Lightweight wind measurement laser radar system based on unmanned aerial vehicle platform

Abstract

The invention discloses a light-weight wind measurement laser radar system based on an unmanned aerial vehicle platform. The light-weight wind measurement laser radar system comprises a servo scanning unit, a radar measurement unit and a system hanging frame, the radar measurement unit adopts a lightweight main body frame, and adopts various lightweight materials in structural design; the internal space of the radar measurement unit is divided into a plurality of different subareas, the plurality of different subareas are arranged in a stacked mode, and the aspects of hardware scheme, composition, stacking mode and the like are redesigned. Hardware and a structure are deeply fused, so that the system has obvious advantages in size and weight, miniaturization and light weight are realized, and the weight index of the radar system reaches a 5-7kg level. Wherein the servo scanning unit further comprises a two-degree-of-freedom scanning servo device which enables the system to realize three-dimensional scanning in a large range, various scanning modes such as PPI, VAD and RHI are realized, and the tail end direction of the servo scanning unit is adjusted according to the current attitude information of the unmanned aerial vehicle platform while scanning is performed; and the influence caused by the attitude change of the unmanned aerial vehicle platform is compensated.

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 laser radar system based on an unmanned aerial vehicle platform. Background Art

[0002] In the field of meteorological observation, wind laser radar measures the Doppler effect of particles in the atmosphere, such as aerosols, tiny water droplets, and gas molecules, to measure the relative speed relationship between these tracers and the laser radar, and uses this speed as the measurement result of wind speed data. Since the advent of laser radar, it has become a powerful tool for current meteorological perception with its high precision, high spatiotemporal resolution, and large coverage. The current main deployment methods of wind laser radar are fixed on land, vehicle-mounted, ship-mounted, ocean buoys, or marine engineering platforms. In recent years, some wind laser radar systems have evolved into versions that can be carried on medium and large aircraft, including some wind laser radars that can be deployed using medium and large drones. Equipped with laser radar on drones, it can combine the advantages of laser radar and drone platforms. The drone platform is flexible and has low deployment cost. After being equipped with wind laser radar technology, thanks to the high spatiotemporal resolution of laser radar, it can provide supplements and reinforcements for the existing meteorological observation network.

[0003] As described in the background above, most of the early wind lidar products were large in size and weight, relatively unportable, and difficult to deploy, especially on small platforms. With the advancement and development of technology, such as the advancement of laser technology and the development of integrated circuit technology, more advanced hardware has made it possible to miniaturize wind lidar. At present, some wind lidar products have reached a level of about 20kg and can be deployed on cars, small boats, buoys, and medium and large aircraft. In view of the current deployment status of wind lidar on aircraft platforms, the high cost of using medium and large aircraft has restricted the further promotion of wind lidar. Summary of the invention

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

[0005] According to the first aspect, an embodiment provides a lightweight wind measurement laser radar system based on an unmanned aerial vehicle platform, wherein the lightweight wind measurement laser radar system is mounted on the unmanned aerial vehicle platform, and the lightweight wind measurement laser radar system comprises a servo scanning unit and a radar measurement unit; wherein the radar measurement unit adopts a lightweight main frame, and the lightweight main frame is made of lightweight materials, and the internal space of the radar measurement unit is divided into a plurality of different partitions, the plurality of different partitions are stacked and arranged, and different modules in the radar measurement unit are deployed in corresponding partitions; The servo scanning unit is used to obtain the current posture information of the UAV platform, calculate the scanning pointing information of the servo scanning unit according to 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 in the earth coordinate system where the end of the servo scanning unit points to the UAV platform, 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 radar measuring unit is used to transmit the laser beam into the atmosphere according to the transmitting 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 pointing information sent by the servo scanning unit, and correct the wind speed information according to the scanning pointing information to obtain the corrected wind speed information.

[0006] In some embodiments, 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 earth coordinate system, calculate the posture difference value according to the posture information in the earth coordinate system and the preset posture value, calculate the scanning pointing information according to 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.

[0007] In some embodiments, the servo scanning unit further includes a drive control module and a motor; 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; The motor is used to receive the terminal control instruction sent by the driving control module, and adjust the terminal direction of the servo scanning unit according to the terminal control instruction.

[0008] In some embodiments, 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 by the laser beam interacting in the atmosphere return to the radar measurement unit according to the emission direction.

[0009] 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.

[0010] 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; 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 according to 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.

[0011] In some embodiments, the radar measurement unit further 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 a 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.

