Calibration method and system of wind measurement laser radar

Abstract

The invention discloses a calibration method and system for a wind measurement laser radar, and relates to the technical field of laser radars. In the method, a radar system is combined with a motor system to control the position of a target object to calibrate the measurement precision of a laser radar system. Specifically, a wind speed value output by a laser radar system is determined according to a signal reflected by a target object; when it is detected that the difference value between the actual wind speed value and the wind speed value output by the laser radar system is not within the preset range, parameters used for calculating the wind speed are corrected, and a new wind speed value output by the laser radar system is obtained; and when it is detected that the difference value between the actual wind speed value and the new wind speed value output by the laser radar system is within a preset range, determining that calibration of the wind measurement precision of the laser radar system is completed. Through the method, calibration of the wind measurement precision of the laser radar is realized, so that the wind measurement precision of the laser radar is ensured, and relatively accurate data service can be provided through the laser radar.

Description

Technical Field

[0001] The present invention relates to the technical field of lidar, and particularly to a calibration method and system for a wind-measuring lidar. Background Art

[0002] Wind power generation is a sustainable energy option that takes into account the environment, energy, and economy. Measuring wind speed is a crucial part of wind power generation projects. As a high-precision wind-measuring means that has emerged in recent years, lidar has been widely used in the wind energy field.

[0003] Lidar usually completes the calibration of measurement accuracy before use or before leaving the factory. As time goes by after leaving the factory, the performance of the light source components inside it will inevitably decline, and its laser frequency shift may change, resulting in a change in the calculated wind speed magnitude based on the Doppler frequency shift, which does not match the actual situation, that is, the measurement accuracy deteriorates.

[0004] Therefore, how to calibrate the wind-measuring accuracy of the radar system to ensure the wind-measuring accuracy of the lidar, so as to provide more accurate data services, is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0005] The purpose of the present invention is to provide a calibration method and system for a wind-measuring lidar to solve the technical problem of low wind-measuring accuracy of the lidar.

[0006] To solve the above technical problem, the present invention provides a calibration method for a wind-measuring lidar, which is applied to a controller in a lidar system, and the controller is connected to a motor system; at least a target object and a motor connected to the target object are included in the motor system, and the motor is used to control the target object to be located on a preset light beam path emitted by the lidar system; the method includes: Obtain the actual wind speed value and control the laser to emit a light beam along the preset light beam path; Receive the signal reflected by the target object and determine the wind speed value output by the lidar system according to the signal reflected by the target object; In the case where the difference between the actual wind speed value and the wind speed value output by the lidar system is not within the preset range, correct the parameters used to calculate the wind speed and obtain a new wind speed value output by the lidar system; In the case where the difference between the actual wind speed value and the new wind speed value output by the lidar system is within the preset range, determine that the calibration of the wind-measuring accuracy of the lidar system is completed.

[0007] Exemplarily, before obtaining the actual wind speed value and controlling the laser to emit a light beam along the preset light beam path, it further includes: Send an instruction for characterizing the calibration of the lidar system to the motor system, so that the motor system controls the motor to be powered on and perform a reset operation after receiving the instruction; Determine whether the current angle of the motor is 0°; If not, send an instruction for characterizing reset to the motor system, so that the motor system performs a reset operation and returns to the step of determining whether the current angle of the motor is 0°; If so, send a command containing a preset angle to the motor system, so that the motor controls the target to be at the preset angle position.

[0008] Exemplarily, before obtaining the actual wind speed value and controlling the laser to emit light along the preset beam path, it further includes: Send an instruction for characterizing the opening of a preset channel to the optical switch in the lidar system, so that the optical switch opens the preset channel according to the instruction; Obtain the currently opened channel of the optical switch; Determine whether the currently opened channel is the preset channel; If so, enter the step of obtaining the actual wind speed value and controlling the laser to emit light along the preset beam path; If not, return to the step of sending an instruction for characterizing the opening of a preset channel to the optical switch in the lidar system.

[0009] Exemplarily, before receiving the signal reflected by the target and determining the wind speed value output by the lidar system according to the signal reflected by the target, it further includes: Obtain the atmospheric signal and the signal reflected by the object; In the case where the signal reflected by the object is detected to be greater than the atmospheric signal, determine the first distance between the object and the lidar system according to the flight time; Obtain the second distance between the target and the lidar system; Obtain the distance difference between the first distance and the second distance; In the case where the detected distance difference is less than the preset distance, determine the signal reflected by the object as the signal reflected by the target, and enter the step of receiving the signal reflected by the target and determining the wind speed value output by the lidar system according to the signal reflected by the target; In the case where the detected distance difference is greater than or equal to the preset distance, return to the step of obtaining the signal reflected by the object.

[0010] Exemplarily, after determining that the signal reflected by the object is the signal reflected by the target, it further includes: Control the attenuation value of the fiber optic attenuator in the lidar system; Simulate the echo signal intensity of the atmosphere under different weather conditions at different attenuation values.

[0011] Exemplarily, when the target is a target board, the actual wind speed value is 0; Or, when the target is an anemometer or a wind vane, the actual wind speed value is the wind speed value measured by the anemometer or the wind vane.

