Vertical take-off and landing fixed-wing unmanned aerial vehicle

Abstract

The invention provides a vertical take-off and landing fixed-wing unmanned aerial vehicle. The vertical take-off and landing fixed-wing unmanned aerial vehicle comprises a vehicle body, a propeller system, a fixed-wing system, a battery assembly and a flight control system, the vehicle body comprises a rectangular frame, a plurality of vehicle arms and a rack, the vehicle arms comprise first vehicle arms arranged on a pair of opposite side edges of the rectangular frame and second vehicle arms arranged on the other pair of opposite side edges of the rectangular frame, and the rack is sequentially provided with a battery compartment, a cargo compartment and an equipment compartment from bottom to top; the propeller system comprises a plurality of propellers, part of the propellers are mounted at the tail end of the first arm, and the other propellers are mounted in the middle of the second arm; the fixed wing system comprises a pair of fixed wings which are connected to the tail end of the second arm to form a tandem wing structure; the battery assembly is arranged in the battery compartment in a pluggable mode, and the flight control system is arranged in the equipment compartment and electrically connected with the battery assembly. The unmanned aerial vehicle is low in structural mechanical complexity, low in manufacturing and maintenance cost and high in reliability.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of unmanned aerial vehicle technology, in particular, the present application relates to a vertical take-off and landing fixed-wing unmanned aerial vehicle. BACKGROUND

[0002] At present, the unmanned aerial vehicle capable of vertical take-off on the market is mainly multi-rotor unmanned aerial vehicle. Multi-rotor unmanned aerial vehicle generates lift through multiple propellers, thereby overcoming the limitation that fixed-wing unmanned aerial vehicle needs to run on the runway to take off, and has good take-off site adaptability. However, multi-rotor unmanned aerial vehicle completely relies on propellers to provide lift to overcome its own gravity during flight, and also needs to allocate part of the thrust for attitude adjustment, forward and cruise control. This way of relying on propellers to provide all the lift results in low energy utilization efficiency, thereby limiting its range and endurance, making it difficult to perform long-distance tasks.

[0003] In the prior art, in order to realize the unmanned aerial vehicle with vertical take-off and long endurance, the vertical take-off and landing fixed-wing layout is mostly used. Common transition schemes include thrust vector control, rotor tilting, wing tilting and the like. Although such schemes can realize smooth transition between vertical take-off and horizontal cruise, they have complex structure, numerous mechanical transmission systems, high manufacturing cost, great maintenance difficulty, and high mechanical failure risk. SUMMARY

[0004] The purpose of the present application is to provide a vertical take-off and landing fixed-wing unmanned aerial vehicle which can not only take off vertically, but also has long endurance and strong load capacity.

[0005] In order to achieve the above purpose, the present application provides the following technical scheme: The present application provides a vertical take-off and landing fixed-wing unmanned aerial vehicle, comprising a body and a propeller system, a fixed-wing system, a battery assembly and a flight control system which are all arranged on the body; the body comprises a rectangular frame, a plurality of arms which are uniformly arranged around the rectangular frame, and a rack which is vertically arranged on the rectangular frame; the plurality of arms comprise first arms arranged on one pair of opposite sides of the rectangular frame and second arms arranged on the other pair of opposite sides of the rectangular frame; the second arms are longer than the first arms; the rack is sequentially provided with a battery compartment, a cargo compartment and an equipment compartment from bottom to top; the propeller system comprises a plurality of propellers, part of which are mounted at the ends of the first arms, and the rest of which are mounted at the middle of the second arms; the fixed-wing system comprises a pair of fixed wings which are connected at the ends of the second arms and form a tandem wing structure; the battery assembly is plug-in arranged in the battery compartment; and the flight control system is arranged in the equipment compartment and electrically connected with the battery assembly.

[0006] In one embodiment, the propeller comprises a motor and a propeller blade mounted on the output shaft of the motor, and the output shaft of each propeller is arranged obliquely relative to the vertical direction.

[0007] In one embodiment, the angle between the motor output shaft and the vertical direction is between 5° and 35°.

