Downward projection reflection type wind profile laser radar

Abstract

The invention discloses a down-projection reflection type wind profile laser radar. The down-projection reflection type wind profile laser radar comprises a laser used for outputting a laser beam; the collimator is used for collimating the laser beam; the telescope is used for emitting laser beams and receiving echo signals; the reflecting mirror is arranged on an emergent light path of the telescope and is used for reflecting the laser beams into the atmosphere; the motor is connected with the reflector and used for driving the reflector to rotate around the axis so as to change the light beam emitting direction. The signal acquisition system is used for receiving echo signals scattered by the atmosphere; the computer is used for processing data output by the signal acquisition system to invert wind field information; the motor driver is controlled by the computer and is used for driving the motor to rotate according to a set angle and speed; the device is simple and diverse in installation mode, and can adapt to various complex environments.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser radar, in particular to a downward reflection type wind profile laser radar. BACKGROUND

[0002] In recent years, the low-altitude economy has shown a high-speed development trend, and its real-time, accuracy and maneuverability monitoring demand for wind field information in the low-altitude airspace (usually refers to the area below 1000 meters from the ground) is increasingly urgent. As the core equipment for obtaining vertical wind field profile information, the wind profile radar can provide key data support for aircraft navigation, airspace safety control and operation risk warning in the low-altitude economic scenario. However, the traditional wind profile radar is mostly designed based on a fixed architecture, and the device is bulky, heavy, needs to be deployed in a fixed place, and is difficult to adapt to the portable application scenarios such as vehicle-mounted maneuvering and temporary operation point rapid construction in the low-altitude economy. Therefore, the development of small and portable wind profile radar has become the core direction of current technical breakthrough.

[0003] The beam scanning mode of the wind profile radar directly determines the structural complexity, volume and portability of the device. The existing mainstream beam scanning schemes are as follows: first, a fixed multi-beam scanning scheme needs to configure multiple independent radio frequency modules and antenna arrays, resulting in a redundant overall volume, a high weight and a high cost of the device; second, a fixed elevation velocity azimuth display (VAD) scanning scheme using a single telescope, which is time-consuming for the mechanical rotation of the telescope around the azimuth axis; third, a multi-beam scheme using multiple optical fibers inserted in a plane to output multiple beams, which realizes multi-beam output through an optical fiber array. However, the above-mentioned traditional beam scanning methods still have some inconveniences, and cannot simultaneously meet the technical requirements of small size, portability, low power consumption and high reliability, resulting in that the existing wind profile radar is difficult to effectively integrate into the mobile application scenarios of the low-altitude economy. SUMMARY

[0004] The present application provides a downward reflection type wind profile laser radar, which can achieve the effects of small size, portability, low power consumption and high reliability, and solves the problems in the background art.

[0005] The technical scheme of the present application is as follows: the downward reflection type wind profile laser radar comprises: a laser for outputting a laser beam; a collimator for collimating the laser beam; a telescope for emitting the laser beam and receiving a return signal; a mirror arranged on the emission light path of the telescope for reflecting the laser beam into the atmosphere; a motor connected with the mirror for driving the mirror to rotate around the shaft to change the emission direction of the light beam; a signal acquisition system for receiving the return signal scattered by the atmosphere; a computer for processing the return signal to retrieve wind field information; and a motor driver controlled by the computer for driving the motor to rotate at a set angle and speed.

[0006] Further, the laser, the signal acquisition system, the computer and the motor driver are arranged in a rectangular mechanical shell in sequence; the telescope is arranged in a cylindrical mechanical shell, and the outgoing center is vertically corresponding to the center of the reflector.

[0007] Further, the reflector and the motor are arranged in a hemispherical mechanical shell with the bottom surface upward; a plurality of outgoing holes are arranged on the bottom surface of the hemispherical shell at equal intervals, for guiding the outgoing of the laser beams at different azimuth angles.

[0008] Further, the motor drives the reflector to align with the outgoing holes in sequence to realize multi-beam scanning; the computer inverses the horizontal wind speed, the horizontal wind direction and the vertical wind speed according to the echo signals of the multi-beam directions in real time.

[0009] Further, a plurality of hidden mounting supports are further included, which are uniformly distributed on the surface of the hemispherical shell; the supports can be unfolded to support the radar system, or folded to be attached to the surface of the shell.

[0010] Further, the length of the support can be adjusted to adjust the posture of the laser radar on a non-horizontal plane, so as to ensure that the laser is vertically downward.

[0011] Further, the laser radar system can be delivered by a parachute, and the supports can be unfolded automatically during the delivery process to maintain the vertical downward outgoing posture of the telescope after landing.

[0012] Further, the reflector is arranged at an angle of 15° with the horizontal plane, and the reflected laser beam is outgoing at a zenith angle of 30°.

