A system and method for aerial refueling of fighter aircraft munitions and fuel based on a through-the-cabin body

Abstract

This invention discloses an in-flight reloading system and method for fighter jet ammunition and fuel based on a through-type cargo bay. The system includes a transport aircraft, a fighter jet, standardized payload containers, an in-flight docking guidance system, a payload delivery system, a buffer receiving system, and an integrated control system. The fighter jet employs a through-type payload bay structure, with an upper opening on the fuselage and a lower opening on the fuselage, connected by the through-type cargo bay. The transport aircraft positions the fighter jet and delivers standardized payload containers in the air. The payload containers enter the through-type payload bay through the upper opening of the fighter jet for buffering, deceleration, and safe reception. Through standardized interfaces, the fuel payload containers refuel the fighter jet, and the ammunition payload containers refuel the fighter jet. This invention achieves, for the first time, the in-flight reloading and replenishment capability of a transport aircraft and fighter jet, significantly improving the fighter jet's combat radius and sustained combat capability.

Description

Technical Field

[0001] This invention relates to the field of aircraft in-flight resupply technology, specifically to a system and method for in-flight reloading of ammunition and fuel for fighter jets using transport aircraft, and particularly to a fighter jet design with a through-type cabin structure and its in-flight docking guidance, buffer reception, ammunition and fuel loading, ammunition release, fuel resupply, and integrated control scheme. Background Technology

[0002] In modern warfare, fighter jets, including unmanned combat aerial vehicles (UAVs), play an increasingly important role in reconnaissance and strike missions. However, fighter jets are limited by their payload capacity, with a limited amount of munitions and fuel that can be carried in a single sortie, greatly restricting their sustained combat capability. Existing solutions mainly include: (1) Aerial refueling technology: Existing mature aerial refueling solutions include probe-and-drogue and boom-and-receptacle systems, used for fuel transfer from transport aircraft to fighter jets and bombers. The aerial refueling docking guidance system mainly uses visual guidance and a boom-and-receptacle capture structure to achieve fuel transfer. This technology is only suitable for liquid fuel transfer and cannot be used for solid ammunition replenishment. Furthermore, the docking technology of this refueling method is complex and heavily dependent on pilot operation. (2) Ammunition replenishment method: Currently, fighter jets rely entirely on ground replenishment bases or aircraft carriers for ammunition replenishment. Fighters must return to the airfield or aircraft carrier for manual / mechanical reloading. This method is time-consuming, and the round trip consumes a lot of fuel, reducing combat efficiency. (3) Modular ammunition load replacement: Some advanced fighter jets support rapid replacement of ammunition load modules on the ground or on the aircraft carrier, but in essence, it is still a ground operation and cannot be carried out in the air.

[0003] The shortcomings of existing technology: (1) Lack of airborne solid ammunition resupply capability: Existing airborne resupply is limited to liquid fuel, and ammunition must return to the ground for reloading; (2) Fighter jets suffer heavy losses on round trips: returning to base or aircraft carrier to refuel or ammunition consumes a lot of fuel and time, which severely limits the combat radius and continuous combat capability; (3) Lack of an integrated ammunition-fuel joint supply scheme: In the field of ammunition and fuel, the supply of ammunition and fuel is separate and there is no unified scheme. Summary of the Invention

[0004] This invention aims to solve the following technical problems: (1) How to resupply fighter jets with ammunition or fuel while they are in flight; (2) How to achieve precise hardware guidance and docking and software system integration between transport aircraft and fighter jets; (3) How to design the structure of a fighter jet so that it can safely receive loads from above and release loads from below; (4) How to ensure the buffering and deceleration of the load and smooth reception during the aerial docking and loading process; (5) How to design a simplified process for integrated ammunition and fuel replenishment.

[0005] System Overall Architecture: A fighter jet ammunition and fuel in-flight reloading system based on a through-hole hull, comprising: Transport aircraft (mother aircraft): a transport platform carrying ammunition and fuel, equipped with an ammunition and fuel load compartment storage system, docking guidance device, load delivery device and integrated control system; Fighter jet (sub-aircraft): As a receiver of munitions and fuel and a combat platform, it adopts a through-body structure with an upper opening for receiving munitions from above and a lower opening for releasing munitions from below; Air-to-air docking guidance system: Enables precise spatial positioning and physical docking between transport aircraft and fighter jets; Payload delivery device: Drops ammunition or fuel payloads from a transport aircraft into the fighter jet bay; Buffer receiving system: Installed in the fighter jet's through-hole, it decelerates and buffers the received payload bucket for safe reception; Integrated control system: coordinates the docking sequence, flight attitude, payload delivery, and system integration of transport aircraft and fighter jets.

