A cross-domain vehicle integrating a catamaran and a rotor-wing unmanned aerial vehicle and a navigation method
By integrating catamaran and rotary-wing UAV into a cross-domain vehicle design, the problems of dynamic instability and low energy efficiency during medium transitions in cross-medium vehicles have been solved, achieving highly adaptable and efficient marine operation capabilities.
Patent Information
- Application Number
- CN202610566731.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-04-27
- Publication Date
- 2026-06-23
AI Technical Summary
Existing cross-medium unmanned vehicles suffer from problems such as dynamic instability, low energy efficiency, and insufficient environmental adaptability during media switching, making it difficult to meet the high-frequency operation requirements of marine environmental monitoring and resource exploration.
The design of the cross-domain vehicle is a fusion of catamaran and rotary-wing UAV, including a foldable rotor system, a composite propulsion module, a hybrid energy system and an adaptive control algorithm. Stable switching is achieved through a fluid-rigid body coupled dynamics model, and the energy transmission path is optimized by combining telescopic structure and center of gravity adjustment.
It has achieved attitude stabilization control of cross-medium vehicles in autonomous switching between water and air amphibious operations, improving the efficiency of marine reconnaissance and resource exploration, and enhancing positioning accuracy and equipment safety in complex environments.
Smart Images
Figure CN122254102A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of cross-domain vehicle technology, specifically relating to a cross-domain vehicle and navigation method that integrates a catamaran and a rotary-wing unmanned aerial vehicle. Background Technology
[0002] As core equipment for air-sea collaborative operations, cross-medium unmanned aerial vehicles (UAVs) have irreplaceable application value in fields such as marine environmental monitoring and resource exploration. However, existing technologies generally suffer from three major bottlenecks: instability during medium switching, low energy efficiency, and insufficient environmental adaptability, which severely restrict their engineering applications.
[0003] In the medium transition phase, traditional cross-medium platforms face dynamic control challenges. When an aircraft enters water from the air, fixed rotors experience sudden high-density fluid impact, leading to severe vibrations and even structural damage, resulting in a high mission interruption rate. Simultaneously, rigid rotors generate significant eddy current drag underwater, significantly reducing propulsion efficiency and endurance. While existing detachable rotor solutions can alleviate underwater drag, the separation mechanism suffers from sluggish response and insufficient reliability, failing to meet the demands of high-frequency medium switching, such as rapid tactical reconnaissance.
[0004] Existing propulsion systems for cross-domain vehicles are ill-suited to the characteristics of multi-domain operations. Vertical takeoff and landing in the air require instantaneous high power output, while underwater cruising relies on continuous low-power operation. The current single-energy architecture cannot reconcile the conflict between power density and energy efficiency. Experimental data shows that the underwater endurance of conventional lithium battery power systems is less than 30% of that in aerial flight mode, severely limiting the ability to monitor large areas of the ocean. More seriously, the dynamic sealing structure of traditional propulsion systems is prone to failure under salt spray corrosion and alternating pressure differentials, leading to frequent water ingress failures in the motors and severely impacting the reliability of deep-sea operations.
[0005] Currently, the multi-domain coordination capability of the control system is weak. Main rotor anti-torque compensation mainly relies on the tail rotor mechanism, but during takeoff and landing at sea, the tail rotor is susceptible to lateral wave interference, potentially causing platform capsizing. While existing vector propulsion schemes improve wave resistance, thrust loss exceeds 20% due to airflow / water flow interference. Furthermore, conventional ducted propulsion systems are prone to cavitation effects during low-speed maneuvers, and turbulence interference reduces steering efficiency by more than 40%, making it difficult to meet the precision operation requirements of complex nearshore waters.
[0006] Current structural design faces a conflict between lightweighting and pressure resistance. To meet the pressure resistance requirement at a water depth of 5 meters, monohull platforms often need to thicken the hull, sacrificing load-bearing space and limiting the capacity to carry mission equipment. While existing modular designs improve maintenance convenience, the spliced sealing structure is prone to leakage under long-term alternating loads, failing to guarantee the safety of precision equipment such as underwater sensors.
[0007] Current maritime strategies place higher demands on cross-medium platforms. Resource exploration urgently needs to improve operational efficiency in complex nearshore terrain and achieve centimeter-level positioning accuracy in strong winds and waves. Environmental monitoring missions require platforms to achieve coordinated observation in both water and air domains during emergencies such as red tides and oil spills. Existing technologies are insufficient to meet these strategic needs, necessitating the development of new cross-medium vehicles to address core bottlenecks. Summary of the Invention
[0008] The purpose of this invention is to provide a cross-domain vehicle and navigation method that integrates a catamaran and a rotary-wing unmanned aerial vehicle, enabling autonomous switching between amphibious and airborne operations and attitude stabilization control, providing a multi-functional and highly efficient operating platform for fields such as marine exploration, emergency rescue, and cross-domain logistics.
