CN114883783A

CN114883783A - Unmanned aerial vehicle double-antenna array system with full-space angular coverage compatible with fuselage structure

Info

Publication number: CN114883783A
Application number: CN202210389858.6A
Authority: CN
Inventors: 刘卫沪; 吕弘; 刘克欣; 宋晓龙
Original assignee: No 60 Institute of Headquarters of General Staff of PLA
Current assignee: No 60 Institute of Headquarters of General Staff of PLA
Priority date: 2022-04-14
Filing date: 2022-04-14
Publication date: 2022-08-09

Abstract

The invention discloses an unmanned aerial vehicle double-antenna array system with full-space angular coverage compatible with a machine body structure, which comprises a built-in empennage antenna, a built-in front abdominal antenna, an antenna selection switch and a flight controller, wherein the built-in empennage antenna is connected with the front abdominal antenna; the built-in empennage antenna is arranged in an empennage cavity of the unmanned aerial vehicle body and is a main control antenna; the built-in front abdominal cavity antenna is arranged in a front abdominal cavity of the unmanned aerial vehicle body and is used as an auxiliary control antenna; the antenna selection switch comprises an SMA radio frequency port and a control port, an inlet port of the SMA radio frequency port is connected with a radio station, two outlet ports of the SMA radio frequency port are respectively connected with a built-in empennage antenna and a built-in forebelly antenna, the control port is connected with a flight controller, and the flight controller controls the switching-off and switching-on of the antenna selection switch according to the quality of a remote control signal to select the built-in empennage antenna and the built-in forebelly antenna. The invention realizes the full-space angular coverage by adopting a double-antenna array mode, solves the problem of wireless signal shielding, gives consideration to the control of radar reflection area and does not increase the air resistance of an airplane.

Description

Unmanned aerial vehicle double-antenna array system with full-space angular coverage compatible with fuselage structure

Technical Field

The invention relates to an unmanned aerial vehicle dual-antenna array, in particular to an unmanned aerial vehicle dual-antenna array system with full-space angular coverage compatible with a fuselage structure.

Background

In recent years, the application of drones in the military, communication, industrial and commercial fields has attracted much attention, and they are widely used for military training, actual combat, exploration, monitoring and multimedia communication, while antennas enable communication between drones and ground stations. When the unmanned aerial vehicle normally flies and turns, the requirement on the coverage rate of the antenna space is not high, and the application requirements can be met by covering the lower half space and the upper half space of the part. When the unmanned aerial vehicle rotates in the air and performs large maneuvering, semi-rolling reversing, barrel rolling and other maneuvering actions, the wireless signal of the unmanned aerial vehicle can be shielded by the fuselage, the wings and the like, so that the signal rapidly descends in certain directions, and a communication blind area occurs. Therefore, the signal quality of the uploading remote control link and the downloading remote measurement link is sharply reduced, the receiving of airborne remote measurement data by the ground station is seriously influenced, and the timely and effective uploading of the remote control instruction of the ground station is seriously influenced.

The airborne antenna is used as communication equipment of an airplane, has strict requirements on the performance of the airplane, and has requirements on the size and the structure of the antenna due to the structural characteristics of the airplane. The common forms of the current airborne antenna are an exposed antenna and a built-in antenna. The exposed antenna has better omni-directionality, but the protruding part of the exposed antenna influences the aerodynamic performance and the stealth performance of the airplane. In order to weaken the influence of the antenna on the aerodynamics of the airplane, a common mode is to add a tail bracket at the tail part of the airplane and place the antenna in the tail bracket, but the additionally added tail bracket still has certain influence on the aerodynamics of the airplane and increases the air resistance of the airplane; and the reflection area of the airplane on the radar is increased due to the fact that the antenna is exposed.

The single antenna is inevitably shielded by the fuselage, wings, etc. of the aircraft. Therefore, it is necessary to adopt an appropriate antenna array to solve the signal blocking problem. Meanwhile, the antenna structure for array needs to be reasonably designed to meet the requirement of compatibility with the machine body structure. The aircraft system is complex, the technical intensity is high, and in order to be compatible with the electrical and control system of the whole aircraft, the antenna array control aspect needs to meet the simple and practical requirements. In order to meet the requirements of fixed-frequency and spread-frequency communication systems, the bandwidth of an airborne antenna system, particularly an unmanned aerial vehicle airborne antenna system, cannot be too narrow, and needs to have a certain bandwidth.