[0012] Exemplarily, controlling the laser to emit a beam along the preset beam path includes: Controlling the current channel of the optical switch of the lidar system to be opened so that the laser emits a beam along the preset beam path corresponding to the current channel; Before determining that the wind measurement accuracy calibration of the lidar system is completed, it further includes: Judging whether all channels of the optical switch have completed the wind measurement accuracy calibration of the lidar system; If so, determine that the wind measurement accuracy calibration of the lidar system is completed; If not, control other channels of the optical switch of the lidar system to be opened so that the laser is controlled to emit a beam along the preset beam path; wherein, the other channels are any channels among all channels of the optical switch that have not completed the wind measurement accuracy calibration of the lidar system.

[0013] Exemplarily, after determining that the wind measurement accuracy calibration of the lidar system is completed, it further includes: Controlling the motor system to perform a reset operation, and power off the motor after detecting that the motor system has completed the reset operation.

[0014] To solve the above technical problems, the present invention further provides a calibration system for a wind measurement lidar, including a motor system, the motor system is connected to a controller in the lidar system; at least the motor system includes a target and a motor connected to the target, and the motor is used to control the target to be located on the preset beam path emitted by the lidar system; The controller is used for: obtaining the actual wind speed value and controlling the laser to emit a beam along the preset beam path; receiving the signal reflected by the target and determining the wind speed value output by the lidar system according to the signal reflected by the target; correcting the parameters for calculating the wind speed and obtaining the new wind speed value output by the lidar system when detecting that the difference between the actual wind speed value and the wind speed value output by the lidar system is not within the preset range; determining that the wind measurement accuracy calibration of the lidar system is completed when detecting that the difference between the actual wind speed value and the new wind speed value output by the lidar system is within the preset range.

[0015] Exemplarily, the lidar system further includes: a beam splitter, a laser amplifier and an acousto-optic modulator, an optical circulator, an optical fiber attenuator, an optical fiber coupler, a balanced detector, a data acquisition system, a multi-channel optical switch and a multi-channel optical antenna; The beam splitter is configured to receive the beam emitted by the laser and split the received beam into a first-path beam and a second-path beam; The laser amplifier and acousto-optic modulator, the optical circulator, the multi-channel optical switch and the multi-channel optical antenna are sequentially located on the transmission direction of the first-path beam; The optical fiber coupler is configured to receive the second-path beam and the third-path beam that is the atmospheric scattering signal after passing through the multi-channel optical antenna, the multi-channel optical switch, the optical circulator and the optical fiber attenuator in sequence; mix the second-path beam and the third-path beam and output the mixed signal to the balanced detector; The input end of the data acquisition system is connected to the output end of the balanced detector and is configured to acquire an electrical signal; The input end of the controller is connected to the output end of the data acquisition system and is configured to process the electrical signal to determine the wind speed value output by the lidar system; The output end of the controller is connected to the multi-channel optical switch and is configured to control the opening of a preset channel of the multi-channel optical switch.

[0016] The calibration method of the wind measurement lidar provided by the present invention is applied to the controller in the lidar system. The controller is connected to the motor system; the motor system at least includes a target and a motor connected to the target, and the motor is configured to control the target to be located on the preset beam path emitted by the lidar system. In this method, the radar system is combined with the motor system to control the position of the target to calibrate the measurement accuracy of the lidar system. Specifically, the wind speed value output by the lidar system is determined according to the signal reflected by the target; when it is detected that the difference between the actual wind speed value and the wind speed value output by the lidar system is not within the preset range, the parameters for calculating the wind speed are corrected and a new wind speed value output by the lidar system is obtained; when it is detected that the difference between the actual wind speed value and the new wind speed value output by the lidar system is within the preset range, it is determined that the calibration of the wind measurement accuracy of the lidar system is completed. Through this method, the calibration of the wind measurement accuracy of the lidar is realized, thereby ensuring the wind measurement accuracy of the lidar, enabling the lidar to provide relatively accurate data services; secondly, according to the signal intensity after reflection of the same target at a fixed distance in the same atmospheric environment, the changes in the performance of the light source component in the radar system and the sensitivity of the balanced detector can be judged.

[0017] In addition, the present invention also provides a system for a wind measurement lidar, which has the same or corresponding technical features as the calibration method of the wind measurement lidar described above, and the effects are the same. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention, the following will briefly introduce the drawings required for the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1 Schematic diagram of a calibration system for a wind measurement lidar provided by an embodiment of the present invention; Figure 2 Working schematic diagram of a calibration system for a wind measurement lidar provided by an embodiment of the present invention; Figure 3 Schematic diagram of an optical circulator provided by an embodiment of the present invention; Figure 4 Flowchart of a calibration method for a wind measurement lidar provided by an embodiment of the present invention; Figure 5 Overall flowchart of a calibration method for a calibration system of a wind measurement lidar provided by an embodiment of the present invention; Figure 6 Structural diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

[0021] The core of the present invention is to provide a calibration method and system for a wind measurement lidar to solve the technical problem of low wind measurement accuracy of the lidar.