[0013] The wind field information inversion method provided by the application is applied to a downward reflection type wind profile laser radar, and includes the following steps:

[0014] (1) controlling the motor to drive the reflector to align with the outgoing holes in sequence, emitting the laser and receiving the echo signals;

[0015] (2) inverting the horizontal wind speed, the horizontal wind direction and the vertical wind speed according to the radial wind speed measurement values of the multi-directions;

[0016] (3) updating the real-time wind field information by superimposing the latest measurement results.

[0017] Further, the inversion of the wind direction includes defining the zero direction and the positive direction of the angle, and calculating the wind direction angle according to the components of the wind speed in the orthogonal coordinate system.

[0018] Beneficial effects: Compared with the prior art, the present application has the following remarkable advantages: a downward-reflecting wind profile radar structure. The structure ensures the minimum mechanical rotating parts (i.e. a mirror and a motor), improves the simplicity and stability of the system, and further improves the feasibility of miniaturization of the system. The system has high scalability and can be developed to any number of beams (≥ three beams). The system has simple and diverse installation methods, can adapt to various complex environments, and can be more effectively integrated into low-altitude economic mobile application scenarios and complex battlefield environments. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is the internal system structure of the present application;

[0020] Figure 2 is the overall structure diagram of the present application;

[0021] Figure 3 is the representation of wind direction in three-beam wind field inversion of the present application;

[0022] Figure 4 is the installation method of the downward-reflecting wind profile laser radar of the present application. DETAILED DESCRIPTION

[0023] The technical solutions of the present application will be further described below in combination with the drawings.

[0024] As shown in Figure 1 , the embodiment of the present application provides a downward-reflecting wind profile laser radar, the internal structure of which is as follows: 1.1 is a laser, 1.2 is a collimator, 1.3 is a telescope, 1.4 is a mirror, 1.5 is a motor, 1.6 is a signal acquisition system, 1.7 is a computer, and 1.8 is a motor driver.

[0025] The laser outputs three paths of light, one path of light as a probe light is emitted by the telescope after passing through the collimator to a mirror at an angle of 15° with the horizontal plane, and the light is emitted at a zenith angle of 30° after being reflected by the mirror. The mirror is controlled by a motor that can rotate 360°, and can direct the reflected light to any angle. The return signal is input to a 2x2 coupler through a circulator in the laser along the outgoing light path and mixed with the intrinsic light. Then, two mixed light paths are output to the signal acquisition system to convert the light signal to an electrical signal and perform signal acquisition, and the acquired signal enters the computer for data processing. In addition, the motor is driven to rotate the mirror at a set speed and angle by setting the motor driver parameters in the computer.

[0026] The overall structure of the downward-reflecting wind profile laser radar is as shown in Figure 2As shown. Among them, 2.1 is a laser, 2.2 is a telescope with a built-in collimator, 2.3 is a mirror, 2.4 is a motor, 2.5 is a signal acquisition system, 2.6 is a computer, and 2.7 is a motor driver.

[0027] The laser, signal acquisition system, computer, and motor driver are arranged in a rectangular mechanical shell from top to bottom, and a cylindrical mechanical shell with a lens built-in downward telescope is arranged in the shell. The outgoing center of the telescope is vertically directed to the center of the mirror.

[0028] Taking 3-beam scanning as an example, the motor and the mirror are placed in a hemispherical mechanical shell with the bottom surface upward. There are three holes (W1, W2, W3) distributed at equal intervals on the bottom surface. The computer controls the motor driver to step drive the motor to rotate the mirror at an angle of 120°, and sequentially passes through W1, W2, and W3 to emit laser and receive corresponding echo signals. Each step collects and processes echo signals in one direction, and updates real-time wind field information combined with the previous two groups of echo signals.

[0029] The installation method of the downward reflection type wind profile laser radar is as shown in Figure 4 The hemispherical mechanical shell is evenly distributed with three hidden installation supports. When the supports are opened, as shown in Figure 4 (a), the laser radar can be stably placed on any surface, and the lengths of the supports are adjusted to make the telescope vertically downward; when the supports are retracted, as shown in Figure 4 (b), it can perfectly fit the radar surface. The above installation method improves the adaptability of the radar system in various environments and reduces the installation difficulty. For example, in a complex battlefield terrain environment, the supports can be opened and the lengths of the supports can be adjusted to ensure that the laser can be vertically downward to the mirror surface; when the laser radar is dropped from high altitude by a parachute, the supports can be automatically extended to stably and safely land on the ground and maintain the vertical emission posture of the telescope after landing.

[0030] The embodiment of the present application provides a wind field information inversion method applied to a downward reflection type wind profile laser radar. Taking three beams as an example, the three-beam wind field inversion is as follows. A rectangular coordinate system is established with the laser radar as the origin, as shown in Figure 3 (a).