Chinese patent with application number 202020668458.5 and publication number CN 212463210U discloses an antenna system for unmanned aerial vehicles, which includes a signal source unit, a plurality of signal processing units, and a plurality of antenna units. The antenna system has clear and definite signal processing flow. The utility model discloses a more be partial to the signal processing technique, do not carry out antenna array to how to offer technical scheme, do not specifically discuss the complementary problem of antenna gain directional diagram in order to solve the signal problem of sheltering from, do not also relate to antenna array and fuselage structure compatibility problem.

Chinese patent with application No. 201620473022.4, No. CN 206163688U discloses an inverted F-shaped unmanned aerial vehicle antenna, which includes: the antenna has the advantages of simple processing, high reliability and light weight, but the patent does not disclose a solution to the floor design problem which has a large influence on the performance of the antenna, and does not disclose a technical solution to the problem of compatibility of the antenna with the structure of the machine body.

Disclosure of Invention

The invention aims to provide an unmanned aerial vehicle double-antenna array system with full-space angular coverage and compatible fuselage structure, which is used for solving the problem of wireless signal shielding in link communication when an unmanned aerial vehicle does maneuvering action; meanwhile, the built-in antenna is compatible with the airplane structure, so that the radar reflection area is controlled, and the air resistance of the airplane is not increased.

The technical scheme for realizing the purpose of the invention is as follows: an unmanned aerial vehicle double-antenna array system with full-space angular coverage compatible with a fuselage structure comprises a built-in empennage antenna, a built-in front abdominal cabin antenna, an antenna selection switch and a flight controller; the built-in empennage antenna is arranged in an empennage cavity of the unmanned aerial vehicle body and is a main control antenna; the built-in front abdominal cavity antenna is arranged in a front abdominal cavity of the unmanned aerial vehicle body and is an auxiliary control antenna; the antenna selection switch comprises an SMA radio frequency port and a control port, an inlet port of the SMA radio frequency port is connected with a radio station, two outlet ports of the SMA radio frequency port are respectively connected with a built-in empennage antenna and a built-in foreabdominal antenna, the control port is connected with a flight controller, and the flight controller controls the switching-off and switching-on of the antenna selection switch according to the quality of a remote control signal to select the built-in empennage antenna and the built-in foreabdominal antenna.

Furthermore, the built-in empennage antenna comprises an upper arm and a lower arm, the upper arm and the lower arm are supported and connected through a support frame, the upper arm and the lower arm are both of a plate-shaped structure, and the thickness of the upper arm is smaller than that of the lower arm; the built-in metal structure of fin of unmanned aerial vehicle organism, built-in fin antenna is located the cavity above the metal structure, fills rigid foam between the cavity above the metal structure and the built-in fin antenna.

Further, the length of the upper arm is 84mm, and the length of the lower arm is 84 mm; the thickness of the upper arm is 1-2 mm, the thickness of the lower arm is 6-10 mm, and the included angle between the long axis of the built-in empennage antenna and the upper plane of the metal structural member is 45-90 degrees.

Further, built-in front abdominal cavity antenna is fixed in the front abdominal cavity of unmanned aerial vehicle organism through aviation plywood support, the one end of aviation plywood support bonds with the metal beam before unmanned aerial vehicle's the intake duct, and the other end bonds with unmanned aerial vehicle's intake duct.

Furthermore, the built-in front abdominal cavity antenna comprises a floor, a first vertical arm, a nylon support, a second vertical arm and a parallel arm, wherein the floor is fixedly connected with the aviation layer plate support, the first vertical arm and the nylon support are both connected with the floor through screws, and the second vertical arm is arranged in a groove of the nylon support. The parallel arm is connected with the first vertical arm and the second vertical arm through screws respectively and is parallel to the floor, and the resonance peak of the built-in front abdominal cavity antenna can be adjusted by adjusting the length of the parallel arm.