[0006] The through-type hull structure of fighter jets mainly includes upper openings, lower openings, and through-type payload compartments.

[0007] (1) Top opening (back hole): Located on the upper part (back) of the fighter jet fuselage, it is equipped with an openable and closable upper cabin door; The upper cargo door adopts a double-opening or sliding structure, forming a receiving window corresponding to the cargo release port of the transport aircraft when opened; The upper cabin door is equipped with a pneumatic sealing strip that restores the aerodynamic shape of the fuselage when closed. The upper opening is surrounded by docking guidance markings (optical marks or radio beacons) for the transport aircraft to position itself.

[0008] (2) Lower opening (ventral orifice): Located below the fuselage (belly) of the drone, it is equipped with an openable and closable lower cabin door; The lower hatch adopts a double-opening or sliding structure, forming a load container release window when opened; The lower and upper hatches are oriented and positioned in the same direction, forming a through passageway.

[0009] (3) Through-type load compartment: The upper and lower openings are connected by a through passage, forming a through-type load compartment; The inner wall of the payload compartment is equipped with a buffer receiving system; The cross-sectional shape of the load chamber is circular, rectangular, or polygonal, depending on the shape of the load barrel. The payload compartment can accommodate one or more payload barrels in the horizontal or vertical direction.

[0010] (4) Guidance and structural reinforcement: The load chamber is equipped with guide grooves to ensure the safe positioning of the load bucket; The load compartment is reinforced with a ring-shaped reinforcing frame and longitudinal reinforcing beams to compensate for the structural strength loss caused by the opening; The cabin door is connected to the fuselage using a hinge-locking dual mechanism to ensure reliable locking of the cabin door during flight.

[0011] The payload container is designed with standardization, and both ammunition and fuel are packaged in standardized payload containers with uniform specifications.

[0012] Ammunition containers: These are standardized cylindrical or cubical containers used to encapsulate munitions (tactical nuclear weapons, air-to-air missiles, anti-ship missiles, glide bombs, etc.), with inner and outer cushioning layers. Typical specifications: cylinder, 0.8m in diameter, 2.0m in height, total weight less than 1000kg.

[0013] Fuel Tank: Aviation fuel is sealed in a standardized pressure-resistant container with standardized interfaces. Typical specifications: cylindrical, 0.8m in diameter, 1.0m in height, and weighing less than 1000kg.

[0014] The outer wall of the load tank is equipped with guide rails that cooperate with guide grooves on the inner wall of the load chamber to ensure accurate positioning of the descent path; The load tank has a buffer contact surface on its outside, which works in conjunction with the buffer receiving system; The payload container is equipped with a data interface (contact or near-field communication) for exchanging data with the fighter jet control system after resupply is completed.

[0015] The air docking guidance system and payload delivery system are responsible for air docking guidance and payload delivery between transport aircraft and fighter jets.

[0016] (1) Relative positioning and guidance: The transport aircraft has a payload delivery port on its belly and is equipped with optical cameras, LiDAR, infrared sensors, etc. The fighter jet is equipped with docking guidance markings (reflective markings, LED arrays, etc.) and radio transponder beacons around the openings. Transport aircraft and fighter jets maintain real-time communication via data link, exchanging GPS / BeiDou position, speed, and attitude data; Centimeter-level relative positioning accuracy is achieved using differential GPS (DGPS) or real-time dynamic positioning (RTK).

[0017] (2) Flight formation control: The transport plane flew over the fighter jet, and the fighter jet adjusted its altitude and speed so that the upper opening was directly below the transport plane's drop-out port; The two aircraft maintain a relatively stationary formation flight (relative speed close to zero); The flight control system compensates for relative displacement caused by atmospheric turbulence in real time.

[0018] (3) Guidance on placement: The transport aircraft's payload delivery port is equipped with a retractable control arm that extends downwards to near the opening on the fighter jet. Alternatively, a laser / millimeter-wave guide beam can be used to indicate the delivery path of the payload bucket.

