. 3 is a schematic structural diagram of a laser wind-finding radar according to an embodiment of the disclosure.

Fig. 4 is a schematic structural diagram of a computer device according to an embodiment of the disclosure.

Detailed Description

Embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

It should be appreciated that the following specific embodiments of the disclosure are described in order to provide a better understanding of the present disclosure, and that other advantages and effects will be apparent to those skilled in the art from the present disclosure. It will be apparent that the described embodiments are merely some, but not all embodiments of the present disclosure. The disclosure may be embodied or practiced in other different specific embodiments, and details within the subject specification may be modified or changed from various points of view and applications without departing from the spirit of the disclosure. It should be noted that the following embodiments and features in the embodiments may be combined with each other without conflict. All other embodiments, which can be made by one of ordinary skill in the art without inventive effort, based on the embodiments in this disclosure are intended to be within the scope of this disclosure.

It is noted that various aspects of the embodiments are described below within the scope of the following claims. It should be apparent that the aspects described herein may be embodied in a wide variety of forms and that any specific structure and/or function described herein is merely illustrative. Based on the present disclosure, one skilled in the art will appreciate that one aspect described herein may be implemented independently of any other aspect, and that two or more of these aspects may be combined in various ways. For example, an apparatus may be implemented and/or a method practiced using any number of the aspects set forth herein. In addition, such apparatus may be implemented and/or such methods practiced using other structure and/or functionality in addition to one or more of the aspects set forth herein.

It should also be noted that the illustrations provided in the following embodiments merely illustrate the basic concepts of the disclosure by way of illustration, and only the components related to the disclosure are shown in the drawings and are not drawn according to the number, shape and size of the components in actual implementation, and the form, number and proportion of the components in actual implementation may be arbitrarily changed, and the layout of the components may be more complicated.

In addition, in the following description, specific details are provided in order to provide a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects may be practiced without these specific details.

Referring to fig. 1, the application discloses a system for measuring wind profiles by using laser wind-finding radars, which comprises a plurality of laser wind-finding radars (31, 32, 33) which cover key areas of a wind power plant through collaborative observation so as to realize the collection of multidimensional wind power plant parameters such as real-time wind speed, wind direction, turbulence intensity and the like. The data server (21) uses a least square inversion algorithm and combines a Kalman filtering technology to respectively send data to a plurality of laser wind measuring radars (31, 32 and 33) for cooperative processing so as to obtain an accurate three-dimensional wind profile. The system is used for measuring the wind profile, the wind speed measurement error is lower than 0.3 m/s, the system is remarkably superior to the traditional wind measuring tower and a single radar, the data acquisition frequency and the measurement resolution can be dynamically adjusted, and the real-time wind field monitoring is supported. The wind power generation system can be flexibly distributed according to the topographic features of the wind power plant, wind speed distribution and main wind direction. The system is suitable for different terrains and climatic conditions, and is stable in performance in complex wind fields and extreme weather. And meanwhile, the horizontal wind direction and the vertical wind direction are obtained, so that comprehensive wind field characteristic analysis is provided.

Referring to fig. 2, the application discloses a method for measuring wind profile by using a laser wind-finding radar, which comprises the following steps:

S100, at least 3 laser wind-finding radars and a data server are configured.

According to the characteristics of the main wind direction and the terrain of the wind power plant, the arrangement position of the laser radar is reasonably selected. And the arrangement in a wake interference area of the fan is avoided so as to ensure the data quality.

And S200, obtaining the geographic position and the inclination angle with the horizontal plane of each laser wind-finding radar.

Laser wind radars are typically equipped with high-precision positioning systems, such as Global Positioning Systems (GPS), beidou satellite navigation systems (BDS), etc., to obtain their precise geographic location information. The positioning systems calculate three-dimensional coordinates of the radar position, including longitude, latitude and altitude, by receiving satellite signals and utilizing satellite orbit parameters, time information, signal propagation time and the like. When the positioning system works, signals of a plurality of satellites are received at the same time, and the most accurate position information is calculated through an algorithm. In order to improve the positioning accuracy, some laser wind-finding radars may also use differential positioning technology, that is, a reference station with a known accurate position is used to correct satellite signals received by the radar, so as to reduce positioning errors and enable the positioning accuracy of the geographic position of the radar to reach centimeter level or even higher.

