Modular fuselage assembly system for heavy lift multicopter drones

Abstract

The application discloses a kind of modular fuselage assembly systems for heavy load multi-rotor unmanned aerial vehicle, belong to unmanned aerial vehicle technical field, this fuselage assembly system includes top cabin, middle cabin and bottom cabin, top cabin is equipped with support assembly, support assembly is equipped with flight management computer, support assembly is connected with arm joint on support assembly, support assembly is connected with motor arm assembly through arm joint, middle cabin is installed for power supply system, middle cabin is fixedly connected with top cabin, middle cabin is equipped with suspension system, suspension system can hang goods, bottom cabin can load goods, bottom cabin is detachably connected with middle cabin, unmanned aerial vehicle is equipped with hanging state and loading state.The modular three-cabin section design of the application realizes the physical separation and modularization of functions to allow independent design, testing, maintenance and upgrading of each module, greatly improving the research and development efficiency and maintenance convenience.

Description

Technical Field

[0001] This invention belongs to the field of unmanned aerial vehicle (UAV) technology, and particularly relates to a modular fuselage assembly system for heavy-duty multi-rotor UAVs. Background Technology

[0002] In recent years, with the rapid development of drone technology, multi-rotor drones have shown great potential in heavy-duty application scenarios such as logistics transportation, emergency rescue, and industrial hoisting due to their advantages such as vertical take-off and landing, hovering, and maneuverability. However, traditional heavy-duty multi-rotor drones usually have many limitations in their design, making it difficult to fully meet the complex and ever-changing mission requirements.

[0003] First, traditional airframe structures are mostly unibody or fixed designs, offering high functional integration but poor flexibility. This design limits drones to a single cargo delivery method: either belly loading or external sling loading, making it difficult to quickly switch between methods based on mission requirements (such as cargo shape, delivery method, and aerodynamic requirements). For example, external sling loading is more advantageous for missions requiring precise airdrops, while internal loading is more suitable for long-distance flights requiring good aerodynamic shape. The inability of a single drone to operate in both modes restricts its mission adaptability and operational efficiency.

[0004] Secondly, in terms of structure, conventional designs often fix the boom joint directly to the relatively thin fuselage skin or simple internal frame. This structure is difficult to effectively cope with heavy-load flight, especially the huge bending moment, torsional load and vibration generated during maneuvering. The stress concentration phenomenon is significant, and metal fatigue or structural deformation is likely to occur at the connection. There are inherent risks of low connection reliability and short structural life. In severe cases, it may cause the boom to fall off and cause flight accidents.

[0005] Therefore, there is an urgent need to design a modular airframe assembly system for heavy-duty multi-rotor UAVs to solve the problems mentioned above. Summary of the Invention

[0006] The purpose of this invention is to provide a modular airframe assembly system for heavy-duty multi-rotor unmanned aerial vehicles (UAVs), which has the advantages of providing extremely high structural strength and rigidity, and the ability to switch mission modes, thus solving the problems mentioned in the background art.

[0007] To achieve the above objectives, the specific technical solution of the modular fuselage assembly system for heavy-duty multi-rotor unmanned aerial vehicles of the present invention is as follows: A modular fuselage assembly system for a heavy-duty multi-rotor unmanned aerial vehicle (UAV) includes a top cabin, a middle cabin, and a bottom cabin. The top cabin houses a support assembly containing a flight management computer. The support assembly is connected to an arm joint, which is connected to a motor arm assembly. The middle cabin houses the power supply system and is fixedly connected to the top cabin. The middle cabin is equipped with a sling system for slinging cargo. The bottom cabin can load cargo, and the bottom cabin and middle cabin are detachably connected. The UAV has both a sling-mounted and a loaded configuration. When the drone is in a suspended state, the bottom cabin is separated from the middle cabin, and the suspension system can suspend cargo. When the drone is loaded, the bottom cabin is connected to the middle cabin, and cargo can be loaded in the bottom cabin.

[0008] Furthermore, the support assembly includes a top bulkhead, a flight management computer located within the top bulkhead, a reinforcing member within the top bulkhead, and an arm joint fixedly connected to the top bulkhead; The top frame is octagonal and includes four straight sections and four inclined sections. Both ends of each straight section are connected to the adjacent inclined sections, and both ends of each inclined section are connected to the adjacent straight sections. The support arm joint is connected to the inclined sections.