[0008] In one embodiment, the propeller is provided with six; the first arm is provided with a pair, which is fixed vertically to the opposite side of the rectangular frame; the second arm is provided with two pairs, which are respectively arranged on the other pair of opposite sides of the rectangular frame and are connected to the rectangular frame at an angle, and the two pairs of second arms are respectively connected to the two fixed wings; the angle between the adjacent two arms is 60°.

[0009] In one embodiment, the second arm is connected to the rectangular frame through the arm folding assembly, so that the fixed wing can be unfolded or folded relative to the rectangular frame.

[0010] In one embodiment, the arm folding assembly includes a hinge, an arm lock and a screw nut assembly; the hinge includes a shaft, a hinge piece and an arm folding rod, the hinge piece and the arm folding rod are both provided with a shaft sleeve and are alternately sleeved on the shaft, the hinge piece is fixed to the rectangular frame, and the second arm is fixed to the arm folding rod; the arm lock is fixed to the rectangular frame from the side of the arm folding rod away from the rectangular frame when the wing is unfolded, so as to press the arm folding rod tightly to the rectangular frame; the screw nut assembly is used to fix the arm lock to the rectangular frame.

[0011] In one embodiment, the end of the arm folding rod is provided with a first pressing inclined surface, the arm lock includes a fixed end and a pressing end, the pressing end is perpendicular to the fixed end, and the pressing end is provided with a second pressing inclined surface; when the arm lock is fixed to the rectangular frame to press the arm folding rod, the second pressing inclined surface cooperates with the first pressing inclined surface.

[0012] In one embodiment, the cargo cabin is arranged in the frame and can be controlled to rotate relative to the frame, so that the cargo cabin always remains horizontal during the flight of the unmanned aerial vehicle.

[0013] In one embodiment, the cargo cabin is connected to the frame through a pair of rotating shafts and a screw nut transmission mechanism; the screw nut transmission mechanism includes a screw rod motor, a screw rod and a nut, the screw rod motor is fixed to the motor mounting structure and is electrically connected to the flight control system of the unmanned aerial vehicle, the screw rod is connected to the output shaft of the screw rod motor, and the nut is fixed to the cargo cabin and is threadedly connected to the screw rod.

[0014] In one of the embodiments, the equipment cabin comprises a first mounting cavity and a second mounting cavity separated in the front-rear direction; the flight control system comprises a flight control assembly, an RTK receiver and a data / video transmission receiver, a computing power module, a power distribution board, a camera and a radar, the flight control assembly, the RTK receiver and the data / video transmission receiver and the computing power module are arranged from top to bottom in the second mounting cavity, the power distribution board is electrically connected with a battery assembly and arranged in the first mounting cavity, and the camera and the radar are mounted at the top end of the equipment cabin.

[0015] In one of the embodiments, the pair of fixed wings comprises a front wing and a rear wing, the front wing and the rear wing are arranged in series in the longitudinal direction of the fuselage and are distributed in an up-down relationship in the vertical direction; each of the propellers is located in the space defined by the front wing and the rear wing.

[0016] Further, the unmanned aerial vehicle further comprises a pair of landing gears arranged below the fuselage and connected with the pair of side edges of the first arm of the rectangular frame respectively.

[0017] Further, the unmanned aerial vehicle further comprises a portable handle connected with the frame.

[0018] The vertical take-off and landing fixed-wing unmanned aerial vehicle provided by the present application has the advantages that: the vertical take-off and landing fixed-wing unmanned aerial vehicle adopts a combined layout form of multiple propellers combined with fixed wings, and has the flexibility of multiple propellers vertical take-off and landing and the long endurance and high efficiency of fixed-wing cruise performance. The unmanned aerial vehicle is not equipped with the control surfaces of the traditional fixed-wing aircraft, that is, no ailerons or flaps are arranged on the wings, and no elevators and rudders are arranged on the tail, and the unmanned aerial vehicle is mainly controlled by the differential thrust of the six propellers, so that smooth transition from vertical take-off to horizontal flight is realized, the thrust vector or tilting mechanism is omitted, the mechanical complexity of the structure is low, the manufacturing and maintenance cost is low, and the reliability is high. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the description of the embodiments of the present application will be briefly introduced.

