Water-based flying vehicle

Abstract

The present invention provides a new water-takeoff and water-landing aircraft by providing an aircraft (particularly a multicopter) with a float section that generates buoyancy through an enclosed space provided in at least a part of the main body. [Solution] A waterborne aircraft comprising a main body and a plurality of rotors attached to the main body that generate a downward wake when hovering, the main body having a float that generates buoyancy through an enclosed space provided in at least a portion of the main body. The main body faces upward from the horizontal when descending, and the float is configured by providing an enclosed space on the rear side of the main body. Alternatively, the main body faces upward from the horizontal when descending, and the float is provided on the underside and rear side of the main body.

Description

[Technical Field]

[0001] The present invention particularly relates to a waterborne aircraft equipped with a buoyancy generating mechanism that utilizes an enclosed space. [Background technology]

[0002] In recent years, research and demonstration experiments have been conducted to commercialize services using drones, unmanned aerial vehicles (UAVs), and other flying objects (hereinafter referred to as "flying objects"). In particular, multicopters, which are equipped with multiple fixed-pitch propellers and move by tilting the aircraft, are one type of flying object that is expected to be used for a variety of purposes.

[0003] As one of the applications, for example, Patent Document 1 discloses a water-based aircraft equipped with a ring-shaped float. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2024-090763 Summary of the Invention [Problem to be solved by the invention]

[0005] However, further improvements in waterborne aircraft are desired.

[0006] Therefore, one object of the present invention is to provide a new water-based aircraft (particularly a multicopter) by providing a float section that generates buoyancy through an enclosed space provided in at least a part of the main body. [Means for solving the problem]

[0007] According to the present invention, it is possible to provide a water-borne aircraft comprising a main body and a plurality of rotors provided on the main body that generate a downward wake when hovering, the main body having a float portion that generates buoyancy through an enclosed space provided in at least a portion thereof. [Effects of the Invention]

[0008] According to the present invention, a new water-based aircraft (particularly a multicopter) can be provided that is equipped with a float unit that generates buoyancy through an enclosed space in at least a portion of the main body, thereby reducing air resistance during flight while ensuring reliable buoyancy compared to conventional ring-shaped floats. Furthermore, the float unit integrated with the main body minimizes the weight increase of the aircraft and achieves stable floating performance on water. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a conceptual side view of the aircraft according to the present invention during flight. [Figure 2] FIG. 2 is a top view of the flying object of FIG. 1 when it is moving forward. [Figure 3] FIG. 2 is a functional block diagram of the aircraft of FIG. 1. [Figure 4] FIG. 2 is a side view of the aircraft of FIG. 1 in hovering. [Figure 5] 10A and 10B are diagrams showing other examples of the main body shape of the flying object. [Figure 6] 10A and 10B are diagrams showing other examples of the main body shape of the flying object. [Figure 7] 10A and 10B are diagrams showing other examples of the main body shape of the flying object. [Figure 8] 10A and 10B are diagrams showing examples of the relationship between a main body and a float. [Figure 9] 10A and 10B are diagrams showing other examples of the relationship between the main body and the float. [Figure 10] 10A and 10B are diagrams showing other examples of the relationship between the main body and the float. [Figure 11] 10A and 10B are diagrams showing other examples of the relationship between the main body and the float. [Figure 12] 10A and 10B are diagrams showing other examples of the relationship between the main body and the float. [Figure 13] 10A and 10B are diagrams showing other examples of the relationship between the main body and the float. [Figure 14] 10A and 10B are diagrams showing other examples of the relationship between the main body and the float. [Figure 15] 10A and 10B are diagrams showing examples of main body shapes in which a lid portion is provided on a main body portion. DETAILED DESCRIPTION OF THE INVENTION