[0009] Furthermore, the reinforcing member includes a first reinforcing part and a second reinforcing part, both of which are fixedly connected within the top partition frame. The first reinforcing part is fixedly connected to the second reinforcing part. The first reinforcing part is arranged longitudinally along the top partition frame, and its shape is the same as the longitudinal cross-section of the top partition frame. The second reinforcing part is arranged transversely along the top partition frame, and its shape is the same as the transverse cross-section of the top partition frame.

[0010] Furthermore, an emergency power supply is installed in the top cabin. In the event of a power system failure, the emergency power supply will provide power to the flight management computer to provide power for the drone to make an emergency landing.

[0011] Furthermore, the top nacelle is equipped with a nose hatch, a flight control maintenance hatch, and a first equipment hatch, which allow the top nacelle to be opened and closed.

[0012] Furthermore, the central cabin contains a fuselage frame that supports the central cabin. The fuselage frame is connected to the bottom of the central cabin, and the sling system is fixedly connected to the fuselage frame. A floor is provided on the fuselage frame, and the power system is located on the floor.

[0013] Furthermore, the power system includes two sets of batteries and a slide rail. The two sets of batteries are connected in parallel to provide power. When one set of batteries fails, the other set of batteries continues to power the flight management computer to provide power for the drone's emergency landing. The batteries are equipped with feet, which allow them to slide along the slide rail for easy installation and removal. It also includes a high-voltage control box and a fuse box. The battery powers the high-voltage control box, which is electrically connected to the flight management computer. The battery can also replenish the emergency power supply through the high-voltage control box.

[0014] Furthermore, two equipment ports are provided on the side of the central nacelle for installing and removing batteries, and also form a maintenance passage for entering the central nacelle. Air intake grilles are installed on the equipment ports, and the two air intake grilles are arranged opposite each other to ventilate and dissipate heat from the power system. The air intake grilles can open and close the central nacelle. The middle engine compartment is equipped with a second equipment port cover and an opening cover at the bottom, which can open and close the middle engine compartment.

[0015] Furthermore, the bottom cabin includes fairing skins, which have wave-transmitting requirements and are specifically designed as a fiberglass foam sandwich structure. The fairing skins form a cargo storage area between them.

[0016] Furthermore, it also includes the cabin skin, which has a partition inside to divide the cabin skin into the top cabin and the middle cabin.

[0017] The present invention has the following advantages: the modular three-section design of the fuselage assembly system realizes the physical separation and modularization of functions. The top cabin focuses on flight control, the middle cabin focuses on energy supply, and the bottom cabin focuses on mission payload. This design allows each module to be designed, tested, maintained and upgraded independently, which greatly improves R&D efficiency and maintenance convenience. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the heavy-duty multi-rotor UAV of the present invention; Figure 2 This is a structural schematic diagram of the top and middle cabins of the present invention; Figure 3 This is a schematic diagram of the bottom cabin structure of the present invention; Figure 4 This is a schematic diagram of the structure of the cabin skin of the present invention; Figure 5 This is a schematic diagram of the structure of the first equipment cover, flight control maintenance cover, nose cover and air intake grille of the present invention; Figure 6 This is a schematic diagram of the structure of the second device cover and the opening cover of the present invention; Figure 7This is a schematic diagram of the structure of the connecting skin of the present invention; Figure 8 This is a schematic diagram of the hanging system of the present invention; Figure 9 This is a schematic diagram of the structure inside the top cabin of the present invention; Figure 10 This is a schematic diagram of the top partition and reinforcing member of the present invention; Figure 11 This is a structural schematic diagram of the fuselage frame, partition, and top partition of the present invention; Figure 12 This is a schematic diagram of the structure inside the central cabin of the present invention; Figure 13 This is a schematic diagram of the longitudinal beam and landing gear assembly of the present invention; Figure 14 This is a schematic diagram of the support arm assembly of the present invention; Figure 15 This is a schematic diagram of the structure of the support arm, connecting joint, and motor mounting base of the present invention; Figure 16 This is an exploded structural diagram of the support arm and fixing component of the present invention; Figure 17 This is a schematic diagram of the structure of the fastener of the present invention; Explanation of markings in the diagram: 1. Fuselage assembly; 11. Top cabin; 111. Top bulkhead; 1111. Straight section; 1112. Sloping section; 112. Reinforcing member; 1121. First reinforcing section; 1122. Second reinforcing section; 113. Boom joint; 114. Emergency power supply; 115. Airborne data link; 116. Flight management computer; 117. Whole-aircraft pylon joint; 12. Mid-cabin; 121. Fuselage frame; 1211. Longitudinal beam; 1212. Mid-cabin; 122. Floor; 124. High-voltage control box; 125. Fuse box; 126. Slide rail; 127. Battery; 128. Pylon system; 13. Bottom cabin; 14. Bulkhead; 1 5. Nacelle Skin; 151. Left Skin; 152. Right Skin; 153. Nose Skin; 154. First Equipment Access Cover; 155. Flight Control Maintenance Access Cover; 156. Nose Access Cover; 157. Second Equipment Access Cover; 158. Exit Cover; 159. Air Intake Grille; 16. Connecting Skin; 2. Motor Support Arm Assembly; 21. Support Arm Component; 22. Connecting Joint; 23. Motor Mounting Mount; 24. Mounting Slot; 25. Electronic Controller; 26. Fixing Component; 261. Fixing Bracket; 2611. Fixing Part; 2612. Extension Part; 262. Reinforcing Frame; 263. Electronic Controller Mounting Port; 27. Motor; 28. Twin-bladed Propeller; 29. ​​Support Arm Access Cover; 3. Landing Gear Assembly. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of the invention and form different embodiments. For example, in the claims, any of the claimed embodiments can be used in any combination.

