Automatic landing control method for large fixed-wing unmanned aerial vehicle

Abstract

The invention discloses an automatic landing control method for a large fixed-wing unmanned aerial vehicle. The landing stage of the unmanned aerial vehicle is divided into an approach flat flight stage, an approach glide stage, a first landing leveling stage, a second landing leveling stage and a landing running stage. In the approaching level flight stage, the unmanned aerial vehicle is controlled to keep the target level flight speed, the target approaching level flight height, the lateral offset distance and the track angle aligned and track the runway extension line; in the approaching gliding stage, the unmanned aerial vehicle is controlled to keep the target gliding speed and the target gliding angle; in the first stage of landing leveling, the unmanned aerial vehicle is controlled to keep the target vertical speed and airspeed; in the second stage of landing leveling, the unmanned aerial vehicle is controlled to keep the target vertical speed and the air speed; in the landing and running stage, the speed of the unmanned aerial vehicle is controlled to be reduced to 0, and meanwhile the unmanned aerial vehicle is controlled to keep the target side offset distance and the course angle on the runway center line. Automatic landing of the unmanned aerial vehicle can be accurately controlled, and the robustness and safety of automatic landing of the unmanned aerial vehicle are greatly improved.

Description

Technical Field

[0001] The invention belongs to the field of unmanned aerial vehicle automatic driving and relates to an automatic landing control method for a large fixed-wing unmanned aerial vehicle. Background Art

[0002] Drone automatic flight is an important direction of drone technology development. It uses advanced algorithms and sensors to achieve self-navigation, path planning, environmental perception and automatic obstacle avoidance. Drone automatic flight technology has shown broad application prospects in many fields due to its advantages of high precision, high efficiency and high safety.

[0003] A complete UAV flight process includes the take-off phase, the air cruising phase and the landing phase. Compared with the air cruising phase, the take-off and landing phases of UAVs are more complex and risky. Most practices have shown that although the take-off and landing time is shorter, the frequency of accidents in these two phases is much higher than that in the air cruising phase, and the accident rate in the landing phase is higher than that in the take-off phase. For fixed-wing UAVs, automatic landing refers to the entire process from the approach and level flight phase to the landing and touchdown roll stop of the UAV. The difficulty reflected is that the control process is more complicated than take-off, and the control accuracy requirements are higher. There are many constraints that need to be considered in the entire landing process, such as the control accuracy of the landing glide path, the aircraft cannot be too early or too late when landing and leveling, and the landing touchdown speed cannot be too large to cause the aircraft to land hard or bounce, etc. In the past, the automatic landing of manned aircraft generally adopted instrument landing, which has relatively high requirements for airport facilities. The automatic landing used by drones is basically simple and does not subdivide the landing phase. Some use vertical speed control and some use attitude control. This is mostly suitable for small drones or mature models that have been in service for a long time, but is no longer suitable for newly developed large drones. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a large fixed-wing UAV automatic landing control method, which can accurately control the automatic landing of the UAV and greatly improve the robustness and safety of the automatic landing of the UAV.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A large fixed-wing UAV automatic landing control method includes the following processes: The landing phase of the UAV is divided into the approach level flight phase, the approach descent phase, the first landing leveling phase, the second landing leveling phase and the landing roll phase; During the approach and level flight phase, the UAV is controlled to maintain the target level flight speed, the target approach and level flight altitude, and the lateral offset and track angle are aligned and track the extended runway line; During the approach glide phase, the UAV is controlled to maintain the target glide speed and target glide angle, and the UAV is controlled to maintain the target side offset and track angle; In the first stage of landing and leveling, the UAV is controlled to maintain the target vertical speed and airspeed, and the UAV is controlled to maintain the target side deviation and track angle; In the second stage of landing and leveling, the UAV is controlled to maintain the target vertical speed and airspeed, and the UAV is controlled to maintain the target side offset and heading angle; During the landing roll phase, the UAV is controlled to decelerate to 0 speed, and at the same time, the UAV is controlled to keep the target side offset and heading angle on the runway centerline.

[0006] Preferably, the approach level flight stage is the stage from the capture of the approach level flight waypoint to the capture of the approach glide path point by the UAV; the approach glide path stage is the stage from the capture of the approach glide path point to the height above the ground being greater than 15m; the first landing leveling stage is the stage from the height above the ground being 15m to the height above the ground being greater than 3m; the second landing leveling stage is the stage from the height above the ground being 3m to the landing touchdown stage; the landing roll stage is the stage from the landing touchdown to the taxiing deceleration stop stage of the UAV.

