Hydraulically-driven multi-rotor aircraft

Abstract

The utility model discloses a hydraulically-driven multi-rotor aircraft, and relates to the technical field of aviation. Aiming at the limitations of short flight time, long charging time, inconvenience in energy supplement and the like of an electric rotor aircraft, the technical scheme that a gasoline engine is adopted as a main power source, an output shaft of the gasoline engine is connected with a hydraulic oil pump, and high-pressure liquid is transmitted to a hydraulic motor through an oil pipe to drive a propeller is provided. The power part stabilizes oil pressure and distributes oil ways through a high-pressure oil pump, an overflow valve and the like, and the control part senses the flight state through various sensors to achieve closed-loop control. According to the aircraft, the flight time can be greatly prolonged, and the long-time continuous operation requirement is met; the stability is obviously improved, and the flight safety under complex weather is guaranteed; and the system has wide adaptability, can complete various tasks in various complex environments, and has a wide application prospect.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of aviation technology, especially a kind of multi-rotor aircraft of hydraulic drive. BACKGROUND

[0002] In the current field of aviation technology, rotary-wing aircraft (especially unmanned aerial vehicles) have been widely used in many fields such as aerial photography, logistics distribution, agricultural plant protection, power inspection and the like due to their flexible flight characteristics. Among them, electric rotary-wing aircraft have become a relatively common type on the market due to their relatively simple structure and convenient operation, and they generally use electric motors as power sources and rely on batteries to provide power to drive propellers to rotate.

[0003] However, with the increasing performance requirements of rotary-wing aircraft in various industries, the limitations of electric rotary-wing aircraft have become increasingly prominent. First, the development bottleneck of battery technology results in limited battery capacity, which directly limits the flight time of the aircraft. Taking a common consumer-level electric unmanned aerial vehicle as an example, even if it is equipped with a high-capacity battery, the endurance time is usually only about 20-30 minutes in the case of full-load flight, which cannot meet the requirements of tasks that require long-time continuous operation such as long-distance inspection and large-area surveying.

[0004] Secondly, the long charging time is also a big problem. The charging process of traditional lithium batteries is relatively slow, and it usually takes several hours from running out of power to being fully charged. This greatly affects the continuous use of the aircraft, and in actual application scenarios, frequent charging can greatly reduce work efficiency and increase operating costs. For example, in the logistics distribution scenario, the electric rotary-wing aircraft needs to be charged for a long time after completing each distribution task, which cannot achieve high-frequency distribution services and limits its large-scale application in this field.

[0005] In addition, the electric rotary-wing aircraft also has inconvenience in energy replenishment. In some remote areas or field operation scenarios, the lack of charging facilities greatly limits the use of electric aircraft. In contrast, traditional fuel is relatively easy to obtain in these scenarios. In summary, the deficiencies of electric rotary-wing aircraft in flight time, charging time and energy replenishment seriously restrict their in-depth application and development in more fields, and a new technical solution is urgently needed to break through these bottlenecks. UTILITY MODEL CONTENT

[0006] The utility model aims to provide a kind of multi-rotor aircraft of hydraulic drive, to solve the problem of short flight time of electric rotary-wing aircraft, long charging time, inconvenient energy replenishment.

[0007] In order to achieve the above-mentioned purpose, the utility model is realized by the following technical scheme: a kind of multi-rotor aircraft of hydraulic drive, comprising:

[0008] A power source, a gasoline engine is used as the main power source, the output shaft of the gasoline engine is connected with a hydraulic oil pump;

[0009] A transmission system, the hydraulic oil pump converts the rotary power generated by the gasoline engine into drivable high-pressure liquid, and delivers the high-pressure liquid to a hydraulic motor through an oil pipe, the hydraulic motor is provided with a propeller;

[0010] A control system, a control microcomputer is arranged at the center of the aircraft, the control microcomputer is connected with a flight state sensor, the flight state sensor comprises a speed sensor, an inclination angle sensor and a height sensor, and a rotation speed encoder is arranged below the propeller, the control microcomputer gives the rotation speed pulse control parameter of the propeller according to the data of the flight state sensor and the speed and torque parameters of the propeller.

[0011] Further, the high-pressure oil pump connected with the hydraulic oil pump compresses the hydraulic oil, so that the pressure of the hydraulic oil reaches 6-13 MPa, and an overflow valve is connected to the output end of the high-pressure oil pump.