[0022] In order to enable those skilled in the art to better understand the solution of the present invention, the present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0023] It should be noted that the lidar system provided by the present invention specifically refers to a nacelle-type Doppler lidar system. This lidar system is a coherent wind-measuring lidar, also known as a Doppler lidar, which is a radar that uses the Doppler effect to detect the position and relative motion speed of a moving target. When there is relative motion between the wave source and the observer, the frequency of the wave received by the observer is different from the frequency sent by the wave source. This phenomenon is called the Doppler effect. When the wave source and the observer approach each other, the received frequency increases; when they move away from each other, it decreases. The Doppler radar is a pulsed radar manufactured using this Doppler effect.

[0024] Figure 1 FIG. is a schematic diagram of a calibration system for a wind-measuring lidar provided by an embodiment of the present invention. As Figure 1 shown, the system includes a lidar system and a motor system. The motor system is connected to the controller in the lidar system; the motor system at least includes a target and a motor (rotating motor) connected to the target. The motor is used to control the target to be located on the preset beam path emitted by the lidar system. The lidar system includes a laser, a beam splitter, a laser amplifier, an acousto-optic modulator, an optical circulator, an optical fiber attenuator, an optical fiber coupler, a balanced detector, a data acquisition system, a controller (which can be a control terminal and a data processing system), a multi-channel optical switch, and a multi-channel optical antenna. The beam splitter is used to receive the beam emitted by the laser and split the received beam into a first beam and a second beam; the laser amplifier, the acousto-optic modulator, the optical circulator, the multi-channel optical switch, and the multi-channel optical antenna are sequentially located in the transmission direction of the first beam; The optical fiber coupler is used to receive the second beam and the third beam after the atmospheric scattering signal passes through the multi-channel optical antenna, the multi-channel optical switch, the optical circulator, and the optical fiber attenuator in sequence; the second beam and the third beam are subjected to mixing processing and the mixed signal is output to the balanced detector; The input end of the data acquisition system is connected to the output end of the balanced detector and is used to collect electrical signals; The input end of the controller is connected to the output end of the data acquisition system and is used to process the electrical signals to determine the wind speed value output by the lidar system; The output end of the controller is connected to the multi-channel optical switch and is used to control the opening of the preset channels of the multi-channel optical switch.

[0025] There is no limitation on the target, which is determined according to the actual situation. For example, the target is a target board. Figure 2 FIG. is a working schematic diagram of a calibration system for a wind-measuring lidar provided by an embodiment of the present invention. Figure 2 The dotted lines in the figure represent the beams emitted by the lidar system along multiple paths, and the yellow lines represent the network cables. One end of the motor is connected to the target board, and a counterweight component is provided on the other side of the motor to keep the target board balanced.

[0026] There is no limit to the number of channels of the multi-channel optical switch and the multi-channel optical antenna, which is determined according to the actual situation. Taking the laser as the seed laser, a 1×4 optical switch and correspondingly a 4-channel optical antenna as an example, the calibration system of the wind measurement lidar provided by the present invention will be described again.

[0027] Seed laser: It generates continuous light with a very narrow spectral width and low energy.

[0028] Optical splitter: It transmits the optical energy transmitted by one optical fiber to two optical fibers for output respectively according to a certain ratio.

[0029] Laser amplifier: It amplifies the power of the input optical signal.

[0030] Acousto-optic modulator: The acousto-optic modulator is a device that uses the acousto-optic effect to achieve modulation of light intensity, frequency, etc.

[0031] Optical circulator: When light is input from port 1, it is output from port 2; when input from port 2, it is output from port 3, as Figure 3 shown, Figure 3 which is a schematic diagram of an optical circulator provided by an embodiment of the present invention.

[0032] Optical fiber attenuator: It can attenuate the input light to any intensity.

[0033] Optical fiber coupler: It enables the optical signals transmitted in the optical fiber to be coupled in a coupling area with a special structure, and distributes and couples the optical power according to a certain ratio.

[0034] 1×4 optical switch: It can switch one input laser into 4 outputs in time sequence.

[0035] Balanced detector: It converts the input optical signal into an electrical signal, and realizes electrical signal balance and electrical signal amplification.

[0036] As Figure 1 shown, the calibration system of the wind measurement lidar is composed of a seed laser, an optical splitter, a laser amplifier, an acousto-optic modulator, an optical circulator, an optical fiber attenuator, an optical fiber coupler, a balanced detector, a data acquisition system, a control terminal, a data processing system, a 1×4 optical switch, a 4-channel optical antenna and a motor system. Among them, the 4-channel optical antenna plays the role of laser emission and reception. The lidar system is composed of a seed laser, an optical splitter, a laser amplifier, an acousto-optic modulator, an optical circulator, an optical fiber attenuator, an optical fiber coupler, a balanced detector, a data acquisition system, a controller, a 1×4 optical switch and a 4-channel optical antenna. The motor system is composed of a mast, a motor and a target plate blade.