[0009] The objective of this invention is achieved through the following technical solution:
[0010] A cross-domain vehicle integrating a catamaran and a rotary-wing unmanned aerial vehicle includes: a catamaran main body, a composite propulsion module, and a semi-submersible floating body structure. The catamaran main body is equipped with an underwater propulsion device, and the catamaran main body is connected to the semi-submersible floating body structure. The central body of the semi-submersible floating body structure is equipped with a flight control computer, a rotary engine, a hybrid energy system, an inertial measurement unit, and a pressure sensor.
[0011] The semi-submersible structure is equipped with a foldable rotor system on top. The foldable rotor system is connected to the rotor engine and retracts and fits tightly against the fuselage of the vehicle during the water entry or underwater phase to reduce fluid resistance.
[0012] The composite propulsion module includes a front anti-torsion ducted propeller and a tail pitch ducted propeller mounted on the semi-submersible structure. The front anti-torsion ducted propeller is mounted at the bow of the vehicle to resist the horizontal torque generated by the operation of the foldable rotor system. The tail pitch ducted propeller is vertically mounted at the tail of the vehicle and lifts the rear side during operation, so that the lift direction of the foldable rotor system forms an angle of attack with the vertical direction, causing the vehicle to move forward.
[0013] Furthermore, the semi-submersible floating structure includes a central body, which is connected to a central bridge, and the central bridge is connected to the catamaran hull via a transverse connecting beam.
[0014] Furthermore, the catamaran hull includes two sealed forward compartments and two power rear compartments. The sealed forward compartments integrate an array of environmental sensing sensors, and the power rear compartments are equipped with the underwater propulsion unit. The underwater propulsion unit includes a brushless motor and a battery pack. The two brushless motors drive the tail ducted propellers through magnetic coupling shafts.
[0015] Furthermore, the catamaran hull includes a nested sleeve connected to a telescopic shaft, which is connected to a linear motor. The axial hull length is adjusted by driving the linear motor.
[0016] Furthermore, the telescopic shaft is embedded with a counterweight slider module, whose position change works in conjunction with the telescopic movement of the central bridge to jointly regulate the center of gravity distribution of the aircraft.
[0017] Furthermore, the catamaran hull is constructed using a lightweight composite material with honeycomb topology optimization.
[0018] Furthermore, the catamaran has a symmetrical structure, which reduces the water surface contact area to improve seakeeping and provides flow guidance and drag reduction performance.
[0019] Furthermore, a pressure sensor array is installed at the bottom of the catamaran hull. The vehicle is based on a fluid-rigid body coupled dynamics model and constructs a state prediction algorithm for the gas-liquid interface motion. When the pressure sensor array detects an interface transition signal, the flight control computer synchronously triggers the forward anti-torsion ducted propeller and the tail pitch ducted propeller to suppress roll and switches the propulsion energy distribution strategy. The underwater thruster dynamically adjusts the control surface deflection parameters by solving the fluid density gradient in real time through the flight control computer.
[0020] Furthermore, the foldable rotor system includes a rotor hub connected to the rotor via a servo folding mechanism, and the rotor tip is equipped with a counterweight to suppress water entry vibration.
[0021] The present invention also includes:
[0022] A navigation method for a cross-domain vehicle integrating the above-mentioned catamaran and rotary-wing UAV, the method comprising the following steps:
[0023] When the aircraft performs a surface navigation mission, the flight control computer first checks whether the blades of the foldable rotor system are fully retracted into the hub and the anti-vibration position is locked by the wingtip counterweight. After confirming safety, the brushless motor in the rear power compartment is started, which drives the tail ducted propeller to rotate through the magnetic coupling drive shaft, thereby propelling the catamaran hull forward through the water. At this time, the multibeam sonar in the environmental perception sensor array in the sealed forward compartment continuously scans the underwater terrain ahead, and the inertial measurement unit in the central body monitors the hull attitude in real time.
[0024] During the cruise propulsion phase, the flight control computer automatically adjusts the speed difference of the tail ducted propeller according to the preset route: when a right turn is required, the output torque of the left tail ducted propeller is increased, and when a left turn is required, the power of the right tail ducted propeller is increased. At the same time, the air pressure sensor inside the central fuselage detects the sealing status of the compartment to prevent external water from seeping into the equipment area. When encountering side wave impacts during navigation, the counterweight effectively suppresses roll resonance.