[0012] Further, a four-way distributor is connected to the output port after the pressure stabilization of the overflow valve, and the four-way distributor uniformly distributes the pressure oil into four branches.

[0013] Further, each branch of hydraulic oil is connected with a group of valves with accurate flow control, and the valves are used for controlling the hydraulic motor.

[0014] Further, the propeller is connected above the hydraulic motor, and a pulse encoder is connected below the hydraulic motor, and the pulse encoder transmits the rotation speed of the hydraulic motor to the control microcomputer.

[0015] Further, the flight state sensor further comprises an acceleration sensor, which is used for more accurately sensing the flight state change of the aircraft, and the control microcomputer adjusts the control parameter of the propeller in combination with the acceleration sensor data.

[0016] Further, the oil pipe between the hydraulic oil pump and the hydraulic motor is made of high-strength pressure-resistant material.

[0017] Further, a plurality of flight modes are preset in the control microcomputer, including but not limited to an automatic cruising mode, a fixed-point hovering mode and an emergency return mode, and the control microcomputer adjusts the rotation speed pulse control parameter of the four propellers according to the requirements of different flight modes and real-time flight data.

[0018] Further, the gasoline engine is equipped with a fuel filter for filtering impurities in gasoline.

[0019] Further, the propeller is made of light high-strength composite material.

[0020] In summary,

[0021] The power source of the utility model: adopt gasoline engine as main power source, its output shaft links with hydraulic oil pump. Gasoline engine energy density is high, endurance time is long, can significantly prolong the flight time of aircraft.

[0022] Transmission system: the hydraulic oil pump converts the rotating power generated by the gasoline engine into drivable high-pressure liquid, and delivers it to the hydraulic motor through the oil pipe. The hydraulic motor is installed with a propeller, which is driven by the hydraulic motor to rotate and generate power. The transmission system has the advantages of high efficiency and good stability.

[0023] Power part specific structure: the gasoline engine is used as the power source, its output shaft connects a high-pressure oil pump, the hydraulic oil is compressed, and the pressure reaches about 6-13 MPa. A relief valve is connected at the output end of the high-pressure oil pump to ensure that the oil pressure is constant at a stable value. Take a quadcopter as an example (not limited to quadcopter), a four-way distributor is connected to the output port after pressure stabilization, and the pressure oil is evenly distributed to four branches. Each branch of hydraulic oil is connected to a group of valves with accurate flow control for controlling the hydraulic motor. The propeller is connected above the hydraulic motor to generate lift for the aircraft; a pulse encoder is connected below, which can transmit the speed of the hydraulic motor to the flight control microcomputer in time. The microcomputer calculates the control data according to the flight attitude data and flight control requirements, and controls the speed and torque of the four hydraulic motors in time to achieve the purpose of flight control.

[0024] Control part specific structure: the control microcomputer is installed with a flight state sensor in the center of the aircraft, including speed sensor, inclination angle sensor, height sensor and other flight parameter sensors, for sensing the flight state. A speed encoder is installed below the four propellers for feeding back the speed of the propellers. After receiving the flight instruction, the control microcomputer combines the data of the flight state sensor and the speed and torque parameters of the propellers, calculates the speed pulse control parameters of the four propellers respectively, adjusts the lift of the propellers, realizes closed-loop control of the state of the aircraft, and finally achieves the purpose of controlling the aircraft.

[0025] The utility model has the following beneficial effects:

[0026] Significantly extend flight time: using a gasoline engine as a power source, the energy density of gasoline is much higher than that of traditional batteries, which makes the aircraft in carrying the same weight of energy, can obtain several times the endurance of electric rotor aircraft. For example, in long-distance inspection tasks, electric rotor aircraft may be insufficient due to insufficient endurance, and need to return frequently to charge, while the hydraulic drive rotor aircraft of the utility model can complete a long inspection task of several hours at a time, greatly improving the work efficiency, reducing the time waste caused by frequent return charging, and meeting the needs of long-time continuous operation such as large-area topographic survey, long-distance power transmission line inspection in remote areas.

[0027] Significantly improve stability: the hydraulic transmission system itself has excellent stability, which ensures that the rotation speed of each propeller is uniform and stable during the flight process through precise oil pressure control and stable power transmission. In complex weather conditions, such as when encountering moderate intensity airflow disturbance, electric rotor aircraft may have unstable flight attitude due to uneven motor response speed and power output. The hydraulic transmission system of the hydraulic drive rotor aircraft can quickly and accurately adjust the power output of each propeller, so that the aircraft maintains stable flight, greatly improves flight safety, and provides reliable protection for tasks that require high flight stability, such as aerial photography and high-altitude operations.