[0010] The contents of the embodiments of the present invention will be described below. A water-based aircraft according to an embodiment of the present invention has the following configuration. [Item 1] a main body; a plurality of rotor blades provided on the main body portion, the rotor blades generating a downward wake during hovering; The main body has a float portion that generates buoyancy by means of an enclosed space provided in at least a part thereof. Water take-off and landing aircraft. [Item 2] The float portion is configured by making the entire inside of the main body portion an enclosed space. Item 1. A waterborne aircraft. [Item 3] The float portion is configured by forming an enclosed space below the lower side of the main body portion and below the lower surface of the rotor portion. Item 1. A waterborne aircraft. [Item 4] The float portion is configured by providing an enclosed space below the main body portion and below the upper and lower half of the main body portion. Item 1. A waterborne aircraft. [Item 5] The float portion is configured by providing an enclosed space below one-third of the main body portion, on the lower side of the main body portion. Item 4. A waterborne aircraft. [Item 6] The float portion is configured by providing an enclosed space below one-fourth of the main body portion, on the lower side of the main body portion. Item 4. A waterborne aircraft. [Item 7] The main body is oriented upward from the horizontal when lowered, The float portion is configured by providing an enclosed space at the rear side of the main body portion. Item 1. A waterborne aircraft. [Item 8] The float portion is configured by providing an enclosed space at the rear side of the main body portion, rearward of the front-rear half of the main body portion. Item 7. A waterborne aircraft. [Item 9] The main body is airfoil-shaped. 9. The waterborne aircraft according to any one of items 1 to 8. [Item 10] The float portion is provided on the lower surface of the main body portion. Item 1. A waterborne aircraft. [Item 11] The main body is oriented upward from the horizontal when lowered, The float portion is provided on the lower surface and rear side of the main body portion. Item 11. A waterborne aircraft according to item 10. [Item 12] The main body and the float are integrally formed into an airfoil shape. Item 12. The water-based takeoff and landing aircraft according to item 10 or 11. [Item 13] The main body is oriented upward from the horizontal when lowered, The main body has landing legs, The float portion is configured by providing an enclosed space in the landing leg. Item 1. A waterborne aircraft. [Item 14] The float section is configured by providing an enclosed space only in the landing gear on the front side of the main body section, and by providing an enclosed space inside or outside the main body section on the rear side. Item 14. A waterborne aircraft according to item 13. [Item 15] The main body has a lid that opens to the interior thereof. 2. The waterborne aircraft according to claim 1. [Item 16] The main body is divided into a lower cover portion that forms a sealed space and an upper cover portion that is releasably attached. Item 1. A waterborne aircraft.

[0011] <Details of the embodiment of the present invention> Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0012] <Details of the First Embodiment>

[0013] As shown in Figures 1 and 2, an aircraft 100 according to an embodiment of the present invention has at least a main body 10 (including a cover) for flight, multiple rotors consisting of propellers 110 and motors 111, a motor mount supporting the motor, a frame 21, and other elements of a typical multicopter, and it is desirable that it is equipped with energy (e.g., a secondary battery, a fuel cell, a fossil fuel, etc.) to operate these components.

[0014] The illustrated flying vehicle 100 is depicted in a simplified manner to facilitate explanation of the structure of the present invention, and detailed configurations of, for example, the control unit, etc. are not shown.

[0015] The flying object 100 moves forward in the direction of arrow D in the figure (-Y direction) (details will be described later).

[0016] In the following explanation, terms may be used according to the following definitions: forward / backward direction: +Y direction and -Y direction, up / down direction (or vertical direction): +Z direction and -Z direction, left / right direction (or horizontal direction): +X direction and -X direction, forward direction (forward): -Y direction, backward direction (rearward): +Y direction, upward direction (upward): +Z direction, downward direction (downward): -Z direction

[0017] The propeller 110 rotates by receiving output from the motor 111. As the propeller 110 rotates, an alternating current is generated downward during ascent (and hovering), generating upward thrust, and a propulsive force is generated to cause the aircraft 100 to take off from a departure point, move, and land at a destination. The propeller 110 can rotate clockwise, stop, and rotate counterclockwise.

[0018] The propeller 110 of the aircraft of the present invention has one or more blades. Any number of blades (rotors) may be used (e.g., 1, 2, 3, 4, or more blades). The blades may be flat, curved, twisted, tapered, or any combination thereof. The blade shape may be variable (e.g., retractable, foldable, or bent). The blades may be symmetrical (having identical upper and lower surfaces) or asymmetrical (having upper and lower surfaces with different shapes). The blades may be formed into airfoils, wings, or any other geometric shape suitable for generating aerodynamic forces (e.g., lift, thrust) as the blade moves through the air. The blade geometry may be selected to optimize the blade's aerodynamic characteristics, such as increasing lift and thrust and reducing drag.

