Inclined plane take-off and landing method and system of tilting four-rotor air-ground unmanned aerial vehicle

Abstract

The invention relates to the technical field of vehicle-mounted unmanned aerial vehicle platforms, in particular to a slope take-off and landing method and system of a tilting four-rotor air-ground unmanned aerial vehicle. An attitude sensor of the unmanned aerial vehicle obtains a current pitching attitude, and a tilting mechanism of the tilting quad-rotor unmanned aerial vehicle is adjusted, so that rotor motor shafts are perpendicular to the horizontal plane; according to the continuity constraint, the dynamics constraint and the safety constraint of the position and the speed, a take-off path is planned, and a take-off track is obtained; tracking the take-off track to complete bevel take-off; determining a final position and an inclined posture of landing; planning a landing path according to the observation constraint, the continuity constraint of the position and the speed, the dynamic constraint and the safety constraint, and obtaining a landing trajectory; if the unmanned aerial vehicle observes the unmanned vehicle, re-planning the path; landing is completed after a landing end point is reached; the safety and stability of the unmanned aerial vehicle taking off and landing on the inclined plane can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle-mounted UAV platforms, and particularly to a slope takeoff and landing method and system for a tilt-rotor quadcopter land-air UAV. Background Art

[0002] Currently, systems that integrate UAVs and unmanned vehicles are very popular. Unmanned vehicles can serve as support platforms for UAVs, improving the overall endurance performance of UAVs; UAVs can assist unmanned vehicles in operation by taking advantage of their high-altitude vision. For collaborative systems where UAVs can land on unmanned vehicles, the takeoff and landing processes of UAVs on unmanned vehicles are involved.

[0003] For vehicle-mounted UAV platforms, since the vehicle may tilt in attitude due to terrain during driving, and mainstream quadcopter UAVs have the characteristic of pose coupling in the pitch and roll directions and can only take off and land stably on a horizontal plane, it is necessary to design a platform mechanism or control method to achieve the slope takeoff and landing process. Currently, there are mainly two types of existing slope takeoff and landing technologies. One type is to install an inclined servo plane on the unmanned vehicle, and the servo plane is leveled to a horizontal plane to realize the takeoff and landing of the UAV on the servo plane. However, in order to ensure the angle adjustment and angle stability of the servo plane, a servo mechanism and a support rod need to be installed, which significantly increases the weight and size of the unmanned vehicle and reduces the overall efficiency of the unmanned vehicle. Another method is to let the quadcopter UAV execute a fast maneuvering trajectory and keep the attitude coordinated with the movement of the unmanned vehicle during flight to achieve precise landing. However, due to the characteristic of quadcopter pose coupling, the trajectory generated by this method requires a large peak angular velocity or position acceleration, which has high requirements for the maneuverability and tracking control performance of the UAV, and the UAV may have a slight impact on the unmanned vehicle during landing, reducing the service life of the system. Therefore, the existing collaborative system of unmanned vehicles and UAVs cannot well solve the problem of slope takeoff and landing of UAVs on unmanned vehicles. Summary of the Invention

[0004] In view of the above problems, the present invention provides a slope takeoff and landing method and system for a tilt-rotor quadcopter land-air UAV, which solves the technical problem of difficult takeoff and landing of quadcopter UAVs on tilted unmanned vehicles in the prior art.

[0005] On the one hand, the present invention provides a slope takeoff and landing system for a tilt-rotor quadcopter land-air UAV, including a tilt-rotor quadcopter UAV and a ground unmanned vehicle. The tilt-rotor quadcopter UAV is provided with an attitude sensor, a perception and positioning module, and a wireless transmission module. The center position of the top plane of the ground unmanned vehicle is provided with a perception and positioning module identification code, and a wireless transmission module is also provided.

[0006] On the one hand, the present invention provides a take-off method for an inclined take-off and landing system of a tilt-rotor quadcopter land-air unmanned aerial vehicle, which is used for the tilt-rotor quadcopter unmanned aerial vehicle to take off on the roof of a ground-inclined unmanned vehicle, and includes the following steps: Step S11: The unmanned vehicle adjusts its own roll angle so that the roll angle is less than a preset threshold to form an inclined roof; Step S12: The attitude sensor of the tilt-rotor quadcopter unmanned aerial vehicle acquires the current pitch attitude, and based on the pitch attitude, adjusts the tilt mechanism of the tilt-rotor quadcopter unmanned aerial vehicle to make the rotor motor shaft perpendicular to the horizontal plane; Step S13: The tilt-rotor quadcopter unmanned aerial vehicle performs take-off path planning according to the continuity constraints of position and speed, dynamic constraints, and safety constraints to obtain a take-off trajectory; Step S14: After receiving the take-off command, the tilt-rotor quadcopter unmanned aerial vehicle tracks the take-off trajectory to complete the inclined take-off.

