Unmanned aerial vehicle, unmanned aerial photography system and unmanned aerial photography method

Abstract

The present application discloses an unmanned aerial vehicle, an unmanned aerial photography system, and an unmanned aerial photography method. The unmanned aerial vehicle includes a fuselage, wings, ducted fans, and a tilt mechanism. The wings include a front wing, a middle wing, and a tail wing. The installation heights of the middle wing, tail wing, and front wing decrease in sequence and are symmetrical about the fuselage axis. Multiple ducted fans are symmetrically arranged on the two wing surfaces of each wing, which are controlled by the tilt mechanism inside the wing. An oblique photography device is installed under the fuselage. The unmanned aerial vehicle adopts a three-wing design and uses a distributed ducted fan as a power system. It can achieve vertical take-off and landing and cruise, with high working reliability and flight stability. The aerodynamic load of the entire aircraft is evenly distributed. The aerodynamic load of the wings is small, the structure is light, and static stability design can be achieved. It has good lift-drag characteristics and a large load capacity. It can be equipped with more equipment and energy sources, and is more suitable for long-distance and multi-requirement aerial photography tasks. It can perform large-scale photography in various weather conditions and obtain high-precision information on the vertical surface of the aerial photography object.

Description

Technical Field

[0001] The present application relates to an unmanned aerial vehicle, specifically a vertical take-off and landing UAV based on a distributed ducted fan, and an aerial photography system and an aerial photography method based on the UAV. Background Art

[0002] my country boasts a long coastline and vast maritime territory, making robust supervision and effective control of its maritime areas particularly crucial. Drones, with their high reliability, accuracy, and real-time capabilities, are widely used in production and daily life. Compared to patrol vessels, drones offer wide coverage, flexibility, and low costs, making them a better fit for maritime regulatory needs. However, the complex maritime environment places certain demands on drones.

[0003] With the advancement of image acquisition sensor technology, aerial photography has been widely used in a variety of applications, including agricultural and forestry resource surveys, urban planning, water surveys, and meteorological and environmental monitoring. Due to the complexity of terrain structures, single-angle observations cannot accurately capture the true characteristic parameters of terrain features. Using multi-angle oblique photography to capture multi-angle terrain images and build three-dimensional models is an important means of obtaining multi-angle remote sensing information. However, with increasing requirements for image data and the diversification of shooting environments, drone aerial photography systems are facing increasing challenges.

[0004] Vertical take-off and landing (VTOL) drones (UAVs) excel at taking off and landing in complex terrain for aerial photography. Currently, a variety of VTOL drone configurations are available for different missions. Some of the most widely adopted configurations include miniature helicopters, quadcopters, tilt-rotors, tilt-ducted tilt-rotors, and tail-seat models. However, helicopter-like aircraft have low forward flight speeds, making them difficult to adapt to short-term, wide-area aerial photography. Tilt-rotor UAVs require wing tilting, resulting in complex mechanical linkages and control challenges. Furthermore, their large wing area makes them sensitive to airflow during hovering, hindering precise aerial photography and surveying at sea. Tilt-rotor UAVs also exhibit significant aerodynamic interference between the rotor and wing, generating considerable operating noise. Ducted fan UAVs offer increased thrust while reducing operating noise. The ducting also provides a degree of heat isolation, improving the aircraft's stealth and adaptability to specialized aerial photography operations. There are also many classifications of ducted fan UAVs, such as coaxial twin-propeller ducted type, double ducted type, etc. Compared with these layouts, the redundancy of distributed ducted fan is greatly improved, and the working safety is greatly enhanced, and it is receiving more and more attention.

[0005] For example, researchers have proposed a vertical takeoff and landing (VTOL) drone using distributed ducted propulsion. This drone features a two-wing design with tiltable canards. While the wings are fixed, the ducted propulsion units in the trailing-edge flaps can change the direction of thrust by tilting the flaps. When the takeoff mass is large, the drone requires additional ducts on the wings. This, on the one hand, increases the overall size of the aircraft and requires a higher landing and takeoff area; on the other hand, it subjects the wings to greater loads, requiring higher material strength. Another example is a distributed electric propulsion tilt-rotor UAV proposed. This uses a three-wing fixed wing with two-tiered front and rear wings. The upper and lower wings each feature an electric propulsion ducted fan, and the middle wing primarily generates lift during fixed-wing flight. This aircraft changes flight state by tilting the front and rear wings as a whole. This places high demands on the output of the tilt mechanism, resulting in a larger mass and negatively impacting overall aircraft performance. Summary of the Invention

[0006] The main purpose of this application is to provide an unmanned aerial vehicle, an unmanned aerial photography system and an aerial photography method to overcome the deficiencies in the prior art.

