A lightweight wind measurement lidar system based on an unmanned aerial vehicle platform

Abstract

A lightweight wind measurement lidar system based on an unmanned aerial vehicle (UAV) platform includes a servo scanning unit, a radar measurement unit, and a system mount. The radar measurement unit utilizes a lightweight main frame and employs a variety of lightweight materials in its structural design. The internal space of the radar measurement unit is divided into multiple distinct partitions, which are stacked in layers, resulting in a complete redesign of the hardware solution, composition, and stacking method. The deep integration of hardware and structure gives the system significant advantages in size and weight, achieving miniaturization and lightweighting, bringing the radar system weight to 5-7kg. The servo scanning unit also includes a two-degree-of-freedom scanning servo device, which enables the system to perform three-dimensional scanning over a wide range, realizing multiple scanning modes such as PPI, VAD, and RHI. During scanning, the servo scanning unit's end-point pointing is adjusted based on the UAV platform's current attitude information to compensate for changes in the UAV platform's attitude.

Description

Technical Field

[0001] The present invention relates to the technical field of meteorological remote sensing instruments and equipment, and in particular to a lightweight wind measurement lidar system based on an unmanned aerial vehicle platform. Background Art

[0002] In meteorological observation, wind lidar measures the Doppler effect of atmospheric particles, such as aerosols, tiny water droplets, and gas molecules, to determine the relative velocity between these tracers and the lidar. This velocity is then used as wind speed data. Since its introduction, lidar has become a powerful tool for meteorological observation, characterized by its high accuracy, high temporal and spatial resolution, and wide coverage. Wind lidar is currently deployed primarily on land, on vehicles, on ships, on ocean buoys, or on offshore engineering platforms. In recent years, some wind lidar systems have evolved into versions that can be deployed on medium- to large-sized aircraft, including some capable of being deployed on medium- to large-sized drones. Installing lidar on drones combines the advantages of lidar and drone platforms. UAVs offer flexibility and low deployment costs. Thanks to lidar's high temporal and spatial resolution, wind lidar technology can complement and strengthen existing meteorological observation networks.

[0003] As described in the background above, most early wind lidar products were large and heavy, making them relatively unportable and difficult to deploy, especially on small platforms. Technological advancements, such as advances in laser technology and integrated circuit technology, have enabled the miniaturization of wind lidars. Currently, some wind lidar products weigh around 20 kg and can be deployed on vehicles, small boats, buoys, and medium- to large-sized aircraft. However, the high cost of operating wind lidar on medium- to large-sized aircraft has hindered its further adoption. Summary of the Invention

[0004] The main technical problem solved by the present invention is to propose a lightweight wind measurement lidar system that can be carried on an unmanned aerial vehicle platform, thereby reducing the difficulty of deploying the wind measurement lidar on the unmanned aerial vehicle platform and promoting the promotion and application of lidar.

[0005] According to a first aspect, an embodiment provides a lightweight wind measurement lidar system based on an unmanned aerial vehicle platform. The lightweight wind measurement lidar system is carried on the unmanned aerial vehicle platform and includes a servo scanning unit and a radar measurement unit. The radar measurement unit uses a lightweight main frame made of lightweight materials, and the internal space of the radar measurement unit is divided into multiple different partitions. The multiple different partitions are arranged in a stacked manner, and different modules in the radar measurement unit are deployed in corresponding partitions.

[0006] The servo scanning unit is configured to obtain current posture information of the UAV platform, calculate scanning pointing information of the servo scanning unit based on the current posture information, and transmit the scanning pointing information to the radar measurement unit; wherein the scanning pointing information includes target coordinate values of the end of the servo scanning unit pointing to the earth coordinate system where the UAV platform is located, and the emission direction of the laser beam in the radar measurement unit is determined by the pointing direction of the end of the servo scanning unit;

[0007] The radar measurement unit is used to transmit the laser beam into the atmosphere in the emission direction, receive the echo signal generated after the laser beam interacts in the atmosphere, calculate the wind speed information corresponding to the echo signal, and receive the scanning direction information sent by the servo scanning unit, and correct the wind speed information according to the scanning direction information to obtain the corrected wind speed information.

[0008] In some embodiments, the servo scanning unit includes a posture detection module and a pointing information calculation module;

[0009] The posture detection module is used to detect the current posture information of the UAV platform in the body coordinate system and send the current posture information to the pointing information calculation module;

[0010] The pointing information calculation module is used to convert the received current posture information into posture information in the geodetic coordinate system, calculate the posture difference value based on the posture information in the geodetic coordinate system and the pre-set posture value, calculate the scanning pointing information based on the posture difference value and the spatial characteristic parameters of the servo scanning unit, and send the scanning pointing information to the radar measurement unit.

[0011] In some embodiments, the servo scanning unit further includes a drive control module and a motor;

[0012] The drive control module is used to generate a corresponding terminal control instruction according to the scanning pointing information and send the terminal control instruction to the motor;

[0013] The motor is used to receive the terminal control instruction sent by the drive control module and adjust the terminal direction of the servo scanning unit according to the terminal control instruction.

[0014] In some embodiments, the servo scanning unit further includes a scanning direction adjustment module;

[0015] The scanning direction adjustment module is used to control the laser beam in the radar measurement unit to be emitted into the atmosphere according to the emission direction, and to make the echo signal generated after the laser beam interacts in the atmosphere return to the radar measurement unit according to the emission direction.