[0007] Preferably, the tilt-rotor quadcopter unmanned aerial vehicle includes four tiltable rotor mechanisms and a tilt mechanism. The tilt mechanism can control the rotor structure to tilt around a set rotation axis to change the orientation of the rotor motor shaft in the rotor mechanism; the tilt-rotor quadcopter unmanned aerial vehicle is integrated with an attitude sensor for real-time acquisition of the pitch attitude of the tilt-rotor quadcopter unmanned aerial vehicle.

[0008] Preferably, step S13 specifically includes: Step S13-1: Set the current position and attitude of the tilt-rotor quadcopter unmanned aerial vehicle as the take-off starting point, and set the specified target position and attitude as the take-off ending point; Step S13-2: Based on the take-off starting point and the take-off ending point, use a path planning method to generate an initial feasible take-off path; Step S13-3: Optimize the initial feasible take-off path according to the continuity constraints of position and speed, dynamic constraints, and safety constraints to obtain a take-off trajectory.

[0009] Preferably, in step S13-3, the continuity constraint of position and speed means that the optimization result of the initial feasible take-off path is set as a polynomial trajectory of the 5th order or above; The dynamic constraints are used to limit the range of the pitch angle of the fuselage, the range of the pitch angle change rate of the fuselage, the range of the fuselage speed, and the range of the fuselage acceleration; The safety constraints are used to limit the distance between the fuselage position and the top plane of the unmanned vehicle and obstacles.

[0010] On the other hand, the present invention provides a landing method for an inclined take-off and landing system of a tilt-rotor quadcopter land-air unmanned aerial vehicle, which is characterized in that it is used for the tilt-rotor quadcopter unmanned aerial vehicle to land on the roof of a ground-inclined unmanned vehicle, and includes the following steps: Step S21: The tilt-rotor quadrotor UAV receives the position and attitude of the unmanned vehicle sent by the unmanned vehicle, and determines the landing end position and the tilt attitude. Step S22: The tilt-rotor quadrotor UAV plans the landing path according to the current position and attitude, the landing end position and the tilt attitude, the observation constraint, the continuity constraint of position and speed, the dynamic constraint, and the safety constraint, and obtains the landing trajectory. Step S23: After receiving the landing command, the tilt-rotor quadrotor UAV tracks the landing trajectory; during the tracking process, if the perception and positioning module on board the tilt-rotor quadrotor UAV observes the unmanned vehicle, the landing end position and the tilt attitude are updated with the observed position and attitude of the unmanned vehicle, and return to Step S22; until the position and attitude of the tilt-rotor quadrotor UAV are consistent with the end position and the tilt attitude, the landing is completed.

[0011] Preferably, Step S22 specifically includes: Step S22-1: Set the current position and attitude of the tilt-rotor quadrotor UAV as the landing start point, and set the landing end position and the tilt attitude as the landing end point. Step S22-2: Based on the landing start point and the landing end point, use the path planning method to generate an initial feasible landing path. Step S22-3: Optimize the initial feasible landing path according to the observation constraint, the continuity constraint of position and speed, the dynamic constraint, and the safety constraint to obtain the landing trajectory.

[0012] Preferably, a perception and positioning module for observing the unmanned vehicle below is provided on the tilt-rotor quadrotor UAV, and a perception and positioning module identification code is provided at the center position of the top plane of the unmanned vehicle.

[0013] Preferably, in Step S22-3, the continuity constraint of position and speed means that the optimization result of the initial feasible landing path is set as a polynomial trajectory of 5th order or above. The observation constraint is used to limit that the center of the top plane of the unmanned vehicle is within the visible range of the perception and positioning module. The dynamic constraint is used to limit the range of the pitch angle of the fuselage, the range of the change rate of the pitch angle of the fuselage, the range of the fuselage speed, and the range of the fuselage acceleration. The safety constraint is used to limit the distance between the UAV position and the top plane of the unmanned vehicle and the obstacles.