[0020] Figure 1 Fig. 1 is a perspective view of the vertical take-off and landing fixed-wing unmanned aerial vehicle provided by one embodiment of the present application; Figure 2 Fig. 2 is a side view of the unmanned aerial vehicle shown in Fig. 1, in which the direction from left to right is the front-rear direction; Figure 1 Fig. 3 is a partial structure schematic view of the unmanned aerial vehicle shown in Fig. 1; Figure 3 Figure 1 Fig. 4 is a perspective view of the hinge provided by one embodiment of the present application; Figure 4 Fig. 5 is a side view of the hinge shown in Fig. 4; and Figure 5 ​A perspective view of a robot arm lock catch is provided for an embodiment of the present application; Figure 6 A schematic view of a vertical take-off and landing fixed-wing unmanned aerial vehicle in a folded state is provided for the present application; Figure 7 A structural schematic view of a vertical take-off and landing fixed-wing unmanned aerial vehicle without a rack protection plate is provided for an embodiment of the present application, showing the relative assembly relationship between the cargo cabin and the stand; Figure 8 A structural schematic view of a vertical take-off and landing fixed-wing unmanned aerial vehicle in a cruising state is provided for an embodiment of the present application; Figure 9 A structural schematic view of a vertical take-off and landing fixed-wing unmanned aerial vehicle without a fixed wing is provided for an embodiment of the present application; Figure 10 An exploded view of the equipment cabin and the flight control system is provided for an embodiment of the present application. DETAILED DESCRIPTION

[0021] Embodiments of the present application will be described in more detail by referring to the drawings. Although certain embodiments of the present application are shown in the drawings, it is understood that the present application can be implemented in various forms and should not be interpreted as being limited to the embodiments set forth herein, but rather these embodiments are provided so as to more completely and thoroughly understand the present application. It is understood that the drawings and embodiments of the present application are for exemplary purposes only and are not intended to limit the scope of protection of the present application.

[0022] It should be understood that each of the steps recited in the method embodiments of the present application can be executed in different orders and / or in parallel. In addition, the method embodiments can include additional steps and / or omit the execution of the steps shown. The scope of the present application is not limited in this respect.

[0023] The term "comprising" and variations thereof as used herein are used inclusively, i.e., "comprising but not limited to". The term "connected" can be direct or indirect, through intervening components (elements). The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Related definitions are given throughout the description.

[0024] It should be noted that the terms "first", "second", and the like used in the present application are merely used to distinguish different devices, modules or units, and do not necessarily mean that the devices, modules or units are different devices, modules or units, nor do they necessarily mean that the functions performed by the devices, modules or units are performed in the order or in the sequence described.

[0025] Reference is made to Figures 1 to 10The application provides a vertical take-off and landing fixed-wing unmanned aerial vehicle (hereinafter referred to as an unmanned aerial vehicle), which comprises a machine body and a propeller system 30, a fixed-wing system 40, a battery assembly and a flight control system 70 which are all arranged on the machine body. The unmanned aerial vehicle has the flexibility of multi-rotor vertical take-off and landing and the high-efficiency cruising characteristics of fixed-wing long endurance. In the military field, the unmanned aerial vehicle can be used for long-distance reconnaissance, monitoring and delivery tasks in the field environment without relying on runways; in the civil field, the unmanned aerial vehicle can be applied to the scenes of medium and long distance goods transportation, emergency rescue, inspection and logistics delivery in urban environment, and has a wide application prospect.

[0026] The machine body comprises a fuselage 10 formed by a rectangular frame, a plurality of arms 20 arranged uniformly around the rectangular frame, and a rack 50 erected on the rectangular frame. The plurality of arms 20 comprise first arms 21 arranged on one pair of opposite sides of the rectangular frame and second arms 22 arranged on the other pair of opposite sides of the rectangular frame, and the second arms 22 are longer than the first arms 21. The rack 50 is sequentially provided with a battery cabin 53, a cargo cabin 51 and an equipment cabin 52 from bottom to top, wherein the battery cabin 53 is located below the rectangular frame, the cargo cabin 51 is arranged in the rack 50, and the equipment cabin 52 is arranged above the rack 50.