[0016] In some embodiments, the scanning direction adjustment module includes an optical lens group; wherein, the optical lens group includes a first reflector and a second reflector, the first reflector is used to control the emission direction of the laser beam, and the second reflector is used to adjust the direction of the laser beam so that the direction of the laser beam controlled by the first reflector and the second reflector covers a preset scanning range.

[0017] In some embodiments, the radar measurement unit includes a laser, a signal transceiver module, a photoelectric balance detector, a signal processing module, a wind speed identification module, and a wind speed correction module;

[0018] The laser is used to generate a laser beam;

[0019] The signal transceiver module is used to transmit the laser beam generated by the laser into the atmosphere according to the emission direction, and receive the echo signal generated after the laser beam interacts in the atmosphere;

[0020] The photoelectric balance detector is used to receive the echo signal and convert the echo signal into a corresponding electrical signal;

[0021] The signal processing module is used to receive the electrical signal output by the photoelectric balance detector, perform sampling processing on the electrical signal, and convert the sampled electrical signal into the frequency domain to obtain spectrum data;

[0022] The wind speed identification module is used to identify and obtain wind speed information based on the spectrum data;

[0023] The wind speed correction module is used to determine a corresponding error value according to the target coordinate value in the scanning pointing information and the actual coordinate value of the servo scanning unit, and correct the wind speed information based on the error value to obtain corrected wind speed information.

[0024] In some embodiments, the radar measurement unit further includes a wireless data transmission module, a power supply module, and a temperature control module;

[0025] The wireless data transmission module is used to transmit the corrected wind speed information to the ground terminal so as to display the corrected wind speed information on the ground terminal;

[0026] The power supply module is used to provide power to the radar measurement unit;

[0027] The temperature control module is used to detect the operating temperature of the radar measurement unit and control the operating temperature within a preset temperature range.

[0028] In some embodiments, the lightweight wind measurement lidar system further includes a system bracket; the system bracket is used to connect the radar measurement unit and the servo scanning unit, and to fix the connected radar measurement unit and the servo scanning unit on the UAV platform.

[0029] In some embodiments, the radar measuring unit includes a power supply module, a photoelectric balance detector, a signal transceiver module, and a laser; the internal space of the radar measuring unit is divided into an electronic component layer, an optical layer, and a heat dissipation layer, and an air duct is included between the electronic component layer and the optical layer, wherein the electronic component layer is the top layer of the radar measuring unit, the optical layer is below the electronic component layer, and the heat dissipation layer is below the optical layer; the power supply module and the photoelectric balance detector are deployed on the electronic component layer, and the signal transceiver module and the laser are deployed on the optical layer, the heat dissipation layer is used to dissipate heat for the laser, and the air duct is used to assist the radar measuring unit in dissipating heat.

[0030] In some embodiments, the lightweight main frame is made of aluminum alloy, and the lightweight main frame includes slotted parts and / or hollow parts, and the slotted parts and / or hollow parts are covered with carbon fiber plates. The radar measurement unit also includes an outer shell, and the outer shell is made of nylon engineering plastic.

[0031] According to the lightweight wind measurement lidar system based on the UAV platform of the above embodiment, since the radar measurement unit adopts a lightweight main frame, and the lightweight main frame is made of lightweight materials, the weight of the wind measurement lidar system is reduced. The internal space of the radar measurement unit is divided into a plurality of stacked partitions, and the different modules in the radar measurement unit are deployed in the corresponding partitions, so that the space utilization rate of the radar measurement unit is greatly improved, and the volume of the system can be controlled. Since the servo scanning unit calculates the scanning pointing information based on the current posture information of the UAV platform and sends the scanning pointing information to the radar measurement unit, the radar measurement unit can correct the wind speed information calculated according to the received scanning pointing information, thereby correcting the wind speed information in real time according to the current posture information of the UAV platform to obtain accurate wind speed information. Therefore, the proposed lightweight wind measurement lidar system not only has a lightweight design, but also can obtain accurate wind speed information. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 1 is a schematic structural diagram of a lightweight wind measurement lidar system based on an unmanned aerial vehicle platform according to an embodiment of the present invention;

[0033] Figure 2 Schematic diagram of the structure of a lightweight wind measurement lidar system based on an unmanned aerial vehicle platform according to another embodiment;

[0034] Figure 3 Schematic diagram of the structure of a lightweight wind measurement lidar system based on an unmanned aerial vehicle platform according to another embodiment;

[0035] Figure 4 Schematic diagram of the structure of a lightweight wind measurement lidar system based on an unmanned aerial vehicle platform according to another embodiment;

[0036] Figure 5 Schematic diagram of the structure of a lightweight wind measurement lidar system based on an unmanned aerial vehicle platform according to another embodiment;

[0037] Figure 6 Schematic diagram of the structure of a lightweight wind measurement lidar system based on an unmanned aerial vehicle platform according to another embodiment;

[0038] Figure 7 A schematic diagram of the system composition of a lightweight wind measurement lidar system based on an unmanned aerial vehicle platform according to an embodiment;