[0025] The beneficial effects of this invention are as follows:
[0026] This invention breaks through the bottleneck of dynamic instability during medium switching, improves hovering stability, and reduces underwater propulsion drag, providing a highly adaptable platform for marine reconnaissance, resource exploration, and ecological monitoring. The telescopic-center-of-gravity coordinated adjustment mechanism enables the vehicle to achieve new modes of fish-dive entry and climb-climb exit. During medium switching, the timing coordination of telescopic buffering and center-of-gravity migration effectively mitigates fluid impact loads, solving the long-standing technical bottleneck of dynamic stability of cross-medium platforms in water entry and exit. It not only expands the vehicle's all-domain operation capability in narrow waterways and open seas, but also establishes an adaptive variable configuration technical paradigm for cross-medium vehicles through the ternary fusion of structure-control-action. Attached Figure Description
[0027] Appendix Figure 1 This is a schematic diagram of the structure of the present invention;
[0028] Appendix Figure 2 This is the front view of the present invention;
[0029] Appendix Figure 3 For the appendix Figure 2 The left view;
[0030] Appendix Figure 4 This is a cross-sectional view of the present invention;
[0031] Appendix Figure 5 For the appendix Figure 2 Top view:
[0032] Appendix Figure 6 This is a cross-sectional view of the main body of the catamaran in this invention;
[0033] Appendix Figure 7 This is a diagram showing the folded rotor state of the foldable rotor system in this invention.
[0034] In the attached image:
[0035] 1. Catamaran hull; 1-1. Sealed forward compartment; 1-2. Aft power compartment; 2. Transverse connecting beam; 3. Stern ducted propeller; 4. Central bridge; 5. Central fuselage; 6. Foldable rotor system; 6-1. Propeller hub; 6-2. Counterweight; 7. Flight control computer; 8. Rotor engine; 9. Forward anti-torsion ducted propeller; 10. Stern pitch ducted propeller; 11. Underwater propulsion; 12. Brushless motor; 13. Waterproof baffle; 14. Telescopic shaft; 15. Linear motor; 16. Semi-submersible structure. Detailed Implementation
[0036] The present invention will now be further described with reference to the accompanying drawings.
[0037] A cross-domain vehicle integrating a catamaran and a rotary-wing unmanned aerial vehicle, as shown in the attached document. Figures 1-5 As shown, it includes: a catamaran hull 1, a semi-submersible floating structure 16, a composite propulsion module, and a foldable rotor system 6;
[0038] The catamaran hull 1 is equipped with an underwater thruster 11. The catamaran hull 1 is connected to a semi-submersible floating structure 16. The semi-submersible floating structure 16 relies on the buoyancy structure to compensate for pitch and roll during the water surface and medium switching phase, suppressing attitude disturbances caused by sudden changes in buoyancy or wave interference.
[0039] The composite propulsion module integrates air propulsion and underwater propulsion, and can switch propulsion modes during medium conversion to optimize the energy transmission path;
[0040] The catamaran hull 1 has a symmetrical structure with a hemispherical bow, which reduces the water surface contact area to improve wave resistance and provides installation space for power equipment and detection equipment.
[0041] The foldable rotor system 6 can be folded up and close to the fuselage during the water entry or underwater phase, reducing fluid resistance.
[0042] The catamaran hull 1 has a telescopic structure, which changes the position of the center of buoyancy and center of gravity by changing the length of the hull, making it easier for the vehicle to maintain stability when entering and leaving the water.
[0043] The central fuselage 5 of the semi-submersible structure 16 is equipped with a flight control computer 7, a rotor engine, a hybrid energy system, an inertial measurement unit, and a pressure sensor; the catamaran hull 1 and the semi-submersible structure 16 are deeply coupled to form a water-air cross-medium dynamic stability control framework.
[0044] The bottom of the central body 5 is connected to the central bridge 4 via a quick-release bracket, and the top integrates the foldable rotor system 6.
[0045] The hybrid energy system uses a lithium battery and a supercapacitor connected in parallel, and the flight control computer 7 automatically switches the power supply mode.
[0046] The semi-submersible floating structure 16 is equipped with a foldable rotor system 6 on its top. The foldable rotor system 6 is connected to the rotor engine and folds up tightly against the fuselage of the vehicle during the water entry or underwater phase to reduce fluid resistance.
[0047] The composite propulsion module includes a front anti-torsion ducted propeller 9 and a tail pitch ducted propeller 10 mounted on the semi-submersible structure 16. The front anti-torsion ducted propeller 9 is mounted at the bow of the vehicle to resist the horizontal torque generated by the operation of the foldable rotor system 6. The tail pitch ducted propeller 10 is vertically mounted at the tail of the vehicle and lifts the rear side during operation, so that the lift direction of the foldable rotor system 6 forms an angle of attack with the vertical direction, causing the vehicle to move forward.
[0048] The foldable rotor system can reduce the contact area by more than 70% after being folded up during the water entry / underwater phase. The foldable rotor system 6 and the central cylindrical structure are connected to the flight control computer 7 via cables, providing vertical lift and attitude adjustment capabilities in air mode.