In the installation and use process of the laser wind-finding radar, a certain horizontal state is required to be maintained so as to ensure the accuracy and reliability of measurement data. In order to obtain the tilt angle of the radar to the horizontal, a high precision level gauge is typically used. Level gauges are typically mounted on the bottom or critical components of the radar and are capable of monitoring the tilt status of the radar in real time. The working principle is generally based on measurement of gravitational acceleration, and the inclination angle of the radar relative to the horizontal plane is calculated by detecting components of the gravitational acceleration in different directions. When the radar is inclined, the level gauge can transmit detected inclination angle information to a radar control system, and the control system adjusts the attitude of the radar according to the information or correspondingly corrects a measurement result during data processing so as to eliminate measurement errors caused by the inclination. In addition, in order to ensure the measurement accuracy of the level, it is required to be subjected to strict calibration at the time of installation, and also to be regularly checked and maintained during the use of the radar to ensure its normal operation.

Through the mode, the laser wind-finding radar can accurately acquire the geographic position and the inclination angle with the horizontal plane, so that a reliable basis is provided for accurate measurement of the atmospheric wind field, and the accuracy and the usability of measurement data are ensured.

S300, configuring a measurement dip angle, a layered acquisition height and an acquisition period for the at least 3 laser wind radars.

In measuring tilt angles for lidar configurations, the pointing angle of the radar antenna is mainly considered to ensure that the radar is able to transmit and receive laser signals at a suitable angle. In general, the pitch and azimuth of a radar are key parameters that need to be configured. The elevation angle determines the vertical direction of the radar beam and the azimuth angle determines the direction of the radar beam in the horizontal plane. The configuration of these angles needs to be determined according to specific observation targets and requirements. In order to achieve accurate angular configuration, lidars are often equipped with high-precision servo control systems that are capable of accurately adjusting the position of the radar antenna according to preset angular parameters. At the same time, the radar may also be equipped with an angle sensor for monitoring and feeding back the actual pointing angle of the radar antenna in real time for adjustment and correction when needed. In addition, under the condition of cooperative observation of a plurality of radars, the measurement inclination angles of the radars need to be planned and coordinated uniformly so as to ensure that the beams of the radars can cover a preset space area, thereby realizing comprehensive detection of an atmospheric wind field. In the invention, the measurement inclination angle of at least 3 laser wind radars can be adjusted according to the actual application scene and the measurement requirement, for example, the measurement inclination angle is set to be-10 degrees, -5 degrees, -0 degrees, 5 degrees, 10 degrees, 15 degrees, 30 degrees, 90 degrees, and the like by taking 5 degrees as an adjustment unit, and the adjustment precision is 0.01 degrees.

The configuration of the layered acquisition heights refers to setting the range and interval of wind field data acquisition of the laser wind-finding radar on different height layers. This configuration needs to be determined based on the observed objectives and the study requirements. For example, for studying wind park structures of near-ground atmospheric boundary layers, it may be desirable to set the acquisition height in a lower range, such as from ground to a height of 1000 meters, and to set a smaller height interval in this range, such as acquiring one layer of data every 10 meters or 20 meters, to acquire high-resolution wind park information. For researching the wind field change of high layers in the atmosphere, the upper limit of the collection height can be properly increased, and the height interval can be properly increased to cover a wider height range.

In actual operation, the laser wind-finding radar realizes wind field data acquisition of different height layers by adjusting signal processing parameters and transmitting and receiving modes in the laser wind-finding radar. The radar-emitted laser pulses, when propagating in the atmosphere, interact with aerosol particles of different heights and produce a backscatter signal. The radar can invert the wind speed and the wind direction of different height layers by receiving the backward scattering signals with different delay times and combining Doppler frequency shift information of the signals. In order to ensure the high accuracy of the layered acquisition and the reliability of the data, the radar also needs to consider its own detection performance and resolution limitations and the influence of atmospheric conditions on signal propagation and scattering when configuring the layered acquisition height. In the invention, the layered acquisition height is equal to 60 layers of the wind measuring height range (0-600 meters), namely, the height of each layer is 10 meters.