[0021] The following is a reference to the appendix. Figure 1 To be continued Figure 17 This invention describes a modular airframe assembly system for a heavy-duty multi-rotor unmanned aerial vehicle.

[0022] The heavy-duty multi-rotor UAV includes fuselage assembly 1, motor arm assembly 2, and landing gear assembly 3.

[0023] Currently, most existing heavy-load multi-rotor UAVs adopt an integrated or fixed structure, which rigidly binds the transportation method (belly loading or external slinging) to the fuselage. The above-mentioned structural design cannot be flexibly and quickly switched according to specific mission requirements (such as airdrop accuracy and flight aerodynamics), which seriously limits the application scenarios and operational efficiency of UAVs. Moreover, the existing support arm joint 113 is usually simply connected to a thin skin or simple frame, which is difficult to effectively distribute the complex stress and vibration generated by heavy-load maneuvering flight.

[0024] Therefore, the fuselage assembly system includes a cabin skin 15, which has a partition 14 inside. The partition 14 divides the cabin skin 15 into a top cabin 11 and a middle cabin 12. The cabin skin 15 covers the top cabin 11 and the middle cabin 12. The cabin skin 15 includes a left skin 151 and a right skin 152. The left skin 151 and the right skin 152 are separated by the fuselage symmetry plane. The left skin 151 is designed with a depression, and the right skin 152 rests on the depression of the left skin 151. The two are then fixed by a glued connection.

[0025] By using a recessed lap joint and adhesive riveting connection process for the left skin 151 and right skin 152, not only is the flatness of the skin joint ensured, which is beneficial to the aerodynamic shape, but the combination of the advantages of adhesive bonding and riveting also significantly improves the overall sealing, structural rigidity and connection reliability of the fuselage.

[0026] The fuselage assembly system also includes a bottom cabin 13, a top cabin 11, a middle cabin 12 and a bottom cabin 13 arranged sequentially from the top to the bottom of the UAV.

[0027] The modular three-section design of the fuselage assembly system realizes the physical separation and modularization of functions. The top cabin focuses on flight control, the middle cabin focuses on energy supply, and the bottom cabin focuses on mission payload. This design allows each module to be designed, tested, maintained and upgraded independently, which greatly improves R&D efficiency and maintenance convenience.

[0028] The top cabin 11 is equipped with a support assembly, which contains a flight management computer 116. The support assembly is connected to a boom joint 113, and the support assembly is connected to the motor boom assembly 2 through the boom joint 113.

[0029] The support assembly includes a top frame 111, which serves as the equipment installation space. The flight management computer 116 is located within the top frame 111. A reinforcing member 112 is provided within the top frame 111. An arm joint 113 is fixedly connected to the top frame 111. Specifically, the top frame 111 is octagonal and includes four straight sections 1111 and four inclined sections 1112. Both ends of each straight section 1111 are connected to the adjacent inclined section 1112, and both ends of each inclined section 1112 are connected to the adjacent straight section 1111. The arm joint 113 is connected to the inclined section 1112.