[0049] In-flight mode: The foldable rotor system 6 unfolds to provide lift, the front anti-torsion ducted rotor 9 counteracts the anti-torque, and the tail pitch ducted rotor 10 controls the pitch.
[0050] Water entry transition: Open the rotor folding mechanism and adjust the center of gravity to balance the fluid impact;
[0051] Underwater mode: Two tail-mounted ducted propellers with 3-speed differential steering.
[0052] In this embodiment, the catamaran hull 1 includes a sealed forward compartment 1-1 and a power rear compartment 1-2. The sealed forward compartment 1-1 integrates an environmental sensing sensor array, and the power rear compartment 1-2 is equipped with an underwater thruster 11. The underwater thruster includes a brushless motor 12 and a battery pack. The two brushless motors 12 drive the tail ducted propeller 3 through magnetic coupling shafts.
[0053] As attached Figure 6 As shown, the catamaran hull 1 includes a nested sleeve, which is connected to a telescopic shaft 14. The telescopic shaft 14 is connected to a linear motor 15, and the axial hull length is adjusted by driving the linear motor.
[0054] The telescopic shaft 14 has an embedded counterweight slider module, whose position change works in conjunction with the telescopic movement of the bridge frame to jointly regulate the center of gravity distribution of the aircraft.
[0055] Furthermore, the main body 1 of the catamaran is made of lightweight composite material with honeycomb topology optimization and is integrally formed by 3D printing process. It includes an overall telescopic structure and can achieve forward and backward tilting movements by adjusting the center of gravity to adapt to different underwater environments.
[0056] In this embodiment, the semi-submersible floating structure 16 includes a central body 5, which is connected to a central bridge 4. The central bridge 4 is connected to the catamaran body 1 via a transverse connecting beam 2.
[0057] The foldable rotor system 6 includes a rotor hub 6-1, which is connected to the rotor via a servo folding mechanism. The rotor tip is equipped with a counterweight 6-2 to suppress water entry vibration. Preferably, the diameter of the rotor blade is 1.2m.
[0058] The bottom of the catamaran hull 1 is equipped with a pressure sensor array. When the pressure sensor array detects an interface transition signal, the system synchronously triggers the front anti-torsion ducted propeller 9 and the tail pitch ducted propeller 10 to suppress rolling and switch the propulsion energy distribution strategy. Meanwhile, the tail ducted propeller 3 calculates the fluid density gradient in real time through the flight control computer and dynamically adjusts the control surface deflection parameters.
[0059] In this embodiment, the central body 5 is fixed by a self-locking quick-release mechanism, and the modular separation of the rotor system from the hull significantly improves the battlefield rapid repair capability.
[0060] At the structural implementation level, the transverse connecting beam 2 has a pre-installed equipment channel inside. Its two ends are sealed to the catamaran hull 1 using a stepped labyrinth seal structure, with the contact surface filled with fluorosilicone-based elastic sealant to form a pressure-adaptive barrier. A conical guide groove and redundant mechanical lock are installed at the joint between the upper end and the central fuselage 5, while a high-damping shock-absorbing layer is embedded in the lower end's connection node with the transverse connecting beam 2. This design ensures that the vehicle effectively absorbs wave impact energy in sea state 4, while the quick-release mechanism allows rotor system replacement to be completed within fifteen minutes under field conditions. In particular, all wiring channels employ a nitrogen-filled sealed sleeve design, with double O-rings at both ends of the sleeve to completely block salt spray penetration paths.
[0061] The implementation of the medium switching mechanism must strictly follow the multi-system collaborative logic. When performing the water exit operation, the underwater thruster 11 first increases its output power to accelerate the hull to a gliding state; when the pressure sensor detects that the water depth has dropped to a predetermined threshold, the servo mechanism drives the rotor 6 to unfold its blades according to a sinusoidal optimized trajectory; at the same time, the front anti-torsion ducted propeller 9 starts pre-rotation to balance the anti-torque of the main rotor; finally, the tail pitch ducted propeller 10 sprays downward to generate a pitching moment, assisting the vehicle to leave the water surface at the optimal hydrodynamic angle of attack. The water entry process executes the reverse sequence: at a specific height above the water surface, the center of gravity control system moves the counterweight forward; the foldable rotor system 6 folds and retracts according to a hydrodynamic optimized path; at the moment of water entry, the tail duct rudder surface deflects to generate an anti-dive moment; the underwater thruster 11 simultaneously takes over the heading control.