The configuration of the acquisition period refers to determining the time interval of wind field data acquisition by the laser wind-finding radar. The setting of the parameter needs to comprehensively consider the factors such as the observation purpose, the data updating frequency requirement, the radar performance and the like. For example, for application scenarios of monitoring changes of an atmospheric wind field in real time, such as weather forecast and aviation security, a shorter acquisition period may need to be set, such as acquiring data once per minute, so as to acquire wind field information with high time resolution, and capture rapid changes of the atmospheric wind field in time. For some long-term climate studies or atmospheric science experiments, it is possible to use a longer acquisition period, such as acquiring data every half hour or once an hour, to reduce the amount of data and to reduce the complexity of data processing.

When the configuration of the acquisition period is realized, the control system of the laser wind-finding radar can automatically control the operations of the radar such as transmitting, receiving, data processing and the like according to the set period parameters, so that the radar is ensured to acquire wind field data according to a preset time interval. Meanwhile, in order to adapt to different observation requirements, the radar may also have a flexible acquisition period adjustment function, so that a user is allowed to dynamically adjust the acquisition period according to actual conditions. In addition, considering that the radar may be affected by external environmental factors, such as temperature change, electromagnetic interference, etc., in the long-time continuous working process, the configuration of the acquisition period also needs to consider the stability and reliability of the radar, so as to avoid the problem of equipment overheating or other faults caused by frequent data acquisition. In the invention, the acquisition period is that each laser wind measuring radar finishes one scanning in 10 seconds to acquire radial wind speed data of the layer, and the arrangement of layered acquisition heights ensures high resolution in the vertical direction and can capture the wind speed change of layers with different heights. The acquisition period is set by considering the performance of the radar and the capability of data processing, and the acquisition period of 10 seconds can be balanced between the data quantity and the real-time performance.

S400, the system clocks of the at least 3 laser wind radars are calibrated by GNSS or mobile base station to achieve time synchronization.

In the case of cooperative operation of multiple lidars, a master control unit is usually required to coordinate the time alignment of the radars in order to achieve time synchronization of the entire system. The main control unit can send synchronous instructions to each radar according to GNSS calibration or accurate time provided by the mobile base station, and each radar adjusts own system clock according to a preset algorithm and flow after receiving the instructions, so that the system clock is consistent with the time of the main control unit. Thus, all radars in the whole system can work cooperatively under a unified time reference, and the time consistency of the measured data is ensured. The main control unit of the invention is a data server or one of the radars in the system.

S500, the at least 3 laser wind-finding radars synchronously emit laser beams to the same coordinate point of each layered acquisition height, and receive the back scattering laser of each layered acquisition height.

In the multi-radar collaborative observation system, a main control unit or a central control system is provided for coordinating the operation of each radar, and in the invention, the data server can be used as the central control system or one of the laser wind-finding radars can be used as the main control unit. When the preset acquisition time is reached, the main control unit can send synchronous transmitting instructions to all the laser wind-finding radars, and each radar immediately starts a laser transmitting program after receiving the instructions.

Each laser wind-finding radar is internally provided with a high-precision clock and timing control circuit, so that laser emission can be accurately triggered in a very short time after a synchronous instruction is received, and the error is usually in the microsecond level or even smaller, thereby realizing almost simultaneous emission of laser beams of multiple radars.

Before observation, a series of layered acquisition heights and corresponding coordinate points are preset according to a research target and an observation area. These coordinate points are target points common to all lidars, which have the same geographic coordinates in space and are distributed over different altitudes. The laser wind-finding radar is provided with a high-precision servo control system and an angle measuring device, and can accurately adjust the transmitting direction according to a preset coordinate point, namely, the pitch angle and the azimuth angle of the radar antenna are adjusted, so that the laser beam accurately points to a target coordinate point. In the adjustment process, the radar can continuously correct the position of the antenna by utilizing an angle feedback mechanism, so that the pointing accuracy of the laser beam is ensured to reach the milliradian level.

When the emitted laser beam reaches the target coordinate point, the emitted laser beam interacts with particles such as atmospheric aerosol, water drops and the like of the high-level layer to generate back scattering laser. Each lidar will collect these scattered laser signals through its receiving system. The receiving system typically includes a high sensitivity photodetector, signal amplifier, filter, etc., which is capable of extracting a weak backscattered laser signal from the background noise.

Because multiple lidars transmit laser light to the same coordinate point from different positions and angles and receive scattered signals, the received data contains wind field information observed from different viewing angles. The data are transmitted to a central data processing center, comprehensive analysis is carried out through a data fusion algorithm, so that the accuracy and reliability of wind field measurement are improved, more comprehensive and accurate three-dimensional structure information of the atmospheric wind field is obtained, and the central data processing center is a data server.