[0014] Preferably, Step S23 specifically includes: During the flight of the drone, the perception and positioning module is used for real-time perception. When the perception and positioning module identifies the perception and positioning module identification code, it confirms that the unmanned vehicle is observed, updates the central position on the top plane of the unmanned vehicle in the observation constraint, and returns to step S2. It continues until the position and attitude error between the unmanned vehicle and the tilt-rotor UAV is less than the preset threshold, at which point the landing is completed.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects: (1) By utilizing the characteristics of the pose decoupling control of the tilt-rotor UAV, the present invention can independently adjust the position and attitude, so that the blade plane of the UAV is horizontal during the inclined takeoff process, achieving attitude adjustment without affecting the position, thereby improving the safety and reliability during the inclined takeoff process.

[0016] (2) During the landing process of the present invention, the tilt-rotor UAV can receive the position and attitude information of the unmanned vehicle in real time, and combine the feedback of the on-board perception and positioning module to re-plan the landing trajectory during flight. When the UAV detects a deviation in its own trajectory or a change in the position of the unmanned vehicle, it re-plans the path until the final position and attitude are consistent with the target, thereby improving the accuracy and reliability of the landing and ensuring that the UAV can land steadily on the inclined roof of the vehicle.

[0017] (3) Compared with the prior art, the present invention does not require additional servo mechanisms or support rods to be installed on the unmanned vehicle, thus reducing the structural complexity and additional energy consumption of the unmanned vehicle and improving the overall efficiency of the UAV and unmanned vehicle cooperation system. At the same time, the present invention uses the pose decoupling planning and control of the tilt-rotor UAV to enable it to execute a smoother trajectory, reducing the requirements for high-frequency response and high-precision control of the controller, improving the reliability and landing safety of the system, and enabling the UAV to complete the takeoff and landing tasks more efficiently and stably. Description of the Drawings

[0018] The drawings are only for the purpose of illustrating specific embodiments and are not considered to be a limitation of the present invention.

[0019] Figure 1 It is a flowchart of the inclined takeoff method of the tilt-rotor land-air UAV provided by the present invention on the roof of an unmanned vehicle.

[0020] Figure 2 It is a flowchart of the inclined landing method of the tilt-rotor land-air UAV provided by the present invention on the roof of an unmanned vehicle.

[0021] Figure 3 It is a detailed flowchart of the inclined takeoff and landing method of the tilt-rotor land-air UAV provided by the present invention on the roof of an unmanned vehicle.

[0022] Figure 4Schematic diagram of the mechanism of the UAV and unmanned vehicle collaborative system provided by the present invention.

[0023] Figure 5 Schematic diagram of the take-off trajectory of the UAV provided by the present invention.

[0024] Figure 6 Schematic diagram of the landing trajectory of the UAV provided by the present invention.

[0025] Figure 7 Schematic diagram of the example of the UAV and unmanned vehicle collaborative system and the inclined take-off and landing trajectories of the UAV example provided by the present invention.

[0026] Reference numerals: 1 - Tilt-rotor UAV, 2 - Perception and positioning module, 3 - Identification code of the perception and positioning module, 4 - Unmanned vehicle, 5 - Wireless transmission module, 6 - Inclined landing trajectory of the UAV example, 7 - Inclined take-off trajectory of the UAV example. Detailed implementation manners

[0027] In order to more clearly understand the above objects, features and advantages of the present invention, the present invention will be further described in detail below with reference to the drawings and specific implementation manners. It should be noted that, without conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. In addition, the present invention can also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0028] Aiming at the problem of the inclined take-off and landing of the UAV on the unmanned vehicle, in order to overcome the deficiencies of the prior art and utilize the pose decoupling characteristics of the tilt-rotor UAV, the present invention aims to propose a method and system for inclined take-off and landing of the air-ground based on the tilt-rotor UAV, so as to improve the stability and robustness of the inclined take-off and landing of the UAV on the unmanned vehicle.

[0029] In order to illustrate the effectiveness of the method proposed by the present invention, the above technical solutions of the present invention will be described in detail below through a specific embodiment.

[0030] As Figure 4 、 Figure 7 shown, the present invention discloses an inclined take-off and landing system for a tilt-rotor air-ground UAV, including a tilt-rotor UAV and a ground unmanned vehicle. The tilt-rotor UAV is provided with an attitude sensor, a perception and positioning module 2 and a wireless transmission module 5. The center position of the top plane of the ground unmanned vehicle is provided with an identification code 3 of the perception and positioning module, and a wireless transmission module 5 is also provided.

