119 results about "Low Gravity" patented technology

A low gravity simulator configured to place an object under a simulated low gravity force is disclosed. The low gravity simulator comprises: a substantially vertically extending support column, wherein the support column comprises an air bearing; a boom, wherein the boom is mounted to the support column, and wherein the boom is rotatable about a vertical axis; a carriage, the carriage translatably mounted on the boom so that the carriage is, in use, movable backwards and forwards along the boom; a cable supported by the carriage and connectable at one end, in use, to the object; and a counterweight attached to the cable at an opposing end to apply a biasing force to the cable. The counterweight is restrained by the support column and the air bearing is configured to facilitate the motion of the counterweight with respect to the support column.

The invention provides gas-magnetic hybrid micro-low gravity simulation test equipment which comprises a plane pose simulator, and a high-pressure gas supply unit, a control cabinet, a direct-current power supply unit and a stroke amplification mechanism which are mounted above the plane pose simulator, and the stroke amplification mechanism is located at the center of the plane pose simulator. And a vertical zero-stiffness mechanism, a spherical pose simulator, a spacecraft centroid adjusting platform and a pose measuring unit are sequentially mounted above the three-dimensional platform. The gas-magnetic hybrid micro-low gravity simulation test equipment lays a foundation for generalization and modularization of a spacecraft on-orbit service simulation test device, conforms to the development direction of technical and economic integration, and has important significance in shortening the space mechanism test period, improving the test precision, improving the reliability and avoiding repeated investment.

The invention discloses a robot carrying method and system in a low-gravity environment and a storage medium, and the method comprises the steps: collecting a stick figure drawn by an operator and a real scene image in a current cabin, and inputting the stick figure and the real scene image into a trained dual-branch visual encoder model; a basic action sequence instruction used for controlling the robot to complete material carrying operation is generated, then the target rotation angular speed is monitored in real time in the process of executing the basic action sequence instruction to conduct target grabbing, and if the target rotation angular speed is larger than a set threshold value, a robot clamping jaw is driven to conduct rotation fine adjustment in the reverse direction. Therefore, pure visual instruction interaction is realized to adapt to the condition that voice interaction in a low-gravity scene is completely unavailable, and meanwhile, the problem that an object is easy to generate irregular rotation and is difficult to grab when being stressed under low gravity is solved.

The utility model discloses a food processor stable in work, which relates to the field of life electric appliances, and comprises a cup body with a built-in stirring piece and a main machine, the cup body comprises an outer cup and an inner cup, the bottom of the outer cup is provided with an inserting part matched with a cutter shaft of the stirring piece in an inserting manner, and the bottom of the inner cup is provided with a matching part matched with the inserting part; the distance between the outer bottom wall of the inner cup and the inner bottom wall of the outer cup is smaller than the height of the inserting part, so that the height of the cup body after the inner cup is embedded into the outer cup can be greatly reduced, the gravity center height of the cup body is further reduced, when a user processes food materials, the food materials can be processed at a relatively low gravity center, the whole machine works more stably, and the user experience is improved. The situation that due to the fact that the gravity center of the whole machine is high, the whole machine generates large vibration noise and even shakes and topples during food material processing is effectively avoided, meanwhile, when a user nests the inner cup into the outer cup to achieve storage, the height of the whole machine is reduced, the user can store the whole machine more conveniently, and the use experience of the user is improved.

The utility model discloses a low-gravity-center lead screw type intelligent lifting working platform which comprises a building body, a heavy frame and a working platform body. A supporting structure is fixedly arranged on the outer side of each layer of beam body of the building main body; the heavy frame is sleeved with the working platform, a lifting device is arranged between the working platform and the heavy frame, and the working platform and the heavy frame move relatively through the lifting device so as to achieve the purpose of lifting; and the lifting device is positioned above the gravity centers of the heavy frame and the working platform. Compared with the prior art, the utility model has the advantages that the structure is simple, and the use is convenient; the problems that the gravity center of a lifted frame body is higher than the stress point of the lifted frame body, and the frame body overturns and falls due to the fact that the frame body is affected by moment are solved. The situation that a traditional protection platform can only achieve one-way falling prevention is thoroughly improved; the working platform can be provided with two anti-falling devices for protection during ascending or descending bidirectional movement; through reverse operation, the effect that the working platform descends on the periphery of the building body layer by layer is achieved; and labor, material and time costs are saved.

