Air-to-ground coordinated UAV take-off and landing control system and method

Abstract

The present application discloses an air-ground coordinated UAV take-off and landing control system and method, and relates to the field of air-ground coordinated formation control technology. The system is applied to an air-ground coordinated formation, wherein a take-off and landing control device on the UAV side is applied to the UAV in the air-ground coordinated formation; a take-off and landing control device on the unmanned vehicle side is applied to the unmanned vehicle in the air-ground coordinated formation; the take-off and landing control device on the UAV side adjusts its own horizontal direction to align with the take-off and landing guidance mark based on real-time images, moves synchronously with the target unmanned vehicle in the horizontal direction, and continuously descends until the landing is completed. When the vertical distance with the target unmanned vehicle is less than a preset vertical distance threshold, the take-off and landing control device on the unmanned vehicle side adjusts its own posture to be the same as that of the UAV, until the UAV is landed, the carrying UAV is restored to the preset posture and preset height, thereby completing the air-ground coordinated UAV take-off and landing in the motion scene.

Description

Technical Field

[0001] The present application relates to the technical field of air-ground coordinated formation control, and in particular to an air-ground coordinated UAV take-off and landing control system and method. Background Art

[0002] With the development of science and technology, the close cooperation between unmanned aerial vehicles (UAVs) and unmanned ground vehicles (UGVs) can demonstrate their application value in a variety of environments. UAVs have the advantage of a wide field of vision, while unmanned ground vehicles can accurately reach the destination to perform tasks. The air-ground collaborative system developed based on this can effectively improve the completion of tasks. The operation methods for drones to take off and land in the field include using automatic take-off and landing drone airports deployed on the ground and vehicle-mounted drone take-off and landing platforms.

[0003] The existing air-ground collaborative vehicle-mounted UAV take-off and landing system has the problem of being unable to accurately dock and land in dynamic docking tasks. During the dynamic docking process, the unmanned vehicle and the UAV are both moving, and an inclination angle will be generated between the two. In order to ensure the safe landing of the UAV, existing research has proposed a three-degree-of-freedom UAV take-off and landing system on the air-ground collaborative platform. The vehicle-mounted take-off and landing platform end of the take-off and landing system can actively dock with the UAV, but the vehicle-mounted take-off and landing platform is constrained by size, and the tolerance area of ​​its landing point is small. The system uses a positioning solution based on GPS (Global Positioning System) + RTK (Rea-time kinematic, real-time dynamic carrier phase difference technology), which cannot ensure that the UAV lands accurately on the moving take-off and landing platform. Therefore, it is necessary to develop an air-ground collaborative UAV precision take-off and landing system suitable for sports scenes. Summary of the invention

[0004] The purpose of this application is to provide an air-ground coordinated UAV take-off and landing control system and method, which can complete air-ground coordinated UAV take-off and landing in motion scenarios.

[0005] To achieve the above objectives, this application provides the following solutions:

[0006] In the first aspect, the present application provides an air-ground coordinated UAV take-off and landing control method, wherein the air-ground coordinated UAV take-off and landing control system is applied to an air-ground coordinated formation, and the air-ground coordinated UAV take-off and landing control system includes: a UAV-side take-off and landing control device and an unmanned vehicle-side take-off and landing control device.

[0007] The UAV take-off and landing control device is applied to UAVs in an air-ground collaborative formation.

[0008] The unmanned vehicle take-off and landing control device is applied to unmanned vehicles in an air-ground collaborative formation.

[0009] The drone-side take-off and landing control device comprises: a drone control module, a drone-side precision take-off and landing system control module and a drone-side air-ground collaborative wireless communication module which are connected in sequence.

[0010] The unmanned vehicle-side take-off and landing control device includes: an unmanned vehicle-side air-ground collaborative wireless communication module, an unmanned vehicle-side precise take-off and landing system control module, and a vehicle-mounted tilt servo take-off and landing platform provided with a take-off and landing guidance mark, which are connected in sequence.

[0011] The air-ground collaborative wireless communication module on the drone side is connected to the air-ground collaborative wireless communication module on the unmanned vehicle side.

[0012] The UAV-side precise take-off and landing system control module is used to obtain real-time images, generate horizontal direction correction instructions based on the position of the take-off and landing guide mark in the real-time image, and send the horizontal direction correction instructions to the UAV control module until the take-off and landing guide mark is located at the center of the real-time image; the UAV-side precise take-off and landing system control module is also used to obtain the real-time horizontal direction movement instructions of the target unmanned vehicle and generate a descent instruction, and send both the real-time horizontal direction movement instructions and the descent instruction to the UAV control module; the real-time image is the image directly below the UAV where the UAV-side take-off and landing control device is located;

[0013] The UAV-side precise take-off and landing system control module is also used to determine the vertical distance between the UAV and the target unmanned vehicle based on the real-time image after the take-off and landing guidance mark is located at the center of the real-time image, and when the vertical distance is less than a preset vertical distance threshold, obtain the posture of the UAV as the first posture, and send the first posture to the target unmanned vehicle.

[0014] The drone control module is used to execute horizontal direction correction instructions, or to execute real-time horizontal direction movement instructions and descent instructions simultaneously.

[0015] The air-ground collaborative wireless communication module on the drone side is used to send a first posture, or receive a real-time horizontal motion instruction of the target unmanned vehicle.

[0016] The unmanned vehicle-side air-ground collaborative wireless communication module is used to receive the first posture, or send a real-time horizontal movement instruction of the unmanned vehicle.

[0017] The unmanned vehicle-side precision take-off and landing system control module is used to generate a posture acquisition instruction to control the vehicle-mounted tilt servo take-off and landing platform to acquire its own posture as a second posture when receiving a first posture, and generate a posture adjustment instruction according to the first posture and the second posture until the first posture is equal to the second posture.

[0018] The vehicle-mounted tilt servo take-off and landing platform is used to adjust its own posture based on the posture adjustment instruction.

[0019] The unmanned vehicle-side precision take-off and landing system control module is also used to generate a landing end instruction after the drone completes landing.

[0020] The vehicle-mounted tilt servo take-off and landing platform is used to carry the UAV to restore to a preset posture and a preset height when receiving a landing end instruction.

[0021] Optionally, the UAV-side precision take-off and landing system control module includes: a camera module and a vision-guided computing module.

[0022] The visual guidance computing module is respectively connected to the camera module, the UAV control module and the UAV-end air-to-ground collaborative wireless communication module.

[0023] The camera module is used to obtain real-time images.

[0024] The visual guidance computing module is used to generate a horizontal direction correction instruction based on the position of the take-off and landing guidance mark in the real-time image, and send the horizontal direction correction instruction to the UAV control module until the take-off and landing guidance mark is located at the center of the real-time image; obtain the real-time horizontal direction movement instruction of the target unmanned vehicle and generate a descent instruction, and send both the real-time horizontal direction movement instruction and the descent instruction to the UAV control module;

[0025] The visual guidance computing module is also used to determine the vertical distance between the UAV and the target unmanned vehicle based on the real-time image after the take-off and landing guidance mark is located at the center of the real-time image, and when the vertical distance is less than a preset vertical distance threshold, obtain the posture of the UAV as a first posture, and send the first posture to the target unmanned vehicle.