[0007] To achieve the aforementioned invention objectives, the technical solutions adopted in this application include:

[0008] One aspect of the present application provides an unmanned aerial vehicle, comprising a fuselage, wings, multiple ducted fans and a tilt mechanism; the wings comprise a front wing, a middle wing and a tail wing, which are sequentially mounted on the fuselage from front to back, with the mounting heights of the middle wing, tail wing and front wing decreasing sequentially; and each of the front wing, middle wing and tail wing comprises two wing surfaces symmetrically distributed relative to the axis of the fuselage, each wing surface is provided with a ducted fan group, each ducted fan group comprises multiple ducted fans, and the multiple ducted fans on the same wing are symmetrically distributed relative to the axis of the fuselage, and the tilt mechanism is also installed in each wing, and the tilt mechanism is at least used to adjust the tilt angle of the corresponding ducted fan group.

[0009] Another aspect of the present application further provides an unmanned aerial photography system, which includes the aforementioned unmanned aerial vehicle, a wireless communication module, an image recording module, an aerial photography information module, a data storage module, and a control unit;

[0010] Wherein, the aerial photography information module, wireless communication module and image recording module are all arranged on the unmanned aerial vehicle;

[0011] The control unit is arranged at the ground station and exchanges information with the image recording module and the unmanned aerial vehicle via the wireless communication module;

[0012] The control unit is at least used to control the flight state of the unmanned aerial vehicle, the working state of the image recording module, and process the information collected by the image recording module, and store the processed data in the data storage module;

[0013] The aerial photography information module is at least used to record corresponding aerial photography work data when the image recording module is working. The aerial photography work data includes aerial photography time, spatial position information of the unmanned aerial vehicle, and posture information of the unmanned aerial vehicle.

[0014] Another aspect of the present application further provides an unmanned aerial photography method, which is implemented based on the unmanned aerial photography system and includes the following steps:

[0015] S1: The control unit determines the starting point of the aerial photography mission and designs the flight path for the UAV;

[0016] S2: After the UAV reaches the starting point of the aerial photography mission, the image recording module starts to work and captures the required image data, and the aerial photography information module starts to record the corresponding aerial photography work data, and transmits the image data and the aerial photography work data to the control unit via the wireless communication module, and the control unit then processes the image data and the aerial photography work data to obtain the required image format;

[0017] S3: After all aerial photography tasks are completed, the image recording module and the aerial photography information module stop working, and the unmanned aerial vehicle returns to the specified landing point and lands vertically at the specified location.

[0018] Compared with the existing technology, the advantages of the technical solution of this application include:

[0019] (1) The unmanned aerial vehicle of the present application adopts a three-wing layout. The position arrangement and structural design of the different wing surfaces reduce the interference between the three rows of wings, improve the stability of the aircraft, and significantly improve the aerodynamic load distribution of the entire aircraft, which can reduce the aerodynamic load on the wings and effectively reduce the weight of the wing structure. At the same time, by installing a tiltable ducted fan on the trailing edge of each wing, the suction effect of the ducted fan is used to generate additional lift on the wing, so that the aircraft can achieve vertical take-off and landing and cruise, and the requirements for the take-off and landing environment are reduced, and the scope of application is greatly expanded. In particular, by adopting the aforementioned ducted fan arrangement, the problem of aircraft loss of control caused by failure of a single engine can be avoided, the working reliability of the aircraft is improved, and it is more conducive to the static stability design of the aircraft, the lift-drag characteristics of the aircraft are improved, and the aerodynamic interference between the ducted fans on adjacent wings is reduced; at the same time, the arrangement of the ducted fan can improve the cruise efficiency and be competent for a wider range of aerial photography tasks. In addition, by installing a vertical baffle on the tail wing, the flight stability of the aircraft can be further improved.