Furthermore, the skin of the front abdominal cavity is made of a wave-transmitting material, and the distance between the built-in front abdominal cavity antenna and the horizontal plane of the metal beam is 42-52 mm; the length, width and height of the floor are respectively 180mm, 150mm and 3 mm; the length of the parallel arm is 77mm, the height of the second vertical arm is 24mm, and the height of the first vertical arm is 22-37 mm.

Furthermore, an inlet port and an outlet port of the SMA radio frequency port are connected with an airborne radio station, a built-in empennage antenna and a built-in front abdominal antenna by adopting radio frequency cables, the upper frequency limit of the radio frequency cables is more than or equal to 1GHz, and the isolation between the SMA radio frequency ports is more than or equal to 53 dB.

Further, the flight controller controls the switching-off and switching-on of the antenna selection switch according to the quality of the remote control signal, and the selection of the built-in empennage antenna and the built-in front abdominal cavity antenna is specifically as follows:

the flight controller controls the antenna selection switch to be switched to the built-in front abdominal antenna by controlling voltage to complete antenna selection when the remote control signal quality in the initial state is less than a set threshold value; if the quality of the remote control signal is larger than or equal to a set threshold value in the state that the front abdominal cavity antenna is built in at the moment, the antenna selection switch is not switched;

if the remote control signal quality under the state of the built-in front abdominal cabin antenna is less than a set threshold value after flying for a period of time, the flight controller controls the antenna selection switch to be switched to the built-in tail wing antenna again;

when the number of times of switching back and forth of the antenna selection switch is larger than or equal to m, the antenna selection switch is switched to the initial state, the set time n s is kept, and then the antenna selection switch switching step is executed again.

Furthermore, the set threshold value of the quality of the remote control signal is 25% -75% of a full frame, and the control voltage is 7.5-8V.

Preferably, the skin of the front abdominal cabin is made of glass fiber, the thickness of the upper arm is 1mm, the thickness of the lower arm is 6mm, and an included angle between the long axis of the built-in empennage antenna and the upper plane of the metal structural member is 45 degrees; the distance between the built-in front abdominal cavity antenna and the horizontal plane of the metal beam is 42mm, and the height of the first vertical arm is 37 mm; the isolation between the SMA radio frequency ports is 70dB, the set threshold value of the quality of the remote control signal is 60%, m is 3, n s is 10s, and the control voltage is 8V.

Compared with the prior art, the invention has the following remarkable effects:

(1) the invention adopts a mode of double antenna array to realize the full-space angular coverage, solves the problem of wireless signal shielding, has two array elements and is simple and reliable;

(2) the built-in empennage antenna is used as a main control antenna, the built-in front abdominal cabin antenna is used as an auxiliary control antenna, the built-in empennage antenna gain directional diagram covers most of the upper half space and part of the lower half space, and the built-in front abdominal cabin antenna covers the lower half space and part of the upper half space, so that the coverage spaces of the double antenna gain directional diagrams in the system can realize complementation;

(3) the device adopted by the invention has simple structure and high isolation between ports; the control logic is simple and reliable;

(4) the double antennas of the invention are all designed in a built-in mode, and are compatible with an airplane structure, so that the control of the reflection area of the radar is considered, and the air resistance of the airplane is not increased.

Drawings

Fig. 1 is a schematic diagram of a dual antenna system of the present invention.

Fig. 2 is a schematic diagram of the layout position of the dual antenna and the structure of the whole device.

Fig. 3 is a schematic view of the internal tail antenna and tail structure of the present invention.

Fig. 4 is a schematic diagram of the internal tail antenna structure of the present invention.

Fig. 5 is a schematic view of the internal front abdominal cavity antenna and front abdominal cavity structure of the present invention.

Fig. 6 is a schematic diagram of the structure of the internal front abdominal cavity antenna of the present invention.

Fig. 7 is a schematic diagram of an antenna selection switch of the present invention.

Fig. 8 is a switch control logic diagram of the present invention.