Systems and methods simulate reduced-gravity environments using passive counterweight architectures that maintain a substantially constant offload force throughout the user's range of motion. The system may include one or more multi-segment articulated arms, each incorporating a cable routing system that preserves effective cable length during articulation. By routing the cable through coaxial apertures at the joints and through pulley assemblies encapsulated within hollow arm tubes, the offload force remains stable regardless of arm orientation. The system may include a magnetic singularity-avoidance mechanism employing opposed magnets positioned on adjacent arm segments. The magnetic detent biases the arm segments away from singular loading geometries, prevents uncontrolled rotation, and substantially reduces cable twist accumulation. Further embodiments may include gantry-based, trolley-based, or tilting-beam structures for enlarged workspace coverage, and optional friction-offset motors, low-stretch cables, or large-diameter pulleys to minimize hysteresis and maintain greater uniformity of the offload force.

The present invention discloses a low-gravity environment simulated lunar soil penetration test platform and test method based on bottom friction, belonging to the technical field of low-gravity simulation devices, including a support adjustment unit; a simulation box, in which simulated lunar soil is placed; the simulation box is arranged on the support adjustment unit; wherein the inclination angle of the simulation box is adjusted by adjusting the length of the support adjustment unit to simulate the gravity of the moon; a monitoring unit, which penetrates into the simulated lunar soil after passing through the simulation box, and monitors the penetration resistance in the simulated lunar soil. The present invention can simulate the low-gravity environment of the moon, and the method principle proposed in the present invention can also simulate the low-gravity environment on other planets; at the same time, the method proposed in the present invention can calculate the corresponding test platform inclination angle α for different lunar soil or star soil materials (different materials have different friction coefficients μ).

The invention discloses engineering machinery for aloft work and a steering method of the engineering machinery, and relates to the field of optimization design. The construction machine includes: a chassis; the steering type tire is connected to the chassis; one end of the connecting frame is connected to the chassis, the other end of the connecting frame is connected to the working platform, and no rotary mechanism exists between the connecting frame and the chassis; the balancing weight is connected to the end, away from the working platform, of the chassis, the balancing weight is movable, and the gravity center heights of the balancing weight at least at two different positions are different. Compared with the prior art, a rotary mechanism between the connecting frame and the chassis is omitted, the balancing weight and the connecting frame are directly installed on the chassis, the engineering machine obtains smaller mass and size through the movable balancing weight structure installed at the lower gravity center position, the stability of the engineering machine is improved, the cost is optimized, and transportation and storage are convenient.

The invention provides a ventilation wall test system and method for Mars aircraft testing, and the system comprises a space environment simulator which can simulate the low-pressure and low-temperature environment of Mars, a gravity unloading device which is installed in the space environment simulator, a ventilation wall assembly which is used for generating a controllable simulation wind field, and a ventilation wall driving device. The wind wall assembly is arranged in a wind guide structure of the space environment simulator and comprises a plurality of fan array units, each fan array unit is of a multi-layer series connection structure, the distance between the adjacent fan array units can be adjusted according to the wind speed of the controllable simulation wind field, and each fan array unit comprises a plurality of fans arranged at non-equal intervals. The Mars transient wind field where the to-be-tested unmanned aerial vehicle is located is accurately simulated, and accurate simulation of distribution of the Mars wind field in time and space and low gravity of the Mars is achieved.

The invention relates to the technical field of environment test, and discloses a comprehensive environment simulation test device and method, the device comprises a vacuum tank, a vacuum unit, a first temperature adjusting mechanism, a second temperature adjusting mechanism and a control system, and an opening at one end of the vacuum tank is provided with a sealing door capable of being opened and closed; the vacuum unit is used for adjusting the vacuum degree in the vacuum tank; the first temperature adjusting mechanism is used for adjusting the internal temperature of the vacuum tank; the second temperature adjusting mechanism is used for lowering the internal temperature of the vacuum tank; a micro-low gravity environment simulation module is arranged in the vacuum tank, and the micro-low gravity environment simulation module is used for driving the test sample to rotate in the first direction while rotating in the axial direction, so that the test sample can be simulated to be tested in a comprehensive environment with high / low temperature alternation, different vacuum degrees and different micro-low gravity factors in a single device; and the cost is saved and the occupied space is small.