[0030] By designing the top frame 111 as an octagon, a robust load-bearing core is formed. Its geometry can efficiently convert the loads from the support arms from multiple directions into compressive and tensile stresses within the frame, avoiding stress concentration and providing excellent bending and torsional stiffness. At the same time, the support arm joint 113 is directly fixed to the inclined section 1112 of the top frame 111, rather than to the skin, so that the huge load from the motor support arm assembly 2 is directly transferred to the strongest core structure of the fuselage. The force flow path is clear and efficient, completely avoiding local instability and fatigue problems caused by connection to the thin skin, and significantly improving safety and lifespan.

[0031] Specifically, the bottom end of the top bulkhead 111 is fixedly connected to the bottom surface of the top cabin 11, that is, the bottom end of the top bulkhead 111 is fixedly connected to the bulkhead 14, and the top end of the top bulkhead 111 is fixedly connected to the top surface of the top cabin 11.

[0032] The reinforcing member 112 includes a first reinforcing part 1121 and a second reinforcing part 1122. Both the first reinforcing part 1121 and the second reinforcing part 1122 are fixedly connected inside the top partition 111. The first reinforcing part 1121 is arranged longitudinally along the top partition 111, and the shape of the first reinforcing part 1121 is the same as the shape of the longitudinal section of the top partition 111. The second reinforcing part 1122 is arranged transversely along the top partition 111, and the shape of the second reinforcing part 1122 is the same as the shape of the transverse section of the top partition 111. The first reinforcing part 1121 and the second reinforcing part 1122 form a three-dimensional, grid-like reinforcing structure, which divides the internal space of the top partition 111 into multiple stable areas, greatly enhancing the stability of the top partition 111 in the longitudinal and transverse directions, preventing it from deforming due to huge loads, and providing an extremely stable and vibration-resistant installation environment for the flight management computer 116.

[0033] There are eight outrigger connectors 113. The eight outrigger connectors 113 are divided into four groups according to the motor outrigger. Each group consists of two adjacent outrigger connectors 113. The four groups of outrigger connectors 113 are symmetrical to each other. The motor outrigger is connected to the fuselage using a fork-ear connection structure. The outrigger connector 113 is designed as a double-ear connector. The bottom surface of the outrigger connector 113 is fixedly connected to the partition plate 14. The top surface of the outrigger connector 113 is fixedly connected to the nacelle skin 15. The side of the outrigger connector 113 is fixedly connected to the inclined section 1112 of the top partition frame 111. An aluminum plate is provided between each group of outrigger connectors 113 for fixing the arm cable separation socket.

[0034] The outrigger joint 113 is fixed to the bulkhead 14, the nacelle skin 15, and the top bulkhead 111 on three sides, forming a multi-path load transfer, which further enhances the reliability and stability of the connection. Furthermore, the modularization and standardization of cable management through the use of aluminum plates avoids mutual interference or wear of cables during vibration, improves system reliability, and facilitates installation and maintenance.

[0035] A connecting skin 16 is provided at the connection between the motor arm assembly 2 and the arm joint 113. The connecting skin 16 has a flanged structure at both the arm end and the fuselage end, which is used to connect with the arm skin and the fuselage skin respectively. It is arranged symmetrically on the left and right, with a total of four groups. Each fairing skin is divided into upper and lower parts, both of which are carbon fiber laminate structures and are detachable to cover the connection between the motor arm assembly 2 and the arm joint 113. The connecting skin 16 not only ensures excellent aerodynamic shape and reduces flight drag, but also facilitates the maintenance of the internal connection structure. The flanged design and the connection with the skin ensure the firmness and smoothness of the fairing itself.

[0036] Each set of boom joints 113 is fixedly connected to a whole-machine lifting joint 117. The whole-machine lifting joint 117 extends beyond the cabin skin 15 and can be connected to the hook of the crane through the whole-machine lifting joint 117, so that the UAV can be lifted and transported. The lifting joint is integrated into the set of boom joints 113, which cleverly utilizes the strongest structure of the fuselage to bear the load when the entire UAV is lifted.