[0062] The main frame of the aircraft is manufactured in one piece using 3D printing technology. The overall skeleton, including the catamaran structure, connecting trusses and rotor drone mounting base, is integrally formed using additive manufacturing process. ABS printing material is used, which significantly reduces costs and speeds up the molding process while ensuring high strength, making it easy to mass-produce. The internal structure adopts a honeycomb topology optimization design, which significantly reduces the overall weight of the aircraft while meeting mechanical strength requirements, thereby improving its maneuverability and energy efficiency.
[0063] This embodiment also provides a navigation method for a cross-domain vehicle that integrates a catamaran and a rotary-wing unmanned aerial vehicle, the method comprising the following steps:
[0064] When the vehicle performs a surface navigation mission, the flight control computer 7 first checks whether the blades of the foldable rotor system 6 are fully retracted into the rotor hub 6-1 and the anti-vibration position is locked by the wingtip counterweight 6-2. After confirming safety, the brushless motor 12 in the rear power compartment 1-2 is started, which drives the tail ducted propeller 3 to rotate through the magnetic coupling drive shaft, thereby propelling the catamaran hull 1 to break through the water and move forward. At this time, the multi-beam sonar in the environmental perception sensor array in the sealed front compartment 1-1 continuously scans the underwater terrain ahead, and the inertial measurement unit in the central fuselage 5 monitors the hull attitude in real time.
[0065] During the cruise propulsion phase, the flight control computer 7 automatically adjusts the speed difference of the tail ducted propeller 3 according to the preset route: when a right turn is required, the output torque of the left propeller is increased, and when a left turn is required, the power of the right propeller is increased. At the same time, the air pressure sensor inside the central fuselage 5 detects the sealing status of the cabin to prevent external water from seeping into the equipment area. When encountering side wave impacts during navigation, the counterweight 6-2 effectively suppresses roll resonance.
[0066] The energy management system is coordinated by the flight computer 7. The battery packs in the rear power nacelles 1-2 maintain the basic cruise power, and only provide auxiliary power during acceleration or countercurrent conditions. In particular, the guide surfaces of the tail pitch ducted propeller 10 remain in a neutral position in this mode to reduce water resistance; the front anti-torsion ducted propeller 9 enters a dormant state to reduce energy consumption.
[0067] The emergency response process includes a two-level response:
[0068] When the gyroscope detects that the roll angle exceeds the critical threshold, the flight control computer 7 immediately activates the differential compensation of the tail ducted propeller 3; if the hull 1 continues to tilt, the active balancing mode of the counterweight 6-2 is triggered, and the center of gravity position is moved by the internal slider. All operational data is transmitted to the control terminal in real time through the fiber optic bus in the central bridge 4.
[0069] Standardized procedures must be followed during the berthing and maintenance phase:
[0070] After shutting down the drive system of the rear power nacelle 1-2, the flight control computer 7 checks the shutdown status of the tail ducted propeller 3; then, it activates the drainage pump in the sealed forward nacelle 1-1 to remove residual water; finally, it checks the salt crystal deposition on the folding mechanism of the rotor hub 6-1. This process ensures that the aircraft is always operational. In-flight operation begins with rotor system activation: when the aircraft performs an in-flight mission, the flight control computer 7 first initiates a self-test program to verify the status of each system. After confirming normal operation, the rotor engine 8 in the central fuselage 5 drives the foldable rotor system 6 to deploy its blades. The servo mechanism in the rotor hub 6-1 locks its working position according to a preset trajectory, and the wingtip counterweight 6-2 is simultaneously activated to suppress aerodynamic flutter. At the same time, the flight computer 7 sends commands to the hybrid energy system, prioritizing power supply from the lithium battery pack to meet instantaneous power demands. The foldable rotor system 6 gradually increases its rotation speed to the cruise range, generating vertical lift to overcome the total weight of the catamaran hull 1.
[0071] During the vertical climb phase, the forward anti-torsion ducted propeller 9 starts synchronously, and its guide vanes automatically adjust the angle of attack based on the main rotor torque value calculated by the flight control computer 7, thus counteracting the anti-torsion torque in real time. The tail pitch ducted propeller 10 controls the downward jet intensity by adjusting the speed of the brushless motor, enabling the tail of the aircraft to obtain precise lift. At this time, the catamaran hull 1 forms a continuous pitch angle of attack of 5°-8°, converting part of the rotor lift into forward thrust. In particular, the airflow sensor in the sealed forward compartment 1-1 collects airspeed data in real time, and the flight control computer 7 dynamically optimizes the rotor pitch angle based on this data.
[0072] After transitioning to level flight cruise, the truss structure composed of the transverse connecting beam 2 and the central bridge 4 bears the aerodynamic loads, and the damping layer inside the central bridge 4 effectively absorbs turbulent vibrations. When encountering crosswind disturbances, the vector control surfaces built into the tail pitch ducted propeller 10 automatically deflect, generating a counter-compensating torque to maintain heading. During this phase, the rear power nacelles 1-2 switch to energy-saving mode, with the fuel cell maintaining basic power supply. The flight control computer 7 continuously monitors the energy distribution status to ensure that the power ratio between the rotor engine 8 and the front anti-torsion ducted propeller 9 is always within the high-efficiency range.