[0028] Wide adaptability: the hydraulic drive rotor aircraft of the utility model not only can fly stably in conventional urban, plain and other environments, but also can adapt to various complex flight environments and diversified task requirements by virtue of its unique power and transmission system. In remote mountainous areas, wild jungles and other areas lacking charging facilities, only a moderate amount of gasoline needs to be carried to ensure the normal operation of the aircraft to complete tasks such as material transportation and emergency rescue. At the same time, through the control of the microcomputer preset multiple flight modes such as automatic cruise, fixed-point hovering and intelligent obstacle avoidance, different task scenarios can be flexibly coped with, whether it is fine operation in narrow space or rapid flight in open area, it can be efficiently completed, showing a wide application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0029] Other features, objects and advantages of the utility model will become more apparent through reading the detailed description of the non-limiting embodiments with reference to the following drawings:

[0030] Figure 1 is a structural schematic view of a hydraulic drive multi-rotor aircraft;

[0031] Figure 2 is a control block diagram of a hydraulic drive multi-rotor aircraft.

[0032] In the figure: 1-gasoline engine; 2-hydraulic oil pump; 3-overflow valve; 4-branch; 5-hydraulic motor; 6-propeller; 7-control microcomputer; 8-speed sensor; 9-inclination angle sensor; 10-height sensor; 11-acceleration sensor. DETAILED DESCRIPTION

[0033] The utility model will be combined with the drawings and specific embodiments to be explained in detail below, here with the utility model of the illustrative embodiment and the explanation is used to explain the utility model, but not as the limitation of the utility model.

[0034] It should be noted that all directional indications (such as up, down, left, right, front, back, upper end, lower end, top, bottom, etc.) in the embodiments of the utility model are only used to explain the relative positional relationship, movement condition, etc. between components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the directional indications will also change accordingly.

[0035] In the utility model, unless otherwise explicitly specified and limited, the term "connection" should be understood broadly, for example, "connection" can be fixed connection, can also be detachable connection, or integral; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship of two elements, unless otherwise explicitly limited. For ordinary skilled in the art, the specific meaning of the above-mentioned term in the utility model can be understood according to the specific circumstances.

[0036] In addition, in the utility model, the description such as "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can be explicitly or implicitly included at least one feature; in addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, also not within the protection scope required by the utility model.

[0037] The utility model will be combined with the drawings and specific embodiments to be explained in detail below, here with the utility model of the illustrative embodiment and the explanation is used to explain the utility model, but not as the limitation of the utility model.

[0038] Please refer to Figure 1 And Figure 2 The utility model provides a kind of technical scheme: a kind of multi-rotor aircraft of hydraulic drive, comprising:

[0039] Power part embodiment

[0040] Power source start and connection: first, select the power of the gasoline engine 1 as the starting point of the entire aircraft. After the gasoline engine 1 starts, its output shaft is connected with the hydraulic oil pump 2 through high-precision coupling, ensuring the stability and efficiency of power transmission process, reducing power loss. This connection mode enables the gasoline engine 1 to smoothly transfer the rotary mechanical energy generated by itself to the hydraulic oil pump 2.

[0041] Hydraulic oil compression and pressure stabilization: after obtaining power, the hydraulic oil pump 2 strongly compresses the hydraulic oil. Through the internal precise plunger pump structure, the pressure of the hydraulic oil is raised to about 6-13 MPa. At the output end of the high-pressure oil pump, the overflow valve 3 is installed. The overflow valve 3 adopts a pilot overflow valve structure, which monitors and adjusts the output oil pressure in real time according to the preset pressure value. When the oil pressure exceeds the set value, the overflow valve 3 opens, allowing part of the hydraulic oil to flow back to the tank, so as to ensure that the output oil pressure is always constant at a stable value, avoiding damage to subsequent components due to excessive oil pressure, and ensuring the safe and stable operation of the entire hydraulic transmission system.