[0031] The attitude sensor is used to obtain the aerial motion attitude information of the unmanned vehicle, and the perception and positioning module 2 is used to locate the perception and positioning module identification code 3 on the unmanned vehicle. The unmanned aerial vehicle and the unmanned vehicle use the wireless transmission module 5 for continuous communication to exchange information such as the positions and attitudes of the unmanned aerial vehicle and the unmanned vehicle.

[0032] Figure 7 Shows a specific example of the collaborative system of the tilt-rotor land-air unmanned aerial vehicle and the unmanned vehicle, a typical inclined-plane landing trajectory 6 and a typical inclined-plane takeoff trajectory 7.

[0033] Such as Figure 1 As shown, the present invention also discloses a method for inclined-plane takeoff of a tilt-rotor quadcopter unmanned aerial vehicle on land, which is used for the tilt-rotor quadcopter unmanned aerial vehicle to take off on the roof of the unmanned vehicle inclined to the ground. The specific implementation steps are as follows: Step S11: The unmanned vehicle adjusts its own roll angle so that the roll angle is less than a preset threshold; The technical solution of the present invention is applied to the scenario of inclined-plane takeoff and landing of an unmanned aerial vehicle on an unmanned vehicle. Before takeoff, the tilt-rotor quadcopter unmanned aerial vehicle stops on the roof of the unmanned vehicle.

[0034] When the unmanned vehicle moves along the terrain, it adjusts its own roll angle so that the roll angle is less than a preset threshold. In this way, the influence of the rugged terrain factor on the attitude of the unmanned aerial vehicle is concentrated on the pitch channel of the tilt-rotor quadcopter unmanned aerial vehicle, which is convenient for the unmanned aerial vehicle to take off stably.

[0035] Step S12: The attitude sensor of the tilt-rotor quadcopter unmanned aerial vehicle obtains the current pitch attitude, and based on the pitch attitude, adjusts the tilt mechanism of the tilt-rotor quadcopter unmanned aerial vehicle so that the rotor motor shaft is perpendicular to the horizontal plane; The tilt-rotor quadcopter unmanned aerial vehicle of the present invention includes at least four tiltable rotor mechanisms, and each rotor mechanism is equipped with a rotor motor and blades. The rotor mechanism can tilt around a set rotation axis to change the orientation of the rotor motor shaft and adjust different flight attitudes. The unmanned aerial vehicle body of the present invention is integrated with an attitude sensor, which can obtain the pitch attitude data of the unmanned aerial vehicle in real time.

[0036] In this step, first, the attitude sensor obtains the current pitch attitude of the unmanned aerial vehicle, then calculates the adjustment amount of the tilt mechanism based on the pitch attitude, and uses the adjustment amount of the tilt mechanism to drive the tilt mechanism of the wing for corresponding adjustment, so that the rotor motor shaft tilts to be perpendicular to the horizontal plane.

[0037] Through the above adjustment, the blade plane of the unmanned aerial vehicle can be parallel to the horizontal plane, so that the unmanned aerial vehicle can be more stable when taking off on the inclined plane of the unmanned vehicle.

[0038] Step S13: The tilt-rotor quadcopter unmanned aerial vehicle performs takeoff path planning according to the continuity constraints, dynamic constraints and safety constraints of position and speed, and obtains a takeoff trajectory; In this step, first determine the starting point and the ending point of the take-off trajectory. Set the current position and attitude of the UAV as the starting point, and set the specified target position and attitude as the ending point.

[0039] Based on the starting point and the ending point of the take-off trajectory, use path planning methods such as A* or RRT* to generate an initial feasible path, and optimize the initial feasible path based on the continuity constraints of position and velocity, dynamic constraints, and safety constraints, which are specifically described as follows.

[0040] Polynomial trajectories of order 5 or higher satisfy the continuity constraints of the UAV's position and velocity. Therefore, set the optimization result as a polynomial trajectory of order 5 or higher; The dynamic constraints include speed limit and acceleration limit, and the expressions are:

[0041] where is the pitch angle of the fuselage at time represents the modulus of the vector, means taking arbitrarily, is the trajectory duration, is the pitch angle limit of the tilt-rotor fuselage, is the UAV speed in the ground coordinate system at time is the UAV speed limit in the ground coordinate system, is the change rate of the pitch angle of the fuselage at time is the limit of the change rate of the pitch angle of the tilt-rotor fuselage, is the UAV acceleration in the ground coordinate system at time is the UAV acceleration limit in the ground coordinate system.

