CN107885223A - Unmanned plane recovery guiding system based on laser - Google Patents

Abstract

The invention relates to a laser-based unmanned aerial vehicle recovery guidance system, including an airborne terminal and a ground terminal. The ground end includes a PAT (Pointing, Acquisition, Tracking ) control unit, a master computer with image processing and control functions. The PAT control unit realizes the aiming, capturing and tracking of UAV targets. The airborne side includes a cooperating target and a photodetector consisting of a corner mirror/indicator. The corner mirror/indicator is used to feed back signals to the ground end, and the photodetector works in simplex mode for laser communication reception. The present invention can reliably upload information such as the recovery guidance position to the UAV without relying on radio communication, has the ability of position measurement and communication synchronous transmission, and can satisfy the autonomous and accurate UAV under the condition of satellite and radio communication rejection Recycling requirements.

Description

Laser-based drone recovery guidance system

technical field

The invention relates to the technical field of laser applications, in particular to a laser-based unmanned aerial vehicle recovery and guidance system.

Background technique

At present, there have been some public reports and mature research results on UAV recovery and guidance measurement systems in foreign countries, generally including radar measurement, GPS and inertial device measurement, photoelectric measurement or their combination. Typical systems such as:

Sierra Nevada of the United States developed the UCARS-V2 UAV tactical recovery system based on radar technology to solve the problems of low short-distance positioning accuracy, poor tracking performance and easy interference of the shipboard radar measurement system, but to improve radar measurement accuracy and Interference immunity is also more expensive.

Raytheon Corporation of the United States adopted the JPALS (Joint Precise Approach and Landing System) system based on GPS technology, and successfully completed the autonomous landing test of the X-47B stealth drone on July 10, 2013. However, due to well-known reasons, GPS is not used as the main means of UAV guidance in my country. Inertial devices have strong anti-interference ability, but their errors gradually accumulate with time, so they are not suitable as the main means of UAV terminal guidance.

Swiss company Ruag has developed a laser-based OPATS (Object Position and Tracking System) system, which can measure the precise attitude of the UAV after the UAV is guided into the landing window by radar or GPS, providing reliable guarantee for landing . The low cost of the system proves the feasibility of laser measurement and tracking technology for UAV guidance, but the system is only designed for landing on land and lacks the necessary means to suppress ship swaying. At the same time, the guidance information upload link is not laser communication link.

At present, almost all communication methods of UAV guidance systems still rely on radio. Considering that the electromagnetic compatibility problems caused by the existing radar and radio frequency communication on ships are becoming more and more complicated, using traditional radio frequency methods to communicate with UAVs Communication will inevitably affect the reliability and real-time performance of data.

In order to solve the problems of satellite denial and radio communication unavailability in the complex electromagnetic countermeasure environment, a ground-based medium The laser guidance system required for the landing/recovery guidance of small UAVs has extremely important practical significance.

Contents of the invention

The satellite positioning system is susceptible to external interference. In order to ensure the high precision, high reliability and precise recovery of UAVs in complex environments, this invention proposes a laser-based UAV recovery guidance system, which has position measurement and communication synchronization transmission The ability to meet the requirements of autonomous and precise recovery of UAVs under the conditions of satellite and radio communication denial.

The present invention adopts following technical scheme to realize:

A laser-based UAV recovery and guidance system, including an airborne end and a ground end, the ground end includes a two-axis stable tracking turntable, a two-dimensional fast galvanometer, a guidance/communication laser emission unit, a CCD camera, and an image processing The PAT unit composed of the master control computer of the control program, the ranging laser emitting module, the ranging laser receiving module, and the I/O interface; the PAT unit realizes the aiming, capturing, and tracking of the UAV; the two-dimensional fast galvanometer, Guidance/communication laser emitting unit, CCD camera, ranging laser emitting module, ranging laser receiving module, and I/O interface are set on the two-axis stable tracking turntable, CCD camera, ranging laser receiving module, two-dimensional fast vibrating The mirror, guidance/communication laser emission unit are respectively connected to the main control computer through the I/O interface, and the ranging laser emission module is connected to the two-dimensional fast galvanometer;

The airborne side includes a cooperative target composed of a corner mirror and an indicator light and a photodetector; the corner mirror/light is used to feed back signals to the CCD camera and the ranging laser receiving module on the ground side, and the photodetector works in simplex mode Next, it is used to realize the laser communication reception of the azimuth, pitch and distance information of the UAV; the cooperative target and the photoelectric detector are respectively connected to the airborne flight control unit;