[0073] Implement a staged deceleration strategy during the landing preparation phase:
[0074] At a specific distance from the target point, the tail pitch ducted propeller 10 reduces the jet intensity to gradually level the hull; the rotational speed of the folding rotor system 6 decreases linearly; and the torque compensation of the front anti-torsion ducted propeller 9 is reduced synchronously. All actions are coordinated by the flight control computer 7 through a closed-loop control algorithm to ensure a smooth attitude transition. Finally, when the altitude sensor detects a predetermined value, the landing procedure is triggered to prepare for the medium transition. The coordinated control during takeoff requires precise timing: first, the underwater thruster 11 outputs full power to establish a stable heading reference; second, the rotational speed of the main rotor 6 is gradually increased to the critical lift value; simultaneously, the tail pitch ducted propeller 10 increases the jet intensity to induce a pitching moment; when the pressure sensor confirms the lift-off signal, the flight control computer 7 immediately switches the control law parameter set and shuts down the underwater propulsion system.
[0075] The air-to-water landing phase of the operation is carried out in steps:
[0076] At a height of 20 meters above the target water area, the multi-beam sonar scanning system is activated to analyze wave spectrum characteristics and trough locations in real time. The vertical descent rate is dynamically adjusted according to the wave height cycle to achieve synchronous contact between the vehicle and the wave trough. At a height of 3 meters above the water surface, the rotor speed 6 decreases according to an exponential decay curve to buffer the impact energy. Upon contact with the water, the underwater thruster 11 immediately takes over heading control and initiates low-speed propulsion mode. The mode switching process must strictly adhere to three categories of specifications: Regarding environmental conditions, medium switching is strictly prohibited when wave height exceeds 1.5 meters or wind speed exceeds 12 m / s; Regarding equipment status, the flight control computer 7 must self-check the sealed chamber pressure value, rotor folding mechanism positioning accuracy, and energy system redundancy before each switch; Regarding maintenance procedures, the folding mechanism slide rails must be replenished with special anti-corrosion grease every fifty hours. When the system detects any abnormal parameters, a three-level alarm mechanism will be triggered, including audible and visual prompts, control authority downgrading, and automatic lock switching functions.
[0077] This invention innovatively integrates a retractable bridge system into the existing catamaran structure. This mechanism consists of a main frame made of nested sleeves, with axial length adjustment achieved via a linear motor. A counterweight slider module is embedded within the telescopic shaft; its positional change coordinates with the bridge's extension and retraction to jointly regulate the vehicle's center of gravity distribution. During underwater exploration missions, the control system instructs the bridge to extend to its maximum stroke, simultaneously moving the counterweight slider forward to tilt the hull forward, facilitating the scanning of complex seabed topography by the exploration equipment in the sealed forward compartment. Under high-speed navigation conditions, the bridge retracts to its mid-stroke section, and the counterweight slider moves backward to induce a backward tilt, significantly reducing the wetted surface area and thus lowering fluid resistance. In particular, the multi-degree-of-freedom design of the articulated supports allows the hull to adaptively adjust its pitch angle during extension and retraction, enabling the vehicle to flexibly respond to swell interference and underwater obstacle avoidance requirements.
[0078] The movement control of the telescopic shaft is achieved by the flight control computer through multi-source information fusion decision-making. The mission planning module generates initial telescopic commands based on preset navigation modes, such as selecting a medium stroke to maintain hull balance when entering and exiting water vertically, and activating the minimum retraction state when maneuvering in narrow waterways. The environmental perception unit provides key data support in real time: the water depth sensor triggers the bridge retraction protection mechanism when it detects shallow water risks; the attitude sensor automatically extends the bridge to enhance the recovery torque when it detects abnormal rolling; and the water flow sensor activates the streamlined optimized retraction mode after identifying strong countercurrent environments. The control process is equipped with multi-level safety protection mechanisms, including dynamic limiting of telescopic rate, immediate locking of mechanical overload, and automatic reset function in emergency situations, to ensure the reliability of the system under extreme conditions.
[0079] The entry and exit methods have been significantly expanded due to the telescopic structure. During a dive-type entry, the bridge extends to its longest possible stroke, and the counterweight slider moves forward, causing the hull to tilt forward. The main rotor reduces its speed to accelerate the dive under gravity. At the moment the bow cuts into the water first, the telescopic shaft retracts at a controlled rate to absorb impact energy. After entry, the counterweight slider moves backward to level the hull, and the underwater propulsion system simultaneously takes over propulsion. The climb-type exit uses the reverse process: the bridge extends in conjunction with the counterweight retraction to create a backward tilt; the underwater propulsion system outputs full power to gain upward kinetic energy; as the stern breaks out of the water first, the telescopic shaft retracts in coordination to reduce rotational inertia; after exiting the water, the main rotor immediately deploys to enter flight mode. These two modes significantly improve the vehicle's ability to switch media in complex sea conditions.