Fig. 9 shows an actually measured 3D gain pattern and a two-dimensional gain pattern of the internal tail antenna according to the present invention, where fig. 9(a) shows an actually measured 3D gain pattern of the internal tail antenna, fig. 9(b) shows a direction gain pattern of the XOY plane, fig. 9(c) shows a direction gain pattern of the XOZ plane, and fig. 9(D) shows a direction gain pattern of the YOZ plane.

Fig. 10 shows a measured 3D gain pattern and a two-dimensional gain pattern of the internal front abdominal cavity antenna according to the present invention, where fig. 10(a) shows the measured 3D gain pattern of the internal front abdominal cavity antenna, fig. 10(b) shows a directional gain pattern of the XOY plane, fig. 10(c) shows a directional gain pattern of the XOZ plane, and fig. 10(D) shows a directional gain pattern of the YOZ plane.

In the figure: 1. an unmanned aerial vehicle body; 2. a tail wing; 3. a control surface; 4. a front abdominal cavity; 5. an empennage antenna is arranged inside; 6. a rigid foam; 7. a metal structural member; 8. an upper arm; 9. a support frame; 10. a lower arm; 11. an air inlet channel; 12. a metal beam; 13. an aviation laminate support; 14. a front abdominal cavity antenna is arranged inside; 15. a floor; 16. a parallel arm; 17. a first vertical arm; 18. a second vertical arm; 19. a nylon bracket; 20. an antenna selection switch; 21. an inlet port; 22. a first output port; 23. a second output port; 24. and controlling the port.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The technical scheme of the invention is further described in detail with reference to the accompanying drawings 1-10 and the embodiment.

Examples

Referring to the attached drawings 1-8, the unmanned aerial vehicle dual-antenna array system with full space angle coverage compatible with the fuselage structure comprises a built-in empennage antenna 5, a built-in front abdominal cabin antenna 14, an antenna selection switch 20 and switch control logic; the problem of signal shielding is solved by adopting a method of complementing dual antenna gain directional diagrams; the dual-antenna array is carried out by adopting a switching mode, and the control logic is simple and practical; specifically, a built-in empennage antenna gain directional diagram covers most of the upper half space and part of the lower half space, a built-in front abdominal cavity antenna covers the lower half space and part of the upper half space, and the built-in front abdominal cavity antenna gain directional diagram and the built-in empennage antenna gain directional diagram are complementary; when the antenna is applied, the built-in empennage antenna is set as a main control antenna, and the built-in front abdominal cavity antenna is used as an auxiliary control antenna. And switching the switch according to the quality of the remote control signal to realize antenna selection.

The built-in empennage antenna 5 is arranged in an empennage 2 cavity of the unmanned aerial vehicle body 1, and the cavity is positioned near the control surface 3. With reference to fig. 3, a metal structural member 7 for strengthening the strength of the empennage is arranged in the empennage 2, a empennage cavity is arranged above the metal structural member 7, hard foam 6 is filled between the empennage cavity and the antenna, with reference to fig. 4, the upper arm 8 and the lower arm 10 of the built-in empennage antenna 5 both adopt plate-shaped structures, so that the antenna has certain bandwidth, the thickness of the upper arm 8 is far lower than that of the lower arm 10, so as to adapt to the characteristic that the empennage space is thin at the top and thick at the bottom, and the upper arm 8 and the lower arm 10 are supported and positioned by a support frame 9.

Referring to fig. 5, the built-in front abdominal cabin antenna 14 is placed in the cavity of the front abdominal cabin 4, the antenna is fixed to the aviation laminate bracket 13, then one end of the aviation laminate bracket 13 is bonded to the metal beam 12 in front of the air inlet 11, and the other end is bonded to the air inlet 11. Referring to fig. 6, the built-in front abdominal cavity antenna 14 is connected to the floor 15 by screws, and the nylon bracket 19 is connected to the floor 15 by screws. The second vertical arm 18 is then placed in the groove of the nylon bracket 19. Then, the parallel arm 16 is connected to the first vertical arm 17 and the second vertical arm 18, respectively, by screws.