[0031] (1) To derive the horizontal wind speed and the vertical wind speed, define the wind speed in different coordinates: the actual wind speed is expressed in the rectangular coordinate system as V 10 , V 20 , and V 30 represent the unit vectors of the three scanning radial directions, and are expressed as formula (1):

[0032]

[0033] (2) V1, V2, V3 are three radial wind speeds actually measured in three beam directions, which can be expressed as formula (2):

[0034]

[0035] From the above formula (2), formula (3) can be solved:

[0036]

[0037] The above are all vectors, V x , V y , V z are the component velocities of the wind speed projected on the orthogonal coordinate system.

[0038] Then

[0039] The wind direction is the direction from which the wind comes, and the zero-degree direction and the positive direction of the angle need to be determined. Here, the counterclockwise direction is defined as the positive direction:

[0040] If east is zero degree, as shown in (b), the wind direction angle θ is the angle from east to the wind vector counterclockwise: Figure 3

[0041] If V x > 0 (corresponding to the first and fourth quadrants), the range

[0042] If V x < 0 (corresponding to the second and third quadrants), the range

[0043] If south is zero degree, then the wind direction angle θ is the angle from south to the wind vector counterclockwise. In the case where east is zero degree, the angle value is offset by

[0044] If V x > 0, the range θ ∈ (-π, 0);

[0045] If V x < 0, the range θ ∈ (0, π).

[0046] It can also be combined into a concise form: Where the sign function sign(V x ) is: when V x > 0, sign(V x ) = 1; when V x < 0, sign(V x ) = -1.​

Claims

1. A down-looking reflective wind profile lidar, characterized in that The application relates to a laser radar system, which comprises the following parts: a laser for outputting a laser beam; a collimator for collimating the laser beam; a telescope for emitting the laser beam and receiving a return signal; a reflector arranged on the light path of the telescope for reflecting the laser beam into the atmosphere; a motor connected with the reflector for driving the reflector to rotate around an axis to change the direction of the laser beam; a signal acquisition system comprising a balanced detector and an acquisition card for receiving the return signal scattered by the atmosphere; a computer for processing the return signal to obtain wind field information; and a motor driver controlled by the computer for driving the motor to rotate at a set angle and speed. The laser, the signal acquisition system, the computer and the motor driver are arranged in a long rectangular mechanical shell in sequence; the telescope is arranged in a cylindrical mechanical shell, and the emission center of the telescope vertically points to the center of the reflector.

2. The down-looking reflective wind profile lidar according to claim 1, characterized in that The reflector and the motor are arranged in a hemispherical mechanical shell with the bottom surface upward; a plurality of emission holes are arranged on the bottom surface of the hemispherical shell at equal intervals for guiding the laser beam to emit at different azimuth angles.

3. The down-looking reflective wind profile lidar according to claim 2, characterized in that The motor drives the reflector to align with the emission holes in sequence in a step-by-step mode to realize multi-beam (three beams or more) scanning; the computer inverses the horizontal wind speed, the horizontal wind direction and the vertical wind speed according to the return signals of the multi-beam directions.

4. The down-looking reflective wind profile lidar according to claim 3, characterized in that, The laser radar system further comprises a plurality of hidden mounting supports which are uniformly distributed on the surface of the hemispherical shell; the supports can be unfolded to support the laser radar system or folded to be attached to the surface of the shell.

5. The down-looking reflective wind profile lidar according to claim 1, wherein, The length of the supports can be adjusted to keep the laser radar system in a horizontal posture on a non-horizontal surface, so that the laser beam can be emitted vertically downward.

6. The down-looking reflective wind profile lidar according to claim 5, characterized in that The laser radar system can be delivered by a parachute, and the supports can be unfolded automatically during the delivery process to keep the telescope in a vertical downward emission posture after landing.

7. The down-looking reflective wind profile lidar according to claim 1, wherein, The reflector is arranged at an angle of 15 degrees with the horizontal plane, and the reflected laser beam is emitted at a zenith angle of 30 degrees.

8. The down-looking reflective wind profile lidar according to claim 1, wherein, The application further relates to a method for measuring wind speed and wind direction, which comprises the following steps: 9.A method for retrieving wind field information, applied to a down-reflecting wind profile lidar, characterized in that, (1) controlling the motor to drive the reflector to align with the emission holes in sequence, emitting the laser beam and receiving the return signal; (2) inverting the horizontal wind speed, the horizontal wind direction and the vertical wind speed according to the radial wind speed measurement values of the multi-directions; and (3) updating the real-time wind field information by superimposing the latest measurement results. The inversion of the wind direction comprises defining a zero-degree direction and an angle positive direction, and calculating the wind direction angle according to the components of the wind speed in the orthogonal coordinate system.

10. The wind farm information inversion method of claim 9, wherein, ​

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