The smoke bomb comprises an outer shell, an inner shell, a cooling filter layer, a smoke filling material and a control assembly, the inner shell is located in the outer shell and used for containing the smoke filling material, the space between the inner shell and the outer shell is filled with the cooling filter layer, and the control assembly is located between the inner shell and the outer shell. The control assembly is located at the inner top end of the outer shell, the bottom end of the inner shell is connected with a balance weight assembly, a protection assembly is installed on the outer side of the top end of the balance weight assembly, multiple sets of through grooves are formed in the circumferential wall of the upper portion of the inner shell at equal intervals, and a release assembly is arranged at the position, below the through grooves, in the inner shell. The smoke bomb can stably stand on various complex terrains such as stair steps, slopes and smooth grounds through the composite structure of the low-gravity-center counterweight design and the large-bottom-area anti-skid rubber mat, and safety accidents and exercise distortion caused by toppling are fundamentally eradicated.

The invention relates to a self-adaptive graded energy dissipation type rock wall anchoring system and a folding and unfolding inflatable residential cabin, which comprise an anchoring assembly, a buffer assembly, an inhaul cable and a prestress adjusting assembly, and realize stable anchoring of a folding and unfolding framework inflatable structure in a lunar lava pipe environment. The anchoring assembly is tightly combined with a rock wall drill hole in an expansion mode, and basic anchoring force is provided for the system. The buffering assembly is arranged in the sliding cavity and can absorb environment energy to achieve graded energy consumption when the local rock wall is slightly shocked. Reliable connection between the anchoring assembly and the prestress adjusting assembly is achieved through the inhaul cable. The prestress adjusting assembly adjusts the prestress of the inhaul cable to counteract stress fluctuation caused by factors such as environment deformation and temperature change. The technical problem that an anchoring structure needs to give consideration to both stability and adaptability in special environments such as low gravity, high radiation and easy slight shock of the moon is solved, and a core guarantee is provided for safe deployment of a folding and unfolding framework inflatable structure in the lunar lava tube.

This invention provides a compound gravity separator, comprising a frame; at least two gravity platforms spaced apart vertically; wherein each pair of adjacent gravity platforms is connected by a transmission support arm; the upper end of the transmission support arm is hinged to the upper gravity platform, the lower end of the transmission support arm is hinged to the lower gravity platform, and the middle part of the transmission support arm is rotatably connected to the frame; and a drive mechanism, mounted on the frame and located around the at least two gravity platforms. The compound gravity separator provided by this invention achieves vibration of multiple gravity platforms driven by a single drive unit through a stacked arrangement and a reverse linkage design of the transmission support arms. This eliminates multiple independent drive systems, significantly reducing costs and energy consumption; utilizes the inertial cancellation principle of reverse motion to significantly reduce overall machine vibration; the stacked structure reduces the floor space compared to traditional series layouts, and the material falls by gravity, eliminating the need for intermediate lifting and conveying devices.

The invention discloses an air-magnetic overhanging type micro-low gravity test air-floating workbench capable of inhibiting residual magnetism and eddy current interference. The air-magnetic overhanging type micro-low gravity test air-floating workbench comprises a rigid bearing framework and a functional composite material layer. The rigid bearing framework is made of non-magnetic high-specific-stiffness aluminum alloy, and mechanical supporting and magnetic field isolation are achieved. And the functional composite material layer is compounded by uniformly dispersing and consolidating corrosion-resistant nickel-based soft magnetic particles in a non-magnetic matrix, and is used as a gas-magnetic coupling working interface. The adopted nickel-based soft magnetic particles have high saturation flux density, low coercive force, high resistivity and good chemical stability, it is ensured that the functional composite material layer formed by the nickel-based soft magnetic particles has lasting and reliable working surface performance, and residual magnetism interference force and eddy current damping force are fundamentally eliminated on the premise that needed vertical adsorption force is maintained. According to the design, the unexpected horizontal disturbing force generated by the air floatation working table is reduced to one thousandth of the rated vertical bearing force of the gas magnetic bearing, and the precision of dynamic simulation in a micro-low gravity ground experiment is remarkably improved.

Oxygen generation systems for use in low-gravity environments include a cell stack having an anode and a cathode. An anode-side phase separator and a cathode-side phase separator are each fluidly coupled to outlets of the cell stack. The anode-side phase separator separates a mixture into liquid water and gaseous oxygen and the cathode-side phase separates a mixture int liquid water and gaseous hydrogen. A ducting system is configured to house the cell stack and the cathode-side phase separator, a hydrogen sensor is arranged at an outlet of the ducting system, and a controller is configured to stop oxygen generation at the cell stack when a concentration of hydrogen is detected at or above a threshold level at the hydrogen sensor at the outlet of the ducting system.