With reference to fig. 7, the antenna selection switch 20 is a conventional switch, and is commercially available, and includes 3 SMA radio frequency ports and 1 control port, where an input port 21 of the SMA radio frequency port is connected to a radio station, and two

output ports

22 and 23 are connected to the internal tail antenna 5 and the internal front abdominal cavity antenna 14, respectively; the control port 24 is connected to a flight controller (hereinafter referred to as flight control), and the isolation between the radio frequency ports is high. The flight control provides a control voltage to the antenna selection switch control port 24 to control the switch switching, thereby realizing antenna selection.

Referring to fig. 8, the switch control logic uses the built-in tail antenna 5 as a main control antenna. The initial state is that the built-in empennage antenna 5 is adopted for communication, and the switch switching reference is the quality of the remote control signal. When the remote control signal quality in the initial state is less than the set threshold value, the antenna is considered to be shielded, and the flight control switch is switched to the built-in front abdominal antenna 14 to complete antenna selection. If the quality of the remote control signal is larger than or equal to the set threshold value in the state of the built-in front abdominal cavity antenna 14, the switch is not switched. If the remote control signal quality under the state of the built-in front abdominal cabin antenna 14 is less than the set threshold value after a period of flight, the switch is switched to the built-in tail wing antenna 5 again. In order to prevent the frequent invalid switching of the switch under the abnormal condition, a protection control logic is set. When the switching times of the switch is more than or equal to m, the switch is switched to the initial state, and the switch enters the switch switching logic path again after the switch is kept for n s a certain time.

The control surface 3 near the built-in empennage antenna 5 is made of a wave-transmitting material, mechanical strength is required to be considered, glass fiber skin is preferably selected, and hard foam is filled inside the glass fiber skin. The length of the upper arm 8 of the built-in empennage antenna 5 is 84mm, and the length of the lower arm 10 is 84 mm; the thickness of the upper arm is 1-2 mm, preferably 1 mm; the thickness of the lower arm is 6-10 mm, preferably 6 mm. The included angle between the long axis of the built-in empennage antenna 5 and the upper plane of the metal structural member 7 is 45-90 degrees, and preferably 45 degrees.

The built-in front abdominal cabin antenna 14 is built in the front abdominal cabin 4, the skin of the front abdominal cabin 4 needs to be made of wave-transparent materials and needs to take mechanical strength into consideration, and the glass fiber materials are preferably selected. The distance between the built-in front abdominal cavity antenna 14 and the horizontal plane of the metal beam 12 is 42-52 mm, and preferably 42 mm. The length, width and height of the floor 15 with the built-in front abdominal chamber antenna 14 are respectively 180mm, 150mm and 3 mm; the length of the parallel arm 16 is 77mm and the height of the second vertical arm 18 is 24 mm; the height of the first vertical arm 17 is 22-37 mm, preferably 37 mm. If the dielectric property of the glass fiber skin fluctuates slightly, the resonance peak of the antenna can be finely adjusted by finely adjusting the length of the parallel arm 16.

An inlet port 21 of the antenna selection switch 20 is connected with a radio station, and

outlet ports

22 and 23 are respectively connected with the built-in empennage antenna 5 and the built-in front abdominal cavity antenna 14. The radio frequency cables are connected, and the upper limit of the application frequency of the radio frequency cables is more than or equal to 1GHz, preferably 3 GHz; the isolation between the radio frequency ports is high, and the isolation is more than or equal to 53dB, preferably 70 dB; the control port is connected with the flight control, the flight control provides control voltage to the control port 24 of the antenna selection switch, and the switch is controlled to switch, so that antenna selection is achieved. The control voltage is 7.5-8V, preferably 8V.