[0037] The front end of the top nacelle 11 is provided with a nose skin 153. The lower end of the nose skin 153 is connected to the corresponding recessed area on the nacelle skin 15. The upper end of the nose skin 153 is connected to the motor support arm and the top bulkhead 111 respectively. Specifically, the fuselage skin is a carbon fiber laminate structure with a recess and an opening in the middle. A nose hatch 156 is connected to the opening of the nose skin 153. The nose hatch 156 can open and close the top nacelle 11.

[0038] The top cabin 11 is equipped with a flight control maintenance cover 155 and a first equipment cover 154. The flight control maintenance cover 155 and the first equipment cover 154 open and close the top cabin 11. The first equipment cover 154 is located at the tail end of the top cabin 11, and the flight control maintenance cover 155 is located directly above the top bulkhead 111 inside the top cabin 11. Through the modular design of the nose cover 156, the flight control maintenance cover 155, and the first equipment cover 154, it is very convenient to access and maintain key equipment such as the flight management computer 116, the airborne data link 115, and the emergency power supply 114 without extensive disassembly of the fuselage.

[0039] The top cabin 11 is equipped with an emergency power supply 114 and an airborne data link 115. In the event of a power system failure, the emergency power supply 114 supplies power to the flight management computer 116 to provide power for the UAV to make an emergency landing. The airborne data link 115 transmits UAV flight control commands, mission payload commands, and link control commands in real time through an antenna. Specifically, the emergency power supply 114, the airborne data link 115, and the flight management computer 116 are all fixedly connected to the partition 14.

[0040] A top antenna is also provided above the top nacelle 11, which is fixed above the joint between the left skin 151 and the right skin 152 of the top nacelle 11.

[0041] The power supply system is installed in the middle cabin 12. The middle cabin 12 is fixedly connected to the top cabin 11. The middle cabin 12 is equipped with a hoisting system 128, which can hoist cargo. Specifically, the middle cabin 12 is equipped with a fuselage frame 121, which supports the middle cabin 12. The fuselage frame 121 is connected to the bottom of the middle cabin 12. The hoisting system 128 is fixedly connected to the fuselage frame 121. The fuselage frame 121 is equipped with a floor 122, and the power supply system is located on the floor 122.

[0042] The fuselage frame 121 includes longitudinal beams 1211 and a central bulkhead 1212. There are two longitudinal beams 1211, which are located at both ends of the central cabin 12. The bottom ends of the two longitudinal beams 1211 are fixedly connected to the bottom surface of the central cabin 12. The two longitudinal beams 1211 are also fixedly connected to the central bulkhead 1212. There are three central bulkheads 1212. The side ends of the central bulkheads 1212 are fixedly connected to the side walls of the central cabin 12, and the top ends of the central bulkheads 1212 are fixedly connected to the top surface of the central cabin 12. That is, the top ends of the central bulkheads 1212 are fixedly connected to the bulkhead 14. In other embodiments of the present invention, the number of central bulkheads 1212 may also be other, as long as they can support the central cabin 12.

[0043] The hanging system 128 is fixedly connected to the central partition 1212. Specifically, the hanging system 128 is fixedly connected to the central partition 1212 in the middle position. In other embodiments of the present invention, the hanging system 128 may also be connected to the central partition 1212 in other positions besides the middle position.

[0044] The fuselage frame 121 provides a strong load-bearing foundation for the central cabin 12, which effectively distributes the load of the suspended cargo, the weight of the battery 127, and the impact force of the landing gear to the entire fuselage structure, avoiding local overload.

[0045] The fuselage frame 121 is fixedly connected to the top bulkhead 111 via the bulkhead 14. Thus, when the UAV is in flight, the huge lift generated by the motor and various loads during maneuvering are first transferred to the top bulkhead 111 through the boom joints 113. The bulkhead 14 acts as a crucial "force transfer station" or "structural bridge". The bulkhead 14 then evenly distributes the load to the entire fuselage frame 121 connected to it. In this way, the huge force that was originally concentrated on a few boom joints 113 is transferred and distributed to the robust frame of the entire central cabin 12.

[0046] Specifically, the floor 122 is installed on two longitudinal beams 1211. The floor 122 is also designed with a downward-facing flange structure around its perimeter. It is fixed to the left skin 151 and right skin 152 of the fuselage by adhesive riveting. The planar area of ​​the floor 122 is fixed to the longitudinal beams 1211 and the central partition 1212 by adhesive riveting.