S600, the at least 3 laser wind-finding radars respectively capture the back scattering laser, the back scattering laser is compared with the emitted laser beam in frequency, the frequency change is analyzed, and the radial speed of the scattering particles is calculated.

The backscattered laser signal received by the lidar is usually very weak, and first the backscattered laser signal needs to be converted into an electrical signal by a high-sensitivity photodetector. The photodetector converts the optical signal into an electrical signal and transmits the signal to the preamplifier. The pre-amplifier performs preliminary amplification on the signal to improve the strength of the signal, so that the signal is easier to process later.

In order to ensure that the signal is amplified to a suitable amplitude while avoiding overload or distortion, the lidar may employ a multi-stage amplification circuit. In the amplifying process, the amplification factor is dynamically adjusted according to the initial strength of the signal by an accurate gain control circuit, so that the signal is ensured to be amplified in an optimal range, and a high-quality electric signal is provided for subsequent signal processing.

The backscattered laser signal may contain disturbances of various frequency components, such as ambient light noise, noise generated by electronic components, etc. The bandpass filter allows signals in a particular frequency range to pass, while attenuating signals of other frequencies. The laser wind-finding radar designs a proper band-pass filter according to the frequency characteristic of working laser, only retains the frequency components related to laser signals, effectively removes interference signals with irrelevant frequencies, and improves the signal-to-noise ratio of the signals.

In practical applications, the characteristics and intensity of the interfering signal may change over time, such as atmospheric turbulence, background light intensity changes, and the like. The self-adaptive filter can monitor the change conditions of signals and interference in real time, and automatically adjust parameters of the filter, such as the center frequency, bandwidth and the like of the filter according to a certain algorithm, so as to always maintain the optimal filtering effect and ensure that useful information in the back scattering laser signal is reserved and extracted to the greatest extent.

The amplified and filtered analog signal is sampled and digitized by a high-speed analog-to-digital converter (ADC) to convert the continuous analog signal into a discrete digital signal. The sampling frequency and resolution of the ADC need to be selected according to the measurement requirements of the radar and the signal characteristics to ensure that detailed information in the signal can be accurately captured.

The laser wind-finding radar calculates the movement velocity of particles in the atmosphere by measuring the frequency shift (Doppler shift) of a back scattering laser signal relative to a transmitting laser signal by utilizing the Doppler effect principle, and further obtains the wind speed. Specifically, the signal processing unit of the radar performs a spectrum analysis method such as Fast Fourier Transform (FFT) on the digitized signal to determine the frequency component of the signal. According to the Doppler frequency shift formula, combining parameters such as the wavelength, the emission angle and the like of the radar, and converting the Doppler frequency shift into the magnitude and the direction of the wind speed.

For example, when the laser wind-finding radar emits a laser beam with the frequency ft, the angle between the laser beam and the wind direction isAt a wind speed v, the frequency fr of the scattered light is shifted by Δf from the frequency of the emitted light:

Where λ is the laser wavelength. By measuring Doppler shift Δf, the radial component of wind speed can be calculated

And S700, each at least 3 laser wind radars send the calculated radial velocity of the scattering particles to the data server, and the data server uses a least square inversion algorithm and combines a Kalman filtering technology to cooperatively process the radial velocity of the scattering particles sent by the at least 3 laser wind radars respectively so as to obtain accurate three-dimensional wind profile data.

The data server receives wind measurement data from the three laser wind measurement radars through the network interface. Each radar transmits data in a 20 second acquisition period, and the data packet contains information such as radar identification, acquisition time, layering height, radial wind speed and the like.

As the system clocks of the three radars are calibrated by GNSS, millisecond-level time synchronization is ensured, and the server can check the time stamp of each data packet when receiving the data, so that the consistency of the data in time is ensured. If there is a slight time offset, the server will make the correction.

The server analyzes the received data packet, and extracts radial wind speed data, layering height information, three-dimensional space coordinates, acquisition time and the like of each radar. The parsed data will be consolidated into a structured format for subsequent processing. And storing the analyzed data in a database, and storing the data in a classified manner according to time, a height layer, the space coordinates of the acquisition points and the radar identification.

The server fuses radial wind speed data acquired by the three radars at the same layering height and at the same time. Since the measured dip angle of each radar is different, they provide wind speed components in different directions, and these components can be combined by trigonometric function relationship to form a more comprehensive wind speed vector.