After the UAV enters the landing window through guidance, the guidance/communication laser emission unit emits the guidance laser, and the laser beam scans the landing window area through the two-dimensional fast galvanometer, and the echo laser or the airborne indicator light will be on the photosensitive surface of the CCD camera. On the imaging, the I/O interface enters the main control computer, and the relative angular position information of the UAV is obtained through the image processing program. The laser beam of the communication laser is stably tracked and irradiated on the UAV to realize the active tracking of the UAV; at this time, the ranging laser emitted by the ranging laser transmitter module will also be stably irradiated on the UAV, and the angle mirror at the airborne end will reflect The echo signal of the ranging laser will be received by the ranging laser receiving module, and the relative distance information of the UAV can be calculated; the three-dimensional position information of the UAV's azimuth, pitch, and distance is output through the I/O interface, and the electrical signal The communication laser beam is modulated by the modulation circuit, and then the guidance/communication laser emission unit transmits upward to the UAV through the two-dimensional fast galvanometer; in this way, the UAV can control the flight based on the continuously refreshed three-dimensional position information received Heading and landing, complete the laser-guided landing process without relying on radio communication;

Through the information modulation of the laser, the system enables the system to complete the information measurement such as distance measurement and angle measurement, and at the same time have the ability of high-speed information communication, so as to realize the precise recovery and guidance of the UAV under the condition of radio rejection.

The two-axis stable tracking turntable and the two-dimensional fast galvanometer in the ground-end PAT unit form a composite axis structure, and the laser beam is emitted from the exit mirror of the two-dimensional fast galvanometer to scan to the airborne end angle reflector. After the mirror, the echo laser or the airborne indicator light will be imaged on the photosensitive surface of the CCD camera, and the relative angular position information of the drone is obtained through the image processing program. The image processing and control program uses the angular information to control the two-dimensional fast galvanometer. Scanning action, the guidance/communication laser beam is stably tracked and irradiated on the UAV; among them, the two-axis stable tracking turntable adopts U-O structure design to realize rough tracking of moving targets; the two-dimensional fast galvanometer performs laser high-speed scanning function to realize motion Accurate tracking of the target; the two-dimensional fast galvanometer includes an incident mirror, an outgoing mirror, a scanning motor and a control circuit. The mirror is fixed on the shaft of the scanning motor, and the deflection angle of the mirror is controlled by the rotation of the motor; Position sensor; the two-dimensional fast vibrating mirror exchanges data with the master control computer through the driver and I/O interface, transmits the corner position information to the image processing and control program, receives the position voltage signal output by the master control computer, and drives the scanning motor to Specifies the corner location.

When the laser beam scans the landing window area through the two-dimensional fast galvanometer, it adopts spiral grating compound scanning, and scans from the area with high capture probability to the area with low capture probability, which is easy to realize.

On the basis of inheriting the traditional laser measurement technology, the present invention draws lessons from the principle of laser communication, and through the information modulation of the emitted laser, the laser system can complete the information measurement such as distance measurement and angle measurement, and at the same time, it has the ability of high-speed information transmission to realize In order to accurately recover and guide the UAV under the condition of radio denial.

Description of drawings

Figure 1 is a composition diagram of the UAV recovery laser guidance system.

Figure 2 is a working schematic diagram of the UAV recovery laser guidance system.

Figure 3 is a block diagram of the working principle of PAT.

Figure 4 is a schematic diagram of a two-axis stable tracking turntable.

Figure 5 is a schematic diagram of a two-dimensional fast galvanometer.

Fig. 6 is a schematic diagram of the spiral raster scanning principle and capture time.

Figure 7 is a schematic diagram of pulse ranging.

Fig. 8 is a schematic diagram of subcarrier operation.

FIG. 9 is a composition diagram of a PAT unit.

Detailed ways

The technical solutions of the present invention will be further specifically described below in conjunction with the accompanying drawings and embodiments.