[0027] The propeller system 30 comprises a plurality of, for example, six propellers, some of which are mounted at the ends of the first arms 21, and the rest of which are mounted at the middle of the second arms 22.

[0028] The fixed-wing system 40 comprises a pair of fixed wings which are connected at the ends of the second arms 22 and form a tandem wing structure. The pair of fixed wings comprises a front wing 42 and a rear wing 41 which are distributed along the front-rear direction of the unmanned aerial vehicle, the front wing 42 and the rear wing 41 are arranged in a tandem along the longitudinal direction of the fuselage 10 and form an up-down distribution relationship in the vertical direction, and each propeller is located in the space defined by the front wing 42 and the rear wing 41.

[0029] In this embodiment, the front wing 42 is located in the area below the propeller and is in a relatively stable free airflow, so that the lift output is stable and the efficiency is high; the rear wing 41 is located in the area above the propeller and is in the accelerated wake range, so that the local lift and thrust can be enhanced by using the wake energy to improve the aerodynamic efficiency and cruising performance of the whole machine.

[0030] The battery assembly 80 is arranged in the battery cabin 53 in a plug-in manner and is used to provide electric energy for the operation of the unmanned aerial vehicle.

[0031] The flight control system 70 is used to realize flight attitude sensing, navigation and task control, and is arranged in the equipment cabin 52 and electrically connected with the battery assembly.

[0032] The vertical take-off and landing fixed-wing unmanned aerial vehicle of the present application is not equipped with the control rudder surface of the traditional fixed-wing aircraft, that is, no aileron or flap is arranged on the wing (i.e. fixed wing), and no elevator and rudder is arranged on the tail. The pitch, roll and yaw control of the whole machine is realized by the speed differential of the six propellers, thereby significantly simplifying the flight control system, reducing the complexity of the mechanism and improving the system reliability.

[0033] In one embodiment, the propeller includes a motor and a blade mounted on the output shaft of the motor, and the output shaft of the motor of each propeller is arranged obliquely relative to the vertical direction. The design angle of the output shaft of the motor relative to the vertical direction can be adjusted in the range of 5° to 35° to adapt to different flight performance requirements.

[0034] Preferably, the angle of the output shaft of the motor relative to the vertical direction is 19.8°.

[0035] Further, the oblique direction of the pair of propellers on the first arm 21 is the same as the front-rear direction of the unmanned aerial vehicle, so that when the unmanned aerial vehicle is cruising, the inclination angle of the fuselage 10 is 70.2°, at this time, the direction of the pulling force of the two motors on the pair of first arms 21 is horizontal forward, and the power for the flight of the unmanned aerial vehicle can be provided by the two propellers on the pair of first arms 21 cooperating with the fixed wing, and the efficiency of the unmanned aerial vehicle is the highest.

[0036] The inclination angle design of the six propeller motors can cooperate with the pitch angle of the machine body during level flight to maximize the efficiency of the propeller blades. At the same time, the inclination angle layout can provide additional stable torque in the environment with side wind or gust, and improve the wind resistance performance and flight attitude stability.

[0037] The inclination angle design of the six propeller motors makes the thrust direction of the unmanned aerial vehicle in the level flight state closer to the horizontal, which can realize smooth transition between vertical take-off and level flight modes, and realize attitude and heading control by adjusting the thrust and speed difference of each rotor, which helps to improve the cruise speed control and energy efficiency.

[0038] In the level flight state, the fixed wing located above the machine body is arranged behind the propeller to form a "front propeller" layout, and the fixed wing located below is arranged in front of the propeller to form a "rear propeller" layout.

[0039] This kind of up-down tandem double-wing structure can effectively utilize the propeller wake when the unmanned aerial vehicle is in level flight, improve the aerodynamic efficiency, reduce the induced drag, and thereby significantly improve the endurance and load capacity. In addition, the lift is shared between the front and rear wings, which significantly reduces the single-wing lift load, makes the airflow distribution more uniform, and obtains larger total lift under relatively smaller wing span, which is beneficial to improve the wing structure strength and reduce the induced drag.