[0019] The propellers of the aircraft of the present invention may be of fixed pitch, variable pitch, or a combination of fixed pitch and variable pitch, but are not limited to these.

[0020] The motor 111 generates the rotation of the propeller 110; for example, the drive unit may include an electric motor or an engine. The blades may be driven by the motor and rotate around the motor's rotation axis (e.g., the motor's longitudinal axis).

[0021] The blades can all rotate in the same direction, or they can rotate independently. Some blades rotate in one direction and others in the other. The blades can all rotate at the same speed, or they can each rotate at a different speed. The speed can be determined automatically or manually based on the dimensions of the moving object (e.g., size, weight) and the control state (speed, direction of movement, etc.).

[0022] The flying object 100 determines the rotation speed of each motor and the flight angle according to wind speed and direction using a flight controller, radio control, etc. This allows the flying object to move by ascending and descending, accelerating and decelerating, and changing direction.

[0023] When taking off or landing on water, the flying vehicle 100 may execute a special control sequence. Specifically, when landing on water, the flight controller coordinates and controls the rotation speed of each rotor, controlling the main body 10 to maintain the designed landing attitude (for example, an upward angle of 5 to 15 degrees relative to the horizontal). Just before landing, the rotation speed of the rotors is gradually reduced to achieve a soft landing. When taking off, the buoyancy of the float unit 30 is used to stabilize the aircraft on the water surface, and each rotor is gradually accelerated until sufficient lift is obtained, at which point the aircraft begins to take off. At this time, the rotation speeds of the front and rear rotors are independently controlled to maintain the fore-and-aft balance of the aircraft.

[0024] The aircraft 100 can fly autonomously according to routes and rules set in advance or during flight, or can fly by being controlled using a radio control.

[0025] The above-described air vehicle 100 has the functional blocks shown in FIG. 3. Note that the functional blocks in FIG. 3 are a minimum reference configuration. The flight controller is a so-called processing unit. The processing unit may have one or more processors, such as a programmable processor (e.g., a central processing unit (CPU)). The processing unit has and can access memory (not shown). The memory stores logic, code, and / or program instructions that the processing unit can execute to perform one or more steps. The memory may include, for example, a separable medium such as an SD card or random access memory (RAM), or an external storage device. Data acquired from a camera or sensors may be directly transmitted to and stored in the memory. For example, still and video data captured by a camera or the like is recorded in an internal or external memory.

[0026] The processing unit includes a control module configured to control the state of the rotorcraft. For example, the control module may have six degrees of freedom (translational x, y, and z, and rotational θ x , θ y and θ z The control module controls the propulsion mechanisms (e.g., motors) of the rotorcraft to adjust the spatial position, speed, and / or acceleration of the rotorcraft. The control module can control one or more of the onboard components and the state of the sensors.

[0027] The processing unit can communicate with a transceiver configured to transmit and / or receive data from one or more external devices (e.g., a terminal, a display device, or other remote controller). The transceiver can use any suitable communication means, such as wired or wireless communication. For example, the transceiver can utilize one or more of a local area network (LAN), a wide area network (WAN), infrared, radio, WiFi, a point-to-point (P2P) network, a telecommunications network, cloud communication, etc. The transceiver can transmit and / or receive one or more of data acquired by sensors, processing results generated by the processing unit, predetermined control data, user commands from a terminal or a remote controller, etc.

[0028] The sensors according to this embodiment may include inertial sensors (acceleration sensors, gyro sensors), GPS sensors, proximity sensors (e.g., LIDAR), or vision / image sensors (e.g., cameras). The sensors may be mounted, for example, on a circuit board within the main body or on a flat frame member (on which various components can be mounted) connected to each arm, or on the top or bottom of the main body (including the cover). In particular, if the sensors are cameras, they may be mounted on the bottom (particularly the front bottom) of the main body. Furthermore, a water takeoff and landing aircraft may also be equipped with a water surface detection sensor (e.g., an ultrasonic sensor or laser distance sensor), an inclination sensor (e.g., a tilt sensor), and a water intrusion detection sensor (e.g., a conductivity sensor or optical sensor). These sensors enable monitoring of the timing of water landing, the aircraft's attitude relative to the water surface, and the sealing of the float unit 30.