The invention relates to a rotary impact wear test device for simulating a lunar comprehensive environment. The rotary impact wear test device comprises a temperature control assembly, a low-gravity simulation assembly, an irradiation simulation assembly, a lunar dust sprinkling assembly, a rotary assembly and a test shell, a test chamber is defined by the test shell, a vacuum environment is formed in the test chamber, the rotating assembly is arranged on an inner bottom plate of the test chamber, a test sample is used for being fixed to the rotating assembly, and the temperature control assembly, the irradiation simulation assembly and the low-gravity simulation assembly are all arranged in the test chamber. The bottom end of the lunar dust sprinkling assembly penetrates through the top of the test shell and is inserted into the test cabin, and the top end of the lunar dust sprinkling assembly extends to the outside of the test shell; by means of the arrangement, friction abrasion between lunar dust and a sample in the moving process can be achieved, and the testing accuracy is improved; meanwhile, the uniform suspension state of lunar dust particles can be kept for a long time, and the accuracy of a test result is improved.

The present application relates to spacecraft ground environment test device technical field, especially to a kind of simulator for spacecraft low gravity test, buffer mechanism is installed on chassis, one side of fork shear mechanism is installed on buffer mechanism, counterweight mechanism is installed on the other side of fork shear mechanism, for simulating spacecraft mass and moment of inertia;Wheel mechanism is arranged on the side of chassis, and is provided with multiple groups. By adding different number of counterweight block to the circumferentially distributed counterweight disc, the mass center horizontal position of counterweight mechanism is changed, so that it is the same as the horizontal position of spacecraft mass center, the mass center height is adjusted by fork shear mechanism, the first spring and hydraulic telescopic rod in buffer mechanism simulate buffer working condition, the stroke of first sliding block in contraction process can be effectively adjusted by stop plate adjusted by screw rod, and it can also be used to assist the extension of fork shear mechanism, for flat ground walking, climbing, in situ steering working condition, wheel mechanism in the present application can be realized.

The utility model relates to mechanical hand positioning technical field, concretely to a kind of accurate positioning mechanism of five-axis side hanging double-arm double-section mechanical hand, including longitudinal slide, longitudinal slide outer side is equipped with sliding slot, sliding block is slidably installed in the sliding slot, the one side of sliding block is fixedly installed with L-shaped plate, the L-shaped plate bottom end is fixedly installed with inclined bracing plate, the top of longitudinal slide is respectively equipped with longitudinal slide rail by bolt, the outer side of longitudinal slide rail is slidably installed with first sliding clamp, first inner thread block is fixedly installed between the first sliding clamp, first inner thread block and L-shaped plate top are equipped with horizontal sliding assembly by bolt, the utility model is equipped with L-shaped plate structure with inclined bracing plate by longitudinal slide side, and the rigidity linkage of combination horizontal platform and longitudinal drive component is formed Space triangular support and low gravity center layout, substantially enhance the bending and torsion resistance of mechanism, ensure positioning stability and motion stability under high load.

Pneumatically supported towers for low gravity applications are disclosed herein. In one aspect, an inflatable tower for use in vacuum environments can have a membrane configured to support a load when inflated with an inflation gas to a pressures less than 100,000 pascals and greater than 0.01 pascal. The inflation gas can be chosen to have a sufficiently low boiling temperature at the inflation pressure of the membrane that the gas will not condense to a liquid or solid within a defined range of temperatures in which the tower is designed to operate. The membrane can be configured to be packaged for transport in deflated condition and rolled onto cylinders from which the membrane can be later unfurled and inflated as part of the tower inflation process.

The space manipulator clamping tool comprises a first shell and a base in the first shell, a trapezoidal lead screw is installed in the middle of the base, a nut is connected to the outer portion of the trapezoidal lead screw in a sleeving mode, and rotary motion of the trapezoidal lead screw is converted into linear motion of the nut; a second end cover is mounted in the first end cover; the interior of the second end cover is connected to a trapezoidal lead screw; a plurality of guide rods are mounted in the circumferential direction of the second end cover; a guide cap is mounted outside the second end cover; and a disc spring is mounted between the top cap and the second guide cover. The space mechanical arm clamping tool for grabbing the base can adapt to the extreme environment of micro-low gravity, high vacuum and severe temperature change in the space, enough clamping force can be generated through motor driving to grab equipment, and the stability and durability under various complex working conditions are guaranteed.