And calculating the horizontal wind speed and the vertical wind speed of each height layer by using a least square inversion algorithm and combining radial wind speed data of three radars. The least square method can minimize measurement errors and improve the accuracy of wind speed inversion. The specific method comprises the following steps:

assume that the measured inclinations of the three radars are θ1, θ2, and θ3, respectively, and their radial wind speeds at a certain altitude layer h and a certain time t are Vr1 (h, t), vr2 (h, t), and Vr3 (h, t), respectively.

The radial wind speed of each radar can be decomposed into components of horizontal wind speed U and vertical wind speed W:

Vr1(h,t)=U1cosθ1+W1sinθ1

Vr2(h,t)=U2cosθ2+W2sinθ2

Vr3(h,t)=U3cosθ3+W3sinθ3

From these equations, a system of linear equations can be established for solving U and W.

The least squares inversion algorithm is used to solve the above-described system of linear equations to find the optimal U and W values so that measurement errors are minimized.

The three equations are written in matrix form, ax=b

Wherein:

The solution of the least squares method is x= (a ^TA)^-1A^T b

The method comprises the following specific steps:

3. Solving for x= (a ^TA)^-1A^T b

By the above steps, the best estimate of the horizontal wind speed U and the vertical wind speed W at the time of the altitude h and t can be obtained. A plurality of radial wind speed components are obtained through the measurement of a plurality of laser beams in different directions, and the horizontal component, the vertical component and the wind direction of the wind speed can be calculated by utilizing the vector synthesis and the trigonometric function relation.

On the basis of the inversion result, the Kalman filtering technology is applied to smooth the wind speed data, so that the stability and reliability of the data are further improved. The Kalman filter can effectively reduce noise interference and provide more accurate wind speed estimation, and the specific steps are as follows:

And inputting wind speed data obtained by inversion of the least square method into a Kalman filter as observation data.

And processing the wind speed data at each moment according to the Kalman filtering iteration step to obtain a smoothed wind speed estimated value.

And outputting the wind speed data after the smoothing processing, wherein the wind speed data comprises horizontal wind speed, vertical wind speed, side wind components and the like.

The data server checks whether the data of each radar is complete, whether there is a data loss or an outlier. If a data loss or anomaly is found, it is marked and an attempt is made to supplement by interpolation or other means. The data server checks whether the data of the three radars at the same height layer and at the same time are consistent. If not, the cause is analyzed and a corresponding adjustment is made. After the data server is processed, the server calculates accurate wind speed data of each height layer, including horizontal wind speed, vertical wind speed, wind direction and the like. The data server displays the processed wind speed data on a user interface in the forms of charts, tables and the like, so that the user can conveniently check and analyze the wind speed data. At the same time, data reports may be generated for further research.

The laser radar wind station realizes high-precision measurement and dynamic optimization of wind field characteristics of the wind power field through cooperative observation of a plurality of radars and advanced data processing technology. The system remarkably improves the running efficiency and the management level of the wind power plant, and provides solid technical support for the construction of the intelligent wind power plant.

Referring to fig. 3, the application discloses a structural schematic diagram of a laser wind-finding radar, wherein main components of the laser wind-finding radar 30 comprise a laser 301, an angle encoder 302, a pan-tilt servo motor 303, an antenna 304, a balance detector 305, a collection card 306, a central control card 307 and a 5G communication card 308.

The laser 301 is used to generate laser pulses, and is one of the core components of a laser wind-finding radar, and its main function is to generate high-energy, high-frequency laser pulses. These laser pulses are emitted into the atmosphere after being processed by an internal optical system. When the wind is measured as a light source, laser pulses emitted into the atmosphere interact with aerosol particles or the like in the atmosphere, and a scattered echo is generated. The laser emitted by the laser has specific wavelength and frequency, and the information such as wind speed, wind direction and the like in the atmosphere can be inverted by analyzing the received scattered echo signals and utilizing the principles such as Doppler frequency shift effect and the like.

The angle encoder 302 is used to measure the tilt angle of the lidar device itself. In practical applications, the device may be tilted due to the installation environment or external factors, and the tilt encoder can monitor the tilt state of the device in real time and feed back the angle information to the central control card 307.