[0012] In some embodiments, 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.

[0013] 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.

[0014] In some embodiments, the lightweight main frame is made of aluminum alloy, the lightweight main frame includes slotted parts and / or hollow parts, the slotted parts and / or hollow parts are covered with carbon fiber plates, and the radar measurement unit also includes an outer shell, which is made of nylon engineering plastic.

[0015] According to the lightweight wind measurement laser radar 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 laser radar 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 according to 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, so as to correct the wind speed information in real time according to the current posture information of the UAV platform and obtain accurate wind speed information. Therefore, the proposed lightweight wind measurement laser radar system not only has a lightweight design, but also can obtain accurate wind speed information. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic structural diagram of a lightweight wind measurement laser radar system based on an unmanned aerial vehicle platform according to an embodiment; Figure 2 A schematic structural diagram of a lightweight wind measurement laser radar system based on an unmanned aerial vehicle platform according to another embodiment; Figure 3 A schematic structural diagram of a lightweight wind measurement laser radar system based on an unmanned aerial vehicle platform according to another embodiment; Figure 4 A schematic structural diagram of a lightweight wind measurement laser radar system based on an unmanned aerial vehicle platform according to another embodiment; Figure 5 A schematic structural diagram of a lightweight wind measurement laser radar system based on an unmanned aerial vehicle platform according to another embodiment; Figure 6 A schematic structural diagram of a lightweight wind measurement laser radar system based on an unmanned aerial vehicle platform according to another embodiment; Figure 7 A schematic diagram of the system composition of a lightweight wind measurement laser radar system based on an unmanned aerial vehicle platform according to an embodiment; Figure 8 The diagram 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 of the present invention. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below by specific embodiments in conjunction with the accompanying drawings. Wherein similar elements in different embodiments adopt associated similar element numbers. In the following embodiments, many detailed descriptions are for making the present application better understood. However, those skilled in the art can easily recognize that some features can be omitted in different situations, or can be replaced by other elements, materials, 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 part of the present application being overwhelmed by too much description, and for those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations according to the description in the specification and the general technical knowledge in the art.

[0018] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various implementations. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a required sequence, unless otherwise specified that a certain sequence must be followed.

[0019] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings).

[0020] Please refer to Figure 1 In an embodiment of the present invention, a lightweight wind measurement laser radar system based on an unmanned aerial vehicle platform is provided. The lightweight wind measurement laser radar system is mounted on the unmanned aerial vehicle platform. The lightweight wind measurement laser radar system includes a servo scanning unit 10 and a radar measurement unit 20, which are described in detail below.

[0021] 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 according to 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, which can realize multiple scanning modes such as PPI, VAD, RHI, etc. according to different directions and user needs.

[0022] 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.

[0023] 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.

[0024] In some embodiments, the attitude detection module 101 is used to detect the current attitude information of the UAV platform in the body coordinate system, and send the current attitude information to the pointing information calculation module 102 .

[0025] In this embodiment, the current attitude information of the UAV platform is sensed in real time by the attitude detection module 101, and the servo scanning unit 10 is adjusted according to the current attitude information, so as to compensate for the attitude change of the UAV platform and keep the pointing direction of the end of the servo scanning unit 10 stable. Among them, the current attitude information of the UAV platform refers to 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, and the attitude information includes but is not limited to the Euler angle values ​​or quaternion values ​​on the three axes of the x-axis, y-axis and z-axis obtained by the gyroscope or inertial measurement unit, and the above-mentioned attitude information is fed back to the main control module of the wind laser radar system.

[0026] In some embodiments, the pointing information calculation module 102 is used to convert the received current posture information into posture information in the earth coordinate system, calculate the posture difference value according to the posture information in the earth coordinate system and the preset posture value, calculate the scanning pointing information according to the posture difference value and the spatial characteristic parameters of the servo scanning unit 10, and send the scanning pointing information to the radar measurement unit 20. The spatial characteristic parameters of the servo scanning unit 10 include the spatial geometric arrangement order of the rotating shaft and the transmission relationship between the motor and the rotating shaft.

[0027] In some embodiments, since 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, and the attitude difference is calculated based on the attitude information in the earth coordinate system and the pre-set attitude value. This attitude difference reflects the change or change trend of the terminal light beam pointing vector in the earth coordinate system. The target coordinate value of the terminal of the servo scanning unit 10 pointing to the earth coordinate system where the UAV platform is located is calculated based on the attitude difference and the spatial characteristic parameters of the servo scanning unit 10, 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.