The switch control logic takes the built-in empennage antenna 5 as a main control antenna, the built-in empennage antenna 5 is used for communication in an initial state, the switch switching reference is the quality of the remote control signal, when the quality of the remote control signal in the initial state is less than a set threshold value, the antenna is considered to be shielded, the flight control switch is switched to the built-in front abdominal cabin antenna 14, and antenna selection is completed. If the quality of the remote control signal is larger than or equal to the set threshold value in the state of the built-in front abdominal cavity antenna 14, the switch is not switched. If the remote control signal quality under the state of the built-in front abdominal cavity antenna 14 is less than the set threshold value after a period of flight, the switch is switched to the built-in tail wing antenna 5 again, and protection control logic is set for preventing the switch from being frequently and ineffectively switched under abnormal conditions. When the switching times of the switch is more than or equal to m, the switch is switched to the initial state, and the switch enters the switch switching logic path again after the switch is kept for n s a certain time. The remote control signal quality setting threshold is 25% to 75%, preferably 60%, of the full frame. The number of times of switching the switch back and forth is larger than or equal to m, and m is preferably 3. After switching to the initial state, the holding time is n s, preferably 10 s.

Fig. 9 and 10 are graphs showing the results of actual measurement of the gain patterns of the internal tail antenna 5 and the internal front abdominal cavity antenna 14, respectively, and it can be seen from the 3D gain patterns that the gain patterns of the dual antennas are complementary; as can be seen from the two-dimensional gain directional diagrams of the xoy plane, the xoz plane and the yoz plane, the gains of the double antennas under the full space angle are all more than or equal to-10 dBi, no dead zone exists in the gains under the full space angle, and the full space angle coverage is realized. In addition, in the range of 740-810 MHz of the dual-antenna system, gain patterns meet the requirement of full-space angular coverage, and the dual-antenna system has a certain bandwidth.

Claims

1. An unmanned aerial vehicle double-antenna array system with full space angle coverage compatible with a fuselage structure is characterized by comprising a built-in empennage antenna (5), a built-in front abdominal cabin antenna (14), an antenna selection switch (20) and a flight controller; the built-in empennage antenna (5) is arranged in an empennage (2) cavity of the unmanned aerial vehicle body (1) and is a main control antenna; the built-in front abdominal cabin antenna (14) is arranged in a cavity of a front abdominal cabin (4) of the unmanned aerial vehicle body (1) and is used as an auxiliary control antenna; the antenna selection switch (20) comprises an SMA radio frequency port and a control port, an inlet port of the SMA radio frequency port is connected with a radio station, two outlet ports of the SMA radio frequency port are respectively connected with the built-in empennage antenna (5) and the built-in forebelly antenna (14), the control port is connected with the flight controller, and the flight controller controls the opening and closing of the antenna selection switch (20) according to the quality of a remote control signal to select the built-in empennage antenna (5) and the built-in forebelly antenna (14).

2. The full spatial angular coverage and fuselage structure compatible unmanned aerial vehicle dual antenna array system of claim 1, wherein the built-in tail antenna (5) comprises an upper arm (8) and a lower arm (10), the upper arm (8) and the lower arm (10) are in supporting connection by a supporting frame (9), the upper arm (8) and the lower arm (10) are both in plate-shaped structures, and the thickness of the upper arm (8) is lower than that of the lower arm (10); the built-in metal structure spare (7) of fin (2) of unmanned aerial vehicle organism (1), built-in fin antenna (5) are located the cavity of metal structure spare (7) top, fill rigid foam (6) between cavity and built-in fin antenna (5) of metal structure spare (7) top.

3. The full spatial angular coverage and fuselage structure compatible unmanned aerial vehicle dual antenna array system of claim 2, wherein the upper arm (8) is 84mm in length and the lower arm (10) is 84mm in length; the thickness of the upper arm (8) is 1-2 mm, the thickness of the lower arm (10) is 6-10 mm, and the included angle between the long axis of the built-in empennage antenna (5) and the upper plane of the metal structural member (7) is 45-90 degrees.

4. The dual-antenna array system for unmanned aerial vehicle with full spatial angular coverage and compatible fuselage structure according to any one of claims 2 or 3, characterized in that the built-in front abdominal cabin antenna (14) is fixed in the cavity of the front abdominal cabin (4) of the unmanned aerial vehicle body (1) through an aviation laminate bracket (13), one end of the aviation laminate bracket (13) is bonded with the metal beam (12) in front of the air inlet (11) of the unmanned aerial vehicle, and the other end is bonded with the air inlet (11) of the unmanned aerial vehicle.