[0026] Optionally, the vehicle-mounted tilt servo lift and landing platform is arranged on the body of the unmanned vehicle. The vehicle-mounted tilt servo lift and landing platform comprises: a plurality of lifting devices, which are arranged and installed on the body, and each of the lifting devices has an independent lifting end.

[0027] The lifting and lowering platform is installed on the plurality of lifting ends, and different lifting ends are connected to different parts of the lifting and lowering platform.

[0028] The posture acquisition unit is arranged on the take-off and landing platform and is used for detecting the posture of the take-off and landing platform in real time.

[0029] A control unit, the control unit is connected to the attitude acquisition unit, the unmanned vehicle-side precise take-off and landing system control module and all lifting devices respectively. The control unit is used to determine the attitude of the vehicle-mounted tilt servo take-off and landing platform based on the attitude of the take-off and landing platform. The control unit is also used to control all lifting devices based on the attitude adjustment instruction or the landing end instruction.

[0030] Optionally, the lifting device is an electric push rod.

[0031] Optionally, there are five electric push rods, namely, a first electric push rod and four second electric push rods, the four second electric push rods are arranged at the four corners of the rectangular structure, the first electric push rod is arranged at the center of the rectangular structure, the second electric push rod is ball-jointed to the vehicle body and the lifting and lowering platform, the first electric push rod is fixedly connected to the vehicle body, and the first electric push rod is ball-jointed to the lifting and lowering platform.

[0032] Optionally, the attitude acquisition unit includes an accelerometer and a gyroscope installed on the take-off and landing platform.

[0033] The accelerometer and the gyroscope are both connected to the control unit.

[0034] In the second aspect, the present application provides an air-ground coordinated UAV take-off and landing control method, which is applied to the air-ground coordinated UAV take-off and landing control system. The air-ground coordinated UAV take-off and landing control method includes: the UAV-side precise take-off and landing system control module obtains real-time images.

[0035] The UAV-side precise take-off and landing system control module generates a horizontal direction correction instruction based on the position of the take-off and landing guidance mark in the real-time image.

[0036] The drone control module executes horizontal correction instructions until the take-off and landing guidance mark is located in the center of the real-time image.

[0037] The UAV-side precision take-off and landing system control module obtains the real-time horizontal motion instructions of the target unmanned vehicle and generates a descent instruction, and controls the UAV control module to execute the real-time horizontal motion instructions and descent instructions until the landing is completed.

[0038] The control module of the precise take-off and landing system on the drone side obtains real-time images and determines the vertical distance between the drone and the target unmanned vehicle based on the real-time images. When the vertical distance is less than a preset vertical distance threshold, the posture of the drone is obtained as a first posture and the first posture is sent to the target unmanned vehicle.

[0039] When receiving the first posture, the control module of the precision take-off and landing system on the unmanned vehicle side generates a posture acquisition instruction to control the vehicle-mounted tilt servo take-off and landing platform to acquire its own posture as the second posture, generates a posture adjustment instruction according to the first posture and the second posture until the first posture is equal to the second posture, and generates a landing end instruction when the landing is completed.

[0040] The vehicle-mounted tilt servo take-off and landing platform restores the UAV with it to a preset attitude and a preset height upon receiving a landing end command.

[0041] Optionally, generating a horizontal direction correction instruction based on the position of the take-off and landing guidance mark in the real-time image includes:

[0042] The real-time image is processed in grayscale to obtain a real-time grayscale image.

[0043] The Canny edge detection algorithm is used to extract multiple boundary contours in real-time grayscale images.

[0044] Use cv2.approxPolyDP function to perform polygonal approximation on each boundary contour, and select all quadrilateral boundary contours as pending boundary contours.

[0045] Determine any pending boundary contour as the current pending boundary contour.

[0046] According to the take-off and landing guidance mark dimensions of the target unmanned vehicle, the area within the current undetermined boundary contour is gridded.

[0047] Determine the grid brightness of each grid. The grid brightness is the average brightness value of all pixels in the corresponding grid.

[0048] The average value of the maximum grid brightness and the minimum grid brightness is determined as the division threshold.

[0049] The average value of the maximum grid brightness and the division threshold is determined as the division white threshold.

[0050] Determine the average value of the minimum grid brightness and the division threshold as the division black threshold.

[0051] Based on the white threshold and the black threshold, the current pending boundary contour is binarized to obtain a contour two-dimensional code of the current pending boundary contour.

[0052] Update the current pending boundary contour and return to step "grid the area within the current pending boundary contour according to the take-off and landing guidance mark dimension of the target unmanned vehicle" until the contour QR code of the current pending boundary contour is the same as the take-off and landing guidance mark of the target unmanned vehicle.

[0053] The current pending boundary contour is determined to be the take-off and landing guidance identification boundary contour.

[0054] The average pixel coordinates of the four vertices of the boundary contour of the take-off and landing guidance mark are obtained as the position of the take-off and landing guidance mark.

[0055] Get the midpoint position of the real-time grayscale image.

[0056] When the position of the take-off and landing guide mark does not coincide with the midpoint position, a horizontal direction correction instruction is generated based on the position of the take-off and landing guide mark and the midpoint position.

[0057] Optionally, determining the vertical distance between the UAV and the target unmanned vehicle based on the real-time image includes:

[0058] The number of pixels of the real-time image is the first number of pixels.

[0059] Determine the boundary outline of the take-off and landing guidance signs.

[0060] Get the number of second pixels within the boundary contour of the take-off and landing guidance mark.

[0061] A ratio of the second number of pixels to the first number of pixels is determined.

[0062] The vertical distance between the UAV and the target UAV is determined based on the ratio.

[0063] Optionally, the posture adjustment instruction is:

[0064] .

[0065] .

[0066] in, LF is the driving amount of the second electric push rod on the left front; is the installation distance between the left front second electric push rod and the right front second electric push rod; b is the installation distance between the left front second electric push rod and the left rear second electric push rod; roll is the left-right tilt of the unmanned vehicle as the reference system, ,in, For relative posture, is the first element of the quaternion representing the relative attitude; is the second element of the quaternion representing the relative attitude; is the third element in the quaternion representing the relative attitude; is the fourth element of the quaternion representing the relative attitude; For the first posture, is the first element of the quaternion representing the first attitude; is the second element of the quaternion representing the first posture; is the third element of the quaternion representing the first posture; is the fourth element of the quaternion representing the first attitude; For the second posture The reverse, the second posture , is the first element of the quaternion representing the second attitude; is the second element of the quaternion representing the second attitude; is the third element of the quaternion representing the second attitude; is the fourth element of the quaternion representing the second attitude; pitch is the tilt in the front-rear direction with the unmanned vehicle as the reference system, ; RF is the driving amount of the second right front electric push rod; LR is the driving amount of the second electric push rod at the left rear; RR is the driving amount of the second electric push rod at the right rear; CT is the driving amount of the first electric push rod; H is the vertical distance between the take-off and landing platform and the vehicle chassis, is the height difference between the UAV and the vehicle-mounted platform chassis, is the height of the take-off and landing platform.