[0028] Please refer to Figure 3 In some embodiments, the servo scanning unit 10 further includes a driving control module 103 and a motor 104, which will be described in detail below.

[0029] In some embodiments, the drive control module 103 is used to generate corresponding terminal control instructions according to the scanning pointing information, and send the terminal control instructions to the motor 104 .

[0030] In this embodiment, the drive control module 103 can also collect information such as the current position, rotation speed, current and voltage of the motor 104, and feed this information back to the main control module of the lightweight wind measurement laser radar system.

[0031] In some embodiments, the motor 104 is used to receive the terminal control instruction sent by the driving control module 103, and adjust the terminal direction of the servo scanning unit 10 according to the terminal control instruction.

[0032] In this embodiment, the distal end pointing direction of the servo scanning unit 10 is adjusted according to the distal end control instruction, thereby keeping the pointing direction of the servo scanning unit 10 stable in the earth coordinate system.

[0033] 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.

[0034] 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.

[0035] In this embodiment, the emission direction of the laser beam in the radar measurement unit 20 is controlled by the scanning direction adjustment module 105, so that the wind laser radar can complete various scanning measurement methods such as VAD, PPI, and RHI. Among them, communication can be established between the servo scanning unit 10 and the radar measurement unit 20, and the servo scanning unit 10 can coordinate the working 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, the servo scanning unit 10 can adjust the terminal beam pointing in real time according to the current attitude information obtained under the coordinated control of the main control module of the system, so as to reduce the impact of the change in the attitude of the drone platform and maintain the stability of the terminal pointing.

[0036] 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.

[0037] In this embodiment, the combined motion of the first reflector and the second reflector can make the direction of the laser beam completely cover a range not less than half the zenith. The emission direction refers to the propagation path of the laser beam after it is emitted from the laser and guided by the first reflector. The direction of the laser beam refers to the direction in which the laser beam finally reaches the target position or area after being reflected by the second reflector during the propagation process.

[0038] 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.

[0039] In some embodiments, the radar measurement unit 20 is used to transmit the laser beam into the atmosphere in an 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 pointing information sent by the servo scanning unit 10, correct the wind speed information according to the scanning pointing information, and obtain the corrected wind speed information.

[0040] In some embodiments, the lightweight wind measurement laser radar system composed of the servo scanning unit 10 and the radar measuring unit 20 can measure radial wind speed information at different distances in a specified direction, and construct 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 physically corrected and calculatedly corrected, respectively, which together constitute a two-stage pointing correction based on the servo scanning unit 10.

[0041] 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.

[0042] In some embodiments, the laser 201 is used to generate a laser beam.

[0043] 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 multiple stages of 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, and then beat-coupled with the local oscillator light, and the coherent echo signal is transmitted to the photoelectric balance detector 203 for photoelectric conversion.

[0044] 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.

[0045] In this embodiment, the signal transceiver module 202 can be a transmitting and receiving integrated coaxial telescope antenna, which is connected to the output optical fiber of the laser 201, collimates and expands the laser beam received from the optical fiber, and then emits it into the atmospheric environment. At the same time, it receives the backscattered signal from the atmospheric environment, couples the signal into the optical fiber of the laser 201, and becomes a part of the optical signal input of the laser 201.

[0046] 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.

[0047] In this embodiment, the photoelectric balanced detector 203 receives the echo signal, the echo signal is combined with the local oscillator light in the coupler, and a beat signal is generated, and the 2×2 beat signal from the laser is photoelectrically converted to obtain a corresponding electrical signal.

[0048] In some embodiments, the signal processing module 204 is used 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 the frequency domain to obtain spectrum data.

[0049] In this embodiment, the electric signal output by the photoelectric balance detector 203 is filtered, and then the filtered electric signal is digitally sampled, and the sampled electric signal is converted into the frequency domain to obtain spectrum data.

[0050] In some embodiments, the wind speed identification module 205 is used to identify and obtain wind speed information based on spectrum data.

[0051] 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.

[0052] 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.

[0053] 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 receiving servo scanning unit 10 is received. The target coordinate value in the scanning pointing information is the coordinate value of the position that the servo scanning unit 10 needs to point to after excluding the influence of the attitude change of the UAV platform, and the actual coordinate value is the coordinate value of the position pointed to by the servo scanning unit 10 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.

[0054] 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.

[0055] 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.