Based on the measured inclination angle, the central control card 307 can perform corresponding correction on the laser emission direction to ensure that the laser is always emitted to the atmosphere at a correct angle, thereby improving the accuracy and reliability of wind measurement.

The main function of the pan-tilt servo motor 303 is to drive the pan-tilt of the laser wind-finding radar to rotate accurately under the control of the central control card 307. The cradle head is a platform for bearing the laser transmitting and receiving device, and can flexibly rotate in the horizontal and vertical directions through the control of the servo motor.

The servo motor can adjust the cradle head to a specified angle position according to the instruction of the central control card 307, so as to realize accurate control of the laser emission direction. Therefore, the laser can be ensured to accurately irradiate the target area or scan according to a preset scanning track, and more comprehensive and accurate wind field data are obtained.

The wind measuring device has the advantages of high response speed and good stability, can complete the adjustment of the angle in a short time, keeps a stable state, and avoids the influence on the accuracy of wind measuring data due to the fact that the cradle head shakes or is not adjusted timely.

The antenna 304 emits a laser pulse signal generated by a laser into the atmosphere. The laser signal is expanded and collimated by the antenna system to ensure that it propagates in the proper direction and intensity to the target area. The direction of the antenna emission can be precisely adjusted by a servo control system to cover different measurement areas and height layers.

When the laser signal propagates in the atmosphere and interacts with aerosol particles or the like, a scattering echo, i.e. backscattering, is generated. The antenna is responsible for receiving these scattered echo signals and focusing them onto the balanced detector. In order to improve the receiving efficiency and the signal quality, the antenna generally has a high gain and a large receiving aperture to collect as many scattered signals as possible.

The balanced detector 305 has two matched photodiodes and a low noise transimpedance amplifier inside. When the received back scattering laser signal and local oscillation optical signal generate photocurrent on the detector, the balance detector can perform subtraction processing on the two paths of signals, so that common mode noise such as background light noise, noise generated by electronic elements and the like can be effectively eliminated. Meanwhile, the transimpedance amplifier amplifies the signal, so that the strength of the signal is improved, and the signal is easier to process and analyze subsequently.

The balanced detector converts the optical signal into an electrical signal and outputs a Radio Frequency (RF) signal. The radio frequency signals comprise beat frequency information, namely Doppler frequency shift information, of the back scattering laser signals and the local oscillation optical signals. The subsequent signal processing unit extracts the Doppler frequency shift and frequency by sampling, filtering, spectrum analysis and other processes on the radio frequency signals, and further calculates the movement speed of particles in the atmosphere, namely the wind speed.

The acquisition card 306 includes a preamplifier, a multi-stage amplification circuit, a filter, a high-speed analog-to-digital converter, a signal processing unit, and the like. The electric signal converted from the back scattering signal is amplified preliminarily by the preamplifier of the acquisition card so as to improve the strength of the signal and make the signal easier to be processed later. To ensure that the signal is amplified to the proper amplitude while avoiding overload or distortion, the acquisition card may employ multiple stages of amplification circuits. In the amplifying process, the amplification factor is dynamically adjusted according to the initial strength of the signal by an accurate gain control circuit, so that the signal is ensured to be amplified in an optimal range, and a high-quality electric signal is provided for subsequent signal processing.

The backscattered signal may contain disturbances of various frequency components, such as ambient light noise, noise generated by electronic components, etc. The bandpass filter allows signals in a particular frequency range to pass, while attenuating signals of other frequencies. The acquisition card designs a proper band-pass filter according to the frequency characteristic of working laser, only retains the frequency components related to the laser signals, effectively removes interference signals with irrelevant frequencies, and improves the signal-to-noise ratio of the signals.

For calculating the velocity of movement of particles in the atmosphere by measuring the frequency shift (doppler shift) of the backscattered signal relative to the transmitted laser signal using the doppler effect principle, and thus obtaining the wind speed. Specifically, the signal processing unit of the radar performs a spectrum analysis method such as Fast Fourier Transform (FFT) on the digitized signal to determine the frequency component of the signal. And according to a Doppler frequency shift formula, combining parameters such as the wavelength, the emission angle and the like of the radar, and converting the Doppler frequency shift into wind speed and wind direction.