The invention is a laser-based unmanned aerial vehicle recovery and guidance system. The system uses ground laser active scanning to realize the capture, tracking and measurement of the unmanned aerial vehicle target, and can provide relative position information of the aircraft. At the same time, the integrated fusion design of laser guidance and laser communication modules is adopted in the present invention, which can provide the ability to upload and communicate guidance information under radio rejection. The system consists of two parts, the airborne end and the ground end, as shown in Figure 1. The ground end mainly includes: a PAT (pointing-pointing system) composed of a two-axis stable tracking turntable, a two-dimensional galvanometer, a ranging laser transmitter module, a ranging laser receiving module, a guidance/communication laser transmitter unit, a CCD camera and an I/O interface. , capture-Acquisition, tracking-Tracking) control unit, and a master control computer with image processing and control functions. The PAT control unit realizes the aiming, capturing and tracking of UAV targets. The airborne end includes a cooperative target composed of a corner mirror/indicator and a photodetector. The corner mirror/indicator is used to feed back signals to the CCD camera and the ranging laser receiving module on the ground side. The photodetector works in simplex mode to realize the laser communication reception of the UAV's azimuth, pitch and distance information.

The main working principle of the present invention is: after the UAV is guided into the landing window by other navigation methods such as radar or GPS, the laser guidance system turns on the laser and the laser fast scanner, and performs laser scanning on the landing/recovery window. When the CCD camera reaches the corner reflector, the reflected laser can be captured by the CCD camera, so that the echo laser or the onboard indicator light will be imaged on the photosensitive surface of the CCD camera, and the relative angular position information of the drone can be obtained after image processing and PAT algorithm processing ,as shown in picture 2. Using the angle information to control the deflection angle of the scanning laser beam through the PAT algorithm, the laser beam can be stably tracked and irradiated onto the UAV, realizing active tracking of the UAV. At the same time, the laser ranging unit measures and calculates the relative distance information of the UAV. In addition, in order to reliably upload information such as the recovery guidance position to the UAV without relying on radio communication, the present invention modulates the data carrier of the communication beam of the emitting laser and transmits it to the airborne cooperative target, thereby realizing laser guidance and Synchronous work of laser communication. The high-sensitivity photodetector installed on the UAV receives the modulated laser signal and transmits it to the airborne flight control unit, thus realizing the recovery and guidance of the UAV.

The technical scheme of the present invention is described in detail below:

The PAT unit is constructed based on the composite axis method, in which the two-axis stable tracking turntable is the actuator for rough tracking, and the two-dimensional fast galvanometer is the actuator for fine tracking. The PAT unit is mainly composed of a two-dimensional fast galvanometer, a two-axis stable tracking turntable, a CCD camera, a guidance/communication laser emission unit, a driver, and an image processing and control program.

The two-axis stable tracking turntable is a universal gimbal structure composed of pitch axis and azimuth axis independently. It is directly driven by a torque motor. The maximum angular velocity is 60 degrees per second. The position detection encoder is a 20-bit incremental encoder, 4 times The post-frequency angular resolution is 1.5μrad; the two-dimensional turntable can make up for the blind area of the scanning galvanometer rotation, so that the PAT system can not only move at a large angle and at a fast speed, but also ensure tracking accuracy at the same time.

The clear aperture of the two-dimensional fast galvanometer is 50mm, the bandwidth is 30Hz in the rotation range of ±20°, the bandwidth is 200Hz in the rotation range of ±1°, and the positioning accuracy is 15μrad. The guidance/communication laser and ranging laser emitted by the ground end share it as the transmitting antenna. Because the speed of the galvanometer is very fast, the design of the co-transmission antenna has three advantages: (1) The mirror boresight stabilization method of the galvanometer can more effectively suppress the sway of the ship than the overall stabilization method of the mechanical turntable. (2) It can greatly reduce the capture time of the drone and improve the capture probability; (3) It can still maintain an effective tracking range when the drone is doing fast and large dynamic movements to ensure the smooth communication link.

The CCD camera works in the visible light band, and is installed in the two-axis stable tracking turntable like the two-dimensional fast galvanometer. The sampling frame rate is 100fps, the resolution is 752ⅹ480, and the matching zoom lens works at a focal length of about 50mm.

The beacon laser uses the 808nm band, the maximum transmission power is 2W, and the far-field divergence angle is 2mrad. The transmission power can be adjusted in real time through the control program (the control program integrates the functions of image processing and control of various action mechanisms) to prevent the detector from being damaged at close range. saturation.

The communication between the ground terminal and the airborne terminal uses laser for one-way communication, and the laser communication unit of the ground terminal is composed of a modulation circuit and a guidance/communication laser emission unit. In order not to increase the load of the UAV and not to change the equipment, the laser communication receiving unit at the airborne end uses photoelectric detectors and corner reflectors/indicators, and does not set the PAT function. After the communication signal is received, the demodulation is performed by the airborne flight control unit. accomplish.