[0029] As shown in Figures 1 and 4, aircraft 100 in an embodiment of the present invention tilts forward in the direction of travel when traveling. The forward-tilted rotors generate upward lift and thrust in the direction of travel, which propels aircraft 100 forward. In particular, Figures 1 and 4 illustrate an example in which main body 10 faces upward relative to the horizontal (e.g., the ground or the aircraft frame) when hovering (including when ascending or descending), and tilts forward during travel so that the main body becomes horizontal or nearly horizontal, and the forward tilt reduces the air resistance of main body 10, but the present invention is not limited to this example.

[0030] The aircraft 100 comprises a main body 10 capable of housing an onboard processing unit, battery, payload, etc. The main body 10 is fixedly connected to a plurality of rotors and a frame 21. By optimizing the shape of the main body 10 and improving the speed in the attitude of the aircraft 100 during cruising, which is expected to be maintained for a long period of time while the aircraft 100 is moving, the flight time can be efficiently shortened.

[0031] The main body 10 preferably includes a cover strong enough to withstand flight, takeoff, and landing. When buoyancy is a priority, the cover can be made of resin foam such as expanded polystyrene (EPS), polyurethane foam (PUR), or polyethylene foam (EPE), or a honeycomb material with a hollow structure (e.g., aluminum honeycomb or resin honeycomb), or hollow fiber reinforced plastic. These materials have a specific gravity (e.g., 0.1 to 0.8 g / cm³) lower than that of water (1.0 g / cm³), allowing the cover itself to generate buoyancy. Plastics and FRP, for example, are suitable cover materials due to their rigidity and waterproof properties. In particular, for aircraft capable of taking off and landing on water, stainless steel (e.g., SUS316), titanium alloys, or seawater-resistant resins (e.g., polyethylene terephthalate (PET) or polypropylene (PP)) are preferred for corrosion resistance in saltwater environments. Furthermore, a silicone- or fluorine-based weather-resistant sealant is applied to the joints of the cover members to ensure long-term watertightness.

[0032] Furthermore, the motor mount, frame 21, and main body 10 may be constructed by connecting the individual components, or may be molded as a single unit using a monocoque structure or integral molding (for example, the motor mount and frame 21 may be molded as a single unit, or the motor mount, frame 21, and main body 10 may all be molded as a single unit, etc.). By integrating the components, it is possible to smooth the joints between the components, which is expected to reduce drag and improve fuel efficiency in aircraft such as blended wing bodies and lifting bodies.

[0033] The shape of the main body 10 of the aircraft 100 may be any shape, but it is preferable that the main body 10 has a streamlined shape that reduces drag when the aircraft 100 is in a cruising position, and more preferably, it may be an airfoil or approximately airfoil-shaped shape.

[0034] An example of an airfoil may be a common airfoil called a flat-bottom airfoil. In this case, the camber line has a curved shape (hereinafter referred to as an arched shape) that is convex upward in the center, and the camber line is mostly above the chord, or entirely above the chord. Alternatively, another example of an airfoil may be an airfoil obtained by turning a common airfoil such as a flat-bottom airfoil upside down (an inverted airfoil; see Figure 5). In this case, the camber line is in an inverted arch shape, and the camber line is mostly below the chord, or entirely below the chord. Alternatively, another example of an airfoil may be a symmetric airfoil. In this case, the camber line is linear, and the camber line and the chord coincide or nearly coincide. Other common airfoils may also be used.

[0035] The shape of the main body 10 of the aircraft 100 may be, for example, as shown in Figures 6 and 7, such that the thickness increases from the front to a predetermined thickness in a side view, and then decreases toward the rear. The propeller may be a push type as well as a pull type as shown in Figure 1, and contra-rotating propellers may be used as shown in Figures 6 and 7.

[0036] Here, in the present invention, the main body 10 has a float part 30 that generates buoyancy by an enclosed space provided in at least a part thereof. For example, when an enclosed space is provided inside the main body 10, the main body 10 may be configured to prevent water from entering by applying a known waterproofing treatment to the main body 10 (cover), thereby generating buoyancy against water by the air in the enclosed space.