[0067] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0068] The present application provides an air-ground coordinated UAV take-off and landing control system and method, which is applied to an air-ground coordinated formation, wherein the UAV-side take-off and landing control device is applied to the UAV in the air-ground coordinated formation. The unmanned vehicle-side take-off and landing control device is applied to the unmanned vehicle in the air-ground coordinated formation. The UAV-side take-off and landing control device adjusts its own horizontal direction to align with the take-off and landing guidance mark based on the real-time image, moves synchronously with the target unmanned vehicle in the horizontal direction, and continuously descends until the landing is completed. When the vertical distance with the target unmanned vehicle is less than the preset vertical distance threshold, the unmanned vehicle-side take-off and landing control device adjusts its own posture to be the same as the UAV, until the UAV is landed, the carrying UAV is restored to the preset posture and preset height, and then the air-ground coordinated UAV take-off and landing in the motion scene is completed. The present application is based on the air-ground coordinated dynamic relative posture correction of the visual guidance tilt and servo platform, and uses visual guidance to realize the precise take-off and landing of the air-ground coordinated platform in the motion scene. The take-off and landing platform is used to realize the attitude synchronization docking of the UAV and the unmanned vehicle-mounted take-off and landing platform, which reduces the control difficulty of stable landing and solves the problem that the existing air-ground coordinated UAV take-off and landing system cannot achieve precise and stable take-off and landing under dynamic docking tasks. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0070] Figure 1 This is a schematic diagram of the structure of an air-to-ground collaborative UAV take-off and landing control system in one embodiment of the present application.

[0071] Figure 2 This is a schematic diagram of an unmanned vehicle in one embodiment of the present application.

[0072] Figure 3 This is a schematic diagram of a lifting device and a landing platform in one embodiment of the present application.

[0073] Figure 4 This is a first partial schematic diagram of a lifting device and a lift platform in one embodiment of the present application.

[0074] Figure 5 This is a second partial schematic diagram of the lifting device and the lifting and landing platform in one embodiment of the present application.

[0075] Figure 6 This is a third partial schematic diagram of the lifting device and the lifting and landing platform in one embodiment of the present application.

[0076] Figure 7 This is a flow chart of the air-to-ground coordinated UAV take-off and landing control method in one embodiment of the present application.

[0077] In the figure: 1-lifting and landing platform; 2-electric push rod; 3-ball joint structure; 4-vehicle body; 5-lifting and landing guide mark; 31-connecting piece; 32-connecting ball; 33-connecting cylinder. DETAILED DESCRIPTION

[0078] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0079] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0080] In an exemplary embodiment, Figure 1As shown, an air-ground coordinated UAV take-off and landing control system is provided. The air-ground coordinated UAV take-off and landing control system is applied to an air-ground coordinated formation. The air-ground coordinated UAV take-off and landing control system includes: a UAV-side take-off and landing control device and an unmanned vehicle-side take-off and landing control device.

[0081] The UAV take-off and landing control device is used for UAVs in air-ground coordinated formations.

[0082] The take-off and landing control device of the unmanned vehicle is applied to the unmanned vehicle in the air-ground collaborative formation, such as Figure 2 .

[0083] The drone-side take-off and landing control device includes: a drone control module, a drone-side precision take-off and landing system control module, and a drone-side air-ground collaborative wireless communication module, which are connected in sequence.

[0084] The unmanned vehicle end take-off and landing control device comprises: an unmanned vehicle end air-ground cooperative wireless communication module, an unmanned vehicle end precise take-off and landing system control module and a vehicle-mounted tilt servo take-off and landing platform provided with a take-off and landing guide mark 5, which are connected in sequence. The precise take-off and landing guidance module (i.e., the take-off and landing guidance mark 5) is located on the top of the take-off and landing platform 1. The precise take-off and landing guidance module includes a positioning guidance mark based on vision. The peripheral device can capture the image information containing the positioning mark with the help of an image sensor, and the three-dimensional relative posture estimation of the positioning mark can be realized with the help of a program algorithm.

[0085] The air-ground collaborative wireless communication module on the UAV side is connected to the air-ground collaborative wireless communication module on the unmanned vehicle side.

[0086] The control module of the precise take-off and landing system on the drone side is used to obtain real-time images, generate horizontal correction instructions based on the position of the take-off and landing guide mark 5 in the real-time image, and send the horizontal correction instructions to the drone control module until the take-off and landing guide mark 5 is located at the center of the real-time image. The control module of the precise take-off and landing system on the drone side is also used to obtain the real-time horizontal movement instructions of the target unmanned vehicle and generate a descent instruction, and send both the real-time horizontal movement instructions and the descent instruction to the drone control module. The real-time image is the image directly below the drone where the take-off and landing control device on the drone side is located.

[0087] The UAV-side precise take-off and landing system control module is also used to determine the vertical distance between the UAV and the target unmanned vehicle based on the real-time image after the take-off and landing guidance mark 5 is located in the center of the real-time image, and when the vertical distance is less than a preset vertical distance threshold, obtain the posture of the UAV as the first posture, and send the first posture to the target unmanned vehicle.

[0088] The drone control module is used to execute horizontal correction instructions, or to execute real-time horizontal movement instructions and descent instructions at the same time.

[0089] The drone control module is installed inside the drone. This module monitors and controls the drone's attitude, speed and acceleration in real time to ensure that the drone can move stably and accurately according to the preset flight path. In the intervention phase of the system proposed in this application (i.e., the take-off and landing phase of the air-ground collaborative drone), the module sends the measured drone attitude to the unmanned vehicle through the wireless communication module for adjusting the attitude of the vehicle-mounted tilt servo take-off and landing platform. At the same time, the module receives the correction value of the flight direction provided by the drone-side precision take-off and landing system control module, inputs the correction value into the drone's control algorithm, controls the drone to move toward the positioning guidance mark, and gradually reduces the horizontal direction error. When the horizontal direction error reaches the allowable value, the module drives the drone to lower its altitude, and finally lands accurately on the vehicle-mounted tilt servo take-off and landing platform.

[0090] The air-ground collaborative wireless communication module is installed on drones and unmanned vehicles. The module has the ability of two-way asynchronous communication and can meet the communication needs of the air-ground collaborative system such as attitude transmission and reception and take-off and landing status synchronization.

[0091] The air-ground collaborative wireless communication module on the UAV side is used to send a first posture, or receive real-time horizontal motion instructions from the target unmanned vehicle.