The effective area of the photodetector on the airborne side is 3mm×3mm. There is a converging lens in front of the detector, and its receiving aperture is 20mm; the diameter of the corner reflector is 35mm, the reflectivity is greater than 0.9, and the scattering angle is 0.1mrad; the weight is about 40g; the indicator light is high brightness White LED with a power of 3W.

In order to overcome the interference of the solar background light on the laser communication, the laser carrier modulation method is used to modulate the circuit. The ground modulation circuit multiplies the 57.6KHz carrier signal and the externally input serial data signal and sends it to the transmitting laser. The emission laser uses the 808nm wave band, the emission power is 500mW～5W, and the emission angle is 1mrad. The effective area of the detector of the airborne receiving module is 3mm×3mm, and there is a converging lens in front of the detector with a focal length of 3mm. The demodulation circuit extracts the useful signal from the output signal of the detector. Laser communication rate can reach 4.8kbps ~ 1Mbps adjustable.

Considering the landing/recovery phase of the land-based small and medium-sized UAV platform, the laser ranging unit uses a 950nm laser, and the maximum operating distance of the laser ranging is set to 3-5km, the ranging accuracy is ±0.8m, and the ranging update frequency is 20Hz .

The image processing adopts the spot centroid calculation method and the wave gate anti-interference method. The single execution time of the image processing and control program is 25.4 μs, and the update frequency of the target angle information is 100 Hz. The workflow of the image processing and control program is as follows:

The UAV first flies to the set landing airspace through other navigation methods such as radar or GPS. The guidance system uses the provided landing window target data to point to the target. If the guidance system fails to directly find the target due to reasons such as visibility, it uses a wide laser beam to actively Search this airspace until the UAV is captured (the UAV fuselage is equipped with an angle mirror); if the UAV is not captured within a certain period of time, the UAV will enter the go-around and re-landing process.

After the UAV is captured, the system enters the PAT tracking process. The PAT unit ensures that the guidance/communication laser beam is irradiated on the UAV stably, and the UAV is positioned at the center of the tracking field of view. During the tracking execution process, the program calculates the UAV The pitch angle, horizontal angle information. At the same time, the ranging laser is also stably irradiated on the UAV, and the reflected ranging laser enters the ranging laser receiving module to calculate the distance information of the UAV.

The three-dimensional position information (azimuth, pitch, distance) of the UAV above is output as an electrical signal through the I/O interface and enters the modulation circuit to modulate the communication laser beam, and then the guidance/communication laser emission unit transmits upward through the two-dimensional fast galvanometer to the drone. In this way, the UAV can control the flight course and landing based on the continuously refreshed three-dimensional position information received, and complete the laser-guided landing process.

Innovations of the present invention include the following:

Innovation 1: High-precision target aiming/acquisition/tracking unit (PAT), the block diagram of its working principle is shown in Figure 3.

PAT is a key part of the UAV recovery laser guidance system. Its core is a two-axis stable tracking turntable and a two-dimensional fast galvanometer, which form a composite axis structure. After the scanning laser beam emitted from the exit mirror of the two-dimensional fast galvanometer scans to the airborne corner mirror, the echo laser or the airborne indicator light will be imaged on the photosensitive surface of the CCD camera. After image processing and PAT algorithm processing, according to the acquired The relative angular position information of the UAV controls the compound action of the two-axis stable tracking turntable and the two-dimensional fast galvanometer, which can stably track and irradiate the laser beam to the UAV.

Among them, the two-axis stable tracking turntable (existing equipment) adopts U-O structure design, as shown in Figure 4, to achieve rough tracking of moving targets; the two-dimensional fast galvanometer (existing equipment) performs laser high-speed scanning function to realize the tracking of moving targets fine tracking. The two-dimensional fast galvanometer is composed of an incident mirror, an outgoing mirror, a scanning motor and a control circuit. The mirror is fixed on the shaft of the scanning motor, and the deflection angle of the mirror is controlled by the rotation of the motor. An angular position sensor is integrated in the scanning motor. The two-dimensional fast galvanometer exchanges data with the main control computer through the driver and I/O interface, transmits the corner position information to the image processing and control program, receives the position voltage signal output by the main control computer, and drives the scanning motor to the specified corner position , as shown in Figure 5.