[0020] (2) The unmanned aerial photography system of the present application uses the unmanned aerial vehicle as a carrier. Compared with the general four-rotor surveying and mapping UAV, the unmanned aerial vehicle is a vertical take-off and landing UAV based on distributed ducted power. It has a large load capacity and can be equipped with more airborne equipment and energy sources, making it more adaptable to aerial photography tasks with longer distances and more requirements. It has strong wind resistance and is less affected by weather. It can take off in more occasions, shortening the time waiting for suitable weather before the mission, and can advance large-scale aerial photography tasks more quickly. It is equipped with more ducted fans and has high operating redundancy, making it more suitable for surveying and mapping work in complex environments. It is not affected by cloud height and has lower requirements for air visibility. In particular, by carrying an image recording module in the form of oblique photography, the three-dimensional data obtained can truly reflect the appearance, position, height and other attributes of the ground object, enhancing the sense of reality brought by the three-dimensional data and making up for the shortcomings of low simulation of artificial models.

[0021] (3) The unmanned aerial photography method of the present application is based on the unmanned aerial photography system and therefore has the characteristics of a wide range of aerial photography and few restrictions on weather and environment. In particular, by using the oblique photography aerial photography method, the oblique photogrammetry data obtained is measurable image data with spatial position information, which can simultaneously output DSM, DOM, DLG and other data results, while meeting the requirements of traditional aerial photogrammetry and obtaining more data. In addition, combined with the methods of batch extraction of oblique images and texturing, it can effectively reduce the cost of three-dimensional modeling in scenes such as cities and islands that require high vertical surface information. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0023] Figure 1 It is a three-dimensional diagram of an unmanned aerial vehicle in one embodiment of the present application.

[0024] Figure 2 This is a right side view of an unmanned aerial vehicle in one embodiment of the present application.

[0025] Figure 3 This is an aerodynamic modification diagram of a ducted fan in one embodiment of the present application.

[0026] Figure 4 This is a principle block diagram of an unmanned aerial photography system in one embodiment of the present application.

[0027] Explanation of the reference numerals: 1-fuselage, 2-front wing, 3-ducted fan, 4-mid-wing, 5-rear landing gear, 6-tail wing, 7-vertical baffle, 8-front landing gear, 9-oblique photography device. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It will be understood that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for ease of description, only some, rather than all, structures related to the present application are shown in the drawings. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0029] The unmanned aerial vehicle provided in this embodiment is a vertical take-off and landing UAV based on distributed ducted fans, which includes a fuselage 1, wings, multiple ducted fans 3 and a tilt mechanism.

[0030] The fuselage is streamlined, with the height gradually increasing and then decreasing from front to back. The middle part of the fuselage is a storage space for accommodating other onboard components and cargo.

[0031] The wings include a front wing 2, a middle wing 4, and a tail wing 6 which are sequentially installed on the fuselage from front to back, and the front wing, middle wing, and tail wing are all single-layer structures.

[0032] Each of the front, mid, and tail wings includes two wing surfaces symmetrically distributed relative to the fuselage axis, which in some cases can be considered to be left and right wing surfaces. Each wing surface is equipped with a ducted fan group. Each ducted fan group includes multiple ducted fans, and the multiple ducted fans on the same wing are symmetrically distributed relative to the fuselage axis. Each wing is also equipped with a tilt mechanism, which is used to adjust the tilt angle of the corresponding ducted fan group. The ducted fans 3 each include a duct, a motor, and a propeller.

[0033] This UAV utilizes a distributed ducted fan power system, effectively preventing the loss of control caused by a single engine failure and improving its operational reliability. Furthermore, by utilizing a tilt mechanism to drive the ducted fan's rotation, the fan's tilt angle can be changed, enabling it to provide pulling force in different directions, thus meeting the UAV's power requirements in various flight modes, such as takeoff and landing, hovering, and cruising.

[0034] Furthermore, the installation heights of the mid-wing, tail wing, and front wing are successively reduced, that is, the installation height of the tail wing is higher than that of the front wing, and the installation height of the mid-wing is higher than that of the tail wing. This layout can reduce the influence of the wake generated by the ducted fan combination on the front wing on the air intake quality of the ducted fan on the rear wing, and avoid the poor air intake quality causing the ducted fan to fail to work normally. In particular, it can greatly reduce the influence of the wake of the mid-wing ducted system on the tail wing ducted system.