[0040] In addition, by adjusting the installation angle difference and relative position of the front wing 42 and the rear wing 41, the matching relationship between the aerodynamic center and the gravity center position can be optimized, the flight stability and maneuverability can be improved, and the imbalance of the unmanned aerial vehicle pitching moment can be reduced.

[0041] In one embodiment, the first arm 21 is provided with a pair of arms which are vertically connected to the side edges of the rectangular frame; the second arm 22 is provided with two pairs of arms which are arranged on the other pair of opposite side edges of the rectangular frame and are obliquely connected to the rectangular frame, and the two fixed wings are correspondingly connected to the two pairs of second arms 22. In this embodiment, the arms are uniformly distributed around the rectangular frame, that is, the included angle between adjacent arms is 60°.

[0042] Please refer to Figures 3 to 6 In one embodiment, the second arm 22 is connected to the rectangular frame through an arm folding assembly, so that the fixed wing can be unfolded or folded relative to the rectangular frame, thereby reducing the size of the unmanned aerial vehicle during storage and transportation, and facilitating storage and carrying.

[0043] In one embodiment, the arm folding assembly includes a hinge 15, an arm lock 16 and a screw nut assembly (not shown, the same below).

[0044] The hinge 15 includes a shaft 151, a hinge piece 152 and an arm folding rod 153, the hinge piece 152 is provided with a first shaft sleeve 1521, the arm folding rod 153 is provided with a second shaft sleeve 1531, and the two are alternately sleeved on the shaft 151 through the respective shaft sleeves, the hinge piece 152 is fixed to the rectangular frame, and the second arm 22 is fixed to the arm folding rod 153. The arm lock 16 is fixed to the rectangular frame from the side opposite to the rectangular frame of the arm folding rod 153 when the wing is unfolded, so as to press the arm folding rod 153 against the rectangular frame; and the screw nut assembly is used to fix the arm lock 16 to the rectangular frame.

[0045] The arm folding rod 153 is provided with an arm mounting block 1532 near each end, and the arm mounting block 1532 is provided with an arm fixing hole group 15321, and the included angle between the connecting line of each arm fixing hole group and the side edge of the rectangular frame is 60°.

[0046] In one embodiment, the arm folding rod 153 is provided with a first pressing inclined surface 1533 at the end, the arm lock 16 includes a fixed end 161 and a pressing end 162, the pressing end is vertically connected to the fixed end, and the pressing end 162 is provided with a second pressing inclined surface 1621; when the arm lock is fixed to the rectangular frame to press the arm folding rod 153, the second pressing inclined surface 1621 and the first pressing inclined surface 1533 are matched through the inclined surfaces.

[0047] Preferably, the fixed end 161 is provided with a locking hole 1611 for the screw rod. The screw rod nut assembly is a screw rod and a hand nut. The rectangular frame is provided with a locking hole corresponding to the locking hole 1611. The locking hole is a threaded hole for screwing the screw rod. When the fixed wing needs to be folded, the hand nut is loosened, and the arm locking buckle can be removed. The arm folding rod 153 can be rotated around the hinge shaft to fold up and down. Thus, the folding can be completed without tools, and the folded unmanned aerial vehicle can be conveniently transported. When the fixed wing needs to be unfolded, the arm folding rod is unfolded, the arm locking buckle is pressed on both ends of the arm folding rod, and the hand nut is tightened to complete the unfolding.

[0048] In other embodiments, the arm folding rod 153 and the rectangular frame can be connected by a threaded connector, a quick locking buckle, or a binding method. The arm folding rod can be tightly attached to the rectangular frame to maintain the wing unfolded state or separated from the rectangular frame for folding the arm relative to the rectangular frame.

[0049] Preferably, the arm folding rod 153 is provided with a weight reduction groove 1534 extending along the length direction of the arm folding rod for reducing the weight of the arm folding rod 153, thereby avoiding increasing the weight of the unmanned aerial vehicle and ensuring the endurance time.

[0050] In this embodiment, a large-capacity cargo cabin 51 is arranged in the middle of the machine body, and the inside of the frame 50 is designed in a modular manner, which can flexibly carry different task equipment or cargo. The six-screw propeller power system has a high thrust-to-weight ratio and can load a large mass of task load, meeting the needs of medium and long distance transportation or emergency material delivery.