[0042] The safety constraints are used to avoid collisions with the top plane of the unmanned vehicle and obstacles. The expressions of the safety constraints are:

[0043] where the superscript represents within the ground coordinate system, is the normal of the top plane of the unmanned vehicle, represents the transpose operation, represents the UAV position in the ground coordinate system, represents the central position on the top plane of the unmanned vehicle, is the matrix determined by the shape of the i-th ellipsoidal obstacle, is the geometric center position of the i-th ellipsoidal obstacle in the ground coordinate system, is the total number of obstacles.

[0044] By optimizing the initial feasible path, the take-off trajectory is finally obtained. As Figure 5 shown, the take-off trajectory of the present invention is shown. Attached Figure 5 the take-off target, that is, the pitch angle of the top plane of the unmanned vehicle is 45° Step S14: After receiving the take-off instruction, the tilt-rotor UAV tracks the take-off trajectory and completes the inclined-plane take-off.

[0045] In this step, after receiving the take-off instruction, the tilt-rotor UAV unlocks and takes off. The UAV completes the tracking of the take-off trajectory by controlling and adjusting the trajectory variables in real time to complete the tracking of the take-off trajectory and finally complete the inclined-plane take-off. is the three-dimensional position of the UAV in the ground coordinate system, is the yaw angle, is the pitch angle.

[0046] As Figure 2 shown, the present invention discloses an inclined-plane landing method for a tilt-rotor land-air UAV, which is used for the tilt-rotor UAV to land on the roof of an unmanned vehicle inclined to the ground. The specific implementation steps are as follows: Step S21: The tilt-rotor UAV receives the position and attitude of the unmanned vehicle sent by the unmanned vehicle, and determines the landing end position and the inclined attitude; In this step, the UAV receives the position and attitude of the unmanned vehicle sent by the unmanned vehicle. According to the position and attitude of the unmanned vehicle, through coordinate transformation and other processing, the landing end position and the inclined attitude of the UAV can be obtained as the target for the UAV's final landing.

[0047] Step S22: The tilt-rotor UAV plans the landing path according to the current position and attitude, the landing end position and the inclined attitude, the observation constraint, the continuity constraint of position and speed, the dynamic constraint, and the safety constraint, and obtains the landing trajectory; In this step, first, the starting point and the ending point of the landing trajectory are determined. The starting point of the landing trajectory is the current position and attitude of the UAV, and the ending point is the position and attitude of the UAV when it lands on the top plane of the unmanned vehicle, that is, the ending position and the inclined attitude in Step S1.

[0048] Based on the starting point and the ending point of the landing trajectory, an initial feasible path is generated by using path planning methods such as A* or RRT*. The landing path is planned based on the observation constraint, the continuity constraint of position and speed, the dynamic constraint, and the safety constraint. Among them, the continuity constraint of position and speed, the dynamic constraint, and the safety constraint are the same as the content in the technical solution during take-off, and will not be repeated here.

[0049] As Figure 4As shown in the figure, the tilt-rotor quadcopter drone 1 carries a downward-looking perception and positioning module 2 for observing the unmanned vehicle 4, and a perception and positioning module identification code 3 is provided at the center position of the top plane of the unmanned vehicle. The tilt-rotor quadcopter drone 1 can determine the three-dimensional position of the center of the top plane of the unmanned vehicle based on the perception and positioning module identification code 3 captured by the perception and positioning module 2.

[0050] In some embodiments, the observation constraint is based on the airborne perception and positioning module carried by the tilt-rotor quadcopter drone being a downward-looking observation camera, and the perception and positioning module identification code carried by the unmanned vehicle is an Apriltag identification code.

[0051] In this observation method, the observation constraint is used to constrain the top plane of the unmanned vehicle within the image of the perception and positioning module, and the expression is:

[0052] where are respectively the three-dimensional positions of the center position on the top plane of the unmanned vehicle in the ground coordinate system, respectively represent the three-dimensional positions of the drone in the ground coordinate system, is an adjustable small quantity, and in the present invention, it is set to be less than half of the viewing angle of the observation camera.