The present invention relates to an effective gravity control device that implements a zero gravity, microgravity, low gravity, or weighted gravity state of an internal module based on a moving external module. In accordance with an embodiment of the present invention, an effective gravity control device that implements a zero gravity, microgravity, low gravity, or weighted gravity state of an internal module mounted in a moving external module includes the external module in which a movement space of the internal module is provided and of which at least one physical quantity related to movement is controlled, the internal module moving independently from the external module within the movement space by an external force transmitted through the external module, and a position detection sensor provided at at least one inner end of the external module and detecting a position of the internal module in the movement space.

This invention discloses a high-precision dynamic compensation algorithm for gravity disturbance torque of a dumbbell-shaped satellite simulator, relating to the field of spacecraft ground zero-gravity simulation experiments. Based on a high-precision dynamic compensation system for gravity disturbance torque of a dumbbell-shaped satellite simulator, a camera field-of-view coordinate system and a simulator body coordinate system are established. A control torque for the dumbbell-shaped simulator is established in the camera field-of-view coordinate system, and the three-axis attitude of the dumbbell-shaped simulator is maintained and controlled. The gravity disturbance torque is calculated in real time and dynamically compensated. The dynamic compensation algorithm provided by this invention can continuously and automatically calculate the compensation torque and obtain the movement distance of the counterweight, performing real-time compensation for the gravity disturbance torque, ensuring that the simulator's center of mass coincides with the center of the ball bearing, greatly improving the accuracy and reliability of spacecraft ground micro-low gravity simulation experiments.

The invention discloses a posture self-adaption balance mechanism in a global low-gravity environment. The posture self-adaption balance mechanism comprises a connecting assembly, a three-axis posture decoupling assembly, a dynamic balance assembly and a human body constraint assembly. The connecting assembly is used for being connected with external suspension equipment. The three-axis attitude decoupling assembly is connected with the connecting assembly, and the three-axis attitude decoupling assembly is used for providing three-degree-of-freedom rotation movement, including pitching, rolling and yawing, of the subject relative to the external suspension equipment; the dynamic balance assembly is connected with the three-axis attitude decoupling assembly, and the dynamic balance assembly is used for generating reverse gravitational torque to offset overturning torque generated by attitude change of the subject; the human body binding assembly is connected with the three-axis posture decoupling assembly, and the human body binding assembly is used for being worn on the body of a subject and transmitting force and torque. Three-degree-of-freedom attitude decoupling and dynamic moment balance are realized by utilizing a pure mechanical principle, and a suspension force vector is ensured to always pass through a system to synthesize a mass center, so that the omnidirectional motion characteristic in a low-gravity environment is accurately reproduced on the ground.

The invention discloses a method for multi-source data joint identification and inversion of a middle and lower earth crust high conductor, and relates to the technical field of geophysical exploration. The method for multi-source data joint identification and inversion of the middle and lower earth crust high conductor mainly comprises the following steps: carrying out potential field separation on Bouguer gravity anomaly data to obtain residual gravity anomaly, regional gravity anomaly and field source depth, and further determining earth crust residual gravity anomaly and middle and lower earth crust density disturbance characteristics; and calculating residual gravity low anomalies reflecting the middle and lower earth crust high conductors in the research area, delineating plane distribution of the middle and lower earth crust high conductors, and performing random sub-domain three-dimensional automatic inversion for the residual gravity low anomalies to obtain a three-dimensional space distribution form of the middle and lower earth crust high conductors. By implementing the multi-source data combined identification and inversion method for the mid-lower earth crust high conductor provided by the invention, the mid-lower earth crust high conductor can be rapidly and effectively identified and inverted, and the three-dimensional space distribution of the mid-lower earth crust high conductor can be obtained.

The application provides a micro-low-gravity simulation system for a complex multi-body target, which is driven by a hybrid method of active and passive driving and adopts a multi-stage suspension method, so that the flexibility of system movement is greatly improved, and aims at meeting the ground experiment requirements of a space mechanical arm, a lunar rover and other complex multi-degree-of-freedom spacecrafts; the system comprises a main frame, the main frame is a frame structure built by a rod body, the main frame supports a top sling driving system and a multi-stage movement system through a plurality of supporting legs; a control cabinet is further installed on the main frame, and the control cabinet is used for controlling the actions of the sling driving system and the multi-stage movement system.