[0037] In a lidar system, a continuous light with a very narrow spectral width is generated by a seed laser, and is split and output at a certain ratio through a splitter. One path with low energy output enters a fiber coupler as the intrinsic light, and the other path with high energy output enters a laser amplifier and an acousto-optic modulator. After optical power amplification and acousto-optic modulation frequency shift, a pulsed laser with a high repetition frequency and a fixed frequency shift is output. The pulsed laser is input from port 1 of an optical circulator and output from port 2 of the optical circulator to a 1×4 optical switch and four optical antennas, and is transmitted into the atmosphere. The atmospheric scattering signal is received by the four optical antennas. The received signal passes through the 1×4 optical switch and port 2 of the optical circulator, and is output from port 3 of the optical circulator to a fiber optic attenuator. The adjustment range of the fiber optic attenuator is controlled by a controller. The laser signal after passing through the fiber optic attenuator enters the fiber coupler and is mixed with the intrinsic light generated by the splitter. The mixed signal is output to a balanced detector, and its electrical signal is collected and processed by a data acquisition system, and finally data processing and wind field inversion are completed in the controller.

[0038] Based on the calibration system of the wind measurement lidar provided above, an embodiment of the calibration method of the wind measurement lidar provided by the present invention will be described below. This method is applied to the controller in the lidar system. Figure 4 It is a flowchart of a calibration method of a wind measurement lidar provided by an embodiment of the present invention, as Figure 4 shown. The method includes: S10: Obtain the actual wind speed value and control the laser to emit light along a preset light beam path; S11: Receive the signal reflected by the target and determine the wind speed value output by the lidar system according to the signal reflected by the target; S12: In the case where the difference between the detected actual wind speed value and the wind speed value output by the lidar system is not within the preset range, correct the parameters for calculating the wind speed and obtain the new wind speed value output by the lidar system; S13: In the case where the difference between the detected actual wind speed value and the new wind speed value output by the lidar system is within the preset range, determine that the calibration of the wind measurement accuracy of the lidar system is completed.

[0039] There is no limitation on the selected target. For example, the target is a target board. When the target board is stationary, its speed is 0, and the actual wind speed is also 0. In addition, the target can also be an anemometer or a wind vane.

[0040] Alternatively, when the target is an anemometer or a wind vane, the actual wind speed value is the wind speed value measured by the anemometer or the wind vane. A wind measurement tower or a target board with a fixed height can be set up at a certain safe distance in front of the wind turbine. A standard anemometer and a wind vane are installed at a fixed height on the wind measurement tower. When the laser beam emitted by the lidar system is aligned with the anemometer and the wind vane on the wind measurement tower, the measurement accuracy of the lidar system can be compared with that of the standard anemometer and wind vane. When the target is an anemometer or a wind vane, the actual wind speed value is the wind speed value measured by the anemometer or the wind vane.

[0041] To obtain the wind speed value output by the lidar system, it is necessary to control the beam emitted by the laser to the target, and determine the wind speed value output by the lidar system according to the received signal reflected by the target.

[0042] To enable the target to receive the beam emitted by the laser, before obtaining the actual wind speed value and controlling the laser to emit a beam along the preset beam path, it further includes: Sending an instruction characterizing the calibration of the lidar system to the motor system, so that the motor system controls the motor to be powered on and perform a reset operation after receiving the instruction; Judging whether the current angle of the motor is 0°; If not, sending an instruction characterizing reset to the motor system, so that the motor system performs a reset operation and returns to the step of judging whether the current angle of the motor is 0°; If so, sending a command containing a preset angle to the motor system, so that the motor controls the target to be located at the preset angle position.

[0043] The preset angle is not limited and is determined according to the actual situation. In this method, the angle of the motor is first judged for reset. When the current angle of the motor is 0°, the angle of the motor is then adjusted. Thus, driven by the motor, the angle of the target is also changed, achieving relatively accurate control of the angle of the target and enabling the target to be located on the preset beam path.

[0044] In addition, controlling the laser to emit a beam along the preset beam path includes: controlling the current channel of the optical switch of the lidar system to be opened, so that the laser emits a beam along the preset beam path corresponding to the current channel. To enable the beam emitted by the laser to be located on the preset beam path, before obtaining the actual wind speed value and controlling the laser to emit a beam along the preset beam path, it further includes: Sending an instruction characterizing the opening of a preset channel to the optical switch in the lidar system, so that the optical switch opens the preset channel according to the instruction; Obtaining the currently opened channel of the optical switch; Judging whether the currently opened channel is the preset channel; If so, proceed to the step of obtaining the actual wind speed value and controlling the laser to emit a light beam along a preset light beam path; If not, return to the step of sending an instruction to the optical switch in the lidar system to characterize the opening of a preset channel.

[0045] In this method, the channel opened by the optical switch is verified, which can ensure as much as possible that the light beam emitted by the laser is located on the preset light beam path.