[0007] Preferably, during the approach and level flight phase, the speed, altitude, pitch angle, track angle and lateral deviation of the UAV are used as control target variables.

[0008] Furthermore, during the approach and level flight phase, the UAV's airspeed is controlled to maintain an aircraft cruising speed of 200 km / h, while the UAV is controlled to maintain a target cruising altitude of 300 m, and the UAV's yaw angle and side offset track are controlled to track the extended runway of the landing airport.

[0009] Preferably, during the approach glide phase, the UAV speed, glide angle, track angle and lateral deviation are used as control target variables.

[0010] Furthermore, during the approach glide phase, the UAV is controlled to maintain a target glide angle of -3° and descend to a height of 15m above the ground, and the UAV is controlled to maintain a glide airspeed of 168km / h while maintaining a target heading angle of 325° and a side deviation of 0m.

[0011] Preferably, in the first stage of the landing and leveling, the vertical speed, speed, track angle and lateral deviation of the UAV are used as control target variables; in the second stage of the landing and leveling, the vertical speed, speed, yaw angle and lateral deviation of the UAV are used as control target variables.

[0012] Furthermore, in the first stage of landing and leveling, the UAV is controlled to maintain a variable target vertical speed, the vertical speed changes with the aircraft altitude, and the UAV is controlled to maintain a landing and leveling speed of 160 km / h, while the UAV is controlled to maintain a target track angle of 325° and a side deviation of 0 m; In the second stage of landing and leveling, the UAV is controlled to maintain a fixed target vertical speed of 0.5m / h, and the UAV is controlled to maintain a landing and leveling speed of 160km / h. At the same time, the UAV is controlled to maintain a target heading angle of 325° and a side deviation of 0m.

[0013] Preferably, during the landing phase, the speed, heading angle and side offset of the UAV are used as target control variables.

[0014] Furthermore, during the landing roll phase, the UAV is controlled to decelerate to 0 km / h, and at the same time, the UAV is controlled to maintain a target heading angle of 325° and a side deviation of 0 m and on the center line of the runway.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention effectively divides the landing phase into approach level flight, approach glide, and the first stage of landing leveling, the second stage of landing leveling, and landing roll, and effectively obtains target control variables of different sub-stages of the landing phase of the unmanned aerial vehicle; the automatic landing of the unmanned aerial vehicle is controlled according to the target control variables of the different sub-stages of the landing phase, and a high-precision control method is used to control the automatic landing of the unmanned aerial vehicle to solve the problem that some parameters of the newly developed aircraft are uncertain and the landing accuracy of the aircraft is not high due to the influence of environmental factors, thereby greatly improving the robustness and safety of the automatic landing of the unmanned aerial vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a control flow chart of the automatic landing control method of fixed-wing UAV.

[0017] Figure 2 This is a diagram showing the stages of automatic landing for fixed-wing UAVs.

[0018] Figure 3 It is the control block diagram of the approach and level flight phase of the automatic landing control method for fixed-wing UAV.

[0019] Figure 4 It is a control block diagram of the approach and glide phase of the automatic landing control method for fixed-wing UAV.

[0020] Figure 5 It is the control block diagram of the first stage of landing and taking off of the automatic landing control method of fixed-wing UAV.

[0021] Figure 6It is the second stage control block diagram of the fixed-wing UAV automatic landing control method landing and pulling up.

[0022] Figure 7 It is the control block diagram of the second stage of landing roll of the automatic landing control method of fixed-wing UAV. DETAILED DESCRIPTION

[0023] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0024] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs. The terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. The term "and / or" used in this article includes any and all combinations of one or more related listed items. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0026] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0027] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplicity and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0028] The present invention proposes an automatic landing control method for a large fixed-wing UAV to solve the problem of improving the robustness and safety of automatic landing under the conditions of multiple landing constraints and uncertainties in related parameters and environmental parameters of the UAV.

[0029] like Figure 1 As shown, the automatic landing control method for a large fixed-wing UAV described in the present invention includes: dividing and defining different sub-stages of the landing stage of the UAV; obtaining target control variables of different sub-stages of the landing stage of the UAV; and controlling the automatic landing of the UAV according to the target control variables of different sub-stages of the landing stage.