[0042] Oil distribution and control: taking a common quadcopter as an example (but this embodiment is also applicable to other multi-rotor structures), the oil path from the output port of the overflow valve 3 after pressure stabilization is connected to a carefully designed four-way distributor. The four-way distributor adopts a symmetrical flow channel structure inside, ensuring that the pressure oil can be evenly distributed to the four branches 4. The hydraulic oil of each branch 4 then flows into a group of valves with precise flow control function. These valves adopt proportional solenoid valve structure, which receives the electrical signals sent by the control microcomputer to accurately adjust the valve opening, so as to realize accurate control of the hydraulic oil flow, and then flexibly control the speed and torque of the hydraulic motor 5.

[0043] Hydraulic motor 5 and propeller 6 linkage: the hydraulic motor 5 is a key component for converting hydraulic energy into mechanical energy, which is stably connected with the propeller 6 through high-strength bolts. When the hydraulic oil enters the hydraulic motor 5 under the regulation of the accurate flow control valve, the plunger inside the hydraulic motor 5 reciprocates under the action of hydraulic oil pressure, thereby driving the output shaft to rotate and finally driving the propeller 6 to rotate at high speed. During the rotation of the propeller 6, a strong lift is generated through the interaction with the air, enabling the aircraft to take off and fly. Meanwhile, the hydraulic motor 5 is connected with a high-precision pulse encoder below through a special connecting shaft. The pulse encoder uses photoelectric sensing principle to accurately subdivide each rotation of the hydraulic motor 5 into a number of pulse signals, monitors the speed of the hydraulic motor 5 in real time, and timely transmits the speed information to the flight control microcomputer in the form of electrical signals.

[0044] II. Control part embodiment

[0045] Sensor Installation and Data Collection: In the center of the aircraft, a control microcomputer 7 is firmly installed. Around the control microcomputer 7, a set of flight state sensors is reasonably arranged. The speed sensor 8 uses the Doppler speed measurement principle, accurately measures the flight speed of the aircraft relative to the surrounding air by transmitting and receiving ultrasonic signals, and transmits the speed data to the control microcomputer 7 in the form of digital signals. The tilt angle sensor 9 uses MEMS (Micro Electro Mechanical System) technology, accurately measures the tilt angle of the aircraft in three coordinate axes directions by detecting the acceleration change of the internal mass block in the gravitational field, and also transmits the angle data to the control microcomputer 7 in the form of digital signals. The height sensor 10 uses the laser ranging principle, transmits laser beams to the ground and receives reflected light, accurately calculates the vertical distance between the aircraft and the ground according to the propagation time of light, and feeds back the height data to the control microcomputer 7. The acceleration sensor 11 also based on MEMS technology, real-time senses the acceleration change of the aircraft during flight, and provides acceleration data for the control microcomputer 7. In addition, speed encoders are installed below the four propellers 6, which monitor the rotation speed of the propellers 6 in real time through electromagnetic induction principle, and transmit the rotation speed information to the control microcomputer 7 in the form of pulse signals. Through the cooperative work of these sensors, the control microcomputer 7 can comprehensively and real-time obtain the flight state data of the aircraft.

[0046] Control Algorithm and Instruction Generation: After receiving the flight instructions, the control microcomputer 7 quickly starts the pre-set complex algorithm program inside. The algorithm first fuses the data from the flight state sensors and the speed and torque parameters of the propellers 6. For example, when calculating the attitude adjustment of the aircraft, the algorithm will consider the tilt angle data of the tilt angle sensor 9, the acceleration data of the acceleration sensor 11, and the rotation speed and torque parameters of the propellers 6, and analyze and calculate through accurate mathematical models. According to the calculation result, the control microcomputer 7 generates rotation speed pulse control parameters for the four propellers 6 respectively. These parameters accurately control the rotation speed of each propeller 6, so as to adjust the lift size generated by the propellers 6.