[0039] Figure 8 The figure is a schematic diagram of the internal stacking layout of a lightweight wind measurement lidar system based on an unmanned aerial vehicle platform according to an embodiment. DETAILED DESCRIPTION

[0040] The present invention will be further described in detail below by means of specific embodiments in conjunction with the accompanying drawings. Similar elements in different embodiments are numbered with associated similar elements. In the following embodiments, many detailed descriptions are provided to enable the present application to be better understood. However, those skilled in the art will readily appreciate that some of the features may be omitted in different circumstances, or may be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification. This is to avoid the core portion of the present application being overwhelmed by excessive descriptions, and for those skilled in the art, it is not necessary to describe these related operations in detail. They will fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0041] In addition, the features, operations, or characteristics described in the specification may be combined in any appropriate manner to form various embodiments. Furthermore, the steps or actions in the method description may be reordered or adjusted in a manner readily apparent to those skilled in the art. Therefore, the various sequences in the specification and drawings are provided solely for the purpose of clearly describing a particular embodiment and are not intended to be mandatory, unless otherwise specified.

[0042] Component numbers used herein, such as "first" and "second," are used solely to distinguish the components being described and do not convey any sequential or technical meaning. References to "connection" and "coupling" herein, unless otherwise specified, include both direct and indirect connections (couplings).

[0043] Please refer to Figure 1 In an embodiment of the present invention, a lightweight wind measurement lidar system based on an unmanned aerial vehicle platform is provided. The lightweight wind measurement lidar system is mounted on the unmanned aerial vehicle platform. The lightweight wind measurement lidar system includes a servo scanning unit 10 and a radar measurement unit 20, which are described in detail below.

[0044] In some embodiments, the servo scanning unit 10 is used to obtain the current posture information of the UAV platform, calculate the scanning direction information of the servo scanning unit 10 based on the current posture information, and send the scanning direction information to the radar measurement unit 20. The servo scanning unit 10 can be a two-degree-of-freedom servo scanning unit that can implement multiple scanning modes such as PPI, VAD, and RHI in different directions according to user needs.

[0045] In some embodiments, the scanning pointing information includes the target coordinate value of the end pointing of the servo scanning unit 10 in the geodetic coordinate system where the UAV platform is located, wherein the end pointing of the servo scanning unit 10 refers to the final pointing position of the servo scanning unit 10 during the scanning process, and the emission direction of the laser beam in the radar measurement unit 20 is determined by the end pointing of the servo scanning unit 10.

[0046] Please refer to Figure 2 In some embodiments, the servo scanning unit 10 includes a posture detection module 101 and a pointing information calculation module 102, which are described in detail below.

[0047] In some embodiments, the posture detection module 101 is used to detect the current posture information of the UAV platform in the body coordinate system, and send the current posture information to the pointing information calculation module 102.

[0048] In this embodiment, the attitude detection module 101 senses the current attitude information of the drone platform in real time, and adjusts the servo scanning unit 10 based on the current attitude information, thereby compensating for attitude changes of the drone platform and maintaining the stable pointing direction of the end of the servo scanning unit 10. The current attitude information of the drone platform refers to the attitude information of the drone platform's current body coordinate system relative to the earth coordinate system or the initial state coordinate system. This attitude information includes but is not limited to the Euler angle values or quaternion values on the x-axis, y-axis, and z-axis obtained by the gyroscope or inertial measurement unit. The above-mentioned attitude information is fed back to the main control module of the wind measurement lidar system.

[0049] In some embodiments, the orientation information calculation module 102 is configured to convert the received current attitude information into attitude information in a geodetic coordinate system, calculate an attitude difference value based on the attitude information in the geodetic coordinate system and a preset attitude value, calculate scanning orientation information based on the attitude difference value and spatial characteristic parameters of the servo scanning unit 10, and transmit the scanning orientation information to the radar measurement unit 20. The spatial characteristic parameters of the servo scanning unit 10 include the spatial geometric arrangement sequence of the rotating axes and the transmission relationship between the motor and the rotating axes.

[0050] In some embodiments, because the received current attitude information is the attitude information of the current body coordinate system of the UAV platform relative to the earth coordinate system or the initial state coordinate system, the current attitude information is converted into attitude information in the earth coordinate system. A attitude difference is calculated based on the attitude information in the earth coordinate system and a pre-set attitude value. This attitude difference reflects the change or trend of the terminal beam pointing vector in the earth coordinate system. Based on the attitude difference and the spatial characteristic parameters of the servo scanning unit 10, the target coordinate value of the terminal pointing of the servo scanning unit 10 in the earth coordinate system where the UAV platform is located is calculated, and the target coordinate value is superimposed with the corresponding timestamp and transmitted to the radar measurement unit 20 in the form of a data packet.

[0051] Please refer to Figure 3 In some embodiments, the servo scanning unit 10 further includes a drive control module 103 and a motor 104, which will be described in detail below.

[0052] In some embodiments, the drive control module 103 is configured to generate corresponding terminal control instructions according to the scanning pointing information, and send the terminal control instructions to the motor 104 .

[0053] In this embodiment, the drive control module 103 can also collect information such as the current position, speed, current and voltage of the motor 104, and feed this information back to the main control module of the lightweight wind measurement lidar system.