[0092] The air-ground collaborative wireless communication module on the unmanned vehicle side is used to receive the first posture, or send the real-time horizontal movement instruction of the unmanned vehicle.

[0093] The control module of the precision take-off and landing system on the unmanned vehicle side is used to generate a posture acquisition instruction to control the vehicle-mounted tilt servo take-off and landing platform to obtain its own posture as a second posture when receiving the first posture, and generate a posture adjustment instruction according to the first posture and the second posture until the first posture is equal to the second posture.

[0094] The unmanned vehicle-side precision take-off and landing system control module is also used to generate a landing end instruction after the drone completes landing.

[0095] The vehicle-mounted tilt servo take-off and landing platform is used to adjust its own attitude based on attitude adjustment instructions.

[0096] The vehicle-mounted tilt servo take-off and landing platform is used to carry the UAV back to a preset attitude and preset altitude when receiving a landing end command.

[0097] The control module of the precise take-off and landing system on the unmanned vehicle is located inside the unmanned vehicle. It can send control instructions to the vehicle-mounted tilt servo take-off and landing platform based on the take-off and landing platform 1, and send instructions to the supporting electric push rod according to the amount of movement required for the take-off and landing platform 1 to reach the desired position, so as to realize real-time control of the three degrees of freedom of the take-off and landing platform 1. The control module can receive the attitude information of the unmanned vehicle through the wireless communication module, and adjust the inclination angle of the take-off and landing platform 1 in real time to make it parallel to the unmanned vehicle. The control module can also obtain the operating status of the unmanned vehicle, drive the take-off and landing platform 1 to keep it horizontal before take-off to ensure the safety and stability of the take-off process, and retract the electric push rod 2 after landing to make the take-off and landing platform 1 fit the body of the unmanned vehicle to realize the storage of the unmanned vehicle.

[0098] The control module of the precise take-off and landing system on the drone side includes: a camera module and a visual guidance computing module. The visual guidance computing module is respectively connected to the camera module, the drone control module and the air-ground collaborative wireless communication module on the drone side. The camera module is used to obtain real-time images. The visual guidance computing module is used to generate a horizontal correction instruction based on the position of the take-off and landing guidance mark 5 in the real-time image, and send the horizontal correction instruction to the drone control module until the take-off and landing guidance mark 5 is located at the center of the real-time image. The real-time horizontal movement instruction of the target unmanned vehicle is obtained and a descent instruction is generated, and both the real-time horizontal movement instruction and the descent instruction are sent to the drone control module. The visual guidance computing module is also used to determine the vertical distance between the drone and the target unmanned vehicle based on the real-time image after the take-off and landing guidance mark 5 is located at the center of the real-time image, and when the vertical distance is less than the preset vertical distance threshold, the posture of the drone is obtained as the first posture, and the first posture is sent to the target unmanned vehicle.

[0099] The control module of the precise take-off and landing system on the drone side is located on the drone body, and includes a camera module installed on the bottom of the drone and a visual guidance computing module installed inside the drone. The camera module has a 60-degree field of view and can obtain a bird's-eye view directly below the drone body. The computing module obtains an image containing a positioning guidance mark from the camera module, uses a recognition program for the mark to extract the position and size of the guidance mark in the picture from the image, and calculates the relative position error between the guidance mark and the drone. Furthermore, the computing module provides a correction value of the flight direction to the control module of the drone platform based on the position error, so as to achieve accurate tracking of the landing point.

[0100] like Figures 3 to 6 The vehicle-mounted tilt servo lift and landing platform is arranged on the body 4 of the unmanned vehicle. The body 4 has walking function and supporting function; the vehicle-mounted tilt servo lift and landing platform includes: a lifting device, a lift and landing platform 1, a posture acquisition unit and a control system.

[0101] Among them, the vehicle body 4 has walking function and supporting function; there are multiple lifting devices installed on the vehicle body 4, each lifting device has an independent lifting end, and the lifting device is preferably an electric push rod 2; the lifting and landing platform 1 is installed on multiple lifting ends, and different lifting ends are connected to different parts of the lifting and landing platform 1; the posture acquisition unit is set on the lifting and landing platform 1 and is used to detect the posture of the lifting and landing platform 1 in real time; the posture acquisition unit can transmit the posture information of the lifting and landing platform 1 to the control unit, and the control unit controls multiple lifting devices to work together according to the posture information so that the lifting platform is in a horizontal state. The control unit is respectively connected to the posture acquisition unit and the unmanned vehicle-side precise landing system control module and all lifting devices. The control unit is used to determine the posture of the vehicle-mounted tilt servo lifting and landing platform based on the posture of the lifting and landing platform 1. The control unit is also used to control all lifting devices based on the posture adjustment instruction or the landing end instruction.

[0102] In some embodiments, five electric push rods 2 are provided, namely, a first electric push rod and four second electric push rods. The four second electric push rods are arranged at the four corners of the rectangular structure, the first electric push rod is arranged at the center of the rectangular structure, the second electric push rod is ball-jointed to the vehicle body 4 and the lifting and lowering platform 1, the first electric push rod is fixedly connected to the vehicle body 4, and the first electric push rod is ball-jointed to the lifting and lowering platform 1.

[0103] This embodiment limits the number of electric push rods 2 and the installation method. The ball joint connection in this application can be realized by any structure with a ball joint function in the prior art, which can be specifically adopted as follows: Figure 3 , Figure 4 The ball joint structure shown in Figure 3 For example, the ball joint structure 3 includes a connecting member 31, a connecting ball 32 and a connecting tube 33. The connecting member 31 and the connecting ball 32 are fixedly connected. The connecting ball 32 is placed in the connecting tube 33 and can rotate freely in the connecting tube 33. The connecting member 31 and the connecting tube 33 are respectively fixedly connected to two ball joint components. In the present application, the ball joint components can be the vehicle body 4, the electric push rod 2 and the lifting and lowering platform 1.

[0104] In some embodiments, the electric push rod 2 is equipped with an encoder, which is connected to the control system for transmitting the pushing stroke information of the electric push rod 2 to the control system, and the attitude acquisition unit includes an accelerometer and a gyroscope installed on the take-off and landing platform 1. The accelerometer and the gyroscope are both connected to the control unit.

[0105] In another embodiment, an air-ground coordinated UAV take-off and landing control method is provided, and the air-ground coordinated UAV take-off and landing control method is applied to the air-ground coordinated UAV take-off and landing control system, and the air-ground coordinated UAV take-off and landing control method includes:

[0106] Step 1: The UAV precision take-off and landing system control module obtains real-time images.

[0107] Step 2: The UAV-side precision take-off and landing system control module generates a horizontal direction correction instruction based on the position of the take-off and landing guidance mark 5 in the real-time image.

[0108] Step 3: The UAV control module executes the horizontal direction correction instruction until the take-off and landing guidance mark 5 is located at the center of the real-time image.