[0019] The buffer receiving system is a buffer receiving system installed inside the through-type payload bay of a fighter jet. It is used to decelerate and buffer the payload barrels dropped from the transport aircraft to prevent impact damage. It includes one or a combination of multiple implementation schemes, and each scheme is selected according to the payload type and weight for the appropriate scenario.

[0020] Option 1: Multi-stage hydraulic / pneumatic shock absorber A buffer platform consisting of multiple hydraulic cylinders or pneumatic cylinders is installed at the bottom of the through-type load compartment (above the lower hatch); Before receiving the load bucket, the buffer platform rises to a preset height. After the load bucket falls and contacts the buffer platform, the hydraulic / pneumatic cylinders compress and absorb kinetic energy in stages. A locking structure is provided at the end of the compression stroke to fix the load barrel in a preset position inside the chamber; Advantages: Mature structure, high reliability, and precise control of buffering force.

[0021] Option 2: Electromagnetic eddy current buffer An array of permanent magnets or electromagnets is installed on the inner wall of the through-type load chamber. The outer wall of the load cell is equipped with a conductive metal ring (such as a copper ring or an aluminum ring). When the load bucket falls, the conductive metal ring cuts the magnetic lines of force to generate eddy currents. The eddy currents interact with the magnetic field to generate braking force (Lenz's law), thus achieving non-contact deceleration. The buffer braking force can be dynamically adjusted by regulating the electromagnet current. Advantages: Non-contact deceleration, no mechanical wear, suitable for large mass loads.

[0022] Option 3: Elastic mesh / airbag capture buffer An deployable elastic net or airbag assembly is installed inside the through-type payload compartment. After the load tank enters, the net / airbag inflates and unfolds rapidly, wrapping around and slowing down the load tank; After deceleration is complete, the net / airbag retracts to position the load barrel; Advantages: Enveloping capture, uniform load distribution, suitable for sensitive and fragile loads.

[0023] Option 4: Friction Track Reducer The inner wall of the through-type load chamber is equipped with a friction guide rail, and the guide groove on the outer wall of the load barrel cooperates with the friction guide rail; The friction track is laid with materials of different friction coefficients (from low to high) in the vertical direction to achieve gradual deceleration; Alternatively, an adjustable friction mechanical clamping device may be used; Advantages: Simple structure, no power requirement, suitable as an auxiliary deceleration method.

[0024] Ammunition release: When a fighter jet needs to fire munitions, it flies over the target area. The integrated control system confirms the target coordinates and release conditions; When the lower hatch opens, the ammunition load cells or ammunition inside the through-type load compartment are released from below under the influence of gravity (or with the aid of an ejection mechanism); After detaching from the drone, the ammunition canister can be separated from the drone shell or used directly as a launch container, where the ammunition is ignited / detonated to carry out combat missions. After release, the lower hatch closes, restoring the aerodynamic shape.

[0025] Fuel replenishment: The fuel payload can be connected to the fighter jet's fuel system via a standardized interface when the fighter jet needs to be refueled, so that fuel can be delivered to the fighter jet's fuel system in mid-air. Fighter jets can keep their fuel canisters indefinitely for refueling, or they can open the lower hatch and discard the fuel canisters after resupply.

[0026] Integrated control system: Flight formation control module: coordinates the flight speed, altitude, heading, etc. of transport aircraft and fighter jets to maintain formation spacing; Docking guidance module: processes sensor data and generates docking guidance commands; Load management module: Manages the inventory, selection, and deployment timing of load bins; Safety control module: Ensures the safe sequence of operations such as hatch opening and closing, load transfer, and buffer reception, specifically including: the upper and lower hatches cannot be opened simultaneously; the lower hatch cannot be opened before the load bucket is fully in place and locked; the buffer reception subsystem is in a safe state during the load bucket release process, etc. Communication module: Encrypted data links between transport aircraft and fighter jets, as well as between the two aircraft and the ground command center. The communication links use military-grade encryption algorithms (such as AES-256) to encrypt data and employ frequency hopping spread spectrum (FHSS) technology to enhance anti-jamming capabilities, ensuring reliable communication in complex electromagnetic environments. Data synchronization module: After the hardware docking is completed, the transport aircraft will synchronize data such as the type and quantity of ammunition and fuel parameters of the payload bucket to the fighter's fire control, flight control and fuel system to achieve hardware alignment and software access.

[0027] To ensure the safety of aerial loading operations, the system is equipped with the following emergency response mechanisms.