[0047] Closed-loop control implementation: The control microcomputer 7 sends the generated rotational speed pulse control parameters to the corresponding precision control flow valves of each propeller 6 in the form of electrical signals. The valves adjust the opening degree in real time according to the received electrical signals, change the hydraulic oil flow, and then precisely control the rotational speed of the hydraulic motor 5, ultimately achieving the adjustment of the lift of the propeller 6. During the flight of the aircraft, the control microcomputer 7 continuously collects sensor data in real time and constantly compares and analyzes with the preset flight trajectory and attitude parameters. If it finds that the actual flight state deviates from the preset state, the control microcomputer 7 immediately recalculates and adjusts the rotational speed pulse control parameters and sends them to the valves again to achieve dynamic closed-loop control of the flight state of the aircraft. This cycle ensures that the aircraft can always fly stably along the predetermined flight trajectory and attitude. In addition, the control microcomputer 7 has multiple flight mode programs preset inside, such as in the automatic cruise mode, the control microcomputer 7 automatically adjusts the rotational speed of the propeller 6 according to the preset route and speed parameters combined with real-time flight data to maintain the aircraft flying at a constant speed along the predetermined route. In the fixed-point hovering mode, the control microcomputer 7 precisely controls the lift of the four propellers 6 to make the aircraft hover stably at the specified location. In the emergency return mode, when the aircraft detects abnormal conditions, the control microcomputer 7 automatically plans a return route and adjusts the propeller 6 parameters to guide the aircraft to return safely to the take-off point. These different flight modes can be flexibly switched according to actual flight tasks and environmental changes through the ground control station or the aircraft's own operation interface, further improving the adaptability and functionality of the aircraft.

[0048] III. Implementation Case

[0049] Case One: Forest Monitoring Task

[0050] Task Background: The forest management department of a certain area needs to regularly monitor a large area of forest to detect forest fire hazards, tree health conditions, etc. The traditional monitoring method is inefficient and cannot quickly cover the entire area. The liquid-driven rotorcraft is selected to perform this task due to its long flight time, strong adaptability, etc.

[0051] Aircraft Preparation: According to the task requirements, select a gasoline engine 1 with appropriate power to ensure that the aircraft can carry enough fuel to meet the long flight requirements. Check the hydraulic oil pump 2, overflow valve 3, four-way distributor, hydraulic motor 5, propeller 6, and various sensors, etc. to ensure their good performance and firm installation. Perform parameter settings on the control microcomputer 7, input the map information of the monitoring area, flight route, and flight height, etc. preset parameters, and select the automatic cruise mode.

[0052] Flight Process: After the aircraft starts, the gasoline engine 1 drives the hydraulic oil pump 2 to work, and the hydraulic oil is compressed and evenly delivered to the four hydraulic motors 5 through the oil distribution system, driving the propeller 6 to rotate and making the aircraft take off. During the flight, the speed sensor 8 monitors the flight speed in real time, and the height sensor 10 ensures that the aircraft maintains the preset monitoring height (such as 100 meters) flight. The inclination angle sensor 9 and the acceleration sensor 11 sense the attitude change of the aircraft in real time. If the aircraft attitude deviates due to factors such as air flow, the control microcomputer 7 quickly calculates and adjusts the propeller 6 speed pulse control parameters according to the sensor data, and adjusts the aircraft to the predetermined flight attitude by controlling the hydraulic oil flow. When the aircraft flies according to the preset route to the designated area, the high-definition camera carried by the aircraft starts to work and collects images of the forest. At the same time, the temperature sensor, smoke sensor and other devices on the aircraft also monitor the environmental data in real time, and these data are transmitted back to the ground control station in real time through the wireless communication module.

[0053] Task Completion: After the aircraft completes the entire monitoring area flight task, the control microcomputer 7 automatically switches to the return mode and guides the aircraft to return to the take-off point safely. Ground staff can discover potential problems in the forest in a timely manner by analyzing the data returned by the aircraft, such as local high-temperature areas that may have fire hazards, and tree color abnormalities that may indicate poor tree health.

[0054] Case Two: Mountain Material Transportation

[0055] Task Background: In a certain mountainous area, due to the rugged road and inconvenient transportation, the material transportation of some remote villages is difficult. The hydraulic drive rotor aircraft is used to transport emergency materials such as medicines and food to these villages.

[0056] Aircraft Preparation: According to the weight and transportation distance of the materials, select the appropriate size of the aircraft, and adjust the power of the gasoline engine 1 to match the load demand. All parts of the aircraft are checked and maintained to ensure its reliability. The geographical position information of the target village is input into the control microcomputer 7, and the related parameters such as fixed-point hovering and emergency return are set. The materials are loaded into the cargo compartment of the aircraft, and the center of gravity is balanced.