[0035] Furthermore, in the axial direction of the fuselage, the spacing between adjacent wings among the front, center, and tail wings is at least 1 times the width of any of the wings. This large axial spacing ensures that the wake generated by the ducted fan assembly on the front wing, when passing over the rear wing, does not significantly alter the airflow near the wing body, thereby destabilizing lift, thereby improving flight safety.

[0036] Furthermore, the distance between adjacent wings in the front, center, and tail wings is greater than 100 mm in the height direction of the fuselage. This height difference can further reduce the impact of the wake generated by the ducted fan assembly on the front wing on the intake quality of the ducted fan on the rear wing, thus preventing poor intake quality from causing the ducted fan to malfunction.

[0037] Furthermore, the wingspan of the front wing is equal to that of the tail wing, and the wingspan of the middle wing is more than twice that of the front wing.

[0038] Furthermore, the ducted fan is installed on the trailing edge of the corresponding wing and connected to the flap, and can tilt as a whole with the flap, with a tilt angle of 0°~90°.

[0039] Preferably, the lower portion of the ducted fan is integrated with the flaps of the corresponding wing. This reduces the number of controlled objects from the original two (the ducted fan and the flap) to one, simplifying flight control. This integration also produces a suction-lift effect, increasing the lift of the UAV. Furthermore, the ducted fan and the upper surface of the wing are streamlined, preventing significant separation of airflow between the wing and the ducted fan housing. When the UAV moves relative to the airflow, the airflow resistance it encounters is significantly reduced, significantly reducing fuel consumption and battery power consumption, thereby extending the photographic coverage area during a single aerial photography session and improving the economic efficiency of a single flight.

[0040] Furthermore, the number of ducted fans provided on the front wing is equal to the number of ducted fans provided on the tail wing, and the number of ducted fans provided on the mid-wing is more than twice the number of ducted fans provided on the front wing. For example, for the front wing and the rear wing, each ducted fan group contains six ducted fans, and each ducted fan group on the mid-wing contains twelve ducted fans. By adopting such a ducted fan arrangement, it is beneficial to the static stability design of the unmanned aerial vehicle, making it easier to adjust the attitude during flight. At the same time, this ducted layout is relatively symmetrical. When a ducted fan loses power, torque balance can be easily achieved by adjusting the output of other ducted fans.

[0041] In this embodiment, the ducted fans on different wing surfaces can be controlled separately, and through the differential of the ducted fans, the unmanned aerial vehicle can also perform maneuvers such as turning and rolling.

[0042] Furthermore, the diameter of the ducted fan is 1 / 8 to 1 / 10 of the maximum fuselage height. Such a design can improve the lift-drag characteristics of the unmanned aerial vehicle and reduce the aerodynamic interference between the ducted fans on adjacent wings.

[0043] The UAV adopts the above-mentioned three-wing layout, and the position arrangement and structural design of different wing surfaces effectively reduce the interference between the three rows of wings, significantly improves the stability of the UAV, significantly improves the aerodynamic load distribution of the entire aircraft, and thus greatly reduces the aerodynamic load on the wings and the weight of the wing structure.

[0044] By installing a tiltable ducted fan on the trailing edge of the wing, the unmanned aerial vehicle can achieve vertical take-off and landing and cruise, reducing the requirements for the take-off and landing environment and greatly expanding its application range. At the same time, each wing section retains most of the wing body to provide lift during the cruise phase, and uses the suction effect of the ducted fan to generate additional lift on the wing, which can effectively improve the wing lift-to-drag ratio and the cruise efficiency of the entire aircraft, making it more suitable for long-distance island aerial photography missions.

[0045] Furthermore, adjacent ducted fans arranged on the same wing surface are provided with ducts of the shape Figure 3 Aerodynamic shaping: By using a streamlined shape between the two ducted fans, not only does it make airflow less likely to separate, reducing resistance during airflow, but it also leaves no gap between the two ducted fans, preventing the potential interference with overall aerodynamic performance caused by airflow passing through a narrow gap.

[0046] Furthermore, the unmanned aerial vehicle also includes two vertical baffles 7, which are fixed at both ends of the tail 6 in a direction perpendicular to the fuselage axis and are symmetrically distributed relative to the fuselage axis. By setting these two vertical baffles 7, the flight stability of the unmanned aerial vehicle can be effectively improved.