In order to achieve rapid and high-probability capture of the guided UAV target, the laser guidance system should firstly minimize the capture uncertainty area and minimize the capture time, and then optimize the capture mode and scanning method to increase the capture probability. First, the UAV can be guided into the pre-set landing/recovery window by other navigation methods such as radar or GPS, and the laser scans the window area. In terms of scanning methods, scanning methods can be divided into helical scanning, raster scanning, helical raster compound scanning, rose scanning and other methods. The present invention adopts spiral raster scanning, which can scan from an area with a high capture probability to an area with a low capture probability, and is also easy to implement, as shown in Figure 6(a). Selecting the scanning interval and overlapping area according to the laser divergence angle and the jitter error of the visual axis can shorten the time to capture the moving target, as shown in Figure 6(b). The capture time depends on the area of the capture uncertain region θ _X θ _Y , the beacon laser divergence angle θ _BC , the dwell time T _d , and the scanning overlap coefficient P, and its approximate expression is

In the formula, _Td is the residence time of the emitted laser beam during the capture process, so that the capture camera receives photons exceeding the set threshold, so as to distinguish whether the detected signal is valid or noise. The scanning overlap coefficient P is used to reduce the impact of the vibration of the launch platform on the capture process, usually 10% to 15%, and the increase of P will increase the capture time. The above two parameters are limited by hardware conditions, and the range of change is limited. It can be seen from the above formula that the larger the ratio of the scanning uncertain region to the laser divergence angle, the square times of the required capture time will increase. Therefore, in engineering practice, an appropriate laser divergence angle can be designed according to the needs.

Innovation 2: Precise remote laser ranging, the principle of which is shown in Figure 7.

Laser ranging adopts the pulse ranging method and uses near-infrared lasers. Laser ranging in this band has low requirements for beam coherence, fast speed, simple structure, high peak output power, high repetition frequency and large range. The laser ranging equipment of the pulse method laser ranging sends light pulses to the measurement target. When the light pulses pass through the optical lens, one beam is reflected by the plane mirror in front of the lens and enters the laser feedback timing module. After photoelectric conversion, amplification, filtering and rectification, The level signal is sent to the start timing terminal of the time-to-digital conversion chip. Another beam of laser pulse starts to fly after the divergence angle is compressed by the lens, diffuse reflection occurs after encountering the target obstacle, part of the laser light returns to the laser receiving and processing circuit, and after the same photoelectric conversion, amplification, filtering and rectification, the formed level signal Sending the time-to-digital conversion chip to end the timing end, that is, to complete the entire measurement process, the microprocessor and the time-to-digital conversion chip in Figure 7 are integrated in the I/O interface.

Innovation 3: wide-beam irradiation laser communication technology.

Laser communication technology has the advantages of high transmission rate, large communication capacity, good directionality of communication beam, high confidentiality, and almost no electromagnetic interference. The communication laser beam used in traditional laser communication applications is very narrow, with a width of only about 10μrad. This requires extremely high alignment accuracy, dynamic performance, and reliability of the PAT unit in the laser communication system, and it is difficult.

On the basis of satisfying the recovery and guidance accuracy and communication capacity of the UAV, the present invention also reduces the design and development difficulty of the laser communication components as much as possible, reduces the weight and volume of the airborne communication components, and the on-board communication receiving unit adopts a large field of view Detector receiving mode, the optical communication beam adopts 1mrad wide beam, and the beam width has enough range within the recovery distance to track and irradiate the drone, thus avoiding the difficulty of design, volume and weight caused by the fine tracking and aiming mechanism. cost.

The laser communication unit uses simplex communication to upload the position and orientation information of the UAV relative to the landing/recovery point measured on the ground to the UAV. In order to improve the anti-interference ability and solve the interference of the sun's background light, the communication adopts the subcarrier modulation method. The relationship between the laser subcarrier modulation and the transmitted bit stream is shown in Figure 8. At the transmitting end, the binary data is multiplied by the subcarrier signal to obtain a new high-frequency digital signal, which is connected to the digital modulation input port of the laser and compared to The optical carrier is modulated; at the receiving end, a photodetector is first used to detect the light intensity signal, and then the modulated subcarrier signal is separated from the background light through a specific detector, and finally the binary data is demodulated from the modulated subcarrier signal. Experiments have proved that this subcarrier modulation method can effectively solve the interference problem of background light.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the technical field of the present invention can make various modifications or supplements to the described specific embodiments, such as using devices with similar functions but different parameters to replace them, but it will not deviate from the spirit of the present invention or go beyond the appended scope defined in the claims.