[0046] After the laser emits a light beam along the preset light beam path, it will receive the signal reflected by the object. Between the lidar system and the target object, there may be other objects, resulting in the reflected signal received by the lidar system not coming from the target object, thus affecting the accuracy of the wind speed value output by the lidar system. Therefore, before receiving the signal reflected by the target object and determining the wind speed value output by the lidar system according to the signal reflected by the target object, it further includes: Obtain the atmospheric signal and the signal reflected by the object; In the case where the signal reflected by the object is detected to be greater than the atmospheric signal, determine the first distance between the object and the lidar system according to the flight time; Obtain the second distance between the target object and the lidar system; Obtain the distance difference between the first distance and the second distance; In the case where the detected distance difference is less than the preset distance, determine the signal reflected by the object as the signal reflected by the target object, and proceed to the step of receiving the signal reflected by the target object and determining the wind speed value output by the lidar system according to the signal reflected by the target object; In the case where the detected distance difference is greater than or equal to the preset distance, return to the step of obtaining the signal reflected by the object.

[0047] In this method, it is judged whether the reflected signal comes from the target object according to the signal reflected by the object and the distance between the target object and the lidar system, so as to realize the verification of the received reflected signal. Only when it is determined that the signal reflected by the object is the signal reflected by the target object, proceed to the step of receiving the signal reflected by the target object and determining the wind speed value output by the lidar system according to the signal reflected by the target object, realizing a more accurate calculation of the wind speed value output by the lidar system.

[0048] After determining that the signal reflected by the object is the signal reflected by the target object, it further includes: controlling the attenuation value of the fiber optic attenuator in the lidar system; simulating the echo signal intensity of the atmosphere under different weather conditions at different attenuation values. That is, by adjusting the fiber optic attenuator to different signal intensities, different weather states can be simulated to eliminate the influence of weather factors on the measurement accuracy.

[0049] After obtaining the actual wind speed value and the wind speed value output by the lidar system, the difference between the two can be calculated. Determine whether the difference is within a preset range. The preset range is not limited. Generally, the closer the two are, the higher the ranging accuracy of the lidar system. When the difference is not within the preset range, correct the parameters used to calculate the wind speed and obtain a new wind speed value output by the lidar system. When it is detected that the difference between the actual wind speed value and the new wind speed value output by the lidar system is within the preset range, it is determined that the calibration of the wind measurement accuracy of the lidar system is completed.

[0050] As described above, the lidar system includes a multi-channel optical switch. In order to calibrate all channels of the lidar system, before determining that the calibration of the wind measurement accuracy of the lidar system is completed, it further includes: Determine whether the wind measurement accuracy calibration of all channels of the optical switch for the lidar system is completed; If so, determine that the calibration of the wind measurement accuracy of the lidar system is completed; If not, control other channels of the optical switch of the lidar system to open, so as to control the laser to emit light along a preset beam path; wherein, the other channels are any of the channels among all channels of the optical switch that have not completed the wind measurement accuracy calibration of the lidar system.

[0051] The calibration of the wind measurement accuracy of all channels is achieved by this method.

[0052] After determining that the calibration of the wind measurement accuracy of the lidar system is completed, it further includes: Control the motor system to perform a reset operation, and cut off the power supply to the motor after checking that the motor system has completed the reset operation. By cutting off the power supply to the motor, the energy consumption is reduced.

[0053] It should be noted that the above calibration process can be carried out regularly, which can better and long-term ensure the measurement accuracy of the lidar system and provide more accurate data services. Since the radar system in this solution is installed above the nacelle and will yaw and rotate with the nacelle to face the wind, when the wind turbine yaws to a specific angle, the laser beam of the radar system will be aligned with the target target board or the wind measurement tower, realizing the calibration of the measurement accuracy of the static target board speed or the actual wind speed measurement accuracy.

[0054] Next, the calibration method of the calibration system of the wind measurement lidar of the present invention will be described again in conjunction with the drawings and embodiments. Figure 5 This is the overall flowchart of the calibration method of the calibration system of a wind measurement lidar provided by an embodiment of the present invention, as Figure 5 shown, the method includes: S14: The lidar stops working, and the controller issues a calibration command; S15: After receiving the calibration command, the rotary motor electronic control switch energizes the motor; S16: The rotating motor performs a reset. S17: Query whether the current angle of the rotating motor is 0°; if not, return to step S16; if so, proceed to step S18. S18: Control the rotating motor to rotate to a specific angle so that the target plate is located on the predetermined beam path. S19: The 1*4 optical switch stops automatic switching, receives and executes a specific command issued by the controller, and switches the optical switch to the specified channel. S20: Query whether the current optical switch is in the specified channel; if not, return to step S19; if so, proceed to step S21. S21: Control the laser to start emitting light. S22: Data acquisition and processing. S23: Determine whether the received signal is from the target plate; if not, proceed to step S24; if so, proceed to step S25. S24: Determine the deviation of the lidar pointing position and determine a calibration anomaly. S25: Control the fiber optic attenuator to output at a certain attenuation ratio to simulate the atmospheric signal intensity in different weather conditions. S26: Determine whether the wind measurement accuracy is within the normal range; if not, proceed to step S27; if so, end. S27: Calibrate the speed retrieved from the target plate signal to 0 m / s.