[0056] In this embodiment, the wireless data transmission module 207 establishes a communication connection with the ground terminal. After the radar measurement unit 20 completes each wind speed measurement, the corrected wind speed information can be transmitted back to the ground terminal for display according to the specified protocol to perform information visualization and display. At the same time, the spectrum data output by the signal processing module 204 can be stored in the industrial computer of the radar measurement unit 20, which can provide more abundant data products for subsequent further analysis.

[0057] In some embodiments, the power supply module 208 is used to provide power for the radar measurement unit 20. The power supply module 208 provides power that meets the power supply standard requirements of each module for each module in the radar measurement unit 20. Compared with most existing product systems that use a decentralized power supply method, the power supply module 208 in this embodiment uses a unified power supply method to simplify the hardware composition of the system.

[0058] In this embodiment, in order to simplify the hardware structure of the system, a power supply module 208 customized according to the radar requirements is used. The power supply module 208 can provide a power output that meets the requirements for modules such as the laser 201, the photoelectric balance detector 203 and the signal processing module 204 under a 24V DC input. The requirements here mainly refer to the voltage, ripple, and EMI performance meeting the requirements. The power uniformly output by the power supply module 208 should be able to meet the needs of direct use of the signal processing module 204, so as to replace the independent power supply of the signal processing module in the normal solution.

[0059] 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.

[0060] In this embodiment, the temperature control module 209 keeps the cavity temperature of the lightweight wind laser radar system within a suitable range by detecting the operating temperature of the internal environment of the radar measurement unit 20, especially the operating temperature information of the laser.

[0061] In some embodiments, the radar measurement unit 20 further includes a main control industrial computer, which plays a role of subsystem control in the radar measurement unit 20. Under the coordination of the upper master control, the main control industrial computer controls the working sequence of signal acquisition and processing, and identifies the generated spectrum data at the same time, and interprets the wind speed information in the spectrum data. In the process of interpreting the wind speed information, the main control industrial computer can correct the wind speed according to the scanning pointing information returned by the servo scanning unit 10, so as to achieve the purpose of obtaining 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.

[0062] In some embodiments, the radar measurement unit 20 adopts a lightweight main frame, which is made of lightweight materials, and the various components in the radar measurement unit 20 are fixed according to the lightweight main frame. It can be known to those skilled in the art that lightweight materials include aluminum alloys, engineering plastics, and carbon fiber composite materials, etc. Therefore, the lightweight main frame is made of aluminum alloy, and the lightweight main frame includes slotted parts and / or hollowed parts, and the slotted parts and / or hollowed parts are covered with carbon fiber plates. The radar measurement unit 20 also includes a shell, wherein the shell is made of nylon engineering plastics. Compared with existing wind laser radar products, the lightweight wind laser radar system in this embodiment adopts a combination of multiple materials, and these materials include but are not limited to aluminum alloys, carbon fibers, and nylon engineering plastics. Among them, the use of aluminum alloy as the main structural frame ensures the main strength and rigidity of the lightweight wind laser radar system, so that the lightweight wind laser radar system will not be damaged under vibration and impact environments. At the same time, a large area of ​​slotting and / or hollowing is performed on the aluminum alloy body, so that the total mass of the frame is significantly reduced compared with the frame of the mainstream laser radar system. The slotted and / or hollowed parts are covered with carbon fiber plates to ensure the isolation and sealing effect of the frame. The parts outside the frame are sealed with a shell made of nylon engineering plastic to prevent the entry of external water and dust, achieving the effect of sealing, dustproof and waterproof. At the same time, the shell made of non-metallic insulating material can effectively reduce the barrier effect on the wireless data transmission module 207 in the lightweight wind measurement laser radar.

[0063] In some embodiments, the outer shell of the radar measurement unit 20 is composed of a combination of multiple materials, and the outer shell is mainly composed of three parts: carbon fiber, aluminum alloy frame, and nylon waterproof shell. Compared with the uniform thickness shell of aluminum alloy or carbon fiber in the conventional solution to ensure structural strength, the structural strength in this embodiment is ensured by the aluminum alloy frame, and carbon fiber or nylon material is used to seal the hollow part. The use of nylon material will not shield or isolate the wireless signal, so that the data transmission antenna can be installed inside the device casing, ensuring the integrity and waterproof and dustproof performance of the device.