[0037] Specifically, the sealed space constituting the float unit 30 can be formed using the following structures. First, the sealed space can be left empty, utilizing the buoyancy of air. In this case, the cover of the main body 10 itself can be made of a buoyant material (e.g., a foamed resin material such as expanded polystyrene, expanded polyurethane, or expanded polyethylene, or a honeycomb material with a hollow structure, hollow fiber reinforced plastic, etc.), thereby achieving high buoyancy performance through the synergistic effect of the buoyancy of the cover material itself and the buoyancy of the air in the sealed space. Second, the sealed space can be formed by filling the gap formed between the cover member of the main body 10 (e.g., carbon fiber reinforced plastic (CFRP), glass fiber reinforced plastic (GFRP), aluminum alloy, etc.) and the inner frame 21 with a lightweight material such as polystyrene foam, urethane foam, or a hollow plastic member. Furthermore, the airtightness of the sealed space can be ensured by sealing using a silicone-based sealant, a butyl rubber-based sealant, or a polyurethane-based sealant. Furthermore, resistance to water pressure can be improved by setting the air pressure within the sealed space to the same as atmospheric pressure or slightly higher (for example, 1.1 to 1.5 atmospheres). If the cover material itself is a buoyant material, adjusting the thickness of the cover can ensure the required buoyancy and also has the advantage of reducing the risk of water entering the sealed space. In particular, when using a foamed resin material, adjusting the foaming rate (porosity) of the material can optimize the balance between strength and buoyancy.

[0038] The float section 30 may be configured by making the entire inside of the main body section 10 an enclosed space, which makes it possible to obtain a large buoyancy.

[0039] Furthermore, the float unit 30 may be configured by providing an enclosed space below the rotor unit (particularly the motor) on the lower side of the main body unit 10. If the rotor unit has a contra-rotating propeller shape, the enclosed space may be provided below the lower push-type rotor unit, or the enclosed space may be provided below the upper rotor unit, with the lower rotor unit being waterproofed. This makes it possible to limit the target of the water-resistant treatment (waterproofing) to only a portion of the main body unit 10, while preventing the electrical system (rotor unit) from becoming submerged in water when floated by the float unit 30.

[0040] The float unit 30 may also be configured by providing an enclosed space below the main body 10, below half of the main body 10 in the vertical direction (see the simplified diagram in FIG. 8). This configuration allows the center of gravity of the aircraft to be positioned lower, improving stability on water. Furthermore, the upper space can be used to store electronic devices and other payloads, resulting in good space efficiency. In particular, the enclosed space may be formed by filling the gap between the cover and the frame 21 within the main body 10 with a sealing material or the like. Furthermore, the float unit 30 may also be configured by providing an enclosed space below one-third of the main body 10, or even below one-quarter of the main body 10, but is not limited to these.

[0041] Furthermore, if the main body 10 is pointing upward relative to the horizontal when descending at the water landing point, the float 30 may be configured by providing an enclosed space at the rear of the main body 10. In particular, the float 30 may be configured by providing an enclosed space at the rear of the main body 10, behind the front-to-rear half of the main body 10 (see the simplified diagram in Figure 9).

[0042] The float section 30 may also be configured by providing an enclosed space on the underside of the exterior of the main body section 10 (see the simplified diagram in Figure 10). In particular, if the main body section 10 is pointing upward relative to the horizontal when descending to the water landing point, the float section 30 may also be configured by providing an enclosed space on the underside and rear side of the exterior of the main body section 10 (see the simplified diagram in Figure 11). Furthermore, in this case, the main body section 10 and the float section 30 may be integrated to form an airfoil shape. 12. The waterborne aircraft according to claim 10 or 11.

[0043] Furthermore, when the main body 10 has landing gear, the float section 30 may be configured by providing an enclosed space in at least a portion of the landing gear (see the simplified diagram in FIG. 12, which shows an example in which an enclosed space is provided in the entire landing gear), or by providing an enclosed space only in the inside or outer tip of the landing gear (see the simplified diagram in FIG. 13, which shows an example in which an enclosed space is provided only in the outer tip of the landing gear).