[0055] The system periodically initiates a calibration process, such as Figure 2 and Figure 5When the calibration process is initiated, the lidar system stops working, and the controller issues a calibration command. After receiving the command, the motor system powers on the rotating motor and performs a reset operation. The controller queries whether the current state angle position of the motor is 0, and then sends a specified angle command to the motor. After the lidar system stops working, the controller sends a specified channel command to the 1×4 optical switch. Subsequently, the controller initiates a status query to the 1×4 optical switch to confirm whether it is the specified channel. Then, the controller controls the laser to start working, and the system enters data acquisition and processing. Since the signal intensity reflected by the target board is much higher than that of the atmospheric signal, the control terminal can determine whether the signal comes from the target board based on the received signal intensity and the target distance. If not, the calibration process ends, and a warning signal indicating the pointing position deviation of the lidar system is output. If it is determined that the signal comes from the target board, the controller can control and adjust the fiber optic attenuator to simulate the signal intensity of atmospheric echoes in different weather conditions. Since the target board is in a stationary state with a speed of 0, the wind speed output by the controller and the data processing system should be 0 m / s. If the wind speed signal is not equal to 0 m / s, the controller corrects the parameters used to calculate the wind speed so that the wind speed value output by the lidar system is 0 m / s. Subsequently, the calibration of the other channels of the 1×4 optical switch is performed in sequence. The channel position of the 1×4 optical switch and the motor position are uniformly controlled by the controller issuing specific commands. After the calibration of all four channels of the 1×4 optical switch is completed, the process ends, and a calibration completion signal is output.

[0056] After calibration is completed, the lidar system resumes normal operation, and the motor system cuts off the power to the motor after performing a reset.

[0057] In the calibration method of the wind measurement lidar provided by the present invention, by using the target board signal and the fact that the speed of a stationary object is 0, the measurement accuracy of the wind speed of the lidar system can be calibrated; by using an anemometer or a wind vane to measure the real-time wind speed, dynamic calibration of the wind measurement accuracy of the lidar system can be achieved; by using the controller to control the target board at a specified position, the beam pointing position of the lidar system can be calibrated to determine whether the installation attitude has changed; by using the fiber optic attenuator to adjust different signal intensities, different weather conditions can be simulated to eliminate the influence of weather factors on the measurement accuracy; by using the signal intensity reflected by the same target board at a fixed distance in the same atmospheric environment, the performance of the light source component in the radar system and the change in the sensitivity of the balanced detector can be judged.

[0058] The above text describes a calibration method for a wind measurement lidar. The present invention also provides a calibration system for a wind measurement lidar, including a motor system, which is connected to the controller in the lidar system; the motor system at least includes a target object and a motor connected to the target object, and the motor is used to control the target object to be located on the preset beam path emitted by the lidar system; The controller is used to: obtain the actual wind speed value and control the laser to emit a light beam along a preset light beam path; receive the signal reflected by the target and determine the wind speed value output by the lidar system according to the signal reflected by the target; when it is detected that the difference between the actual wind speed value and the wind speed value output by the lidar system is not within the preset range, correct the parameters for calculating the wind speed and obtain the new wind speed value output by the lidar system; when it is detected that the difference between the actual wind speed value and the new wind speed value output by the lidar system is within the preset range, determine that the calibration of the wind measurement accuracy of the lidar system is completed.

[0059] In addition, the lidar system further includes: a beam splitter, a laser amplifier, an acousto-optic modulator, an optical circulator, an optical fiber attenuator, an optical fiber coupler, a balanced detector, a data acquisition system, a multi-channel optical switch, and a multi-channel optical antenna; The beam splitter is used to receive the light beam emitted by the laser and split the received light beam into a first light beam and a second light beam; The laser amplifier, the acousto-optic modulator, the optical circulator, the multi-channel optical switch, and the multi-channel optical antenna are sequentially located on the transmission direction of the first light beam; The optical fiber coupler is used to receive the second light beam and the third light beam that is the atmospheric scattering signal passing through the multi-channel optical antenna, the multi-channel optical switch, the optical circulator, and the optical fiber attenuator in sequence; perform mixing processing on the second light beam and the third light beam and output the mixed signal to the balanced detector; The input end of the data acquisition system is connected to the output end of the balanced detector and is used to collect electrical signals; The input end of the controller is connected to the output end of the data acquisition system and is used to process the electrical signals to determine the wind speed value output by the lidar system; The output end of the controller is connected to the multi-channel optical switch and is used to control the opening of a preset channel of the multi-channel optical switch.

[0060] The calibration system of the wind measurement lidar provided in this embodiment has the same or corresponding technical features as the calibration method of the wind measurement lidar described above. The embodiments of the calibration method of the wind measurement lidar have been described in detail above, and the embodiments of the calibration system of the wind measurement lidar will not be elaborated here, and the effects are the same.

[0061] In the above embodiments, the calibration method of the wind measurement lidar has been described in detail. The present invention also provides corresponding embodiments of a calibration device and an electronic device for the wind measurement lidar. It should be noted that the present invention describes the embodiments of the device part from two perspectives, one is from the perspective of functional modules, and the other is from the perspective of hardware.