[0028] (1) Handling docking interruptions: During the docking process, if a sudden atmospheric turbulence causes the relative displacement of the two machines to exceed the safety threshold (horizontal deviation > 20 cm or angular deviation > 5°), the system will automatically trigger the docking interruption procedure. The transport aircraft immediately stopped dropping the load, retracted its control arm, and the two aircraft automatically increased their vertical distance to a safe distance (≥50m). The fighter jet closes the upper cabin door (if it is already open) and resumes safe flight status; Once the turbulence conditions are eliminated, the docking process will be re-executed.

[0029] (2) Handling of load bucket deviation from the path: If the payload bucket deviates from the predetermined path during deployment (detected by in-cabin photoelectric sensors), the system will immediately trigger the following measures: The transport aircraft deployment was suspended. If the payload bucket has partially entered the through compartment but is not aligned with the guide slot, the emergency braking device inside the compartment (such as a side airbag) will be activated to prevent the payload bucket from falling further. If the payload container deviates completely from the drone, the fighter jet will automatically evade it, and the payload container will disengage from the self-destruct mechanism (if equipped) to prevent it from falling into a non-target area.

[0030] (3) System fault handling: If the buffer receiving system malfunctions during the receiving process (such as hydraulic failure), the fighter jet's flight control system automatically switches to emergency jettison mode, opens the lower hatch, releases the payload directly, and the fighter jet simultaneously climbs to avoid the risk of collision. If the communication link is interrupted, the two aircraft will automatically break away from the formation according to the preset security protocol and return to their respective alternate landing bases.

[0031] (4) Experimental verification: It is recommended to verify the aerodynamic interference characteristics during formation flight through scaled-down model wind tunnel tests before formal deployment; Optimize the formation spacing and relative position between transport aircraft and drones using computational fluid dynamics (CFD) simulation; The strength margin of the reinforced structure surrounding the through-passage compartment was verified using finite element analysis (FEA). The deceleration performance and reliability of the buffer receiving system were verified through ground simulation tests. Beneficial effects

[0032] Compared with the prior art, the present invention has the following beneficial effects: (1) First time to achieve airborne solid ammunition replenishment: It breaks through the limitation of existing technology that can only refuel in the air, enabling fighter jets to replenish ammunition without returning to base, greatly improving combat endurance; (2) The through-type cabin structure is ingeniously designed: the through-type structure makes the load receiving and releasing paths consistent, simplifies the load transfer mechanism inside the cabin, and reduces the weight of the fighter jet. (3) Integrated ammunition and fuel replenishment: The standardized load container is compatible with ammunition and fuel, and the same system can complete ammunition replenishment and fuel replenishment at the same time, with strong versatility; (4) Multiple buffer schemes ensure safety: multiple buffer schemes are provided, each corresponding to the preferred applicable scenario. They can be flexibly configured according to the load weight, speed and type to ensure the safe reception of the load. (5) Software and hardware integration: After the payload bucket is loaded, the data is automatically synchronized to the fighter jet system, realizing immediate use and reducing manual configuration steps; (6) Increased combat radius and response speed: Fighter jets do not need to return to base and can be resupplyed at the front line of the battlefield and immediately put into combat, significantly shortening the mission cycle; (7) Comprehensive emergency response capabilities: It has multiple emergency response mechanisms for docking interruption, load deviation, system failure, etc., to ensure the safety of aerial reloading operations. Attached Figure Description

[0033] Figure 1 System overall operation diagram: The transport aircraft is located above the fighter jet. The payload container enters the fighter jet's opening through the transport aircraft's release port, and reaches its position inside the payload bay via the through-type payload compartment.

[0034] Figure 2 Cross-sectional view of a fighter jet's through-type payload bay structure—showing the relative positions of the upper opening, upper door, through-type bay, buffer receiving subsystem, lower door, and lower opening.

[0035] Figure 3 Schematic diagram of standardized structure of ammunition and fuel containers – showing the external structure, guide groove, buffer contact surface, and data interface of ammunition and fuel containers.

[0036] Figure 4: Working status diagram of the buffer receiving system (hydraulic and pneumatic solution) - showing the initial position, compression position, and locking position of the buffer platform.

[0037] Figure 5 : Buffer receiving system (electromagnetic eddy current scheme) working status diagram - showing the relative positions of the permanent magnet / electromagnet array and the conductive ring of the load barrel

[0038] Figure 6 : Timeline diagram of aerial docking and payload delivery process - showing the complete timeline of transport aircraft approach, positioning, guided docking, payload delivery, and detachment.