[0044] Furthermore, if the main body 10 is pointing upward relative to the horizontal when descending to the water landing point, the float section 30 may be configured by providing an enclosed space only in the front landing legs of the main body 10, and by providing an enclosed space inside or outside the rear of the main body 10 (see simplified diagram in Figure 14).

[0045] The float unit 30 may also be composed of multiple sealed spaces distributed across multiple locations on the main body 10. Specifically, providing three or more independent sealed spaces at the front, center, and rear of the main body 10 ensures redundancy, allowing the other sealed spaces to maintain buoyancy even if one location is damaged. Adjusting the size and location of each sealed space also optimizes the fore-aft and lateral balance of the aircraft. By independently waterproofing each of the distributed sealed spaces, the impact on overall buoyancy can be minimized even if the airtightness of one location is compromised.

[0046] Furthermore, the float unit 30 may be a detachable float unit configured to be detachable from the main body unit 10. The detachable float unit can be removed for land use to reduce the aircraft weight, and attached only for water use to ensure buoyancy as needed. Fixing means may include magnetic fixation using a magnet, mechanical fixation using a spring clamp, or a screw-type fixing mechanism. The detachable float unit can be attached to the underside, side, or rear of the main body unit 10, and a corresponding fixing part (e.g., a metal plate, a screw hole, or a clamp receptacle) is provided on the main body unit 10 depending on the attachment position. The detachable float unit itself is made of a lightweight foam material, a hollow plastic member, a hollow metal container, or the like.

[0047] The float unit 30 may also have a multi-layer structure in which multiple independent sealed spaces are arranged in layers. For example, the main body 10 may have a two-layer structure consisting of an upper sealed space and a lower sealed space, or a three-layer structure consisting of an upper layer, a middle layer, and a lower layer. Each sealed space may be made of a different material (e.g., the upper layer may be polystyrene foam and the lower layer a hollow plastic container) or may be filled with a different gas (e.g., air, helium, or nitrogen). A multi-layer structure allows buoyancy to be maintained by the other layers even if one layer is damaged, and also allows for optimal buoyancy distribution by utilizing the material properties of each layer. Waterproof partitions or membranes are placed between the layers to ensure the independence of each layer.

[0048] The main body 10 may also have a lid 40 that leads to its interior (see the simplified diagram in FIG. 15). The periphery of the lid 40 may be treated with a known water-resistant treatment (e.g., by providing a gasket in the gap between the lid 40 and the cover). By providing the lid 40, when a processing unit such as a sensor or a circuit board is placed on the upper half of the main body 10, a battery is placed thereon, or an item to be delivered (e.g., a package, a delivery box) is placed thereon, the lid 40 allows workers to easily reach inside the main body 10, facilitating replacement and other operations. Instead of or in addition to the lid 40, the cover that constitutes the main body 10 may be divided into a lower cover portion that forms an enclosed space and an upper cover portion that can be opened and closed. In this case, removing the upper cover portion facilitates the above-mentioned operations.

[0049] The detailed configuration of the lid 40 is described below. The lid 40 has an opening that allows access to the internal space of the main body 10 and is configured to cover this opening in an openable and closable manner. The following configurations can be used for the opening and closing mechanism of the lid 40. First, in a configuration using a hinge mechanism, a rotation axis is provided on one side of the lid 40, and the lid 40 rotates around this axis to open and close. The hinge can be a stainless steel or titanium pin hinge, a resin living hinge, or a magnetic hinge using a magnet. Second, in a configuration using a sliding mechanism, the lid 40 opens and closes by sliding along the surface of the main body 10. A resin or ceramic guide rail is provided in the sliding portion to achieve smooth opening and closing. Third, in a configuration using a rotation mechanism, the lid 40 opens and closes by rotating around its central axis.