[0051] Please refer to Figure 7 and Figure 8 In one embodiment, the cargo cabin 51 is arranged in the frame 50 and can be controlled to rotate relative to the frame 50, so that the cargo cabin 51 always remains horizontal during the flight of the unmanned aerial vehicle, thereby avoiding the cargo cabin 51 from overturning and ensuring the smooth progress of the flight task.

[0052] In one embodiment, the cargo cabin 51 is connected to the frame 50 through a pair of rotating shafts 56 and a screw nut transmission mechanism 55. A rotatable motor seat is installed on the frame 50. The screw nut transmission mechanism 55 includes a screw motor 551, a screw rod 552, and a nut 553. The screw motor 551 is fixed to the motor seat and electrically connected to the flight control system 70 of the unmanned aerial vehicle. The screw rod 552 is connected to the output shaft of the screw motor through a component such as a shaft coupling. The nut 553 is fixed to the cargo cabin 51 and threadedly connected to the screw rod 552. When the screw motor 551 rotates, the nut 553 slides on the screw rod 552, thereby driving the cargo cabin 51 to rotate relative to the frame 50.

[0053] Please refer to Figure 9 and Figure 10 In one embodiment, the equipment cabin 52 comprises a cavity 521 and a cover 522 covering the upper end of the cavity, and the cavity 521 is divided into a first mounting cavity 524 and a second mounting cavity 523 by a partition 525 in the front-rear direction.

[0054] The flight control system 70 comprises a flight control assembly 71, an RTK receiver and a data / video transmission receiver 72, a computing power module 73, a power distribution board 74, a camera and a radar 75. The flight control assembly 71, the RTK receiver and the data / video transmission receiver 72, and the computing power module 73 are arranged from top to bottom in the second mounting cavity 523, the power distribution board 74 is electrically connected with the battery assembly and arranged in the first mounting cavity 524, and the camera and the radar 75 are mounted at the top end of the equipment cabin 52. In addition, the antenna 76 of the RTK receiver and the data / video transmission receiver is arranged on one side of the equipment cabin 52.

[0055] The flight control assembly 71 is the core controller of the whole unmanned aerial vehicle, responsible for attitude control, heading keeping, flight stabilization, etc., receiving sensor data (such as gyroscopes, accelerometers, barometers, etc.), calculating the state of the aircraft body, and then controlling the rudder, motor and other actuators according to the task instructions to keep the aircraft stable flight and complete the route planning and other tasks.

[0056] The RTK receiver is responsible for receiving high-precision differential signals from ground base stations or satellites to obtain very accurate positions.

[0057] The data / video transmission receiver comprises a data transmission receiver and a video transmission receiver. The data transmission receiver transmits flight data of the unmanned aerial vehicle, such as position, speed, power, flight mode, sensor data, etc., and can also receive task instructions sent from the ground to the unmanned aerial vehicle, such as takeoff, return, change of waypoint, etc. The video transmission receiver is used to transmit real-time video captured by the camera of the unmanned aerial vehicle to the ground.

[0058] The computing power module is the “smart brain” of the unmanned aerial vehicle, used to complete high-complexity tasks other than flight control, such as target recognition (such as recognizing people, vehicles, and ships), path planning, visual positioning, map construction (SLAM), advanced decision logic (such as obstacle avoidance and tracking), etc. Compared with the flight control assembly, the flight control assembly is mainly responsible for “flying”, and the computing power module is responsible for “intelligent decision-making”.

[0059] The power distribution board (PDB, Power Distribution Board) is the “power distribution center”. The battery outputs a whole voltage (such as 12V, 24V), and the power distribution board distributes the power to the flight control, video transmission, RTK, computing power module, motor and other devices according to the demand. In addition, the power distribution board is also responsible for voltage stabilization, protection, current and voltage detection, etc.

[0060] The camera is one of a normal RGB camera, an infrared camera, and a night vision camera, and its overall function is to collect images or videos for completing real-time picture transmission (picture transmission), completing visual recognition (target recognition such as person / car / ship), assisting positioning (visual SLAM), avoiding obstacles (visual obstacle avoidance), and precise landing (recognizing a sign).