[0080] This telescopic system brings multiple technical benefits to the vehicle: the variable bridge length allows the vehicle to adapt to diverse operating environments, from narrow waterways to open seas; the pitch adjustment function supports differentiated mission attitudes such as detection scanning and high-speed cruise; and the optimized water entry and exit modes reduce energy consumption and improve operational reliability. During manufacturing, special lubrication treatment is applied to the moving parts of the telescopic mechanism, and a reinforced anti-corrosion coating is applied to the surface of the hinged supports to ensure durability during long-term underwater operation.
[0081] Coordinated control method during takeoff: To ensure a smooth takeoff and transition from water to air, this invention innovatively introduces a dual-propeller propulsion and quadcopter coordinated control mechanism. During the initial takeoff phase, the stern propeller of the catamaran operates at full power, continuously outputting horizontal thrust to effectively resist lateral drift caused by water flow disturbances and precisely maintain the initial heading stability of the vehicle. Simultaneously, the four UAV rotors start synchronously, and the flight control computer dynamically and precisely adjusts the rotational speed of each rotor based on real-time sensor feedback, gradually increasing lift output. When the lift is sufficient to overcome the vehicle's own weight, the vehicle smoothly leaves the water and ascends into the air. Subsequently, the flight control computer further optimizes the rotor speed distribution to ensure stable climbing in the air until the predetermined flight altitude and attitude are reached, completing a perfect transition from water to air.
[0082] Precautions during mode switching:
[0083] During the switching between surface navigation mode and air flight mode, the continuity and stability of energy supply are crucial. Before the switch, the aircraft control system will conduct a comprehensive test of the energy management system to accurately assess whether the remaining power is sufficient for the mode switch and subsequent mission execution. During the switch, the control system monitors the energy consumption and supply status of each key device in real time, automatically performs equipment status detection, parameter optimization and adjustment, and fault diagnosis and early warning to ensure a smooth, safe, and stable switch process, and avoid the loss of control of the aircraft or other unexpected situations due to abnormal energy supply or equipment failure.
[0084] Routine maintenance and upkeep:
[0085] To ensure the long-term stable operation and performance of the aircraft, the following maintenance and upkeep work must be carried out regularly:
[0086] A comprehensive inspection of the catamaran hull was conducted, with a focus on hull sealing to prevent moisture leakage into the engine room and affecting the operation of electrical equipment. The structural strength of the connecting beams was tested to promptly identify and repair any potential structural fatigue damage or loose connections. The engines and propellers underwent performance testing and cleaning and maintenance to ensure stable power output and high propulsion efficiency.
[0087] Perform meticulous maintenance on the rotorcraft UAV system, regularly inspect the rotor blades for wear, deformation, cracks, etc., and replace damaged rotors in a timely manner; test motor performance indicators, including speed stability, torque output, insulation resistance, etc., to ensure reliable motor operation; perform software updates, system calibration, and operational status monitoring on the flight control computer to ensure that its control accuracy and response speed meet mission requirements.
[0088] Conduct in-depth inspections and maintenance of the energy management system, test key parameters such as the charge and discharge performance, capacity retention rate, and self-discharge rate of the lithium battery pack, and replace aging or degraded battery cells in a timely manner; check the connection reliability and insulation of the charging circuit and power distribution line to prevent electrical faults from causing safety hazards, and ensure that the energy supply system provides stable, efficient, and safe power support for all components of the aircraft.
[0089] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A cross-domain vehicle integrating a catamaran and a rotary-wing unmanned aerial vehicle, characterized in that, include: The catamaran main body (1), composite propulsion module, and semi-submersible floating body structure (16) are equipped with an underwater thruster (11) on the catamaran main body (1). The catamaran main body (1) is connected to the semi-submersible floating body structure (16). The central body (5) of the semi-submersible floating body structure (16) is equipped with a flight control computer (7), a rotor engine (8), a hybrid energy system, an inertial measurement unit, and a pressure sensor. The semi-submersible floating structure (16) is equipped with a foldable rotor system (6) on top. The foldable rotor system (6) is connected to the rotor engine and retracts and fits tightly against the fuselage of the aircraft during the water entry or underwater phase to reduce fluid resistance. The composite propulsion module includes a front anti-torsion ducted propeller (9) and a tail pitch ducted propeller (10) installed on the semi-submersible structure (16). The front anti-torsion ducted propeller (9) is installed at the bow of the vehicle to resist the horizontal torque generated by the operation of the foldable rotor system (6). The tail pitch ducted propeller (10) is installed vertically at the tail of the vehicle and lifts the rear side during operation, so that the lift direction of the foldable rotor system (6) forms an angle of attack with the vertical direction, causing the vehicle to move forward.