[0062] The calibration device of the wind measurement lidar provided by the embodiment of the present invention, from the perspective of functional modules, includes: An acquisition module, configured to acquire an actual wind speed value and control a laser to emit a light beam along a preset light beam path; A receiving and determining module, configured to receive a signal reflected by a target and determine a wind speed value output by the lidar system according to the signal reflected by the target; A calibration and acquisition module, configured to correct a parameter for calculating the wind speed and acquire a new wind speed value output by the lidar system when it is detected that the difference between the actual wind speed value and the wind speed value output by the lidar system is not within a preset range; A determining module, configured to determine that the calibration of the wind measurement accuracy of the lidar system is completed when it is detected that the difference between the actual wind speed value and the new wind speed value output by the lidar system is within a preset range.

[0063] Since the embodiments of the device part correspond to the embodiments of the method part, please refer to the description of the embodiments of the method part for the embodiments of the device part, which will not be elaborated here.

[0064] Figure 6 The figure is a structural diagram of an electronic device provided by an embodiment of the present invention. From a hardware perspective, as Figure 6 shown, the electronic device includes: A memory 20, configured to store a computer program; A processor 21, configured to implement the steps of the calibration method of the wind measurement lidar as mentioned in the above embodiments when executing the computer program.

[0065] Wherein, the processor 21 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 21 may be implemented in at least one hardware form of a digital signal processor (DSP), a field-programmable gate array (FPGA), and a programmable logic array (PLA). The processor 21 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the wake state, also known as a central processing unit (CPU); the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the processor 21 may be integrated with a graphics processing unit (GPU), and the GPU is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 21 may further include an artificial intelligence (AI) processor, and the AI processor is used to process calculation operations related to machine learning.

[0066] The memory 20 may include one or more computer-readable storage media, which may be non-transitory. The memory 20 may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices and flash storage devices. In this embodiment, the memory 20 is at least used to store the following computer program 201. After the computer program is loaded and executed by the processor 21, it can implement the relevant steps of the calibration method of the wind measurement lidar disclosed in any of the foregoing embodiments. In addition, the resources stored in the memory 20 may also include an operating system 202 and data 203, etc., and the storage method may be transient storage or permanent storage. Among them, the operating system 202 may include Windows, Unix, Linux, etc. The data 203 may include, but is not limited to, the data involved in the calibration method of the wind measurement lidar mentioned above.

[0067] In some embodiments, the electronic device may further include a display screen 22, an input / output interface 23, a communication interface 24, a power supply 25, and a communication bus 26.

[0068] Those skilled in the art can understand that Figure 6 the structure shown in does not constitute a limitation on the electronic device, and it may include more or fewer components than shown in the figure.

[0069] The electronic device provided by the embodiment of the present invention includes a memory and a processor. When the processor executes the program stored in the memory, it can implement the following method: the calibration method of the wind measurement lidar, and the effect is the same as above.

[0070] Finally, the present invention also provides an embodiment corresponding to a computer-readable storage medium. A computer program is stored on the computer-readable storage medium, and when the computer program is executed by the processor, it implements the steps recorded in the above method embodiments.

[0071] It can be understood that if the method in the above embodiments is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and executes all or part of the steps of the methods described in the various embodiments of the present invention. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs that can store program codes.

[0072] The computer-readable storage medium provided by the present invention includes the above-mentioned calibration method of the wind-measuring lidar, and the effect is the same as above.

[0073] The above has introduced in detail a calibration method and system of a wind-measuring lidar provided by the present invention. The various embodiments in the specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the various embodiments, reference can be made to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and reference can be made to the description of the method part for the relevant parts. It should be noted that for those of ordinary skill in the art in the technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the present invention.

[0074] It should also be noted that in this specification, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of another identical element in the process, method, article or device including the said element.

Claims

1. A calibration method for a wind laser radar, characterized in that: A controller used in a laser radar system, wherein the controller is connected to a motor system; the motor system at least includes a target and a motor connected to the target, and the motor is used to control the target to be located on a preset light beam path emitted by the laser radar system; the method includes: Acquiring an actual wind speed value and controlling the laser to emit a light beam along the preset light beam path; receiving a signal reflected by the target object and determining a wind speed value output by a laser radar system according to the signal reflected by the target object; When it is detected that the difference between the actual wind speed value and the wind speed value output by the laser radar system is not within a preset range, correcting the parameters used to calculate the wind speed and obtaining a new wind speed value output by the laser radar system; When it is detected that the difference between the actual wind speed value and the new wind speed value output by the laser radar system is within the preset range, it is determined that the calibration of the wind measurement accuracy of the laser radar system is completed.

2. The calibration method of the wind laser radar according to claim 1, characterized in that: Before obtaining the actual wind speed value and controlling the laser to emit a light beam along the preset light beam path, the method further includes: Sending an instruction for characterizing the calibration of the laser radar system to the motor system, so that the motor system controls the motor to be powered on and performs a reset operation after receiving the instruction; Determine whether the current angle of the motor is 0°; If not, sending a command for indicating a reset to the motor system so that the motor system performs a reset operation and returns to the step of determining whether the current angle of the motor is 0°; If so, a command including a preset angle is sent to the motor system so that the motor controls the target object to be located at the preset angle position.