[0053] By optimizing the initial feasible path, the landing trajectory is finally obtained. As Figure 6 shown, the landing trajectory of the present invention is presented. The Figure 6 landing target, that is, the pitch angle of the top plane of the unmanned vehicle is 35°.

[0054] Step S23: After the tilt-rotor quadcopter drone receives the landing command, it tracks the landing trajectory; if during the tracking process, the airborne perception and positioning module of the tilt-rotor quadcopter drone observes the unmanned vehicle, it returns to step S22; until the position and attitude of the drone are consistent with the end position and the tilted attitude, the landing is completed.

[0055] In this step, after the tilt-rotor quadcopter drone receives the landing command, it tracks the landing trajectory and uses the perception and positioning module 2 to capture images in real time. When the captured image contains the perception and positioning module identification code 3, it is confirmed that the unmanned vehicle is observed. At this time, the observation constraint is updated using the three-dimensional position of the center position on the top plane of the unmanned vehicle detected currently, the landing end position and the tilted attitude are updated with the observed position and attitude of the unmanned vehicle, and it returns to step S2. The landing trajectory is replanned with the current position and attitude of the drone as the landing starting point, the landing trajectory is updated and tracked until the position and attitude error between the unmanned vehicle and the drone is less than the preset threshold. At this time, it is considered that the drone has completed the landing process, and the drone stops the propellers and locks.

[0056] During the takeoff and landing processes of the above-mentioned drone, the wireless transmission module 5 of the drone and the unmanned vehicle can communicate continuously to exchange information such as the positions and postures of the drone and the unmanned vehicle.

[0057] Figure 3 The detailed process of the slope takeoff and landing method of the tilt-rotor quadcopter land-air drone provided by the present invention is shown.

[0058] By the above method, the present invention can perform multiple trajectory replannings when observing the unmanned vehicle during the landing process, which can improve the safety and stability of landing.

[0059] Although the specific embodiments of the present invention depict various actions or steps in a specific order, this should be understood as requiring such actions or steps to be performed in the specific order shown or in a sequential order, or requiring all the illustrated actions or steps to be performed to achieve the desired result. In certain circumstances, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details are included in the above discussion, these should not be construed as limitations on the scope of the present disclosure. Certain features described in the context of separate embodiments can also be implemented in combination in a single implementation. Conversely, the various features described in the context of a single implementation can also be implemented separately or in any suitable sub-combination in multiple implementations.

[0060] As described above, the above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.

Claims

1. An inclined take-off and landing system for a tilt-rotor quadcopter for land and air use, comprising a tilt-rotor quadcopter and a ground unmanned vehicle. The tilt-rotor quadcopter is provided with an attitude sensor, a perception and positioning module (2) and a wireless transmission module (5). At the center position of the top plane of the ground unmanned vehicle, there is a perception and positioning module identification code (3), and a wireless transmission module (5) is also provided.

2. A take-off method for the inclined take-off and landing system of the tilt-rotor quadcopter land-air UAV according to claim 1, characterized in that, For the tilt-rotor quadcopter to take off on the inclined roof of the unmanned vehicle that is inclined to the ground, it includes the following steps: Step S11: The unmanned vehicle adjusts its own roll angle so that the roll angle is less than a preset threshold to form an inclined roof. Step S12: The attitude sensor of the tilt-rotor quadcopter obtains the current pitch attitude, and based on the pitch attitude, adjusts the tilt mechanism of the tilt-rotor quadcopter so that the rotor motor shaft is perpendicular to the horizontal plane. Step S13: The tilt-rotor quadcopter conducts take-off path planning according to the continuity constraints of position and speed, dynamic constraints, and safety constraints to obtain a take-off trajectory. Step S14: After receiving the take-off command, the tilt-rotor quadcopter tracks the take-off trajectory to complete the inclined take-off.

3. The take-off method of the inclined take-off and landing system of the tilt-rotor quadcopter for land and air drones according to claim 2, characterized in that: The tilt-rotor quadcopter includes four tiltable rotor mechanisms and a tilt mechanism. The tilt mechanism can control the rotor structure to tilt around a set rotation axis to change the orientation of the rotor motor shaft in the rotor mechanism. The tilt-rotor quadcopter is integrated with an attitude sensor for real-time acquisition of the pitch attitude of the tilt-rotor quadcopter.