[0054] In some embodiments, the motor 104 is configured to receive an end control instruction sent by the drive control module 103 and adjust the end direction of the servo scanning unit 10 according to the end control instruction.

[0055] In this embodiment, the distal end orientation of the servo scanning unit 10 is adjusted according to the distal end control instruction, thereby maintaining the orientation of the servo scanning unit 10 stable in the earth coordinate system.

[0056] Please refer to Figure 4 In some embodiments, the servo scanning unit 10 further includes a scanning direction adjustment module 105, which will be described in detail below.

[0057] In some embodiments, the scanning direction adjustment module 105 is used to control the laser beam in the radar measurement unit 20 to be emitted into the atmosphere according to the emission direction, and to make the echo signal generated after the laser beam interacts in the atmosphere return to the radar measurement unit 20 according to the emission direction.

[0058] In this embodiment, the scanning direction adjustment module 105 controls the emission direction of the laser beam in the radar measurement unit 20, enabling the wind laser radar to perform various scanning measurement modes, such as VAD, PPI, and RHI. Communication can be established between the servo scanning unit 10 and the radar measurement unit 20. The servo scanning unit 10 can coordinate the operating mode of the radar measurement unit 20 to ensure that the scanning and measurement of the two are unified to obtain accurate wind speed measurement results. At the same time, under the coordinated control of the system's main control module, the servo scanning unit 10 can adjust the terminal beam pointing in real time based on the current attitude information obtained, thereby reducing the impact of changes in the drone platform's attitude and maintaining the stability of the terminal pointing.

[0059] In some embodiments, the scanning direction adjustment module 105 includes an optical lens group; wherein the optical lens group includes a first reflector and a second reflector, the first reflector is used to control the emission direction of the laser beam, and the second reflector is used to adjust the direction of the laser beam so that the direction of the laser beam controlled by the first reflector and the second reflector covers a preset scanning range.

[0060] In this embodiment, the combined motion of the first and second reflectors enables the laser beam to be oriented over a range no less than half the zenith. The emission direction refers to the path the laser beam takes after being emitted from the laser and guided by the first reflector. The laser beam's direction of travel refers to the direction the laser beam takes, after being reflected by the second reflector, until it reaches the target location or area.

[0061] In some embodiments, the servo scanning unit 10 also includes a system main structure, which is used to connect the various modules in the servo scanning unit 10. Through the combination of the various modules, a structure that can adapt to the scanning action is realized, completing the main functions such as power transmission, combination of electrical parts and structures, and overall combination sealing, waterproofing, and dustproofing.

[0062] In some embodiments, the radar measurement unit 20 is used to transmit the laser beam into the atmosphere in the emission direction, receive the echo signal generated after the laser beam interacts in the atmosphere, calculate the wind speed information corresponding to the echo signal, and receive the scanning direction information sent by the servo scanning unit 10, correct the wind speed information according to the scanning direction information, and obtain the corrected wind speed information.

[0063] In some embodiments, the lightweight wind measurement lidar system composed of the servo scanning unit 10 and the radar measuring unit 20 is capable of measuring radial wind speed information at different distances in a specified direction, and constructing three-dimensional wind field data through the radial wind speed information. After receiving the scanning pointing information sent by the servo scanning unit 10, further data correction can be performed in the process of inverting wind speed and wind direction in combination with the scanning pointing information to obtain more accurate wind direction, horizontal wind and vertical wind information. At the same time, the terminal pointing of the servo scanning unit 10 is also adjusted through the terminal control instruction to keep the pointing of the servo scanning unit 10 stable in the geodetic coordinate system. In summary, in the process of measuring wind speed, the pointing is corrected physically and calculatedly, respectively, which together constitute a two-stage pointing correction based on the servo scanning unit 10.

[0064] Please refer to Figure 5 In some embodiments, the radar measurement unit 20 includes a laser 201, a signal transceiver module 202, a photoelectric balance detector 203, a signal processing module 204, a wind speed identification module 205 and a wind speed correction module 206, which are described in detail below.

[0065] In some embodiments, the laser 201 is used to generate a laser beam.

[0066] In this embodiment, the laser 201 can generate narrow-linewidth seed light that meets the requirements of the coherent Doppler wind measurement lidar, and after multi-stage amplification, the light is transmitted to the telescope antenna through optical fiber. At the same time, the echo signal received by the telescope antenna is separated by a circulator, beat-coupled with the local oscillator light, and the coherent echo signal is transmitted to the photoelectric balance detector 203 for photoelectric conversion.

[0067] In some embodiments, the signal transceiver module 202 is used to transmit the laser beam generated by the laser 201 into the atmosphere according to the emission direction, and receive the echo signal generated after the laser beam interacts in the atmosphere.

[0068] In this embodiment, the signal transceiver module 202 can be a coaxial telescope antenna that transmits and receives signals. It is connected to the output optical fiber of the laser 201 and collimates and expands the laser beam received from the optical fiber before emitting it into the atmosphere. It also receives backscattered signals from the atmosphere and couples them into the optical fiber of the laser 201, where they become part of the optical signal input of the laser 201.

[0069] In some embodiments, the photoelectric balanced detector 203 is used to receive the echo signal and convert the echo signal into a corresponding electrical signal.