[0109] Step 4: The UAV precision take-off and landing system control module obtains the real-time horizontal movement command of the target unmanned vehicle and generates a descent command, and controls the UAV control module to execute the real-time horizontal movement command and descent command until the landing is completed.

[0110] Step 5: The control module of the precise take-off and landing system on the drone side obtains real-time images, and determines the vertical distance between the drone and the target unmanned vehicle based on the real-time images, until the vertical distance is less than the preset vertical distance threshold, the posture of the drone is obtained as the first posture, and the first posture is sent to the target unmanned vehicle.

[0111] Step 6: When the unmanned vehicle-side precision take-off and landing system control module receives the first posture, it generates a posture acquisition instruction to control the vehicle-mounted tilt servo take-off and landing platform to obtain its own posture as the second posture, and generates a posture adjustment instruction according to the first posture and the second posture until the first posture is equal to the second posture, and generates a landing end instruction when the landing is completed.

[0112] Step 7: Upon receiving the landing end command, the vehicle-mounted tilt servo take-off and landing platform carries the UAV back to the preset attitude and preset height.

[0113] Wherein, generating a horizontal direction correction instruction based on the position of the take-off and landing guidance mark 5 in the real-time image includes:

[0114] The real-time image is processed in grayscale to obtain a real-time grayscale image.

[0115] The Canny edge detection algorithm is used to extract multiple boundary contours in real-time grayscale images.

[0116] Use cv2.approxPolyDP function to perform polygonal approximation on each boundary contour, and select all quadrilateral boundary contours as pending boundary contours.

[0117] Determine any pending boundary contour as the current pending boundary contour.

[0118] According to the 5-dimensional take-off and landing guidance mark of the target unmanned vehicle, the area within the current undetermined boundary outline is gridded.

[0119] Determine the grid brightness of each grid. The grid brightness is the average brightness value of all pixels in the corresponding grid.

[0120] The average value of the maximum grid brightness and the minimum grid brightness is determined as the division threshold.

[0121] The average value of the maximum grid brightness and the division threshold is determined as the division white threshold.

[0122] Determine the average value of the minimum grid brightness and the division threshold as the division black threshold.

[0123] Based on the white threshold and the black threshold, the current pending boundary contour is binarized to obtain a contour two-dimensional code of the current pending boundary contour.

[0124] Update the current pending boundary contour and return to step "grid the area within the current pending boundary contour according to the 5-dimensional take-off and landing guidance mark of the target unmanned vehicle" until the contour QR code of the current pending boundary contour is the same as the take-off and landing guidance mark 5 of the target unmanned vehicle.

[0125] The current pending boundary contour is determined to be the boundary contour of the take-off and landing guidance mark 5.

[0126] The average pixel coordinates of the four vertices of the boundary contour of the take-off and landing guide mark 5 are obtained as the position of the take-off and landing guide mark 5 .

[0127] Get the midpoint position of the real-time grayscale image.

[0128] When the position of the take-off and landing guide mark 5 does not coincide with the midpoint position, a horizontal direction correction instruction is generated based on the position of the take-off and landing guide mark 5 and the midpoint position.

[0129] Among them, include:

[0130] The number of pixels of the real-time image is the first number of pixels.

[0131] Determine the boundary outline of the take-off and landing guidance mark 5.

[0132] The number of second pixel points within the boundary contour of the take-off and landing guidance mark 5 is obtained.

[0133] A ratio of the second number of pixels to the first number of pixels is determined.

[0134] The vertical distance between the UAV and the target UAV is determined based on the ratio.

[0135] The posture adjustment instructions are:

[0136] .

[0137] .

[0138] in, LF is the driving amount of the second electric push rod on the left front; is the installation distance between the left front second electric push rod and the right front second electric push rod; b is the installation distance between the left front second electric push rod and the left rear second electric push rod; roll is the left-right tilt of the unmanned vehicle as the reference system, ,in, For relative posture, is the first element of the quaternion representing the relative attitude; is the second element of the quaternion representing the relative attitude; is the third element in the quaternion representing the relative attitude; is the fourth element of the quaternion representing the relative attitude; For the first posture, is the first element of the quaternion representing the first attitude; is the second element of the quaternion representing the first posture; is the third element of the quaternion representing the first posture; is the fourth element of the quaternion representing the first attitude; For the second posture The reverse, the second posture , is the first element of the quaternion representing the second attitude; is the second element of the quaternion representing the second attitude; is the third element of the quaternion representing the second attitude; is the fourth element of the quaternion representing the second attitude; pitch is the tilt in the front-rear direction with the unmanned vehicle as the reference system, ; RF is the driving amount of the second right front electric push rod; LR is the driving amount of the second electric push rod at the left rear; RR is the driving amount of the second electric push rod at the right rear; CT is the driving amount of the first electric push rod; H is the vertical distance between the take-off and landing platform and the vehicle chassis, is the height difference between the UAV and the vehicle-mounted platform chassis, is the height of the take-off and landing platform.

[0139] In this embodiment, when the drone is landing, the drone observes the positioning guidance mark on the vehicle-mounted tilt servo platform through the camera module installed at the bottom, uses the drone-side precise take-off and landing system control module to obtain the relative positioning of itself and the positioning guidance mark, and drives the center of the drone to align with the positioning guidance mark to achieve the search and tracking flight of the landing point. The drone-side precise take-off and landing system control module also extracts the relative distance from the positioning guidance mark, that is, the vertical distance between the drone and the vehicle-mounted tilt servo take-off and landing platform. The drone gradually lowers its altitude and sends its own attitude information to the unmanned vehicle when it reaches the preset threshold; the unmanned vehicle-side precise take-off and landing system control module receives the attitude information of the drone, and the accelerometer and gyroscope installed on the vehicle-mounted tilt servo take-off and landing platform start working, reporting its own attitude to the control module, so that it adjusts the attitude of the vehicle-mounted tilt servo take-off and landing platform according to the attitude information, and realizes the attitude synchronization of the vehicle-mounted tilt servo take-off and landing platform with the drone. The drone continues to reduce its flight altitude on the basis of precise alignment with the take-off and landing platform 1, and finally lands stably on the take-off and landing platform 1, the drone stops flying, the take-off and landing platform 1 is retracted, and the landing process ends.

[0140] When the UAV takes off, the accelerometer and gyroscope installed on the vehicle-mounted tilt servo landing platform start working to measure the platform's attitude in real time. The unmanned vehicle-side precision landing system control module calculates the amount of drive required to achieve a horizontal state, and outputs the tilt angle to the tilt servo landing platform, so that the landing platform 1 does not tilt with the terrain on which the unmanned vehicle is traveling. The UAV is controlled to take off, and after the UAV leaves the landing platform 1, the landing platform 1 is folded, and the take-off process ends.