2. The cross-domain vehicle integrating a catamaran and a rotary-wing unmanned aerial vehicle according to claim 1, characterized in that, The semi-submersible floating structure (16) includes a central body (5), which is connected to a central bridge (4), and the central bridge (4) is connected to the catamaran body (1) via a transverse connecting beam (2).
3. The cross-domain vehicle integrating a catamaran and a rotary-wing unmanned aerial vehicle according to claim 1, characterized in that, The catamaran hull (1) includes two sealed forward chambers (1-1) and two power rear chambers (1-2). The sealed forward chambers (1-1) are equipped with an array of environmental sensing sensors. The power rear chambers (1-2) are equipped with underwater thrusters (11). The underwater thrusters (11) include brushless motors (12) and battery packs. The two brushless motors (12) drive the tail ducted propellers (3) through magnetic coupling shafts.
4. The cross-domain vehicle integrating a catamaran and a rotary-wing unmanned aerial vehicle according to claim 3, characterized in that, The catamaran body (1) includes a nested sleeve, which is connected to a telescopic shaft (14). The telescopic shaft (14) is connected to a linear motor (15), and the axial hull length is adjusted by driving the linear motor.
5. The cross-domain vehicle integrating a catamaran and a rotary-wing unmanned aerial vehicle according to claim 4, characterized in that, The telescopic shaft (14) has an embedded counterweight slider module. Its position change works in conjunction with the telescopic movement of the central bridge (4) to jointly regulate the center of gravity distribution of the aircraft.
6. The cross-domain vehicle integrating a catamaran and a rotary-wing unmanned aerial vehicle according to claim 3 or 4, characterized in that, The main body (1) of the catamaran is made of lightweight composite material with honeycomb topology optimization.
7. The cross-domain vehicle integrating a catamaran and a rotary-wing unmanned aerial vehicle according to claim 6, characterized in that, The catamaran hull (1) has a symmetrical structure, which reduces the water surface contact area to improve wave resistance and has the function of guiding flow and reducing drag.
8. The cross-domain vehicle integrating a catamaran and a rotary-wing unmanned aerial vehicle according to claim 1, characterized in that, The catamaran hull (1) is equipped with a pressure sensor array at its bottom. The vehicle is based on a fluid-rigid body coupled dynamics model and constructs a state prediction algorithm for the gas-liquid interface motion. When the pressure sensor array detects the interface transition signal, the flight control computer (7) synchronously triggers the front anti-torsion ducted propeller (9) and the tail pitch ducted propeller (10) to suppress the roll and switch the propulsion energy distribution strategy. The underwater thruster (11) dynamically adjusts the control surface deflection parameters by solving the fluid density gradient in real time through the flight control computer.
9. The cross-domain vehicle integrating a catamaran and a rotary-wing unmanned aerial vehicle according to claim 1, characterized in that, The foldable rotor system (6) includes a rotor hub (6-1), which is connected to the rotor via a servo folding mechanism. The rotor tip is equipped with a counterweight (6-2) to suppress water entry vibration.
10. A navigation method for a cross-domain vehicle integrating a catamaran and a rotary-wing unmanned aerial vehicle as described in any one of claims 1-9, characterized in that, The method includes the following steps: When the aircraft performs a surface navigation mission, the flight control computer (7) first checks whether the blades of the foldable rotor system (6) are completely retracted into the rotor hub (6-1) and the anti-vibration position is locked by the wingtip counterweight (6-2). After confirming safety, the brushless motor (12) in the rear power compartment (1-2) is started, and the tail ducted propeller (3) is driven to rotate through the magnetic coupling drive shaft, thereby pushing the catamaran body (1) to break through the water and move forward. At this time, the multibeam sonar in the environmental perception sensor array in the sealed front compartment (1-1) continuously scans the underwater terrain in front, and the inertial measurement unit in the central body (5) monitors the hull attitude in real time. During the cruise propulsion phase, the flight control computer (7) automatically adjusts the speed difference of the tail ducted propeller (3) according to the preset route: when a right turn is required, the output torque of the left tail ducted propeller (3) is increased, and when a left turn is required, the power of the right tail ducted propeller (3) is increased. At the same time, the air pressure sensor inside the central fuselage (5) detects the sealing status of the cabin to prevent external water from seeping into the equipment area. When encountering side wave impact during navigation, the counterweight (6-2) effectively suppresses roll resonance.