[0039] Figure 7 Schematic diagram of ammunition load canister release process – showing the process of fighter jet lower hatch opening, ammunition load canister release, canister shell separation / ammunition launch. Specific implementation methods

[0040] Example 1: A fighter jet ammunition in-flight reloading system and method based on a through-hole hull, and an ammunition loading system based on multi-stage hydraulic buffer.

[0041] Transport aircraft configuration: Select a modified large transport aircraft (such as the Y-20) and modify the cargo hold bottom with a load release port; The inlet dimensions are 1m x 3m (length x width), and it is equipped with an electric roller shutter door. A robotic arm with an extension length of 3-5m is installed below the delivery port; An optoelectronic sensing pod (including a visible light camera, an infrared thermal imager, a laser rangefinder, etc.) is installed on the belly of the aircraft. With the installation of a differential GPS / BeiDou positioning system, the positioning accuracy is better than 10cm; Install air-to-air data link communication equipment, and adopt AES-256 encryption and FHSS frequency hopping spread spectrum anti-interference technology.

[0042] Fighter configuration: Select a modified unmanned combat aircraft (such as Attack-11) and modify a through-type payload bay in the middle of the fuselage; The upper opening measures 3m × 1.2m, and the upper hatch is a double-opening type; The lower opening measures 3m × 1.2m, and the lower hatch is a double-opening type; The through-type load compartment is 2.5m high and can hold two standard ammunition barrels (each barrel is 2.0m high and 0.8m in diameter). The inner wall of the through-type load chamber is equipped with four guide grooves (one each at the front, back, left, and right). The buffer platform uses a three-stage hydraulic buffer with a maximum buffer stroke of 2m; The upper opening edge is equipped with four LED optical beacons (such as near-infrared with a wavelength of 850nm) and one radio transponder beacon.

[0043] Loading bucket specifications: Ammunition container: cylindrical, 2.0m high, 0.8m in diameter, maximum weight 1000kg (including ammunition and container body); The outer wall of the barrel is equipped with four guide rails (which cooperate with the guide grooves inside the chamber). The outer wall of the barrel is equipped with a buffer contact structure; An auxiliary positioning device (for electromagnetic-assisted positioning detection) is installed in the middle section of the outer wall of the barrel. The top of the barrel is equipped with a contact-type data interface, which automatically connects to the data interface inside the fighter jet's cabin after loading.

[0044] The workflow will be explained step by step below.

[0045] Step 1 – Formation and Rendezvous : The ground control center sent the rendezvous point coordinates and formation parameters to the transport aircraft and fighter jets; The transport plane flew to the rendezvous point at cruising speed, while the fighter jets turned from the mission airspace to the rendezvous point. The two aircraft continuously exchange position, speed, and altitude information via an encrypted data link; The transport plane flew to the front and above the fighter jet, gradually reducing its speed to match that of the fighter jet.

[0046] Step 2 – Relative Positioning : The transport aircraft descended to a vertical distance of approximately 50 meters above the fighter jet; The transport aircraft's optoelectronic sensors lock onto the docking guidance markers on the opening of the fighter jet to obtain a precise relative position; The fighter jet adjusted its flight attitude to maintain level flight; Differential GPS / RTK systems provide centimeter-level position correction; The relative speed between the two machines is controlled within ±0.5m / s.

[0047] Step 3 – Precise Docking : The transport aircraft continued to descend to a vertical distance of approximately 10 meters above the fighter jet; The transport aircraft extends its robotic arm, and the end of the robotic arm descends to a position 2-3 meters above the opening on the fighter jet. The fighter jet fine-tunes its position based on the laser guide beam to ensure that the center line of the upper opening is aligned with the center line of the robotic arm; Alignment accuracy requirements: horizontal deviation ≤ 5cm, angular deviation ≤ 2°; If the relative displacement exceeds the safety threshold (horizontal deviation > 20 cm or angular deviation > 5°), the docking interruption procedure will be triggered.

[0048] Step 4 – Fighter jets prepare for reception : The fighter jet's upper cargo door opens, revealing an opening in the through-type payload bay; The hydraulic buffer platform rises to the receiving position (approximately 0.5m from the top opening). The in-cabin sensors (photoelectric sensor array) confirmed that the passage was clear; The fighter jet's flight control system switches to payload receiving mode—increasing the flight control response frequency and pre-compensating for impending changes in the center of gravity.