The invention relates to a Mars ascender launching stage gravity simulation test device and a test method. Simulation of a preparation stage before launching of an ascender in an inclined ground environment, simulation of a Mars gravity environment in a launching stage and gravity restoration of a launching completion stage are realized. The device comprises two functional units, namely a suspension type low-gravity simulation functional unit and a counterweight and unlocking system functional unit. The suspension type low-gravity simulation function unit is a set of gravity compensation device and is connected with the counterweight system and the launching platform through a fixed pulley, and the simulation effect of the gravity of the Mars in the ground environment is achieved through rope tension. The counterweight and unlocking system function unit is connected with the counterweight through an electromagnetic lock, and counterweight locking before launching and gravity restoration after launching are achieved. According to the invention, the Mars gravity suspension balance is carried out on the Mars sampling ascender, and the Mars environment in the launch process of the ascender is simulated.

The invention relates to a mechanical falling body device for controlling falling acceleration and a falling simulation method, and belongs to the technical field of star soil tests. According to the device, a vertical rail is composed of four steel wire ropes, a mechanical falling body device is arranged on the vertical rail, the mechanical falling body device and the four steel wire ropes are clamped and loosened respectively, and therefore friction force between the mechanical falling body device and the steel wire ropes is changed so as to adjust the acceleration during falling. According to the mechanical falling body device for controlling the falling acceleration, the falling acceleration is controlled based on friction force, and the problem that a low-gravity test for a soil body is difficult is effectively solved. Any 0-1G gravity field environment can be generated, test conditions are provided for tests needing to be carried out under the low-gravity condition, generation of the low-gravity field is more flexible, and the test reproduction difficulty is reduced. According to the simulation method, mechanical tests of a series of star soil in a low-gravity environment are realized, so that comprehensive sounding response of lunar soil in a small-gravity environment and influence action mechanism analysis of a gravity field are realized.

Oxygen generation systems for use in low-gravity environments include a cell stack with an anode-side phase separator and a cathode-side phase separator fluidly coupled to outlets of the cell stack. An anode-side flow controller and a cathode-side flow controller are arranged downstream from the respective phase separators. A pressure differential is induced upstream of the anode-side flow controller that is greater in pressure than a downstream side thereof. A pressure differential is induced upstream of the cathode-side flow controller that is greater in pressure than a downstream side thereof. An input flow controller is arranged upstream from the stack inlet, the input flow controller configured to cause a pressure differential such that an upstream side of the input flow controller is greater than a downstream side of the input flow controller.

The present invention discloses a salt water experiment method for simulating the movement of fire smoke under low gravity on the moon. First, an analogy relationship between salt water and fire smoke under a microgravity / low gravity environment is established; then, a salt water experiment is used to simulate the smoke spread scene of a building fire under a microgravity / low gravity environment. The salt water experiment method for simulating the movement of fire smoke under low gravity on the moon can simulate the smoke spread scene of a building fire under a microgravity / low gravity environment at a low research cost. The simulated microgravity / low gravity environment has stable numerical values, a clear smoke spread simulation process, and data can be quantitatively obtained without contact. It can provide a theoretical basis and data support for studying the smoke spread characteristics of building fires under microgravity / low gravity environments.

The invention belongs to the technical field of cross-medium unmanned aerial vehicles, and discloses a tandem type double-rotor cross-medium unmanned aerial vehicle which comprises a bow part, a middle fuselage and a stern part which are connected into a whole in a sealed mode through end seals. The middle fuselage is formed by longitudinally butting two fuselage sections and penetrates out of the stern end seal after penetrating through the bow end seal, the two fuselage sections and the middle end seal in sequence through a full-length bolt, and the two ends of the middle fuselage are locked through clamping plate nuts respectively. The unmanned aerial vehicle has a high gravity center mode that the motor is higher than the vehicle back and a low gravity center mode that the motor is installed in the vehicle body and provided with the fin stabilizer. The problems that an existing cross-medium unmanned aerial vehicle is low in underwater propulsion efficiency and large in navigation power consumption are solved, the problem that additional airborne equipment influences the gravity center and stability of the unmanned aerial vehicle is solved, good flight performance and underwater navigation capacity are achieved, and the diversified requirements of the civil field are met.