4. The take-off method of the inclined take-off and landing system of the tilt-rotor quadcopter UAV according to claim 3, characterized in that: Step S13 specifically includes: Step S13-1: Set the current position and attitude of the tilt-rotor quadcopter as the take-off starting point, and set the specified target position and attitude as the take-off ending point. Step S13-2: Based on the take-off starting point and take-off ending point, use a path planning method to generate an initial feasible take-off path. Step S13-3: Optimize the initial feasible take-off path according to the continuity constraints of position and speed, dynamic constraints, and safety constraints to obtain a take-off trajectory.

5. The take-off method of the inclined take-off and landing system of the tilt-rotor quadcopter UAV according to claim 4, characterized in that: In step S13-3, the continuity constraint of position and speed means setting the optimization result of the initial feasible take-off path as a polynomial trajectory of the 5th order or above. The dynamic constraints are used to limit the range of the pitch angle of the fuselage, the range of the change rate of the pitch angle of the fuselage, the range of the fuselage speed, and the range of the fuselage acceleration. The safety constraints are used to limit the distance between the fuselage position and the top plane of the unmanned vehicle and obstacles.

6. A landing method for the inclined takeoff and landing system of the tilt-rotor quadcopter land-air unmanned aerial vehicle according to claim 1, characterized in that, For the tilt-rotor quadcopter to land on the inclined roof of the unmanned vehicle that is inclined to the ground, it includes the following steps: Step S21: The tilt-rotor quadcopter receives the position and attitude of the unmanned vehicle sent by the unmanned vehicle, and determines the landing end position and inclined attitude. Step S22: The tilt-rotor quadcopter conducts landing path planning according to the current position and attitude, landing end position and inclined attitude, observation constraints, continuity constraints of position and speed, dynamic constraints, and safety constraints to obtain a landing trajectory. Step S23: After the tilt-rotor quadcopter UAV receives the landing instruction, it tracks the landing trajectory. If the perception and positioning module (2) on board the tilt-rotor quadcopter UAV observes the unmanned vehicle during the tracking process, the landing end position and the tilt attitude are updated with the observed position and attitude of the unmanned vehicle, and then return to step S22. It lands until the position and attitude of the tilt-rotor quadcopter UAV are consistent with the end position and the tilt attitude.

7. The landing method of the inclined takeoff and landing system of the tilt-rotor quadcopter land-air UAV according to claim 6, characterized in that, Step S22 specifically includes: Step S22-1: Set the current position and attitude of the tilt-rotor quadcopter UAV as the landing start point, and set the end position and the tilt attitude of the landing as the landing end point. Step S22-2: Based on the landing start point and the landing end point, use a path planning method to generate an initial feasible landing path. Step S22-3: Optimize the initial feasible landing path according to the observation constraint, the continuity constraint of position and velocity, the dynamic constraint, and the safety constraint to obtain the landing trajectory.

8. The landing method of the inclined takeoff and landing system of the tilt-rotor land-air UAV according to claim 7, characterized in that: A perception and positioning module (2) for observing the unmanned vehicle below is provided on the tilt-rotor quadcopter UAV, and a perception and positioning module identification code (3) is provided at the center position of the top plane of the unmanned vehicle.

9. The landing method of the inclined takeoff and landing system of the tilt-rotor quadcopter UAV according to claim 8, characterized in that: In step S22-3, the continuity constraint of the position and velocity means that the optimization result of the initial feasible landing path is set as a polynomial trajectory of 5th order or above. The observation constraint is used to limit the center of the top plane of the unmanned vehicle within the visible range of the perception and positioning module (2). The dynamic constraint is used to limit the range of the pitch angle of the fuselage, the range of the pitch angle change rate of the fuselage, the range of the fuselage speed, and the range of the fuselage acceleration. The safety constraint is used to limit the distance between the UAV position and the top plane of the unmanned vehicle and obstacles.

10. The landing method of the inclined takeoff and landing system of the tilt-rotor quadcopter UAV according to claim 9, characterized in that: Step S23 specifically includes: Use the perception and positioning module (2) to sense in real time during the flight of the UAV. When the perception and positioning module recognizes the perception and positioning module identification code (3), it is confirmed that the unmanned vehicle is observed. Update the center position on the top plane of the unmanned vehicle in the observation constraint, update the landing end position and the tilt attitude with the observed position and attitude of the unmanned vehicle, and return to step S22 until the position and attitude error between the unmanned vehicle and the tilt-rotor quadcopter UAV is less than the preset threshold, and then the landing is completed.

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