[0047] The power system includes two sets of batteries 127 and a slide rail 126. The two sets of batteries 127 are connected in parallel to provide power. When one set of batteries 127 fails, the other set of batteries 127 continues to provide power to enable the drone to make an emergency landing. The batteries 127 are equipped with feet, which allow them to slide along the slide rail 126 for easy installation and removal. Specifically, the feet are made of polytetrafluoroethylene (PTFE) to reduce the friction between the batteries 127 and the slide rail 126. A PTFE abrasion-resistant plate is fixedly connected to the floor 122 to prevent wear and tear on the composite floor 122 when the batteries 127 are installed or removed.

[0048] The power system also includes a high-voltage control box 124 and a fuse box 125. A battery 127 supplies power to the high-voltage control box 124. The high-voltage control box 124 is electrically connected to the flight management computer 116. The battery 127 can supplement the emergency power supply 114 with power through the high-voltage control box 124. The emergency power supply 114 is activated when the high-voltage control box 124 and the fuse box 125 fail.

[0049] Two equipment ports are provided on the central engine compartment 12, forming a maintenance passage for entering the central engine compartment 12 to install and remove the battery 127. Air intake grilles 159 are installed on the equipment ports. The two air intake grilles 159 are arranged opposite each other to ventilate and dissipate heat from the power system. The air intake grilles 159 can open and close the central engine compartment 12. The equipment ports and air intake grilles 159 on both sides serve as natural ventilation ducts to effectively dissipate heat from the battery 127 system, which generates a lot of heat, and also form a convenient maintenance passage, making it easy for personnel to enter the compartment for operation and maintenance.

[0050] The middle cabin 12 is provided with a second equipment access cover 157 and an opening cover 158 at the bottom. The second equipment access cover 157 and the opening cover 158 can open and close the middle cabin 12. The landing gear assembly 3 can be installed or removed from the fuselage frame 121 by entering through the opening cover 158 from the bottom of the middle cabin 12.

[0051] The bottom cabin 13 can be loaded with cargo. The bottom cabin 13 and the middle cabin 12 are detachably connected. The drone has a hoisting state and a loading state. When the drone is in the hoisting state, the bottom cabin 13 is separated from the middle cabin 12, and the hoisting system 128 can hoist cargo. When the drone is in the loading state, the bottom cabin 13 is connected to the middle cabin 12, and cargo can be loaded in the bottom cabin 13.

[0052] The detachable connection of the bottom cabin 13 enables the drone to quickly and flexibly switch between two modes: sling-mounted and loaded. This solves the core pain point of the traditional drone's single transport mode, allowing it to perfectly adapt to different mission requirements, such as internal cargo transport requiring low-drag long-distance flight and external sling-mounted operations requiring precise airdrop, significantly expanding application scenarios and mission efficiency.

[0053] The bottom cabin 13 includes a fairing skin, which has wave-transmitting requirements and is specifically a fiberglass foam sandwich structure. The fairing skin forms a placement area for placing cargo. Preferably, when the UAV is in a loaded state, the bottom cabin 13 is screwed to the middle cabin 12. In other embodiments of the present invention, the bottom cabin 13 and the middle cabin 12 can also be connected by other detachable connection methods.

[0054] The motor support arm assembly 2 includes four support arm components 21, which are symmetrically arranged. Each support arm component 21 is fixedly connected to a connecting joint 22, which can be connected to a support arm connector 113 to connect the motor support arm assembly 2 to the body assembly 1. Specifically, the connecting joint 22 is a single-ear connector. When the connecting joint 22 is connected to the support arm connector 113, the connecting joint 22 is inserted into the gap of the double-ear connector of the support arm connector 113, and the through hole on the connecting joint 22 coincides with the through hole on the support arm connector 113. Then, the connecting joint 22 and the support arm connector 113 are fixed by bolts passing through the coincident through holes.

[0055] The connection between the motor support arm assembly 2 and the body assembly 1 adopts a fork-ear connection with a single-ear joint and a double-ear joint, and is fixed by high-strength bolts. This allows it to perfectly withstand the combined loads of tension, compression, and shear generated by the motor thrust, gravity, and motor inertia. Compared with a simple flange connection, the fork-ear connection can better disperse stress, avoid stress concentration, and significantly improve fatigue life.