3. The calibration method of the wind laser radar according to claim 1, characterized in that: Before obtaining the actual wind speed value and controlling the laser to emit a light beam along the preset light beam path, the method further includes: Sending an instruction for indicating opening a preset channel to an optical switch in the laser radar system, so that the optical switch opens the preset channel according to the instruction; Obtaining the channel currently turned on by the optical switch; Determine whether the currently opened channel is the preset channel; If yes, proceed to the step of obtaining the actual wind speed value and controlling the laser to emit a light beam along the preset light beam path; If not, return to the step of sending an instruction to the optical switch in the laser radar system to indicate opening the preset channel.

4. The calibration method of the wind laser radar according to any one of claims 1 to 3, characterized in that: Before receiving the signal reflected by the target object and determining the wind speed value output by the laser radar system according to the signal reflected by the target object, the method further includes: Acquire atmospheric signals and acquire signals reflected by objects; When it is detected that the signal reflected by the object is greater than the atmospheric signal, determining a first distance between the object and the laser radar system according to the flight time; Acquire a second distance between the target object and the laser radar system; Obtaining a distance difference between the first distance and the second distance; In the case where it is detected that the distance difference is less than the preset distance, determining that the signal reflected by the object is the signal reflected by the target object, and entering the step of receiving the signal reflected by the target object and determining the wind speed value output by the laser radar system according to the signal reflected by the target object; When it is detected that the distance difference is greater than or equal to the preset distance, the process returns to the step of acquiring the signal reflected by the object.

5. The calibration method of the wind laser radar according to claim 4, characterized in that: After determining that the signal reflected by the object is the signal reflected by the target object, the method further includes: Control the attenuation value of the fiber attenuator in the laser radar system; Simulate the echo signal strength of the atmosphere under different weather conditions at different attenuation values.

6. The calibration method of the wind laser radar according to claim 1, characterized in that: When the target object is a target plate, the actual wind speed value is 0; Alternatively, when the target object is an anemometer or an anemometer, the actual wind speed value is a wind speed value measured by the anemometer or anemometer.

7. The calibration method of the wind laser radar according to claim 3, characterized in that: The controlling the laser to emit a light beam along the preset light beam path comprises: Controlling the current channel of the optical switch of the laser radar system to open so that the laser emits a light beam along the preset light beam path corresponding to the current channel; Before determining that the calibration of the wind measurement accuracy of the laser radar system is completed, the method further includes: Determining whether all channels of the optical switch have completed the calibration of the wind measurement accuracy of the laser radar system; If yes, it is determined that the calibration of the wind measurement accuracy of the laser radar system is completed; If not, the other channels of the optical switch of the laser radar system are controlled to open so as to control the laser to emit a light beam along the preset beam path; wherein the other channels are any channels among all the channels of the optical switch for which the calibration of the wind measurement accuracy of the laser radar system has not been completed.

8. The calibration method of the wind laser radar according to claim 7, characterized in that: After the determination of completion of the calibration of the wind measurement accuracy of the laser radar system, the method further includes: The motor system is controlled to perform a reset operation, and after checking that the motor system completes the reset operation, the motor is powered off.

9. A calibration system for a wind laser radar, characterized in that: The motor system comprises a motor system connected to a controller in a laser radar system; the motor system comprises at least a target object and a motor connected to the target object, and the motor is used to control the target object to be located on a preset light beam path emitted by the laser radar system; The controller is used to: obtain the actual wind speed value and control the laser to emit a light beam along the preset light beam path; receive the signal reflected by the target and determine the wind speed value output by the laser radar system according to the signal reflected by the target; when it is detected that the difference between the actual wind speed value and the wind speed value output by the laser radar system is not within a preset range, correct the parameters used to calculate the wind speed and obtain a new wind speed value output by the laser radar system; when it is detected that the difference between the actual wind speed value and the new wind speed value output by the laser radar system is within the preset range, determine that the calibration of the wind measurement accuracy of the laser radar system is completed.

10. The calibration system for wind laser radar according to claim 9, characterized in that: The laser radar system also includes: a spectrometer, a laser amplifier and an acousto-optic modulator, an optical circulator, a fiber attenuator, a fiber coupler, a balanced detector, a data acquisition system, a multi-channel optical switch and a multi-channel optical antenna; The beam splitter is used to receive the light beam emitted by the laser, and split the received light beam into a first light beam and a second light beam; The laser amplifier and the acousto-optic modulator, the optical circulator, the multi-channel optical switch and the multi-channel optical antenna are sequentially located in the transmission direction of the first light beam; The optical fiber coupler is used to receive the second optical beam and the third optical beam after receiving the atmospheric scattered signal through the multi-channel optical antenna, the multi-channel optical switch, the optical circulator and the optical fiber attenuator in sequence; perform mixing processing on the second optical beam and the third optical beam and output the mixed signal to the balanced detector; The input end of the data acquisition system is connected to the output end of the balanced detector for collecting electrical signals; The input end of the controller is connected to the output end of the data acquisition system, and is used to process the electrical signal to determine the wind speed value output by the laser radar system; The output end of the controller is connected to the multi-way optical switch and is used to control the opening of a preset channel of the multi-way optical switch.

Images