[0030] like Figure 2 As shown, the landing phase of the UAV is divided and defined as the approach level flight phase, the approach glide phase, the first landing leveling phase, the second landing leveling phase and the landing roll phase. The approach level flight phase is defined as the phase from the UAV capturing the approach level flight waypoint to the approach glide waypoint; the approach glide phase is defined as the phase from the UAV capturing the approach glide point to the height above the ground being greater than 15m; the first landing leveling phase is defined as the phase from the UAV being 15m above the ground to the height above the ground being greater than 3m; the second landing leveling phase is defined as the phase from the UAV being 3m above the ground to the landing touchdown phase; the landing roll phase is defined as the phase from the UAV landing touchdown to the taxiing deceleration stop phase.

[0031] In the approach and level flight stage, the speed, altitude, pitch angle, track angle and lateral offset of the UAV are used as control target variables; in the approach and glide stage, the speed, glide angle, track angle and lateral offset of the UAV are used as control target variables; in the first stage of landing and leveling, the vertical speed, speed, track angle and lateral offset of the UAV are used as control target variables; in the second stage of landing and leveling, the vertical speed, speed, yaw angle and lateral offset of the UAV are used as control target variables; in the landing and touchdown stage, the speed, heading angle and lateral offset of the UAV are used as target control variables.

[0032] like Figure 3-Figure 7 As shown, the automatic landing of the UAV is controlled according to the target control variables of different sub-stages of the landing stage, wherein K_I in the figure is the integral gain, K_P and K_Q are both proportional gains, including the following process: like Figure 3 As shown, during the approach and level flight phase, the UAV is controlled to maintain the target level flight speed, the target approach and level flight altitude, and the lateral offset and track angle are aligned and track the runway extension line.

[0033] Specifically, the airspeed after signal limiting is used as the negative feedback of the airspeed command, and after the proportional gain and integral gain links are superimposed, the engine throttle control is performed.

[0034] The altitude value after signal limiting is used as the negative feedback of the altitude command. After passing through the proportional gain and integral gain links, the pitch angle rate after signal limiting is used as negative feedback to control the elevator and the descent speed.

[0035] The yaw angle rate after signal limiting and proportional gain is used as negative feedback and superimposed with the roll angle after signal limiting and proportional gain to perform rudder control.

[0036] The track angle after signal limiting is used as the negative feedback of the track angle command. After the signal limiting and proportional gain link, the lateral deviation change rate is used as the positive feedback. After the proportional and integral gain link, the outputs of the above two links are summed to perform aileron control to maintain the target lateral deviation and track angle.

[0037] like Figure 4 As shown, during the approach glide phase, the UAV is controlled to maintain the target glide speed and target glide angle while the UAV is controlled to maintain the target side offset and track angle (along the extended runway line).

[0038] Specifically, the airspeed after signal limiting is used as the negative feedback of the airspeed command, and after the proportional gain and integral gain links are superimposed, the engine throttle control is performed.

[0039] The glide angle after signal limiting is used as the negative feedback of the glide angle command. After passing through the proportional gain and integral gain links, the pitch angle rate after signal limiting is used as negative feedback to control the elevator and the descent speed.

[0040] The yaw angle rate after signal limiting and proportional gain is used as negative feedback and superimposed with the roll angle after signal limiting and proportional gain to perform rudder control.

[0041] The track angle after signal limiting is used as the negative feedback of the track angle command. After the signal limiting and proportional gain link, the lateral deviation change rate is used as the positive feedback. After the proportional and integral gain link, the outputs of the above two links are summed to perform aileron control to maintain the target lateral deviation and track angle.

[0042] like Figure 5 As shown, in the first stage of landing and leveling, the UAV is controlled to maintain a variable target vertical speed and airspeed while controlling the UAV to maintain a target side offset and track angle (along the extended runway line).

[0043] Specifically, the airspeed after signal limiting is used as the negative feedback of the airspeed command, and the engine throttle control is performed after signal limiting and proportional gain links.

[0044] The vertical speed after signal limiting is used as negative feedback of the vertical speed command. The vertical speed command in the landing phase changes with the aircraft altitude. After passing through the proportional gain and integral gain links, the pitch angle rate after signal limiting is used as negative feedback to control the elevator and the descent speed.