[0049] Step 5 – Payload Deployment : The transport plane moved the first ammunition canister from the cargo hold to the drop port; The delivery port roller shutter door opens, and the ammunition barrel is manipulated by a robotic arm; The ammunition canister robotic arm works in conjunction with the ammunition canister to maintain a slow descent. After the ammunition canister leaves the robotic arm, it enters the opening on the fighter jet in free fall. The guide rail of the ammunition canister engages with the guide groove on the inner wall of the through-type load compartment to ensure that the load canister falls along a predetermined path. If the load barrel deviates from the predetermined path, the emergency braking device inside the cabin will be activated.

[0050] Step 6 – Buffered Reception : As the ammunition canister falls, its bottom buffer contact structure first contacts the buffer platform. The three-stage hydraulic buffer compresses sequentially: Level 1 (Low Pressure): Buffer force ≈ 5000N, compression stroke 0.6m, absorbs initial impact; Second level (medium pressure): buffer force ≈15000N, compression stroke 0.6m, continuous deceleration; Level 3 (High Pressure): Buffer force ≈ 30000N, compression stroke 0.6m, finally stopping; Once the buffer platform reaches the bottom, the mechanical locking mechanism automatically locks and secures the ammunition barrel's position. Each filling and buffering process takes about 5-10 seconds, and the maximum deceleration that the load bucket can withstand is ≤15g.

[0051] Step 7 – System Integration : Once the ammunition canister is in place, the data interface (contact or near-field communication) on the canister body automatically connects to the data interface inside the compartment. Information about the ammunition inside the container (type, quantity, status, batch number) is transmitted to the fighter jet's fire control system via an encrypted data link; The fighter jet's fire control system updated its ammunition inventory to include newly loaded ammunition in the list of available weapons; If a fuel canister is being loaded, the standard interface of the fuel line will connect to the fighter jet's fuel system to begin fuel transfer.

[0052] Step 8 – Repeated Loading and Unloading : If a second ammunition canister needs to be loaded, repeat steps 5-7; Once loading is complete, the fighter jet's upper cargo door closes, restoring its aerodynamic shape. The transport aircraft retracted its robotic arm, closed the delivery port, and ascended to break away from the formation. Both aircraft continued to carry out their respective subsequent missions.

[0053] Step 9 – Ammunition Release : Once the fighter jet reaches the target area, the fire control system calculates the launch parameters. The lower hatch opens, and the load barrel locking mechanism is released; If gravity release is used: the ammunition canister falls from the bottom opening under the action of gravity, and the canister shell separates after detaching from the fighter jet; If ejection release is used: the ejection mechanism applies an initial velocity to ensure that the ammunition canister quickly leaves the fighter jet's aerodynamic interference zone; After the ammunition barrels detached, the lower hatch closed; The ammunition is ignited / detonated according to a preset program to carry out combat missions.

[0054] Example 2: Example 1: A fighter jet fuel in-flight reloading system and method based on a through-hull design and a fuel transfer system and method based on electromagnetic eddy current buffering. The main difference between this embodiment and Embodiment 1 is that the buffer receiving system adopts an electromagnetic eddy current buffering scheme, which is suitable for fuel load barrels with large weight.

[0055] Electromagnetic eddy current buffer configuration: A row of permanent magnets (neodymium iron boron N52 with high surface magnetic induction intensity) is installed on each of the four sides of the inner wall of the through-cabin, with the magnetic poles arranged alternately (NSNS...). Each column of permanent magnets is 2.2m long, covering the entire load drop path; A conductive copper ring (10mm thick, 50mm high) is installed in the middle section of the outer wall of the load tank. When the load bucket falls, the conductive copper ring cuts the magnetic lines of force, generating eddy current braking force. Braking force is directly proportional to falling speed: F = k·v (k is the damping coefficient); When the load barrel speed drops to about 0.5 m / s, the bottom mechanical locking mechanism captures and secures the load barrel.