[0141] The tilt servo take-off and landing platform includes a total of five actuators, namely the second electric push rod in the left front, the second electric push rod in the right front, the second electric push rod in the left rear, the second electric push rod in the right rear, and the first electric push rod. The posture that the tilt servo take-off and landing platform can produce can be decomposed into three basic movements of freedom, namely lifting movement, pitching movement and rolling movement. Due to the effect of motion coupling, the length of the five electric push rods can determine the unique position and posture of the take-off and landing platform 1. By coordinating the control of the five actuators, the control of each degree of freedom of the take-off and landing platform 1 can be achieved. The length of the central electric push rod will determine the average height of the plane of the take-off and landing platform 1. When the platform is in motion and docks with the landing drone, the first electric push rod will extend, leading the movement of the take-off and landing platform 1 to rise and make contact with the drone in the air. The left front electric push rod, right front electric push rod, left rear electric push rod and right rear electric push rod located around the first electric push rod will control the inclination of the lifting and landing platform 1, and make real-time adjustments according to the required inclination posture of the lifting and landing platform 1. Thanks to the advantages of the motion coupling of the four actuators, the platform can be precisely controlled without unexpected deviation. During the dynamic docking and landing process, the body posture obtained by the flight controller on the UAV is represented by Q1, the posture of the take-off and landing platform 1 obtained by the sensor on the vehicle-mounted take-off and landing platform 1 is represented by Q2, the height difference between the UAV and the vehicle-mounted platform chassis is h1, and the height of the vehicle-mounted take-off and landing platform 1 is h2. The computer on the vehicle-mounted platform will calculate the difference between Q2 and Q1, and the difference between h2 and h1; and convert the difference result into an electric push rod control amount, and send it to the electric push rod driver, actively drive the platform's tilt posture Q2 to align with the UAV's body posture Q1, and while ensuring the alignment, calculate the control amount for slowly raising the take-off and landing platform 1 according to the height posture difference and send it to the electric push rod driver, so that the take-off and landing platform 1 plane can follow the UAV in posture in real time and gradually approach the UAV in height.

[0142] Specifically, the electric push rod driver controls the driving amount of the left front (LF), right front (RF), left rear (LR), right rear (RR) and middle (CT) respectively. The tilt posture Q2 of the active driving platform and the body posture Q1 of the UAV are both postures represented by quaternion Q= (w, x, y, z). The body posture obtained by the flight controller on the UAV is the roll with the forward direction of the body as the rotation axis, the pitch with the right direction of the body as the rotation axis, and the heading with the bottom of the body as the rotation axis. The attitude of the take-off and landing platform obtained by the sensor on the vehicle-mounted take-off and landing platform 1 is the roll with the forward direction of the take-off and landing platform as the rotation axis, the pitch with the right direction of the take-off and landing platform as the rotation axis, and the heading with the bottom of the take-off and landing platform as the rotation axis. In order to realize the calculation of the relative posture of the UAV and the vehicle-mounted take-off and landing platform, the two platforms obtain the roll α, pitch β and heading γ and convert them into quaternions: the conversion method is as follows:

[0143] .

[0144] The following formula establishes the driving model of the electric push rod:

[0145] .

[0146] .

[0147] After the UAV is stably docked with the take-off and landing platform 1, the electric push rod 2 is driven to return to the shortest state, so that the take-off and landing platform 1 carrying the UAV is retracted to the minimum height of the unmanned vehicle.

[0148] like Figure 7 As shown, the air-to-ground coordinated UAV take-off and landing control method provided in this embodiment includes five stages:

[0149] S1: After the UAV and the unmanned vehicle receive the docking command, the UAV quickly approaches the unmanned vehicle and arrives above the unmanned vehicle. The UAV observes the positioning guidance mark on the vehicle-mounted tilt servo platform through the camera module installed at the bottom.

[0150] S2: The control module of the precise take-off and landing system on the drone side extracts information from the positioning guidance mark in the picture, obtains its offset from the center of the picture, and autonomously adjusts the flight path of the drone to align with the center of the moving take-off and landing platform 1 according to the error.

[0151] The method for determining the positioning guide mark is as follows:

[0152] 1. Image preprocessing: The detection of QR code is performed on grayscale images. The original image captured by the camera is in color, which is converted into a grayscale image to reduce the amount of calculation and speed up the positioning speed.

[0153] 2. Edge detection: Apply Canny edge detection to identify high-contrast edges in the image. Since the QR code is composed of black and white blocks, its edges will stand out in the results of the detection algorithm.

[0154] 3. Corner point search: Find the area with quadrilateral geometry in the edge detection result (traverse all detected contours and use the cv2.approxPolyDP function to perform polygonal approximation on the contours to filter out contours with four vertices).

[0155] 4. Label decoding: The decoding process is as follows:

[0156] (1) Divide the image of each detected quadrilateral area into Small grid (i.e., according to the pixel x,y coordinates of the four corner points of the quadrilateral, each side is divided equally according to 1 / 6 of the pixel side length to form grid).

[0157] (2) Take the average brightness of all pixels in each small grid to obtain the evaluation brightness of the small grid. The brightest evaluation brightness and the darkest evaluation brightness of the quadrilateral area are averaged to obtain the division threshold of the quadrilateral area. The average value of the division threshold and the brightest evaluation brightness is defined as the division white threshold, and the average value of the division threshold and the darkest evaluation brightness is defined as the division black threshold. The evaluation brightness of each small grid is compared with the division threshold, and the black and white values ​​of each small grid are determined (black is smaller than the division black threshold, and white is greater than the division white threshold).

[0158] (3) Let black and white be represented by 0 and 1, then A quadrilateral region can be decoded as 0-1 matrix, with the pre-set Matrix check to see if the area is the landing location QR code.

[0159] 5. Label positioning: Extract the four corner points of the label of the successfully decoded landing positioning QR code (using the result of process 3), take the average of the x and y pixel coordinates of the four corner points, and obtain the x_center and y_center pixel coordinates of the geometric center of the outline. It is known that the total number of pixels in the x and y directions of the image captured by the camera is x_image and y_image (Note: (0, 0) pixel point is the pixel point in the upper left corner of the picture, (x_image, 0) pixel point is the pixel point in the upper right corner of the picture, and (0, y_image) pixel point is the pixel point in the lower left corner of the picture). Calculate x_image×0.5-x_center to obtain the x-direction deviation x_diff of the geometric center of the QR code outline relative to the center of the picture (if the deviation is greater than 0, the geometric center is to the left of the center of the picture), and calculate y_image×0.5-y_center to obtain the y-direction deviation y_diff of the geometric center of the QR code outline relative to the center of the picture (if the deviation is greater than 0, the geometric center is to the upper side of the center of the picture).

[0160] Next determine the distance.

[0161] 1. Define the distance calculation method: Based on the pixel coordinates of the four corner points of the positioning guide mark in the image obtained in the previous step, calculate the proportion of pixels occupied by the quadrilateral in the picture. The calculation method is to count the total number of pixels occupied by the quadrilateral divided by the total number of pixels in the entire picture. According to the camera imaging principle, the proportion of the same object in the picture will change with distance.