[0070] In this embodiment, the photoelectric balanced detector 203 receives the echo signal, and the echo signal is combined with the local oscillator light in the coupler to generate a beat signal. The 2×2 beat signal from the laser is photoelectrically converted to obtain a corresponding electrical signal.

[0071] In some embodiments, the signal processing module 204 is configured to receive the electrical signal output by the photoelectric balance detector 203 , perform sampling processing on the electrical signal, and convert the sampled electrical signal into a frequency domain to obtain spectrum data.

[0072] In this embodiment, the electric signal output by the photoelectric balance detector 203 is filtered, the filtered electric signal is digitally sampled, and the sampled electric signal is converted into the frequency domain to obtain spectrum data.

[0073] In some embodiments, the wind speed identification module 205 is configured to obtain wind speed information based on spectrum data.

[0074] In this embodiment, the frequency point position of the wind speed is determined by identifying and judging the spectrum data, thereby obtaining the wind speed information.

[0075] In some embodiments, the wind speed correction module 206 determines a corresponding error value according to the target coordinate value in the scanning pointing information and the actual coordinate value of the servo scanning unit 10 , and corrects the wind speed information based on the error value to obtain corrected wind speed information.

[0076] In this embodiment, after the radar measurement unit 20 completes the inversion of the radial wind speed, in the process of reconstructing the two-dimensional or three-dimensional wind vector information, in order to improve the quality of the reconstructed data, the scanning pointing information sent by the servo scanning unit 10 will be received. The target coordinate value in the scanning pointing information is the coordinate value of the position to which the servo scanning unit 10 needs to point after excluding the influence of the attitude change of the UAV platform, and the actual coordinate value is the coordinate value of the position to which the servo scanning unit 10 points during actual use. Due to the influence of the attitude change, there is an error value between the two coordinate values. The wind speed information is corrected according to the error value to reduce the influence of the deviation between the actual pointing and the ideal pointing of the terminal light beam.

[0077] Please refer to Figure 6 In some embodiments, the radar measurement unit 20 further includes a wireless data transmission module 207, a power supply module 208, and a temperature control module 209, which are described in detail below.

[0078] In some embodiments, the wireless data transmission module 207 is used to transmit the corrected wind speed information to a ground terminal so that the corrected wind speed information is displayed on the ground terminal.

[0079] In this embodiment, wireless data transmission module 207 establishes a communication connection with a ground terminal. After each wind speed measurement, radar measurement unit 20 transmits the corrected wind speed information back to the ground terminal for display according to a specified protocol, enabling visualization and display of the information. Furthermore, the spectrum data output by signal processing module 204 can be stored in the industrial computer of radar measurement unit 20, providing richer data products for subsequent analysis.

[0080] In some embodiments, the power supply module 208 is used to provide power to the radar measurement unit 20. The power supply module 208 provides power to each module in the radar measurement unit 20 in accordance with the power supply standard requirements of each module. Compared with the decentralized power supply method adopted by most existing product systems, the power supply module 208 in this embodiment adopts a unified power supply method to simplify the hardware composition of the system.

[0081] In this embodiment, to simplify the system's hardware architecture, a power supply module 208 customized for radar requirements is used. Power supply module 208, operating at a 24V DC input, can provide the required power output for modules such as the laser 201, the photoelectric balanced detector 203, and the signal processing module 204. This compliance primarily refers to voltage, ripple, and EMI performance. The power output from power supply module 208 should be sufficient for direct use by the signal processing module 204, replacing the independent power supply typically used by the signal processing module.

[0082] In some embodiments, the temperature control module 209 is used to detect the operating temperature of the radar measurement unit 20 and control the operating temperature within a preset temperature range.

[0083] In this embodiment, the temperature control module 209 maintains the cavity temperature of the lightweight wind measurement lidar system within an appropriate range by detecting the operating temperature of the internal environment of the radar measurement unit 20, especially the operating temperature information of the laser.

[0084] In some embodiments, the radar measurement unit 20 also includes a master industrial control computer, which functions as a subsystem controller within the radar measurement unit 20. Under the coordination of the superior master control, the master industrial control computer controls the timing of signal acquisition and processing, identifies the generated spectrum data, and interprets wind speed information from the spectrum data. During wind speed interpretation, the master industrial control computer can perform wind speed correction based on the scanning direction information returned by the servo scanning unit 10 to obtain higher-quality wind speed data. After obtaining the corrected wind speed data, the corrected wind speed data is packaged and stored as a data product.

[0085] In some embodiments, the radar measurement unit 20 uses a lightweight main frame, which is made of lightweight materials. The various component modules in the radar measurement unit 20 are fixed according to the lightweight main frame. Those skilled in the art will know that lightweight materials include aluminum alloy, engineering plastics and carbon fiber composite materials. Therefore, the lightweight main frame is made of aluminum alloy, and the lightweight main frame includes slotted parts and / or hollowed parts. The slotted parts and / or hollowed parts are covered with carbon fiber plates. The radar measurement unit 20 also includes an outer shell, wherein the outer shell is made of nylon engineering plastic. Compared with existing wind measurement laser radar products, the lightweight wind measurement laser radar system in this embodiment adopts a multi-material combination. These materials include but are not limited to aluminum alloy, carbon fiber, and nylon engineering plastic. Among them, the use of aluminum alloy as the main structural frame ensures the main strength and rigidity of the lightweight wind measurement laser radar system, so that the lightweight wind measurement laser radar system will not be damaged in vibration and impact environments. At the same time, the aluminum alloy body is slotted and / or hollowed out over a large area, significantly reducing the overall mass of the frame compared to the frames of mainstream lidar systems. The slotted and / or hollowed-out portions are covered with carbon fiber panels to ensure the frame's isolation and sealing properties. Areas outside the frame are sealed with a housing made of nylon engineering plastic to prevent the ingress of water and dust from the outside, achieving a dustproof and waterproof seal. At the same time, a housing made of non-metallic insulating material can effectively reduce the barrier effect on the wireless data transmission module 207 within the lightweight wind lidar.