[0064] Please refer to Figure 7 In some embodiments, the lightweight wind laser radar system further includes a system bracket 30; the system bracket 30 is used to connect the servo scanning unit 10 and the radar measuring unit 20, and fix the connected servo scanning unit 10 and the radar measuring unit 20 on the UAV platform. The system bracket 30 can adapt to the mechanical structure characteristics of the UAV platform, so that the servo scanning unit 10 and the radar measuring unit 20 are combined with the UAV platform to form a complete lightweight wind laser radar system.

[0065] 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.

[0066] 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, wherein 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, the power supply module 208, the signal processing module 204, and the photoelectric balance detector 203 are deployed in the electronic component layer, and the signal transceiver module 202 and the laser 201 are deployed in the optical layer, and the heat dissipation layer includes a heat sink and a heat dissipation fan, and the heat sink and the heat dissipation fan are used to dissipate heat for the laser 201. In addition, there is also an air duct between the electronic component layer and the optical layer, which can also be called an auxiliary heat dissipation air duct, and the auxiliary heat dissipation air duct is used to assist the radar measurement unit 20 in heat dissipation.

[0067] In this embodiment, a stacked stacking method is adopted to divide the internal space of the radar measurement unit 20 into three main parts: an electronic component layer, an optical layer, and a heat dissipation layer. At the same time, a narrow area is opened between the electronic component layer and the optical layer as an auxiliary heat dissipation layer to prevent the heat of the system from accumulating in a certain area. At the same time, the stacked stacking method is adopted, so that the space utilization rate is greatly improved while taking into account the heat dissipation efficiency.

[0068] In some embodiments, in the above stacking scheme, the electronic component layer and the optical layer are completely sealed, and the protection level is above IP65. 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 dustproof nets, the protection level can reach IP55. Each layer is divided by an aluminum alloy frame. In addition to the heat dissipation layer as the main heat dissipation channel, the electronic component layer and the optical device layer are divided by an aluminum alloy frame, and a narrow air duct is included as an auxiliary heat dissipation air duct to prevent heat accumulation and assist heat dissipation.

[0069] In one embodiment, in order to achieve more efficient stacking of electronic components, the power supply module 208, the posture detection module 101, the main control module, the industrial computer and the servo scanning unit 10 can be integrated. The main thing is to integrate the functional modules on the same PCB circuit board, or after different modules are made into core functional boards, customize the carrier board according to the needs, install and combine different core functional boards, and form a more tightly connected whole.

[0070] In some embodiments, the aluminum alloy frame of the servo scanning unit 10 is expanded to install a front-end servo scanning unit module. Among them, a one-two degree-of-freedom omnidirectional servo head can be installed to achieve a scanning coverage of not less than the half-zenith range. Through the combination of two reflectors, diversified and flexible scanning can be performed, especially in combination with an unmanned aerial vehicle platform, through multi-angle and multi-point measurement, it is possible to achieve three-dimensional wind field reconstruction in a large range.

[0071] In one embodiment, similar to the radar measurement unit 20, in order to meet the lightweight requirements of the whole machine, the servo scanning unit 10 also uses a large amount of nylon material as a strength structural member. On the one hand, the self-lubricating property of nylon can help the servo scanning unit 10 obtain better motion characteristics and reduce maintenance costs. On the other hand, reusing the PCB circuit board as part of the structural strength member and reducing the number of parts is also a means of reducing system complexity and integration in the embodiment of the present application. In this embodiment, the servo scanning unit 10 is not limited to a two-degree-of-freedom scanning mechanism, and can also be a single-degree-of-freedom scanning or optical wedge scanning mechanism after deformation.

[0072] In some embodiments, since most of the early wind laser radar products have the characteristics of large size and heavy weight, they are relatively unportable and difficult to deploy in a mobile manner, especially on small platforms. Generally, wind laser radars usually use larger general-purpose laser light sources. At the same time, in terms of electricity, the connection between the various parts of its hardware is relatively loose, there is too much redundancy and some idle time that is not included in the overall system, resulting in waste. At the same time, the structural design is relatively simple, mainly with metal shells such as aluminum alloy or stainless steel, the internal space utilization rate of the body is low, and the design defects in the space stacking also lead to low heat dissipation efficiency. Under the influence of multiple factors, the existing products are large in size and weight, and cannot meet the application requirements on small and micro platforms. With the advancement and development of technology, such as the advancement of laser technology and the development of integrated circuit technology, more advanced hardware has made it possible to miniaturize wind laser radars. At present, some wind laser radar products have reached a level of about 20kg, which can be deployed in a mobile manner on cars, small boats, buoys, and medium and large aircraft. In view of the current deployment status of wind laser radars on aircraft platforms, the operation cost of medium and large aircraft is relatively high, which has formed certain constraints on the further promotion of wind laser radars. To address this problem, this application divides the internal space of the radar measurement unit in a stacked 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 mobile deployment of wind measuring lidar on aircraft and promote the promotion of lidar.