[0162] 2. Calibrate the ranging method: With an increment of 5 cm, when the drone is vertically aligned with the positioning and guiding marker, record the distance from the bottom of the drone to the guiding marker ranging from 0 cm to 100 cm, and the proportion of the quadrilateral in the pixels of the image. Save the recorded data in the precise takeoff and landing system control module of the drone.

[0163] 3. Perform ranging based on prior data: Determine the proportion of the pixels occupied by the quadrilateral of the positioning and guiding marker in the image, compare this data with the data in "Calibrate the ranging method", find the closest proportion, and read the distance represented by this proportion.

[0164] Define the pixel threshold for autonomous docking as margin, where margin is x_image × 0.1. If x_diff > margin, send a displacement adjustment instruction to the flight controller to move left; if x_diff < margin, send a displacement adjustment instruction to the flight controller to move right. Similarly, when y_diff > margin, send a displacement adjustment instruction to move forward; when y_diff < margin, send a displacement adjustment instruction to move backward.

[0165] S3: On the basis of dynamic alignment, the precise takeoff and landing system control module of the drone calculates the distance between itself and the takeoff and landing platform 1 according to the size information of the positioning and guiding marker in the image, and gradually reduces its own height to 100 cm above the takeoff and landing platform 1 according to the distance.

[0166] S4: The drone sends its real-time attitude information to the unmanned vehicle. The vehicle-mounted instruction unit in the precise takeoff and landing system control module of the vehicle-mounted end calculates the real-time target attitude of the takeoff and landing platform 1 according to the attitude of the drone. The vehicle-mounted instruction unit sends an adjustment instruction to the supporting electric push rod to drive the supporting electric push rod to align the pitch and roll of the takeoff and landing platform 1 with the corresponding attitude of the drone in real time, and make the takeoff and landing platform 1 gradually rise and approach the drone from below the drone.

[0167] S5: The takeoff and landing platform 1 contacts the drone. After the drone contacts the takeoff and landing platform 1, it stops flying. The drone sends a landing end indication to the precise takeoff and landing system control module of the unmanned vehicle end, and this module drives the takeoff and landing platform 1 to retract to the minimum height, and the landing process ends.

[0168] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0169] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. An air-to-ground coordinated UAV take-off and landing control system, characterized in that: The air-ground coordinated UAV take-off and landing control system is applied to an air-ground coordinated formation, and the air-ground coordinated UAV take-off and landing control system comprises: a UAV end take-off and landing control device and an unmanned vehicle end take-off and landing control device; The UAV take-off and landing control device is applied to UAVs in an air-ground collaborative formation; The unmanned vehicle take-off and landing control device is applied to unmanned vehicles in an air-ground collaborative formation; The drone-side take-off and landing control device comprises: a drone control module, a drone-side precision take-off and landing system control module, and a drone-side air-ground collaborative wireless communication module connected in sequence; The unmanned vehicle end take-off and landing control device comprises: an unmanned vehicle end air-ground cooperative wireless communication module, an unmanned vehicle end precise take-off and landing system control module and a vehicle-mounted tilt servo take-off and landing platform provided with a take-off and landing guidance mark, which are connected in sequence; The air-ground collaborative wireless communication module on the drone side is connected to the air-ground collaborative wireless communication module on the unmanned vehicle side; The UAV-side precise take-off and landing system control module is used to obtain real-time images, generate horizontal direction correction instructions based on the position of the take-off and landing guide mark in the real-time image, and send the horizontal direction correction instructions to the UAV control module until the take-off and landing guide mark is located at the center of the real-time image; the UAV-side precise take-off and landing system control module is also used to obtain the real-time horizontal direction movement instructions of the target unmanned vehicle and generate a descent instruction, and send both the real-time horizontal direction movement instructions and the descent instruction to the UAV control module; the real-time image is the image directly below the UAV where the UAV-side take-off and landing control device is located; The UAV-side precise take-off and landing system control module is also used to determine the vertical distance between the UAV and the target unmanned vehicle based on the real-time image after the take-off and landing guidance mark is located at the center of the real-time image, and when the vertical distance is less than a preset vertical distance threshold, obtain the posture of the UAV as a first posture, and send the first posture to the target unmanned vehicle; The drone control module is used to execute horizontal direction correction instructions, or to execute real-time horizontal direction movement instructions and descent instructions simultaneously; The air-ground collaborative wireless communication module on the UAV side is used to send a first posture, or receive a real-time horizontal motion instruction of the target UAV; The unmanned vehicle-side air-ground collaborative wireless communication module is used to receive the first posture, or send a real-time horizontal movement instruction of the unmanned vehicle; The unmanned vehicle-side precision take-off and landing system control module is used to generate a posture acquisition instruction to control the vehicle-mounted tilt servo take-off and landing platform to acquire its own posture as a second posture when receiving the first posture, and generate a posture adjustment instruction according to the first posture and the second posture until the first posture is equal to the second posture; The vehicle-mounted tilt servo take-off and landing platform is used to adjust its own posture based on the posture adjustment instruction; The unmanned vehicle-side precise take-off and landing system control module is also used to generate a landing end instruction after the drone has landed; The vehicle-mounted tilt servo take-off and landing platform is used to carry the UAV to restore to a preset posture and a preset height when receiving a landing end instruction.

2. The air-to-ground coordinated UAV take-off and landing control system according to claim 1 is characterized in that: The UAV-side precise take-off and landing system control module includes: Camera module and vision-guided computing module; The visual guidance computing module is respectively connected to the camera module, the drone control module and the drone-side air-to-ground collaborative wireless communication module; The camera module is used to obtain real-time images; The visual guidance computing module is used to generate a horizontal direction correction instruction based on the position of the take-off and landing guidance mark in the real-time image, and send the horizontal direction correction instruction to the UAV control module until the take-off and landing guidance mark is located at the center of the real-time image; obtain the real-time horizontal direction movement instruction of the target unmanned vehicle and generate a descent instruction, and send both the real-time horizontal direction movement instruction and the descent instruction to the UAV control module; The visual guidance computing module is also used to determine the vertical distance between the UAV and the target unmanned vehicle based on the real-time image after the take-off and landing guidance mark is located at the center of the real-time image, and when the vertical distance is less than a preset vertical distance threshold, obtain the posture of the UAV as a first posture, and send the first posture to the target unmanned vehicle.