[0047] Furthermore, the UAV includes front and rear landing gears. The front landing gear 8 is mounted on the front lower portion of the fuselage 1, approximately aligned with the front wing 2 in terms of axial position. The rear landing gear 5 is mounted on the lower middle portion of the fuselage 1, approximately aligned with the center wing 4 in terms of axial position. The pair of rear landing gears 5 are symmetrically distributed about the fuselage axis.

[0048] In addition, the overall structure of the unmanned aerial vehicle does not have any exposed propeller structure or any dangerous moving components, thereby improving the safety of use.

[0049] Based on the position and layout of the ducted fans on the UAV, all distributed ducted fans on the same wing can be approximated as a single rotor. Therefore, when hovering, the UAV can be approximated as a hexacopter. Combined with the structural characteristics of a hexacopter, the relationship between each torque and speed is easy to derive, resulting in the mapping equation:

[0050]

[0051] in, is the efficiency coefficient of the UAV motor in generating thrust, k is the efficiency coefficient of the motor in generating yaw torque, is the arm length, ω i is the speed of a row of distributed ducted fans, the thrust moment is T, the rolling moment is L, the pitch moment is M, and the yaw moment is N.

[0052] By mapping the speeds of the six ducted fan groups on the six wings of the UAV to four torques, this approach provides greater redundancy than the existing mapping of four ducted fan groups to four torques. If a ducted fan fails, the speeds of the other distributed ducted fans in the same group can be adjusted to balance the forces and torques, effectively improving the UAV's operational reliability.

[0053] Furthermore, the dynamic equation of the unmanned aerial vehicle during flight is:

[0054]

[0055] Where: k = 1, 2, 3, 4, 5, 6, is the wing number; 、 are the longitudinal coordinate and vertical coordinate of the relative center of gravity of the corresponding numbered pneumatic components; is the distance from the duct tension center to the tilt axis; is the tilt angle of the kth ducted fan group on the trailing edge of the airfoil, which is 90° in helicopter mode and 0° in fixed-wing aircraft mode. is the pull of the ducted fan group on the kth airfoil trailing edge; is the angle of attack of the corresponding numbered wing; are the lift, drag, angle of attack, and pitching moment of the fuselage respectively; G is the overall gravity of the fixed-wing aircraft.

[0056] In the strong sea breeze environment for offshore aerial photography missions, the drone can not only adjust the duct tension, but also quickly generate wind-resistant lateral force by adjusting the tilt angles of the six sets of ducted fans, thereby improving the response speed to time-varying wind interference, having strong wind resistance and being less affected by weather.

[0057] The unmanned aerial vehicle of this embodiment has at least three working states: vertical take-off, cruising and vertical landing. In the vertical take-off stage, the unmanned aerial vehicle is parked on the ground, and each ducted fan 3 in the ducted power group carried by the front wing 2, the middle wing 4 and the tail wing 6 is in a plumb position. During take-off, the ducted power group generates a pulling force to overcome the aircraft's own gravity and achieve vertical take-off. When the flight mode is switched, the ducted fans arranged on the front wing 2 and the tail wing 6 rotate forward around the tilt axis under the action of the tilt mechanism inside the wing. During the rotation process, the horizontal component of the pulling force generated by the ducted power group causes the unmanned aerial vehicle to generate acceleration. When the unmanned aerial vehicle accelerates forward, the wings generate a certain amount of lift, which together with the vertical component of the pulling force generated by the ducted power group overcomes the aircraft's own gravity. When the speed of the unmanned aerial vehicle reaches the lowest cruising speed, the ducted fans all tilt to a horizontal state, such as Figure 1 、 Figure 2 As shown, the UAV's transition mode ends and it fully transitions to cruise mode. The traction generated by the ducted power pack offsets the vehicle's drag, and the lift generated by the wings overcomes the UAV's own weight. The ducted fans located at the trailing edge of the wings draw boundary layer airflow from the wing's upper surface, improving the wing's aerodynamic efficiency. In cruise mode, the UAV's attitude is controlled by the ducted power pack's differential motion. The transition from cruise mode to fixed-point hovering or vertical landing is the reverse of vertical takeoff. The ducted fans rotate backward about their tilt axes under the action of the tilt mechanism. When the transition is complete, the ducted fans return to a vertical position, with the traction axis aligned vertically, effectively overcoming the UAV's weight and achieving fixed-point hovering. When all the distributed ducted power packs are in the vertical position, the power of each ducted fan is gradually increased to decelerate the UAV and lower its altitude until it touches down and completes a vertical landing. If a ducted fan on the ducted power group fails during flight, the UAV can adjust the output power of the remaining motors to keep the pulling force on the front and back, left and right sides of the UAV balanced, thereby ensuring the flight safety of the UAV.