[0073] In some embodiments, the lightweight wind laser radar system based on the drone platform adopts a new hardware system framework compared to the existing wind laser radar system, and the hardware stacking and mechanical structure design are deeply integrated, so that the lightweight wind laser radar system has the characteristics of small size and light weight. A lightweight wind laser radar system with high integration, small size and light weight is proposed. By reconstructing the topological relationship between the commonly used hardware in the current laser radar 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 performed according to the needs, which effectively compresses the volume and weight of the actual system.

[0074] 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 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 small and micro drones, especially multi-rotor drone platforms.

[0075] In some embodiments, the servo scanning unit 10, the radar measuring unit 20 and the system bracket 30 are all modularly designed and electrically connected using standardized interfaces such as aviation line plugs. This modular design allows each part to be transplanted into other types of laser radar systems and arranged and combined to form other types of wind laser radar systems. For example, by changing the three-dimensional radar servo scanning unit in the current embodiment to an optical wedge, the system can become a vertical wind profile type wind laser radar system.

[0076] Those skilled in the art will appreciate that all or part of the functions of the various methods in the above-mentioned embodiments can be implemented by hardware or by computer programs. When all or part of the functions in the above-mentioned embodiments are implemented by computer programs, 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-mentioned 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-mentioned functions can be implemented. In addition, when all or part of the functions in the above-mentioned embodiments are implemented by computer programs, 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 can be downloaded or copied and saved in the memory of the local device, or the system of the local device is updated, and when the program in the memory is executed by the processor, all or part of the functions in the above-mentioned embodiments can be implemented.

[0077] The above specific examples are used to illustrate the present invention, which are only used to help understand the present invention and are not used to limit the present invention. For those skilled in the art to which the present invention belongs, some simple deductions, modifications or substitutions can be made according to the idea of ​​the present invention.

Claims

1. A lightweight wind measurement laser radar system based on an unmanned aerial vehicle platform, wherein the lightweight wind measurement laser radar system is mounted on the unmanned aerial vehicle platform, and is characterized in that: The lightweight wind measurement laser radar system includes a servo scanning unit and a radar measurement unit; wherein the radar measurement unit adopts a lightweight main frame, the lightweight main frame is made of lightweight materials, the internal space of the radar measurement unit is divided into a plurality of different partitions, the plurality of different partitions are stacked and arranged, and different modules in the radar measurement unit are deployed in corresponding partitions; The servo scanning unit is used to obtain the current posture information of the UAV platform, calculate the scanning pointing information of the servo scanning unit according to 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 in the earth coordinate system where the end of the servo scanning unit points to the UAV platform, 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 radar measuring unit is used to transmit the laser beam into the atmosphere according to the transmitting 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 pointing information sent by the servo scanning unit, and correct the wind speed information according to the scanning pointing information to obtain the corrected wind speed information.

2. The lightweight wind laser radar system according to claim 1, characterized in that: 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 earth coordinate system, calculate the posture difference value according to the posture information in the earth coordinate system and the preset posture value, calculate the scanning pointing information according to 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 laser radar 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 used 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 driving control module, and adjust the terminal direction of the servo scanning unit according to the terminal control instruction.

4. The lightweight wind laser radar system according to claim 3, characterized in that: The servo scanning unit also 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 by the laser beam interacting in the atmosphere return to the radar measurement unit according to the emission direction.

5. The lightweight wind laser radar system according to claim 4, characterized in that: 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.

6. The lightweight wind laser radar system according to claim 1, characterized in that: 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 according to 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 laser radar system according to claim 6, characterized in that: 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 a 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 laser radar system according to claim 1, characterized in that: The lightweight wind measurement laser radar 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 laser radar system according to claim 1, characterized in that: The radar measurement unit includes a power supply module, a photoelectric balance detector, a signal transceiver module, and a laser; the internal space of the radar measurement unit is divided into an electronic component layer, an optical layer, and a heat dissipation layer, 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, 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.

10. The lightweight wind laser radar system according to claim 1, characterized in that: The lightweight main frame is made of aluminum alloy, and includes slotted parts and / or hollowed parts, and the slotted parts and / or hollowed 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 plastics.

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