[0086] In some embodiments, the housing of the radar measurement unit 20 utilizes a combination of materials, primarily consisting of carbon fiber, an aluminum alloy frame, and a nylon waterproof shell. Compared to conventional solutions that utilize uniformly thick aluminum alloy or carbon fiber shells to ensure structural strength, this embodiment utilizes an aluminum alloy frame to ensure structural strength, with carbon fiber or nylon sealing the hollowed-out areas. The use of nylon prevents shielding or isolation of wireless signals, allowing the data transmission antenna to be installed inside the device housing, ensuring the integrity and waterproof and dustproof performance of the device.

[0087] Please refer to Figure 7 In some embodiments, the lightweight wind measurement lidar system further includes a system bracket 30. The system bracket 30 is used to connect the servo scanning unit 10 and the radar measurement unit 20 and secure the connected servo scanning unit 10 and radar measurement unit 20 to the UAV platform. The system bracket 30 can adapt to the mechanical structure of the UAV platform, allowing the servo scanning unit 10 and radar measurement unit 20 to be combined with the UAV platform to form a complete lightweight wind measurement lidar system.

[0088] In some embodiments, the internal space of the radar measurement unit is divided into multiple different partitions, and the multiple different partitions are arranged in a stacked manner. Different modules in the radar measurement unit are deployed in corresponding partitions. The radar measurement unit adopts a stacked manner to greatly improve the utilization of space, while also being able to control the volume of the radar measurement unit and taking into account the efficiency of heat dissipation.

[0089] Please refer to Figure 8 In some embodiments, the radar measurement unit 20 includes a power supply module 208, a photoelectric balance detector 203, a signal transceiver module 202, and a laser 201. The internal space of the radar measurement unit 20 is divided into an electronic component layer, an optical layer, and a heat dissipation layer. The electronic component layer is the top layer of the radar measurement unit 20, the optical layer is below the electronic component layer, and the heat dissipation layer is below the optical layer. The industrial computer, power supply module 208, signal processing module 204, and photoelectric balance detector 203 are deployed in the electronic component layer, and the signal transceiver module 202 and laser 201 are deployed in the optical layer. The heat dissipation layer includes a heat sink and a cooling fan, which dissipate heat from the laser 201. In addition, an air duct, also called an auxiliary heat dissipation duct, is located between the electronic component layer and the optical layer. This auxiliary heat dissipation duct is used to assist the radar measurement unit 20 in dissipating heat.

[0090] In this embodiment, a layered stacking approach divides the internal space of the radar measurement unit 20 into three main areas: an electronic component layer, an optical layer, and a heat sink. A narrow area is created between the electronic component layer and the optical layer as an auxiliary heat sink to prevent system heat from accumulating in a single area. Furthermore, this layered stacking approach significantly improves space utilization while maintaining heat dissipation efficiency.

[0091] In some embodiments, in the aforementioned stacking scheme, the electronic component layer and the optical layer are completely sealed, with a protection level of IP65 or higher. The heat dissipation layer is in direct contact with the outside world and cannot be completely isolated from the outside world. With the help of protective measures such as dust screens, it can achieve a protection level of IP55. Each layer is separated by an aluminum alloy frame. In addition to the heat dissipation layer serving as the main heat dissipation channel, the aluminum alloy frame separates the electronic component layer and the optical device layer, and also includes a narrow air duct that serves as an auxiliary heat dissipation channel to prevent heat accumulation and assist in heat dissipation.

[0092] In one embodiment, to achieve more efficient stacking of electronic components, the power supply module 208, attitude detection module 101, main control module, industrial computer, and servo scanning unit 10 can be integrated. This is done by integrating the functional modules onto a single PCB circuit board, or by customizing a carrier board based on the needs of the different modules after they are each manufactured as a core functional board. The core functional boards can then be mounted and combined to form a more tightly connected whole.

[0093] In some embodiments, the aluminum alloy frame of the servo scanning unit 10 can be expanded to accommodate a front-end servo scanning unit module. A one- or two-degree-of-freedom omnidirectional servo head can be installed to achieve scanning coverage of at least the semi-zenith range. The combination of two reflectors enables diverse and flexible scanning. In particular, when integrated with an unmanned aerial vehicle (UAV) platform, multi-angle and multi-point measurements can be used to achieve 3D wind field reconstruction over a wide area.