[0056] Specifically, the support arm 21 has an installation groove 24, and the fixing member 26 is limited in the support arm 21 by the installation groove 24.

[0057] The end of the support arm 21 away from the connecting joint 22 is connected to a motor mounting base 23. The electric propulsion system is installed on the motor mounting base 23. The electric propulsion system is the core power source of this heavy-duty multi-rotor UAV, providing the thrust required for hovering and flight. Specifically, the motor mounting base 23 has a support arm mounting interface, into which the support arm 21 can be inserted. The motor mounting base 23 has an electric propulsion mounting interface, into which the electric propulsion system can be installed.

[0058] The boom member 21 is provided with a mounting slot 24 for mounting an electronic speed controller 25. The electronic speed controller 25 receives speed commands from the flight management computer 116 and drives the electric propulsion system through a vector control algorithm to ensure the operation of the electric propulsion system. Specifically, each boom member 21 has two mounting slots 24, and the two mounting slots 24 are located on the same straight line to utilize the oncoming airflow during flight to form a chimney effect and achieve efficient heat dissipation.

[0059] The support arm 21 includes two support arm skins. The two support arm skins are joined together to form the support arm 21. The mounting groove 24 is opened on the two support arm skins. A maintenance opening is opened on either support arm skin. A support arm cover 29 is provided on the maintenance opening. The support arm cover 29 can open and close the maintenance opening to facilitate the maintenance of the power regulator 25.

[0060] By setting up maintenance openings, maintenance personnel do not need to disassemble the entire support arm. They can directly access the power regulator 25 by simply opening the support arm cover 29 to perform operations such as inspection, replacement, or plugging and unplugging cables, thus greatly increasing maintenance efficiency.

[0061] A fixing member 26 is provided in the mounting slot 24 of the boom 21 to facilitate the fixed installation of the ESC 25 and to enhance the structural environment of the mounting slot 24. The fixing member 26 includes a fixing bracket 261 and a reinforcing frame 262. The fixing bracket 261 has an ESC mounting port 263 adapted to the ESC 25. Both ends of the fixing bracket 261 are fixedly connected to the reinforcing frame 262. The reinforcing frame 262 is arranged longitudinally along the boom 21, and the shape of the reinforcing frame 262 is the same as the shape of the longitudinal section of the boom 21. The reinforcing frame 262 provides support for the installation of the ESC 25 and significantly improves the overall bending and torsional stiffness of the boom. When the heavy-load UAV is maneuvering, the root of the boom is subjected to huge stress. The reinforcing frame 262 can effectively prevent the boom from deforming and ensure aerodynamic efficiency and flight stability.

[0062] The fixed bracket 261 includes a fixed part 2611 and an extension part 2612. The fixed part 2611 and the extension part 2612 are fixedly connected. The ESC mounting port 263 is opened in the fixed part 2611 and the extension part 2612. The fixed part 2611 is larger than the mounting groove 24. The extension part 2612 is adapted to the mounting groove 24. When the extension part 2612 extends beyond the mounting groove 24, the extension part 2612 is flush with the outer wall of the support arm 21. At this time, the ESC 25 also does not protrude beyond the support arm 21, so as to facilitate heat dissipation and reduce wind resistance.

[0063] The electric propulsion system includes eight motors 27 and eight double-bladed propellers 28. Every two motors 27 and every two double-bladed propellers 28 form a group. Each group of motors 27 and double-bladed propellers 28 is connected to the support arm 21. Each motor 27 drives its corresponding double-bladed propeller 28.

[0064] The landing gear assembly 3 is fixedly connected to the fuselage frame 121. Specifically, the landing gear assembly 3 includes a landing gear crossbeam, which is fixedly connected to the longitudinal beam 1211 of the fuselage frame 121. Both ends of the landing gear crossbeam are fixedly connected to connecting joints 22. The landing gear crossbeam is connected to the landing gear bracket through the connecting joints 22. The landing gear bracket and the landing gear crossbeam are detachable.

[0065] Preferably, a limiting flange is added to the inner side of the docking between the landing gear crossbeam and the longitudinal beam 1211 of the fuselage frame 121 to control the landing gear crossbeam from shifting.