[0061] The camera is one of a normal RGB camera, an infrared camera, and a night vision camera.

[0062] The radar transmits electromagnetic waves and receives reflected echoes for a flight system to judge a distance, thereby assisting flight safety.

[0063] The devices are electrically connected through aviation plugs, and the power distribution board and the battery assembly are electrically connected, so that the electrical signal and power connection between the devices are ensured, thereby ensuring the safety of flight.

[0064] In the embodiment, the flight control system 70 is installed at the top end of the rack 50, so that the unmanned aerial vehicle has a good field of view. The flight control assembly 71, the RTK and data transmission / picture transmission receiver 72, and the computing power module 73 are separated into two chambers with the power distribution board 74, so that the heat generated by the battery power supply does not affect the working efficiency and service life of the three modules. The three modules are stacked, which improves the space utilization of the equipment cabin 52 and is conducive to reducing the size of the equipment cabin 52.

[0065] Further, the unmanned aerial vehicle further comprises a pair of landing gears 60 for absorbing impact load during vertical take-off and landing of the unmanned aerial vehicle, and playing a role of supporting and protecting the machine body. The pair of landing gears 60 are arranged below the fuselage 10 and are respectively connected with a pair of side edges of the rectangular frame provided with the first arm 21.

[0066] Further, the unmanned aerial vehicle further comprises a portable handle 54, which is connected with the rack 50.

[0067] The working process (flight profile) of the unmanned aerial vehicle of the present application mainly includes the following six stages: 1) Vertical take-off: the unmanned aerial vehicle starts the multi-screw system 30 to provide sufficient vertical lift to realize stable vertical take-off and leave the ground obstacle area.

[0068] 2) Horizontal flight transition: the unmanned aerial vehicle rises to a preset flight height, and adjusts the attitude (increases the pitch angle) gradually during flight to increase the forward flight speed. In this stage, the lift is gradually transferred from the multi-screw to the fixed wing to realize smooth transition from hovering to horizontal flight.

[0069] 3) Conversion cruise: After the attitude adjustment is completed, enter the fixed-wing mode cruise flight, mainly rely on the serial wing to generate lift, by the propeller propulsion, carry out the medium-high speed, long range flight, the energy efficiency is higher, is applicable to the long distance material delivery task.

[0070] 4) Task execution: After approaching the target area, the unmanned aerial vehicle gradually reduces the flight height and speed, switches back to the multi-rotor mode, and realizes hovering operation above the task point. By identifying the ground two-dimensional code or other visual markers, precise positioning is completed to carry out material delivery or delivery operation.

[0071] 5) Return flight: After the task is completed, the unmanned aerial vehicle is re-raised and accelerated to the preset height and speed, switches to the fixed-wing cruise mode through attitude adjustment, and returns to the take-off area or the specified recovery point.

[0072] 6) Vertical landing: After the unmanned aerial vehicle returns to the landing area, the flight speed and height are reduced, the multi-rotor mode is switched, and finally landed smoothly to the specified landing point in a vertical manner.

[0073] The above description is only the preferred embodiment of the present application and the explanation of the applied technical principles. Those skilled in the art should understand that the scope of the application involved in the present application is not limited to the technical solutions formed by the specific combination of the above technical features, and should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above inventive concept. For example, the above features are replaced with the technical features with similar functions in the present application (but not limited to) to form a technical solution.

[0074] Although the present subject matter has been described in terms of specific structural features and / or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as illustrative forms of implementing the claims.