[0057] Flight process: After the aircraft takes off, it quickly climbs to a certain height and then flies towards the target village according to the preset route. During the flight process, the control microcomputer 7 adjusts the rotation speed of the propeller 6 in real time according to the data transmitted by the speed sensor 8, the height sensor 10, the inclination angle sensor 9 and the acceleration sensor 11, so as to ensure the stable flight of the aircraft. When approaching the target village, the control microcomputer 7 switches to the fixed-point hovering mode, and adjusts the lift of the four propellers 6 to make the aircraft hover stably above the designated open area of the village. At this time, the ground staff interacts with the aircraft through the wireless communication device, and after confirming the safety, the aircraft slowly lowers the supplies to the ground through the rope.

[0058] Emergency response: If abnormal conditions such as severe weather (such as strong wind) are encountered during flight, the acceleration sensor 11 and the inclination angle sensor 9 will quickly feed back the data to the control microcomputer 7. The control microcomputer 7 immediately starts the emergency algorithm to automatically adjust the rotation speed and torque of the propeller 6 to resist the influence of strong wind on the aircraft and maintain flight stability. If the wind is too strong and exceeds the response capability of the aircraft, the control microcomputer 7 automatically switches to the emergency return mode to guide the aircraft to return to a safe area, ensuring the safety of the supplies and the aircraft.

[0059] Through the above two implementation cases, it can be clearly seen that the liquid-driven rotor aircraft has the working process and advantages in practical application, and can effectively meet the flight task requirements in different scenes.

[0060] The above describes the technical solutions provided by the embodiments of the present application in detail. The principles and implementation modes of the embodiments of the present application are described by applying specific examples. The above description of the embodiments is only applicable to help understand the principles of the embodiments of the present application; at the same time, for those skilled in the art, according to the embodiments of the present application, the specific implementation modes and application ranges will be changed, and the above description should not be understood as a limitation of the present application.

Claims

1. A hydraulically powered multicopter characterized in that, It comprises: a power source, which adopts a gasoline engine as the main power source, the output shaft of the gasoline engine being connected with a hydraulic oil pump; a transmission system, the hydraulic oil pump converting the rotary power generated by the gasoline engine into drivable high-pressure liquid, and delivering the high-pressure liquid to a hydraulic motor through an oil pipe, the hydraulic motor being provided with a propeller; a control system, which comprises a control microcomputer located at the center of the aircraft, the control microcomputer being connected with a flight state sensor, the flight state sensor comprising a speed sensor, an inclination angle sensor, a height sensor, and a rotation speed encoder being arranged below the propeller, the control microcomputer giving the rotation speed pulse control parameters of the propeller according to the data of the flight state sensor and the speed and torque parameters of the propeller.

2. A hydraulically powered multicopter according to claim 1, characterized in that: The high-pressure oil pump connected with the hydraulic oil pump compresses the hydraulic oil, so that the pressure of the hydraulic oil reaches 6-13 MPa, and an overflow valve is connected at the output end of the high-pressure oil pump.

3. A hydraulically powered multicopter according to claim 2, characterized in that: A four-way distributor is connected at the output port after the pressure of the hydraulic oil is stabilized by the overflow valve, the four-way distributor uniformly distributing the pressure oil into four branches.

4. A hydraulically powered multicopter according to claim 3, characterized in that: Each branch of the hydraulic oil is connected with a group of valves with accurate flow control, the valves being used for controlling the hydraulic motor.

5. A hydraulically powered multicopter according to claim 4, characterized in that: The hydraulic motor is connected with the propeller above and an impulse encoder below, the impulse encoder transmitting the rotation speed of the hydraulic motor to the control microcomputer.

6. A hydraulically powered multi-copter according to claim 1, wherein: The flight state sensor further comprises an acceleration sensor, which is used for more accurately sensing the change of the flight state of the aircraft, and the control microcomputer adjusts the control parameters of the propeller in combination with the data of the acceleration sensor.

7. A hydraulically powered multi-copter according to claim 1, wherein: The oil pipe between the hydraulic oil pump and the hydraulic motor is made of high-strength pressure-resistant material.

8. A hydraulically powered multi-copter according to claim 1, wherein: The control microcomputer is pre-set with multiple flight modes, including but not limited to an automatic cruise mode, a fixed-point hovering mode, and an emergency return mode, the control microcomputer adjusting the rotation speed pulse control parameters of the four propellers according to the requirements of different flight modes and real-time flight data.

9. A hydraulically powered multi-copter according to claim 1, wherein: The gasoline engine is provided with a fuel filter for filtering impurities in gasoline.

10. A hydraulically powered multi-copter according to claim 1, wherein: The propeller is made of light-weight high-strength composite material.

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