[0066] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A modular fuselage assembly system for a heavy-load multi-rotor unmanned aerial vehicle, characterized in that, It includes a top cabin, a middle cabin, and a bottom cabin. The top cabin contains a support assembly, which houses a flight management computer. The support assembly is connected to an arm connector, which is connected to the motor arm assembly. The middle cabin is for the installation of the power supply system and is fixedly connected to the top cabin. The middle cabin is equipped with a hoisting system that can hoist cargo. The bottom cabin can be loaded with cargo and is detachably connected to the middle cabin. The UAV has both a hoisting state and a loading state. When the drone is in a suspended state, the bottom cabin is separated from the middle cabin, and the suspension system can suspend cargo. When the drone is loaded, the bottom cabin is connected to the middle cabin, and cargo can be loaded in the bottom cabin; The support assembly includes a top bulkhead, a flight management computer located inside the top bulkhead, a reinforcing member inside the top bulkhead, and an arm joint fixedly connected to the top bulkhead. The top frame is octagonal and includes four straight sections and four inclined sections. Both ends of each straight section are connected to the adjacent inclined sections, and both ends of each inclined section are connected to the adjacent straight sections. The support arm joint is connected to the inclined sections. The reinforcing member includes a first reinforcing part and a second reinforcing part, both of which are fixedly connected inside the top partition frame. The first reinforcing part is fixedly connected to the second reinforcing part. The first reinforcing part is arranged longitudinally along the top partition frame, and the shape of the first reinforcing part is the same as the shape of the longitudinal section of the top partition frame. The second reinforcing part is arranged transversely along the top partition frame, and the shape of the second reinforcing part is the same as the shape of the transverse section of the top partition frame.

2. The modular fuselage assembly system for heavy-duty multi-rotor unmanned aerial vehicles according to claim 1, characterized in that, An emergency power supply is installed in the top cabin. In the event of a power system failure, the emergency power supply will provide power to the flight management computer to provide power for the drone to make an emergency landing.

3. The modular fuselage assembly system for heavy-load multi-rotor unmanned aerial vehicles according to claim 1, characterized in that, The top nacelle is equipped with a nose hatch, a flight control maintenance hatch, and a first equipment hatch, which allow the top nacelle to be opened and closed.

4. The modular fuselage assembly system for heavy-duty multi-rotor unmanned aerial vehicles according to claim 1, characterized in that, The fuselage frame is located inside the mid-section of the cabin, which supports the mid-section of the cabin. The landing gear assembly is connected to the fuselage frame, which is connected to the bottom of the mid-section of the cabin. The pylon system is fixedly connected to the fuselage frame, and the floor is located on the fuselage frame. The power system is located on the floor.

5. The modular fuselage assembly system for heavy-duty multi-rotor unmanned aerial vehicles according to claim 4, characterized in that, The power system includes two sets of batteries and a slide rail. The two sets of batteries are connected in parallel to provide power. When one set of batteries fails, the other set of batteries continuously supplies power to the flight management computer to provide power for the drone's emergency landing. The batteries are equipped with feet, which allow them to slide along the slide rail for easy installation and removal. It also includes a high-voltage control box and a fuse box. The battery powers the high-voltage control box, which is electrically connected to the flight management computer. The battery can also replenish the emergency power supply through the high-voltage control box.

6. The modular fuselage assembly system for a heavy-load multi-rotor unmanned aerial vehicle according to claim 4, characterized in that, Two equipment ports are provided on the side of the central nacelle, forming a maintenance passage for entering the central nacelle to install and remove batteries. Air intake grilles are installed on the equipment ports, and the two air intake grilles are arranged opposite each other to ventilate and dissipate heat from the power system. The air intake grilles can open and close the central nacelle. The middle cabin is equipped with a second equipment access cover and a lifting cover at the bottom. The second equipment access cover and the lifting cover can open and close the middle cabin. By entering the middle cabin through the lifting cover, the landing gear assembly can be installed or removed from the fuselage frame.

7. The modular fuselage assembly system for heavy-duty multi-rotor unmanned aerial vehicles according to claim 1, characterized in that, The bottom cabin includes fairing skins, which have wave-transmitting requirements and are specifically made of fiberglass foam sandwich structures. The fairing skins form a cargo storage area between them.

8. The modular fuselage assembly system for heavy-duty multi-rotor unmanned aerial vehicles according to claim 1, characterized in that... It also includes the cabin skin, which has a partition that divides the cabin skin into the top cabin and the middle cabin.

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