[0058] The unmanned aerial vehicle of this embodiment can take off and land in a small area, and can be used for tasks such as cargo transportation in harsh conditions, disaster relief in remote areas, agricultural irrigation, climate monitoring, and maritime patrols.

[0059] For example, the unmanned aerial vehicle of this embodiment can be used to construct an unmanned aerial photography system. Figure 4 The unmanned aerial photography system includes an unmanned aerial vehicle (UAV) (hereinafter referred to as the UAV), a wireless communication module, an image recording module, an aerial photography information module, a data storage module, and a control unit. The aerial photography information module, wireless communication module, and image recording module are all mounted on the UAV. The control unit is located at a ground station and exchanges information with the image recording module and the UAV via the wireless communication module. The control unit is configured to control at least the flight status of the UAV, the operating status of the image recording module, and process information collected by the image recording module (i.e., image information) and store the processed data in the data storage module. The aerial photography information module is configured to record corresponding aerial photography operating data (hereinafter referred to as "operating information") when the image recording module is operating. The aerial photography operating data includes the time of the aerial photography, the spatial position information of the UAV, and the attitude information of the UAV. The control unit controls the operating status of these functional components by sending control commands to the UAV and the image recording module.

[0060] A cargo compartment may be provided inside the fuselage of the UAV, and at least the aerial photography information module and the wireless communication module may be loaded in the cargo compartment, and the image recording module may be installed on the central axis of the lower part of the fuselage.

[0061] Please refer to the preferred Figure 2 The image recording module includes an oblique photography device 9, which includes at least one vertical camera and multiple oblique cameras. Exemplarily, the oblique photography device is composed of one vertical camera and four oblique cameras.

[0062] The wireless communication module may be a Wi-Fi, Bluetooth communication module, etc. The data storage module may be a hard disk or other commonly used storage element in the art. The control unit may be a personal computer or a smart terminal device such as a smartphone or tablet computer.

[0063] Accordingly, this embodiment further provides an unmanned aerial photography method, which is implemented based on the unmanned aerial photography system and includes the following steps:

[0064] S1: The control unit determines the starting point of the aerial photography mission and designs a flight path for the UAV. In some cases, the UAV can also be controlled manually.

[0065] S2: After the UAV reaches the starting point of the aerial photography mission, the image recording module starts working and captures the required image data. At the same time, the aerial photography information module starts recording the corresponding aerial photography work data, and transmits the image data and aerial photography work data to the control unit through the wireless communication module. The control unit then processes the image data and aerial photography work data to obtain the required image format.

[0066] In this step, in order to obtain clear image data of a selected location, the UAV can be decelerated and hovered above the selected location, then the UAV can be vertically descended to a set height, and then the image recording module can capture the required image data. After completing the shooting task of the selected location, the UAV can be vertically ascended to the original planned height and subsequent shooting tasks can be carried out.

[0067] S3: After all aerial photography tasks are completed, the image recording module and the aerial photography information module stop working, and the unmanned aerial vehicle returns to the specified landing point and lands vertically at the specified location.

[0068] The above description is only an implementation method of the present application and does not limit the scope of protection of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the scope of patent protection of this application.