Claims (3)

1. A laser-based UAV recovery guidance system, characterized in that: it includes an airborne end and a ground end, and the ground end includes a two-axis stable tracking turntable, a two-dimensional fast galvanometer, a guidance/communication laser emission unit, and a CCD PAT unit composed of camera and master control computer with image processing and control program installed, ranging laser emitting module, ranging laser receiving module, and I/O interface; PAT unit realizes aiming, capturing and tracking of UAV; Two-dimensional fast galvanometer, guidance/communication laser emitting unit, CCD camera, ranging laser emitting module, ranging laser receiving module, and I/O interface are all set on the two-axis stable tracking turntable, CCD camera, ranging laser receiving The module, the two-dimensional fast galvanometer, and the guidance/communication laser emission unit are respectively connected to the master control computer through the I/O interface, and the ranging laser emission module is connected to the two-dimensional fast galvanometer; The airborne side includes a cooperative target composed of a corner mirror and an indicator light and a photodetector; the corner mirror/light is used to feed back signals to the CCD camera and the ranging laser receiving module on the ground side, and the photodetector works in simplex mode Next, it is used to realize the laser communication reception of the azimuth, pitch and distance information of the UAV; the cooperative target and the photoelectric detector are respectively connected to the airborne flight control unit; After the UAV enters the landing window through guidance, the guidance/communication laser emission unit emits the guidance laser, and the laser beam scans the landing window area through the two-dimensional fast galvanometer, and the echo laser or the airborne indicator light will be on the photosensitive surface of the CCD camera. On the imaging, the I/O interface enters the main control computer, and the relative angular position information of the UAV is obtained through the image processing program. The laser beam of the communication laser is stably tracked and irradiated on the UAV to realize the active tracking of the UAV; at this time, the ranging laser emitted by the ranging laser transmitter module will also be stably irradiated on the UAV, and the angle mirror at the airborne end will reflect The echo signal of the ranging laser will be received by the ranging laser receiving module, and the relative distance information of the UAV can be calculated; the three-dimensional position information of the UAV's azimuth, pitch, and distance is output through the I/O interface, and the electrical signal The communication laser beam is modulated by the modulation circuit, and then the guidance/communication laser emission unit transmits upward to the UAV through the two-dimensional fast galvanometer; in this way, the UAV can control the flight based on the continuously refreshed three-dimensional position information received Heading and landing, complete the laser-guided landing process without relying on radio communication; Through the information modulation of the laser, the system enables the system to complete the information measurement such as distance measurement and angle measurement, and at the same time have the ability of high-speed information communication, so as to realize the precise recovery and guidance of the UAV under the condition of radio rejection. 2. The laser-based UAV recovery and guidance system according to claim 1, characterized in that: the two-axis stable tracking turntable and the two-dimensional fast galvanometer in the PAT unit at the ground end form a composite Axis structure, the laser beam is emitted from the exit mirror of the two-dimensional fast galvanometer and scanned to the airborne end angle mirror, the echo laser or the airborne indicator light will be imaged on the photosensitive surface of the CCD camera, and the UAV will be obtained through the image processing program. The relative angular position information of the image processing and control program uses the angular information to control the scanning action of the two-dimensional fast galvanometer, and stably track and irradiate the guidance/communication laser beam to the UAV; among them, the two-axis stable tracking turntable adopts U-O Structural design to achieve rough tracking of moving targets; two-dimensional fast galvanometers perform laser high-speed scanning functions to achieve fine tracking of moving targets; two-dimensional fast galvanometers include incident mirrors, outgoing mirrors, scanning motors and control circuits, mirrors Fixed on the scanning motor shaft, the deflection angle of the mirror is controlled by the rotation of the motor; the scanning motor is integrated with a rotation angle position sensor; the two-dimensional fast galvanometer exchanges data with the master control computer through the driver and I/O interface, and the rotation angle position information Pass it to the image processing and control program, receive the position voltage signal output by the master control computer, and drive the scanning motor to the specified corner position. 3. The laser-based UAV recovery guidance system according to claim 1 or 2, characterized in that: the laser beam scans the landing window area via a two-dimensional fast galvanometer using a spiral grating compound scan, from the captured The area with high probability scans to the area with low capture probability, which is easy to implement.