[0094] In one embodiment, similar to the radar measurement unit 20, to meet the overall lightweight requirements, the servo scanning unit 10 also utilizes a significant amount of nylon material as a strength component. Nylon's self-lubricating properties can help the servo scanning unit 10 achieve better motion characteristics and reduce maintenance costs. Furthermore, reusing the PCB as a structural strength component reduces the number of components, a method used in this embodiment to reduce system complexity and achieve integration. In this embodiment, the servo scanning unit 10 is not limited to a single two-degree-of-freedom scanning mechanism; it can also be modified to a single-degree-of-freedom scanning mechanism or an optical wedge scanning mechanism.

[0095] In some embodiments, most early wind lidar products were large and heavy, making them relatively unportable and difficult to deploy on small platforms. Typical wind lidars typically use large, general-purpose laser light sources. Electrically, the connections between their hardware components are loose, resulting in excessive redundancy and unused space that is not integrated into the overall system, leading to waste. Furthermore, their structural design is relatively simple, primarily using metal housings such as aluminum alloy or stainless steel. Internal space utilization is low, and design flaws in the stacking space also lead to low heat dissipation efficiency. These multiple factors contribute to the large size and weight of existing products, making them unsuitable for application on small and micro platforms. Technological advancements, such as advances in laser technology and integrated circuit technology, have led to more advanced hardware that has enabled the miniaturization of wind lidars. Currently, some wind lidar products weigh approximately 20 kg and can be deployed on vehicles, small boats, buoys, and medium- to large-sized aircraft. The current deployment of wind lidar on aircraft platforms is currently hampered by the high operating costs of medium- to large-sized aircraft, which has hindered the further promotion of wind lidar. To address this problem, this application divides the internal space of the radar measurement unit in a layered manner and uses an aluminum alloy frame and carbon fiber design to reduce the structural weight of the entire unit to less than 7kg. This lightweight wind measuring lidar can be carried on small or micro UAV platforms, especially multi-rotor UAV platforms. With its low operating cost, it can greatly reduce the difficulty of maneuvering the wind measuring lidar on aircraft and promote the promotion of lidar.

[0096] In some embodiments, the lightweight wind-measuring lidar system based on the drone platform adopts a new hardware system framework compared to the existing wind-measuring lidar system. At the same time, the hardware stacking and mechanical structure design are deeply integrated, so that the lightweight wind-measuring lidar system has the characteristics of small size and light weight. A lightweight wind-measuring lidar system with high integration, small size and light weight is proposed. By reconstructing the topological relationship between the commonly used hardware in the current lidar system, the circuits of the power supply, control, signal processing and other parts of the system are simplified and integrated, the volume is reduced, and the complexity of the electrical part is reduced. The hardware stacking relationship is rearranged in structure, the internal devices are partitioned, and the partition heat dissipation design is carried out according to the needs, which effectively compresses the volume and weight of the actual system.

[0097] In some embodiments, the radar measurement unit 20 uses an aluminum alloy frame combined with nylon and carbon fiber design, so that the structural weight of the entire wind measurement lidar system is within 7 kg. At the same time, the size and weight of the radar measurement unit 20 are adapted to the requirements of small and micro drones, especially multi-rotor drone platforms.

[0098] In some embodiments, the servo scanning unit 10, radar measurement unit 20, and system pylon 30 all employ a modular design, electrically connected using standardized interfaces such as aviation plugs. This modular design allows each component to be ported to other types of lidar systems, allowing for permutations and combinations to form other types of wind lidar systems. For example, by replacing the three-dimensional radar servo scanning unit in the current embodiment with an optical wedge, the system can become a vertical wind profiler-type wind lidar system.

[0099] Those skilled in the art will appreciate that all or part of the functions of the various methods in the above embodiments can be implemented by hardware or by computer program. When all or part of the functions in the above embodiments are implemented by computer program, the program can be stored in a computer-readable storage medium, and the storage medium can include: read-only memory, random access memory, disk, optical disk, hard disk, etc., and the program is executed by a computer to implement the above functions. For example, the program is stored in the memory of the device, and when the program in the memory is executed by the processor, all or part of the above functions can be implemented. In addition, when all or part of the functions in the above embodiments are implemented by computer program, the program can also be stored in a storage medium such as a server, another computer, disk, optical disk, flash disk or mobile hard disk, and saved in the memory of the local device by downloading or copying, or the system of the local device is updated. When the program in the memory is executed by the processor, all or part of the functions in the above embodiments can be implemented.

[0100] The above examples are used to illustrate the present invention, which are only used to help understand the present invention and are not intended to limit the present invention. Those skilled in the art can make several simple deductions, modifications or substitutions based on the concept of the present invention.