[0045] The yaw angle rate after signal limiting and proportional gain is used as negative feedback and superimposed with the roll angle after signal limiting and proportional gain to perform rudder control.

[0046] The track angle after signal limiting is used as the negative feedback of the track angle command. After the signal limiting and proportional gain link, the lateral deviation change rate is used as the positive feedback. After the proportional and integral gain link, the outputs of the above two links are summed to perform aileron control to maintain the target lateral deviation and track angle.

[0047] like Figure 6 As shown, in the second stage of landing and leveling, the UAV is controlled to maintain a fixed target vertical speed and airspeed while controlling the UAV to maintain a target side offset and heading angle (along the extended runway line).

[0048] Specifically, the airspeed after signal limiting is used as the negative feedback of the airspeed command, and the engine throttle control is performed after signal limiting and proportional gain links.

[0049] The vertical speed after signal limiting is used as negative feedback of the vertical speed command. After passing through the proportional gain and integral gain links, the pitch angle rate after signal limiting is used as negative feedback to control the elevator and the descent speed.

[0050] The yaw angle rate after signal limiting and proportional gain is used as negative feedback and superimposed with the roll angle after signal limiting and proportional gain to perform rudder control.

[0051] The yaw angle after signal limiting is used as the negative feedback of the yaw angle command. After the signal limiting and proportional gain link, the lateral offset change rate is used as the positive feedback. After the proportional and integral gain link, the outputs of the above two links are summed to perform aileron control to maintain the target lateral offset and track angle.

[0052] like Figure 7 As shown, during the landing roll phase, the UAV is controlled to decelerate to 0 km / h while controlling the UAV to keep the target side offset and heading angle on the runway centerline.

[0053] Specifically, the current engine throttle after signal limiting is used as negative feedback to decelerate the UAV speed to 0km / h, and the engine throttle is controlled after rate limiting.

[0054] The roll angle after signal limiting is used as the negative feedback of the roll angle command. After passing through the proportional gain link, the roll angle rate is used as the negative feedback signal and passes through the signal limiting and proportional gain links to perform roll attitude control to ensure that the UAV always maintains the target roll of 0°.

[0055] The yaw angle after signal limiting is used as the negative feedback of the yaw angle command. After the signal limiting and proportional gain link, the lateral deviation change rate is used as the positive feedback. After the proportional gain and integral gain link, the yaw angle rate is used as the negative feedback. After the limiting and proportional gain link, the outputs of the above four links are summed up for rudder control to ensure that the yaw angle and lateral deviation of the UAV are aligned with the center line of the runway.

[0056] The specific actual control method is: During the approach and level flight phase, the UAV's airspeed is controlled to maintain the aircraft cruising speed of 200km / h, while the UAV is controlled to maintain the target cruising altitude of 300m, and the UAV's yaw angle and side deviation track are controlled to track the landing airport runway extension line.

[0057] During the approach descent phase, the UAV is controlled to maintain a target descent angle of -3° and descend to a height of 15m above the ground (target landing airport), and the UAV is controlled to maintain a descent airspeed of 168km / h. At the same time, the UAV is controlled to maintain a target heading angle of 325° (along the extended runway line) and a side deviation of 0m.

[0058] In the first stage of landing and leveling, the UAV is controlled to maintain a variable target vertical speed (the target vertical speed changes with the aircraft altitude), and when the UAV is controlled to maintain a landing and leveling speed of 160km / h, the UAV is controlled to maintain a target track angle of 325° (along the extended runway line) and a side deviation of 0m.

[0059] In the second stage of landing and leveling, the UAV is controlled to maintain a fixed target vertical speed of 0.5m / h, and the UAV is controlled to maintain a landing and leveling speed of 160km / h. At the same time, the UAV is controlled to maintain a target heading angle of 325° (along the extended line of the runway) and a side deviation of 0m.

[0060] During the landing roll phase, the UAV is controlled to decelerate to 0 km / h while maintaining a target heading angle of 325° and a side deviation of 0 m and on the runway centerline.

[0061] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0062] In the above embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0063] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0064] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0065] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

[0066] It should be understood that the above description is for illustration and not for limitation. Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of this patent should not be determined with reference to the above description, but rather with reference to the preceding claims and the full scope of equivalents to which such claims are entitled. For the purpose of comprehensiveness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the preceding claims is not intended to be a waiver of such subject matter, nor should it be considered that the applicant has not considered such subject matter to be part of the disclosed inventive subject matter.