Claims

1. A vertical take-off and landing fixed-wing unmanned aerial vehicle, comprising a body and a propeller system, a fixed-wing system, a battery assembly and a flight control system, characterized in that the body comprises a rectangular frame, a plurality of arms uniformly arranged around the rectangular frame, a rack vertically arranged on the rectangular frame, the plurality of arms comprising first arms arranged on one pair of opposite sides of the rectangular frame and second arms arranged on another pair of opposite sides of the rectangular frame, and the rack sequentially comprises a battery compartment, a cargo compartment and an equipment compartment from bottom to top; the propeller system comprises a plurality of propellers, some of which are mounted on the ends of the first arms and the rest of which are mounted on the middle of the second arms; the fixed-wing system comprises a pair of fixed wings connected to the ends of the second arms and forming a tandem wing structure; the battery assembly is plug-in arranged in the battery compartment, and the flight control system is arranged in the equipment compartment and electrically connected with the battery assembly. The propeller comprises a motor and a propeller blade mounted on the output shaft of the motor, and the output shaft of each propeller is arranged obliquely to the vertical direction; the included angle between the output shaft and the vertical direction is between 5° and 35°. The propeller comprises a motor and a propeller blade mounted on the output shaft of the motor, and the output shaft of each propeller is arranged obliquely to the vertical direction; the included angle between the output shaft and the vertical direction is between 5° and 35°. The propeller comprises a motor and a propeller blade mounted on the output shaft of the motor, and the output shaft of each propeller is arranged obliquely to the vertical direction; the included angle between the output shaft and the vertical direction is between 5° and 35°. The propeller comprises a motor and a propeller blade mounted on the output shaft of the motor, and the output shaft of each propeller is arranged obliquely to the vertical direction; the included angle between the output shaft and the vertical direction is between 5° and 35°.

2. The VTOL fixed-wing drone of claim 1, wherein, The propeller comprises a motor and a propeller blade mounted on the output shaft of the motor, and the output shaft of each propeller is arranged obliquely to the vertical direction; the included angle between the output shaft and the vertical direction is between 5° and 35°.

3. The VTOL fixed-wing drone of claim 1, wherein, The propeller comprises a motor and a propeller blade mounted on the output shaft of the motor, and the output shaft of each propeller is arranged obliquely to the vertical direction; the included angle between the output shaft and the vertical direction is between 5° and 35°.

4. The VTOL fixed-wing drone of claim 3, wherein, The propeller comprises a motor and a propeller blade mounted on the output shaft of the motor, and the output shaft of each propeller is arranged obliquely to the vertical direction; the included angle between the output shaft and the vertical direction is between 5° and 35°.

5. The VTOL fixed-wing drone of claim 4, wherein, The propeller comprises a motor and a propeller blade mounted on the output shaft of the motor, and the output shaft of each propeller is arranged obliquely to the vertical direction; the included angle between the output shaft and the vertical direction is between 5° and 35°. The propeller comprises a motor and a propeller blade mounted on the output shaft of the motor, and the output shaft of each propeller is arranged obliquely to the vertical direction; the included angle between the output shaft and the vertical direction is between 5° and 35°. The cargo compartment is arranged in the rack and can be controlled to rotate relative to the rack to keep the cargo compartment horizontal during flight of the unmanned aerial vehicle. The cargo compartment is connected to the rack through a pair of rotating shafts and a screw nut transmission mechanism; 6. The VTOL fixed-wing drone of claim 5, wherein, The screw nut transmission mechanism comprises a screw nut motor, a screw rod and a nut, the screw nut motor is fixed to the motor mounting structure and electrically connected to the flight control system of the unmanned aerial vehicle, the screw rod is connected to the output shaft of the screw nut motor, and the nut is fixed to the cargo compartment and threadedly connected to the screw rod. The equipment compartment comprises a first mounting cavity and a second mounting cavity separated in the front-rear direction; ​ 7. The VTOL fixed-wing drone of claim 1, wherein, ​ 8. The VTOL fixed-wing drone of claim 7, wherein, ​ ​ 9. The VTOL fixed-wing drone of claim 1, wherein, ​ The flight control system comprises a flight control assembly, an RTK receiver and a data transmission / map transmission receiver, a computing power module, a power distribution board, a camera and a radar, the flight control assembly, the RTK receiver and the data transmission / map transmission receiver and the computing power module are arranged from top to bottom in the second mounting cavity, the power distribution board is electrically connected with the battery assembly and arranged in the first mounting cavity, and the camera and the radar are mounted at the top end of the equipment cabin.

10. The VTOL fixed-wing drone of claim 1, wherein, Further comprising a pair of landing gears arranged below the fuselage and respectively connected with a pair of sides of the first arm of the rectangular frame.

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