Claims

1. A lightweight wind measurement lidar system based on an unmanned aerial vehicle platform, wherein the lightweight wind measurement lidar system is mounted on the unmanned aerial vehicle platform, and is characterized in that: The lightweight wind measurement lidar system includes a servo scanning unit and a radar measuring unit; wherein, the radar measuring unit adopts a lightweight main frame, the lightweight main frame is made of lightweight materials, the lightweight main frame is made of aluminum alloy, the lightweight main frame includes slotted parts and / or hollowed parts, the slotted parts and / or hollowed parts are covered with carbon fiber plates, the radar measuring unit also includes an outer shell, the outer shell is made of nylon engineering plastic, the internal space of the radar measuring unit is divided into multiple different partitions, the multiple different partitions are stacked, the partitions of the internal space of the radar measuring unit include an electronic component layer, an optical layer and a heat dissipation layer, and different modules in the radar measuring unit are deployed in corresponding partitions; The servo scanning unit is used to obtain current posture information of the UAV platform, calculate scanning pointing information of the servo scanning unit based on the current posture information, and send the scanning pointing information to the radar measurement unit; wherein the scanning pointing information includes the target coordinate value of the end of the servo scanning unit pointing to the earth coordinate system where the UAV platform is located, and the emission direction of the laser beam in the radar measurement unit is determined by the end pointing of the servo scanning unit. The servo scanning unit is a two-degree-of-freedom servo scanning unit, which adjusts the end beam pointing in real time according to the obtained current posture information to reduce the impact of changes in the UAV platform posture and maintain the stability of the end pointing; The radar measurement unit is used to transmit the laser beam into the atmosphere in the emission direction, receive the echo signal generated after the laser beam interacts in the atmosphere, calculate the wind speed information corresponding to the echo signal, and receive the scanning direction information sent by the servo scanning unit, and correct the wind speed information according to the scanning direction information to obtain the corrected wind speed information.

2. The lightweight wind measurement lidar system according to claim 1, wherein: The servo scanning unit includes a posture detection module and a pointing information calculation module; The posture detection module is used to detect the current posture information of the UAV platform in the body coordinate system and send the current posture information to the pointing information calculation module; The pointing information calculation module is used to convert the received current posture information into posture information in the geodetic coordinate system, calculate the posture difference value based on the posture information in the geodetic coordinate system and the pre-set posture value, calculate the scanning pointing information based on the posture difference value and the spatial characteristic parameters of the servo scanning unit, and send the scanning pointing information to the radar measurement unit.

3. The lightweight wind measurement lidar system according to claim 1 or 2, characterized in that: The servo scanning unit also includes a drive control module and a motor; The drive control module is configured to generate a corresponding terminal control instruction according to the scanning pointing information and send the terminal control instruction to the motor; The motor is used to receive the terminal control instruction sent by the drive control module and adjust the terminal direction of the servo scanning unit according to the terminal control instruction.

4. The lightweight wind measurement laser radar system according to claim 3, wherein: The servo scanning unit further includes a scanning direction adjustment module; The scanning direction adjustment module is used to control the laser beam in the radar measurement unit to be emitted into the atmosphere according to the emission direction, and to make the echo signal generated after the laser beam interacts in the atmosphere return to the radar measurement unit according to the emission direction.

5. The lightweight wind measurement laser radar system according to claim 4, wherein: The scanning direction adjustment module includes an optical mirror group; wherein, the optical mirror group includes a first reflector and a second reflector, the first reflector is used to control the emission direction of the laser beam, and the second reflector is used to adjust the direction of the laser beam so that the direction of the laser beam controlled by the first reflector and the second reflector covers a preset scanning range.

6. The lightweight wind measurement laser radar system according to claim 1, wherein: The radar measurement unit includes a laser, a signal transceiver module, a photoelectric balance detector, a signal processing module, a wind speed identification module and a wind speed correction module; The laser is used to generate a laser beam; The signal transceiver module is used to transmit the laser beam generated by the laser into the atmosphere according to the emission direction, and receive the echo signal generated after the laser beam interacts in the atmosphere; The photoelectric balance detector is used to receive the echo signal and convert the echo signal into a corresponding electrical signal; The signal processing module is used to receive the electrical signal output by the photoelectric balance detector, perform sampling processing on the electrical signal, and convert the sampled electrical signal into the frequency domain to obtain spectrum data; The wind speed identification module is used to identify and obtain wind speed information based on the spectrum data; The wind speed correction module is used to determine a corresponding error value according to the target coordinate value in the scanning pointing information and the actual coordinate value of the servo scanning unit, and correct the wind speed information based on the error value to obtain corrected wind speed information.

7. The lightweight wind measurement laser radar system according to claim 6, wherein: The radar measurement unit also includes a wireless data transmission module, a power supply module and a temperature control module; The wireless data transmission module is used to transmit the corrected wind speed information to the ground terminal so as to display the corrected wind speed information on the ground terminal; The power supply module is used to provide power to the radar measurement unit; The temperature control module is used to detect the operating temperature of the radar measurement unit and control the operating temperature within a preset temperature range.

8. The lightweight wind measurement laser radar system according to claim 1, wherein: The lightweight wind measurement lidar system also includes a system bracket; the system bracket is used to connect the radar measurement unit and the servo scanning unit, and fix the connected radar measurement unit and the servo scanning unit on the UAV platform.

9. The lightweight wind measurement laser radar system according to claim 1, wherein: The radar measurement unit includes a power supply module, a photoelectric balance detector, a signal transceiver module, and a laser; and an air duct is also included between the electronic component layer and the optical layer, wherein: The electronic component layer is the top layer of the radar measuring unit, the optical layer is below the electronic component layer, and the heat dissipation layer is below the optical layer; the power supply module and the photoelectric balance detector are deployed on the electronic component layer, and the signal transceiver module and the laser are deployed on the optical layer. The heat dissipation layer is used to dissipate heat for the laser, and the air duct is used to assist the radar measuring unit in dissipating heat.

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