3. The air-to-ground coordinated UAV take-off and landing control system according to claim 1 is characterized in that: The vehicle-mounted tilt servo take-off and landing platform is arranged on the body of the unmanned vehicle; the vehicle-mounted tilt servo take-off and landing platform comprises: A plurality of lifting devices are provided and installed on the vehicle body, and each of the lifting devices has an independent lifting end; A lifting and landing platform is installed on the plurality of lifting ends, and different lifting ends are connected to different parts of the lifting and landing platform; A posture acquisition unit, which is arranged on the take-off and landing platform and is used to detect the posture of the take-off and landing platform in real time; A control unit, wherein the control unit is respectively connected to the posture acquisition unit, the unmanned vehicle-side precise take-off and landing system control module, and all lifting devices; the control unit is used to determine the posture of the vehicle-mounted tilt servo take-off and landing platform based on the posture of the take-off and landing platform; the control unit is also used to control all lifting devices based on the posture adjustment instruction or the landing end instruction.

4. The air-to-ground coordinated UAV take-off and landing control system according to claim 3 is characterized in that: The lifting device is an electric push rod.

5. The air-to-ground coordinated UAV take-off and landing control system according to claim 4 is characterized in that: There are five electric push rods, namely a first electric push rod and four second electric push rods. The four second electric push rods are arranged at the four corners of the rectangular structure. The first electric push rod is arranged at the center of the rectangular structure. The second electric push rod is connected to the vehicle body and the lifting and lowering platform by ball joints. The first electric push rod is fixedly connected to the vehicle body, and the first electric push rod is connected to the lifting and lowering platform by ball joints.

6. The air-to-ground coordinated UAV take-off and landing control system according to claim 3 is characterized in that: The attitude acquisition unit includes an accelerometer and a gyroscope installed on the take-off and landing platform; The accelerometer and the gyroscope are both connected to the control unit.

7. A method for controlling the take-off and landing of an air-to-ground coordinated UAV, characterized in that: The air-ground coordinated UAV take-off and landing control method is applied to the air-ground coordinated UAV take-off and landing control system according to any one of claims 1 to 6, and the air-ground coordinated UAV take-off and landing control method includes: The control module of the precise take-off and landing system on the drone side obtains real-time images; The UAV-side precise take-off and landing system control module generates a horizontal direction correction instruction based on the position of the take-off and landing guidance mark in the real-time image; The drone control module executes the horizontal correction command until the take-off and landing guidance mark is located in the center of the real-time image; The control module of the precise take-off and landing system on the drone side obtains the real-time horizontal movement command of the target unmanned vehicle, generates a descent command, and controls the drone control module to execute the real-time horizontal movement command and descent command until the landing is completed; The control module of the precise take-off and landing system on the drone side obtains real-time images, and determines the vertical distance between the drone and the target unmanned vehicle based on the real-time images, until the vertical distance is less than a preset vertical distance threshold, the posture of the drone is obtained as a first posture, and the first posture is sent to the target unmanned vehicle; When receiving the first posture, the control module of the precision take-off and landing system on the unmanned vehicle side generates a posture acquisition instruction to control the vehicle-mounted tilt servo take-off and landing platform to acquire its own posture as the second posture, generates a posture adjustment instruction according to the first posture and the second posture until the first posture is equal to the second posture, and generates a landing end instruction when the landing is completed; The vehicle-mounted tilt servo take-off and landing platform restores the UAV with it to a preset attitude and a preset height upon receiving a landing end command.

8. The air-to-ground coordinated UAV take-off and landing control method according to claim 7 is characterized in that: Generating a horizontal direction correction instruction based on the position of the take-off and landing guidance mark in the real-time image includes: Performing grayscale processing on the real-time image to obtain a real-time grayscale image; Use the Canny edge detection algorithm to extract multiple boundary contours in real-time grayscale images; Use cv2.approxPolyDP function to perform polygonal approximation on each boundary contour, and select all quadrilateral boundary contours as pending boundary contours; Determine any pending boundary contour as a current pending boundary contour; According to the take-off and landing guidance mark dimensions of the target unmanned vehicle, the area within the current undetermined boundary contour is gridded; Determine the grid brightness of each grid; the grid brightness is the average brightness value of all pixels in the corresponding grid; Determine the average value of the maximum grid brightness and the minimum grid brightness as the division threshold; Determine the average value of the maximum grid brightness and the division threshold as the division white threshold; Determine the average value of the minimum grid brightness and the division threshold as the division black threshold; Based on the white threshold and the black threshold, binarization is performed on the current pending boundary contour to obtain a contour two-dimensional code of the current pending boundary contour; Update the current pending boundary contour, and return to step "grid the area within the current pending boundary contour according to the take-off and landing guidance mark dimension of the target unmanned vehicle" until the contour QR code of the current pending boundary contour is the same as the take-off and landing guidance mark of the target unmanned vehicle; Determine that the current pending boundary contour is the take-off and landing guidance mark boundary contour; Obtain the average pixel coordinates of the four vertices of the boundary contour of the take-off and landing guidance mark as the position of the take-off and landing guidance mark; Get the midpoint position of the real-time grayscale image; When the position of the take-off and landing guide mark does not coincide with the midpoint position, a horizontal direction correction instruction is generated based on the position of the take-off and landing guide mark and the midpoint position.

9. The air-to-ground coordinated UAV take-off and landing control method according to claim 8 is characterized in that: Determine the vertical distance between the UAV and the target unmanned vehicle based on real-time images, including: The number of pixels of the real-time image is the first number of pixels; Determine the boundary outline of take-off and landing guidance signs; Obtain the number of second pixel points within the boundary contour of the take-off and landing guidance mark; Determine a ratio of the second number of pixels to the first number of pixels; The vertical distance between the UAV and the target UAV is determined based on the ratio.

10. The air-to-ground coordinated UAV take-off and landing control method according to claim 8 is characterized in that: The posture adjustment instruction is: ； ； in, LF is the driving amount of the second electric push rod on the left front; is the installation distance between the left front second electric push rod and the right front second electric push rod; b is the installation distance between the left front second electric push rod and the left rear second electric push rod; roll is the left-right tilt of the unmanned vehicle as the reference system, ,in, For relative posture, is the first element of the quaternion representing the relative attitude; is the second element of the quaternion representing the relative attitude; is the third element in the quaternion representing the relative attitude; is the fourth element of the quaternion representing the relative attitude; For the first posture, is the first element of the quaternion representing the first attitude; is the second element of the quaternion representing the first posture; is the third element of the quaternion representing the first posture; is the fourth element of the quaternion representing the first attitude; For the second posture The reverse, the second posture , is the first element of the quaternion representing the second attitude; is the second element of the quaternion representing the second attitude; is the third element of the quaternion representing the second attitude; is the fourth element of the quaternion representing the second attitude; pitch is the tilt in the front-rear direction with the unmanned vehicle as the reference system, ; RF is the driving amount of the second right front electric push rod; LR is the driving amount of the second electric push rod at the left rear; RR is the driving amount of the second electric push rod at the right rear; CT is the driving amount of the first electric push rod; H is the vertical distance between the take-off and landing platform and the vehicle chassis, is the height difference between the UAV and the vehicle-mounted platform chassis, is the height of the take-off and landing platform.

Images