5. The full-space angular coverage and fuselage structure compatible unmanned aerial vehicle dual antenna array system according to claim 4, wherein the built-in front abdominal cavity antenna (14) comprises a floor (15), a first vertical arm (17), a nylon bracket (19), a second vertical arm (18) and a parallel arm (16), the floor (15) is fixedly connected with the aviation laminate bracket (13), the first vertical arm (17) and the nylon bracket (19) are both connected with the floor (15) through screws, the second vertical arm (18) is placed in a groove of the nylon bracket (19), the parallel arm (16) is respectively connected with the first vertical arm (17) and the second vertical arm (18) through screws and is parallel to the floor (15), and the resonance peak of the built-in front abdominal cavity antenna (14) can be adjusted by adjusting the length of the parallel arm.

6. The unmanned aerial vehicle dual antenna array system with full spatial angular coverage and fuselage structure compatibility of claim 5, wherein the skin of the front abdominal cavity (4) is made of wave-transparent material, and the distance between the built-in front abdominal cavity antenna (14) and the horizontal plane of the metal beam (12) is 42-52 mm; the length, width and height of the floor (15) are respectively 180mm, 150mm and 3 mm; the length of the parallel arm (16) is 77mm, the height of the second vertical arm (18) is 24mm, and the height of the first vertical arm (17) is 22-37 mm.

7. The unmanned aerial vehicle dual antenna array system with full space angle coverage and fuselage structure compatibility according to any one of claims 5 or 6, wherein the inlet port and the outlet port of the SMA radio frequency port are connected with an airborne radio, an internal empennage antenna (5) and an internal front abdominal cavity antenna (14) by adopting radio frequency cables, the upper frequency limit of the radio frequency cables is more than or equal to 1GHz, and the isolation between the SMA radio frequency ports is more than or equal to 53 dB.

8. The dual-antenna array system for unmanned aerial vehicle with full spatial angular coverage and compatible fuselage structure according to claim 7, wherein the flight controller controls the opening and closing of the antenna selection switch (20) according to the quality of the remote control signal, and the selection of the internal empennage antenna (5) and the internal forebelly antenna (14) is specifically as follows:

the initial state adopts a built-in empennage antenna (5) for communication, an antenna selection switch (20) switches the reference to be the quality of a remote control signal, and when the quality of the remote control signal in the initial state is less than a set threshold value, a flight controller controls the antenna selection switch (20) to be switched to a built-in forebelly antenna (14) through control voltage to complete antenna selection; if the quality of the remote control signal is larger than or equal to the set threshold value in the state that the front abdominal cavity antenna (14) is arranged, the antenna selection switch (20) is not switched;

if the remote control signal quality under the state of the built-in front abdominal cabin antenna (14) is less than a set threshold value after flying for a period of time, the flight controller controls the antenna selection switch (20) to be switched to the built-in empennage antenna (5) again;

when the number of times of switching back and forth of the antenna selection switch (20) is larger than or equal to m, the state is switched to the initial state, and the switching step of the antenna selection switch (20) is executed again after the set time n s is kept.

9. The unmanned aerial vehicle dual antenna array system with full spatial angular coverage and fuselage structure compatible according to claim 8, wherein the set threshold value of the remote control signal quality is 25% -75% of a full frame, and the control voltage is 7.5-8V.

10. The full spatial angular coverage and fuselage structural compatibility unmanned aerial vehicle dual antenna array system of claim 9, wherein the skin of the front belly compartment (4) is made of glass fiber, the upper arm (8) is 1mm thick, the lower arm (10) is 6mm thick, and the included angle between the long axis of the built-in empennage antenna (5) and the upper plane of the metal structural member (7) is 45 °; the distance between the built-in front abdominal cavity antenna (14) and the horizontal plane of the metal beam (12) is 42mm, and the height of the first vertical arm (17) is 37 mm; the isolation between the SMA radio frequency ports is 70dB, the upper limit of the frequency of the radio frequency cable is 3GH, the set threshold value of the quality of the remote control signal is 60%, m is 3, n is 10, and the control voltage is 8V.