[0056] Fuel tank interface and transmission design: The top of the fuel tank is equipped with a quick connector that corresponds to the interface of the fighter jet's fuel system pipeline. Once the fuel tank is in place, the quick connector automatically engages, and fuel transfer begins. Fuel transfer is carried out in one of the following ways: the fuel tank is pre-charged with inert gas (approximately 2-3 bar), and fuel flows into the fighter jet's main fuel tank through a one-way valve under pressure differential; or the fighter jet's fuel pump provides negative pressure to assist in suction, accelerating fuel transfer. During fuel transfer, a fuel leak detection sensor is installed inside the through-type load compartment. Once a leak is detected, the transfer will be stopped immediately and the pipeline valves will be closed. After fuel transfer is complete, the empty barrels can be left in the cabin as ballast, or jettisoned from the bottom opening in safe airspace to reduce the weight of the fighter jet.

Claims

1. An in-flight reloading system for fighter jet ammunition and fuel based on a through-hole compartment, characterized in that, include: The transport aircraft (1) is used to carry ammunition and fuel loads and is equipped with an aerial docking guidance device (11) and a load delivery device (12). At least one fighter jet (2), the fighter jet (2) having a through-type payload bay (20) in its fuselage, the through-type payload bay (20) comprising: An upper opening (21) is provided on the upper part of the fighter jet fuselage, equipped with an openable and closable upper cabin door (211). The lower opening (22) located under the fuselage of the fighter jet is equipped with an openable and closable lower hatch (221). The upper opening (21) and the lower opening (22) are connected by a through channel (23) to form a through load channel; The buffer receiving subsystem (3) is installed inside the through-type load chamber (20) and is used to buffer, decelerate and safely receive the load barrel (4) that enters from the upper opening (21). The load container (4) is used to encapsulate ammunition or fuel, and its shape matches the cross-sectional shape of the through-type load compartment (20); The integrated control system (5) is used to coordinate the flight formation, docking sequence, load transfer and system data integration of the transport aircraft (1) and the fighter jet (2).

2. A method for in-flight reloading of fighter jet ammunition and fuel based on a through-hole compartment, characterized in that, Includes the following steps: S1: The transport aircraft (1) and the fighter jet (2) meet in the air and form a formation flight, with the transport aircraft (1) positioned above the fighter jet (2); S2: The payload delivery port of the transport aircraft (1) is spatially aligned with the upper opening (21) of the fighter jet (2) by means of the aerial docking guidance device (11); S3: The fighter (2) opens the upper hatch (211), revealing the upper opening (21) of the through-type payload compartment (20). S4: The transport aircraft (1) drops the load barrel (4) from above through the load release device (12), and the load barrel (4) enters the through-type load compartment (20) through the upper opening (21) of the fighter (2). S5: The buffer receiving subsystem (3) buffers and decelerates the incoming load barrel (4) and safely receives it, and fixes the load barrel (4) in a preset position inside the through-type load chamber (20); S6: The integrated control system (5) synchronizes the ammunition / fuel information in the payload container (4) to the fire control system or fuel management system of the fighter (2); S7: Fighter (2) closes the upper hatch (211) and completes loading.

3. The system according to claim 1, characterized in that, The aerial docking guidance device (11) includes: The photoelectric sensor (111) installed near the load delivery port of the transport aircraft (1) includes at least one of a visible light camera, an infrared thermal imager, and a laser rangefinder; Docking guidance markings (212) installed around the opening (21) on the UAV (2), including at least one of reflective markings and an LED array; Differential satellite positioning devices (112) installed on transport aircraft (1) and drones (2) are used to provide centimeter-level relative position information.

4. The system according to claim 1, characterized in that, The load delivery device (12) includes: A telescopic control arm (121) extends downward from the delivery port of the transport aircraft (1) to the vicinity of the upper opening (21) of the fighter jet (2) when the load barrel (4) is released, guiding the load barrel (4) into the through-type load compartment (20). The inner wall of the through-type load chamber (20) is provided with a guide groove (24), and the outer wall of the load barrel (4) is provided with a guide rail (41) that cooperates with the guide groove (24) to ensure that the load barrel (4) falls along a predetermined path.