[0050] The lid 40 is most commonly located on the top of the main body 10, but it can also be located on the side (left / right or front / back), front, or rear. A top-mounted lid 40 has the advantage of naturally closing due to gravity and is also effective in preventing the intrusion of rainwater and other elements. A side-mounted lid 40 allows for easy access when the aircraft is horizontal, facilitating maintenance work. A front- or rear-mounted lid 40 minimizes the impact on air resistance in the direction of flight. To ensure airtightness, a weather-resistant gasket made of silicone rubber, EPDM (ethylene propylene rubber), fluororubber, or other suitable material is provided around the periphery of the lid 40. The gasket can be shaped as an O-shaped, D-shaped, or rectangular cross section, and compresses and deforms according to the tightening force of the lid 40 to ensure airtightness. A screw-type, clamp-type, or lever-type locking mechanism can be used to secure the lid 40, ensuring a reliable airtight seal.

[0051] As a multiple-lid configuration, multiple lids 40 can be provided according to functional divisions within the main body 10. For example, by providing a separate lid for the electronic device storage section, a separate lid for the battery storage section, and a separate lid for the load storage section, it is possible to minimize the impact on other sections during maintenance of each section. Each lid 40 may have a different size, shape, or opening / closing mechanism.

[0052] The lid 40 can be made of the same material as the cover of the main body 10 (for example, carbon fiber reinforced plastic, glass fiber reinforced plastic, aluminum alloy, etc.), thereby ensuring matching of material properties. Furthermore, by making the lid 40 itself out of a transparent or translucent material (for example, acrylic resin, polycarbonate resin), there is an advantage that the internal state can be visually confirmed without opening the lid 40.

[0053] The relationship between the lid 40 and the float 30 will now be described. In order to maintain the airtightness of the float 30 even when the lid 40 is open, the following configurations can be adopted. First, the opening of the lid 40 is positioned so that it does not directly communicate with the sealed space of the float 30. In this case, a partition is provided within the main body 10 between the sealed space of the float 30 and the opening of the lid 40, making each space independent. Second, even when the opening of the lid 40 and the sealed space of the float 30 are connected, a double sealing structure is provided in which an additional sealing cover is provided inside the lid 40, so that the airtightness of the float 30 is maintained by the inner sealing cover even when the outer lid 40 is open.

[0054] It is also preferable to provide a safety mechanism for the lid 40. For example, a sensor (e.g., a magnetic sensor, proximity sensor, or mechanical switch) is provided to detect incomplete closure of the lid 40, and a warning signal is issued if the lid 40 is not securely closed. It is also preferable to provide a double locking mechanism (e.g., a combination of a main lock and an auxiliary lock) to prevent the lid 40 from being unintentionally opened due to vibrations or impacts during flight.

[0055] Waterproofing treatment for water-based aircraft will now be described in detail. In addition to the main body 10, it is important to apply the following waterproofing treatment to the motor, arms, frame, and other mounted components.

[0056] One way to waterproof the motor 111 is to cover the entire motor housing with a silicone or polyurethane waterproof coating material. Alternatively, the motor's bearings can be filled with water-resistant grease, and the shaft seal can be fitted with an oil seal or mechanical seal. Waterproof connectors (e.g., IP67 or IP68 grade) are used for the motor's electrical connections, and the entire connection is covered with waterproof tape or self-fusing tape. Furthermore, to completely prevent water from entering the motor, the entire motor can be housed in a waterproof case.

[0057] To waterproof the arm, if the arm is hollow, seal both ends with airtight caps to prevent water from seeping inside. The arm surface is coated with weather-resistant paint (for example, urethane paint or epoxy paint) or a waterproof film such as a PVC sheet. If wiring runs inside the arm, install grommets or waterproof bushings at the wiring penetration points to ensure airtightness.

[0058] To waterproof the frame 21, if the frame material is an aluminum alloy, an oxide film is formed on the surface by anodizing or anodizing to improve corrosion resistance. If the frame is made of carbon fiber reinforced plastic (CFRP), a clear coat (e.g., urethane clear, acrylic clear) is applied to the surface to prevent the fibers from being exposed. A waterproof sealant is applied to the joints of the frame in combination with a structural adhesive (e.g., epoxy-based, urethane-based).

[0059] To waterproof electronic components and circuit boards, the entire control board is conformally coated with a moisture-proof coating material (e.g., silicone, acrylic, or urethane). Additionally, the board is housed in a waterproof case (e.g., IP65 or higher) and the inside of the case is dehumidified with a desiccant (e.g., silica gel, activated alumina). Waterproof connectors or waterproof harnesses are used for the electrical connections on the board.