Claims

1. A large fixed-wing UAV automatic landing control method, characterized in that: The process includes: The landing phase of the UAV is divided into the approach level flight phase, the approach descent phase, the first landing leveling phase, the second landing leveling phase and the landing roll phase; During the approach and level flight phase, the UAV is controlled to maintain the target level flight speed, the target approach and level flight altitude, and the lateral offset and track angle are aligned and track the extended runway line; During the approach glide phase, the UAV is controlled to maintain the target glide speed and target glide angle, and the UAV is controlled to maintain the target side offset and track angle; In the first stage of landing and leveling, the UAV is controlled to maintain the target vertical speed and airspeed, and the UAV is controlled to maintain the target side deviation and track angle; In the second stage of landing and leveling, the UAV is controlled to maintain the target vertical speed and airspeed, and the UAV is controlled to maintain the target side offset and heading angle; During the landing roll phase, the UAV is controlled to decelerate to 0 speed, and at the same time, the UAV is controlled to keep the target side offset and heading angle on the runway centerline.

2. The automatic landing control method for a large fixed-wing UAV according to claim 1 is characterized in that: The approach level flight phase is the phase from when the UAV captures the approach level flight waypoint to when it captures the approach glide path point; the approach glide path phase is the phase from when the UAV captures the approach glide path point to when the height above the ground is greater than 15m; the first landing leveling phase is the phase from when the UAV is at a height above the ground of 15m to when the height above the ground is greater than 3m; the second landing leveling phase is the phase from when the UAV is at a height above the ground of 3m to when it touches down; the landing roll phase is the phase from when the UAV touches down to when it decelerates and stops during gliding.

3. The automatic landing control method for a large fixed-wing UAV according to claim 1 is characterized in that: During the approach and level flight phase, the speed, altitude, pitch angle, track angle and lateral deviation of the UAV are used as control target variables.

4. The automatic landing control method for a large fixed-wing UAV according to claim 3 is characterized in that: During the approach and level flight phase, the UAV's airspeed is controlled to maintain an aircraft cruising speed of 200 km / h, while the UAV is controlled to maintain a target cruising altitude of 300 m, and the UAV's yaw angle and side offset track are controlled to track the extended runway of the landing airport.

5. The automatic landing control method for a large fixed-wing UAV according to claim 1 is characterized in that: During the approach glide phase, the UAV speed, glide angle, track angle and lateral deviation are used as control target variables.

6. The automatic landing control method for a large fixed-wing UAV according to claim 5 is characterized in that: During the approach glide phase, the UAV is controlled to maintain a target glide angle of -3° and descend to a ground height of 15m, and the UAV is controlled to maintain a glide airspeed of 168km / h while maintaining a target heading angle of 325° and a side deviation of 0m.

7. The automatic landing control method for a large fixed-wing UAV according to claim 1 is characterized in that: In the first stage of the landing and leveling, the vertical speed, speed, track angle and lateral deviation of the UAV are used as control target variables; in the second stage of the landing and leveling, the vertical speed, speed, yaw angle and lateral deviation of the UAV are used as control target variables.

8. The automatic landing control method for a large fixed-wing UAV according to claim 7, characterized in that: In the first stage of landing and leveling, the UAV is controlled to maintain a variable target vertical speed, the vertical speed changes with the aircraft altitude, and the UAV is controlled to maintain a landing and leveling speed of 160km / h, while the UAV is controlled to maintain a target track angle of 325° and a side deviation of 0m; In the second stage of landing and leveling, the UAV is controlled to maintain a fixed target vertical speed of 0.5m / h, and the UAV is controlled to maintain a landing and leveling speed of 160km / h. At the same time, the UAV is controlled to maintain a target heading angle of 325° and a side deviation of 0m.

9. The automatic landing control method for a large fixed-wing UAV according to claim 1, characterized in that: During the landing phase, the speed, heading angle and side offset of the UAV are used as target control variables.

10. The automatic landing control method for a large fixed-wing UAV according to claim 9, characterized in that: During the landing roll phase, the UAV is controlled to decelerate to 0 km / h, and at the same time, the UAV is controlled to maintain a target heading angle of 325° and a side deviation of 0 m and on the center line of the runway.

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