5. The system according to claim 1, characterized in that, The buffer receiving subsystem (3) is one of the following schemes or a combination thereof: A multi-stage hydraulic / pneumatic buffer includes at least two stages of hydraulic cylinders (31) and a buffer platform (32) located on top of the hydraulic cylinders. The buffer platform (32) rises to a preset height before receiving the load barrel (4). After the load barrel (4) contacts the buffer platform (32), the hydraulic cylinders compress and absorb kinetic energy step by step. It is preferably suitable for medium and light ammunition. The electromagnetic eddy current buffer includes a permanent magnet array or an electromagnet array (33) installed on the inner wall of the through-type load chamber (20) and a conductive ring (42) set on the outer wall of the load barrel (4). When the load barrel (4) falls, the conductive ring (42) cuts the magnetic lines of force to generate eddy current braking force, thereby achieving non-contact deceleration. It is preferably suitable for heavy-duty fuel barrels. The elastic net bag capture system includes an expandable elastic net bag (34) and an inflation drive device. After the load bucket (4) enters, the elastic net bag (34) inflates and expands to wrap and decelerate the load bucket (4). It is preferably suitable for irregular or fragile loads.

6. The system according to claim 1, characterized in that, The load container (4) is a standardized design. Ammunition and fuel are both packaged in a load container (4) with uniform external dimensions. The load container (4) can be a horizontally placed cylinder, a vertically placed cylinder, a cube, or other shapes. A typical specification is a horizontally placed cylinder with a diameter of 0.8m and a side height of 2m. When the load container (4) is an ammunition container, it can be filled with one or more munitions, including but not limited to tactical nuclear weapons, air-to-air missiles, anti-ship missiles, glide bombs, etc. When the load cell (4) is a fuel cell, it can be filled with liquid fuel such as aviation kerosene, solid energy such as lithium-ion batteries, etc. The load container (4) is equipped with a data interface (43) for exchanging data with the control system of the fighter jet (2) after loading is completed, so as to realize the automatic synchronization of load information.

7. The system according to claim 1, characterized in that, The cargo hold of the transport aircraft (1) is equipped with an automated storage system (13), including multi-layer racks (131) and elevators (132), for storing and managing various types of load bins (4), and automatically selecting the type and quantity of load bins (4) according to task requirements; The through-type payload compartment (20) of the fighter (2) can receive one or more payload barrels (4) in the horizontal or vertical direction. The fighter jet (2) has a ring-shaped reinforcing frame (25) and a longitudinal reinforcing beam (26) around its through-type payload compartment (20) to compensate for the structural strength loss caused by the opening; The fighter jet (2) has an ammunition ejection release structure (222) at the lower opening (22) to give the ammunition load barrel (4) an initial release velocity when the ammunition is released.

8. The system according to claim 1, characterized in that, The integrated control system (5) includes a safety control module (51), which ensures the safe timing of the following operations: The upper cabin door (211) and lower cabin door (221) of the fighter (2) cannot be opened at the same time; The lower hatch (221) shall not be opened until the load barrel (4) is fully in place and locked; During the release of ammunition load barrel (4) or ammunition, or during the refueling of fuel load barrel (4), the buffer receiving subsystem (3) is in a safe state; The transport aircraft (1) may be equipped with multiple load release ports, which can simultaneously or sequentially reload multiple fighter jets (2), while other fighter jets (2) maintain a safe distance from the transport aircraft (1) and the fighter jets (2).

9. The method according to claim 2, characterized in that, In step S2, the relative speed between the transport aircraft (1) and the fighter jet (2) is controlled within ±0.1m / s, the horizontal deviation is ≤5cm, and the angular deviation is ≤2°; in step S5, the maximum deceleration of the load bucket (4) is ≤15g, and the total buffering time is ≤2.0 seconds.

10. The method according to claim 2, characterized in that, Also includes: Step S8: After the fighter jet (2) reaches the target area, it opens the lower hatch (221). When the load barrel (4) is an ammunition load barrel, it releases the load barrel (4) or ammunition from the lower opening (22). After the load barrel (4) or ammunition leaves the fighter jet (2), it performs combat missions. Step S6 also includes: when the load tank (4) is a fuel load tank, after the fuel load tank is in place, its standardized pipeline interface is automatically connected to the fuel system of the fighter jet (2) to realize in-flight fuel reloading; Step S6 also includes: when the load container (4) is an ammunition load container, after the ammunition load container is in place, its data interface (43) automatically connects with the fighter jet ammunition system and receives combat data to realize the reloading of air ammunition; Step S2 also includes: if the relative displacement between the two machines exceeds the safety threshold (horizontal deviation > 20 cm or angular deviation > 5°) or the load bucket (4) deviates from the safety threshold, the integrated control system (5) triggers the docking interruption procedure, the two machines increase the distance to the safety distance, and dock again after the conditions are restored.

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