[0060] To waterproof the wiring and cables, all wiring is coated with a water-resistant coating (for example, PVC coating or fluoride resin coating), and the wiring connections are treated with waterproof connectors, crimp terminals, or waterproof tape. A waterproof gland (cable gland) is provided where the wiring exits the main body 10 to ensure airtightness around the wiring.

[0061] To waterproof the sensors, a waterproof cover glass is installed on the camera lens, a waterproof radome is installed on the GPS receiver, and a waterproof membrane is installed on the ultrasonic sensor. Waterproof packing or liquid sealant is applied to the mounting points of each sensor.

[0062] Waterproofing performance is graded according to the international standard IP (Ingress Protection) rating, with ratings ranging from IP65 (dustproof and water-jetproof) to IP68 (dustproof and water-resistant) set depending on the aircraft's intended use. If use in a saltwater environment is anticipated, higher corrosion resistance is required, so the use of stainless steel (such as SUS316L), titanium alloy, or seawater-resistant resin materials should be considered.

[0063] To deal with deterioration of waterproofing treatment over time, it is necessary to periodically inspect and update the waterproofing performance. Specifically, this involves reapplication of sealant, replacement of packings, reapplication of waterproof coating, etc. It is also advisable to periodically conduct water immersion tests (for example, immersion tests in a water tank) to confirm the effectiveness of the waterproofing treatment.

[0064] The configuration of the aircraft in each embodiment can be implemented by combining multiple configurations. It is desirable to consider an appropriate configuration depending on the cost of manufacturing the aircraft and the environment and characteristics of the location where the aircraft will be operated.

[0065] As safety features, the flying vehicle 100 preferably has the following functions: Water ingress detection sensors that monitor the water level inside the float section 30 are installed in multiple locations, and a warning signal is sent in the event of water ingress. The flying vehicle 100 may also be equipped with a mechanism that manually or automatically deploys additional buoyancy material (e.g., an inflatable airbag using CO2 gas) inside the float section 30 in an emergency. Furthermore, by linking with the GPS function and providing a function that automatically communicates the emergency water landing location, rescue operations can be expedited.

[0066] The water takeoff and landing control algorithm will now be described in detail. Based on a signal from the water surface detection sensor, the control module transitions to water landing mode when the distance to the water surface falls below a predetermined value (e.g., 1 to 5 m). In water landing mode, the aircraft attitude is controlled to an angle suitable for landing (5 to 15 degrees upward from the horizontal), and the descent speed is limited to a predetermined value (e.g., 0.5 to 2.0 m / s). After landing, the aircraft's stability is maintained by the buoyancy of the float unit 30 and the fine lift control of the rotors.

[0067] The above-described embodiment is merely an example for facilitating understanding of the present invention, and is not intended to limit the present invention. The present invention can be modified and improved without departing from the spirit thereof, and it goes without saying that the present invention includes equivalents thereof. [Explanation of symbols]

[0068] 10 Main body 21 frames 30 Float section 40 Lid 100 flying objects 110a~110h propeller 111a~111h motor

Claims

1. a main body; a plurality of rotor blades provided on the main body portion, the rotor blades generating a downward wake during hovering; The main body has a float portion that generates buoyancy by an enclosed space provided in at least a part thereof, The main body is upwardly oriented relative to the horizontal at least when landing on water or descending, The main body further has landing legs, The float section is configured by providing a first sealed space only in the landing legs that are on the front side of the main body section, and providing a second sealed space below and behind the main body section. Water take-off and landing aircraft.

2. The second sealed space is configured by making the lower and rear sides of the interior of the main body part a sealed space. The waterborne aircraft according to claim 1.

3. The second sealed space is provided below and behind the exterior of the main body. The waterborne aircraft according to claim 1.

4. The main body portion is wing-shaped.

4. The waterborne aircraft according to claim 1.

5. The main body and the float are integrally formed into an airfoil shape.

4. The waterborne aircraft according to claim 1.

6. The main body has a lid that opens to the interior thereof.

4. The waterborne aircraft according to claim 1.

7. The main body is divided into a lower cover portion that forms a sealed space and an upper cover portion that is releasably attached.

4. The waterborne aircraft according to claim 1.

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