The central control card 307 is a control and information processing center of the product, and serves as a unique control instruction issuing unit to reduce time errors for consistency of actions of each module. In the aspect of information processing, time and space coordinates are added to signals, time service is unified, pitch angle data of an angle encoder are read to calculate three-dimensional space coordinates, and horizontal data are fixed after being aligned with a wind profile. The central control card 307 is responsible for controlling the laser 301, the angle encoder 302, the pan-tilt servo motor 303, the antenna 304, the balance detector 305, the acquisition card 306 and the 5G communication card 308.

The 5G communication card 308 is used for data communication with a data server and other laser wind radars.

A computer device according to an embodiment of the present disclosure includes a memory and a processor. The memory is for storing non-transitory computer readable instructions. In particular, the memory may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and/or non-volatile memory. The volatile memory may include, for example, random Access Memory (RAM) and/or cache memory (cache), and the like. The non-volatile memory may include, for example, read Only Memory (ROM), hard disk, flash memory, and the like.

The processor may be a Central Processing Unit (CPU) or other form of processing unit having data processing and/or instruction execution capabilities, and may control other components in the computer device to perform the desired functions. In one embodiment of the present disclosure, the processor is configured to execute the computer readable instructions stored in the memory, so that the computer apparatus performs all or part of the steps of the learning outcome prediction method based on learning behavior data mining of the foregoing embodiments of the present disclosure.

It should be understood by those skilled in the art that, in order to solve the technical problem of how to obtain a good user experience effect, the present embodiment may also include well-known structures such as a communication bus, an interface, and the like, and these well-known structures are also included in the protection scope of the present disclosure.

Fig. 4 is a schematic structural diagram of a computer device according to an embodiment of the disclosure. A schematic diagram of a computer device suitable for use in implementing embodiments of the present disclosure is shown. The computer device illustrated in fig. 4 is merely an example and should not be construed as limiting the functionality and scope of use of the disclosed embodiments.

As shown in fig. 4, the computer device may include a processor (e.g., a central processing unit, a graphic processor, etc.), which may perform various appropriate actions and processes according to a program stored in a Read Only Memory (ROM) or a program loaded from a storage device into a Random Access Memory (RAM). In the RAM, various programs and data required for the operation of the computer device are also stored. The processor, ROM and RAM are connected to each other by a bus. An input/output (I/O) interface is also connected to the bus.

In general, devices may be connected to the I/O interface including input devices such as sensors or visual information gathering equipment, output devices such as display screens, storage devices such as magnetic tape, hard disk, and communication devices. The communication means may allow the computer means to communicate wirelessly or by wire with other devices, such as edge computing devices, to exchange data. While a computer device having various means is illustrated, it is to be understood that not all illustrated means are required to be implemented or provided. More or fewer devices may be implemented or provided instead.

In particular, according to embodiments of the present disclosure, the processes described above with reference to flowcharts may be implemented as computer software programs. For example, embodiments of the present disclosure include a computer program product comprising a computer program embodied on a non-transitory computer readable medium, the computer program comprising program code for performing the method shown in the flow chart. In such an embodiment, the computer program may be downloaded and installed from a network via a communication device, or installed from a storage device, or installed from ROM. All or part of the steps of the learning outcome prediction method based on learning behavior data mining of the embodiments of the present disclosure are performed when the computer program is executed by a processor.

The detailed description of the present embodiment may refer to the corresponding description in the foregoing embodiments, and will not be repeated herein.

A computer-readable storage medium according to an embodiment of the present disclosure has stored thereon non-transitory computer-readable instructions. When executed by a processor, the non-transitory computer readable instructions perform all or part of the steps of the learning outcome prediction method based on learning behavior data mining of the various embodiments of the disclosure described above.

Such computer readable storage media include, but are not limited to, optical storage media (e.g., CD-ROM and DVD), magneto-optical storage media (e.g., MO), magnetic storage media (e.g., tape or removable hard disk), media with built-in rewritable non-volatile memory (e.g., memory card), and media with built-in ROM (e.g., ROM cartridge).

The basic principles of the present disclosure have been described above in connection with specific embodiments, but it should be noted that the advantages, benefits, effects, etc. mentioned in the present disclosure are merely examples and not limiting, and these advantages, benefits, effects, etc. are not to be considered as necessarily possessed by the various embodiments of the present disclosure. Furthermore, the specific details disclosed herein are for purposes of illustration and understanding only, and are not intended to be limiting, since the disclosure is not necessarily limited to practice with the specific details described.

In this disclosure, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions, and the block diagrams of devices, apparatuses, devices, systems involved in this disclosure are merely illustrative examples and are not intended to require or implicate that connections, arrangements, configurations must be made in the manner shown in the block diagrams. As will be appreciated by one of skill in the art, the devices, apparatuses, devices, systems may be connected, arranged, configured in any manner. Words such as "including," "comprising," "having," and the like are words of openness and mean "including but not limited to," and are used interchangeably therewith. The terms "or" and "as used herein refer to and are used interchangeably with the term" and/or "unless the context clearly indicates otherwise. The term "such as" as used herein refers to, and is used interchangeably with, the phrase "such as, but not limited to.

It is also noted that in the systems and methods of the present disclosure, components or steps may be disassembled and/or assembled. Such decomposition and/or recombination should be considered equivalent to the present disclosure.

The previous description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects without departing from the scope of the disclosure. Thus, the present disclosure is not intended to be limited to the aspects shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

The foregoing description has been presented for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the disclosure to the form disclosed herein. Although a number of example aspects and embodiments have been discussed above, a person of ordinary skill in the art will recognize certain variations, modifications, alterations, additions, and subcombinations thereof.

Claims

1. A method of measuring wind profile by a laser wind lidar, the method comprising:

at least 3 laser wind-finding radars and a data server are configured;

Obtaining geographic position coordinates and inclination angles with a horizontal plane of each laser wind-finding radar;

2. The method of claim 1, wherein the step of obtaining the geographic location and tilt angle to the horizontal of each lidar comprises:

The laser wind-finding radar determines the three-dimensional coordinate of the position of the laser wind-finding radar through a positioning system;

3. The laser wind lidar wind profile measurement method according to claim 1 or 2, wherein:

The measurement dip angle is used for determining dip angle direction of a wave beam of the laser wind-finding radar and a horizontal plane;

4. A method of measuring wind profile with a lidar according to claim 3, wherein the at least 3 lidars simultaneously emit laser beams to the same coordinate point of each of the layered acquisition heights and receive backscattered laser light of each of the layered acquisition heights, comprising:

when the emitted laser beams reach the common measurement target point, the emitted laser beams interact with particles in the atmosphere to generate back scattering laser, and the at least 3 laser wind-finding radars collect the back scattering laser.

5. The method for measuring wind profile by using laser wind-finding radar according to claim 1 or 2, wherein the at least 3 laser wind-finding radars respectively capture the back-scattered laser light, the back-scattered laser light is compared with the emitted laser beam in frequency, the frequency change is analyzed, and the radial velocity of the scattering particles is calculated, comprising:

Wherein Δf is the frequency offset of the backscattered laser light relative to the emitted laser beam, fr is the frequency of the emitted laser beam, ft is the frequency of the backscattered laser light, λ is the wavelength of the emitted laser beam, v is the radial velocity of the out-scattered particles, And forming an included angle between the emitted laser beam and the wind direction.

6. The method for measuring a wind profile by using laser wind-finding radars according to claim 1, wherein each of the at least 3 laser wind-finding radars transmits the calculated radial velocity of the scattering particles to the data server, and the data server uses a least square inversion algorithm to cooperatively process the radial velocity of the scattering particles respectively transmitted by the at least 3 laser wind-finding radars by combining a kalman filtering technology, so as to obtain an accurate three-dimensional wind profile, and the method comprises the following steps:

the at least 3 laser wind-finding radars send the radial velocity information of the scattering particles obtained by calculation to the data server, wherein the radial velocity information comprises radar identification, acquisition time, layering height and radial velocity of the scattering particles;

The data server fuses the radial speeds of the scattering particles collected by the at least 3 laser wind measuring radars at the same layering height and at the same time, and a wind speed vector is formed through a trigonometric function relation;

7. A laser wind-finding radar system, characterized in that the system comprises:

at least 3 laser wind-finding radars and a data server are configured;

8. A computer apparatus, the computer apparatus comprising:

at least one processor, and

A memory communicatively coupled to the at least one processor, wherein,

The memory stores instructions executable by the at least one processor to enable the at least one processor to perform the lidar wind profile method of any of claims 1-6.

9. A computer readable storage medium storing computer instructions for causing a computer to perform the laser wind radar wind profile method according to any one of claims 1-6.

10. A computer program product comprising computer instructions which, when executed by a processor, implement the steps of the method of any of claims 1-6.