Claims

1. An unmanned aerial vehicle comprising a fuselage and wings, characterized in that: The unmanned aerial vehicle also includes a plurality of ducted fans and a tilt mechanism; the wings include a front wing, a middle wing and a tail wing, the wingspan of the front wing and the tail wing are equal, the wingspan of the middle wing is more than twice the wingspan of the front wing, the front wing, the middle wing and the tail wing are sequentially mounted on the fuselage from front to back, the mounting heights of the middle wing, the tail wing and the front wing decrease in sequence, and the spacing between adjacent wings in the front wing, the middle wing and the tail wing in the axial direction of the fuselage is more than 1 times the width of any one of the wings, and the spacing between adjacent wings in the front wing, the middle wing and the tail wing in the height direction of the fuselage is more than 100 mm; and each wing of the front wing, the middle wing and the tail wing includes a relative Two wing surfaces are symmetrically distributed about the fuselage axis, and a ducted fan group is provided on each wing surface. Each ducted fan group includes a plurality of the ducted fans, and the plurality of the ducted fans on the same wing are symmetrically distributed relative to the fuselage axis. The tilt mechanism is also installed in each wing, and the tilt mechanism is at least used to adjust the tilt angle of the corresponding ducted fan group, wherein the number of ducted fans arranged on the canard is equal to the number of ducted fans arranged on the tail, and the number of ducted fans arranged on the mid-wing is more than twice the number of ducted fans arranged on the canard; the diameter of the ducted fan is 1 / 8 to 1 / 10 of the maximum value of the fuselage height.

2. The unmanned aerial vehicle according to claim 1, wherein: The front wing, the middle wing and the tail wing are all single-layer structures.

3. The unmanned aerial vehicle according to claim 1, wherein: The ducted fan is mounted on the trailing edge of the corresponding wing.

4. The unmanned aerial vehicle according to claim 1, wherein: The ducted fan is connected to the flap of the corresponding wing and can tilt as a whole with the flap, with a tilt angle of 0° to 90°.

5. The unmanned aerial vehicle according to claim 1, wherein: The lower portion of the ducted fan is integrated with the flap of the corresponding wing.

6. The unmanned aerial vehicle according to claim 1, wherein: The ducted fan and the upper wing surface of the wing are streamlined structures.

7. The unmanned aerial vehicle according to claim 1, wherein: Streamlined shaping is adopted between adjacent ducted fans arranged on the same wing surface.

8. The unmanned aerial vehicle according to claim 1, wherein: The fuselage is a streamlined fuselage, and the height of the fuselage gradually increases and then gradually decreases from front to back.

9. The unmanned aerial vehicle according to claim 1, wherein: The unmanned aerial vehicle further comprises two vertical baffles, which are respectively fixed at two ends of the tail wing in a direction perpendicular to the axis of the fuselage and are symmetrically distributed relative to the axis of the fuselage.

10. The unmanned aerial vehicle according to claim 1, wherein: The unmanned aerial vehicle also includes a front landing gear and a rear landing gear. The front landing gear is located below the front wing and connected to the fuselage, and the rear landing gear is located below the middle wing and connected to the fuselage, and the rear landing gear is symmetrically distributed with respect to the fuselage axis.

11. The unmanned aerial vehicle according to claim 1, wherein: The dynamic equation of the unmanned aerial vehicle during flight is: Where: k = 1, 2, 3, 4, 5, 6, is the wing number; x k 、y k are the longitudinal coordinate and vertical coordinate of the relative center of gravity of the corresponding numbered aerodynamic components; l is the distance from the duct tension center to the tilt axis; i Nk is the tilt angle of the kth ducted fan group on the trailing edge of the airfoil, which is 90° in helicopter mode and 0° in fixed-wing aircraft mode. k is the pull of the kth ducted fan group on the trailing edge of the airfoil; α k,W is the angle of attack of the corresponding numbered wing; L F 、D F , α F 、M F They are the lift, drag, angle of attack and pitching moment of the fuselage respectively; G is the overall gravity of the fixed-wing aircraft.

12. An unmanned aerial photography system, characterized in that: The unmanned aerial vehicle according to any one of claims 1 to 11, a wireless communication module, an image recording module, an aerial photography information module, a data storage module, and a control unit; Wherein, the aerial photography information module, wireless communication module and image recording module are all arranged on the unmanned aerial vehicle; The control unit is arranged at the ground station and exchanges information with the image recording module and the unmanned aerial vehicle via the wireless communication module; The control unit is at least used to control the flight state of the unmanned aerial vehicle, the working state of the image recording module, and process the information collected by the image recording module, and store the processed data in the data storage module; The aerial photography information module is at least used to record corresponding aerial photography work data when the image recording module is working. The aerial photography work data includes aerial photography time, spatial position information of the unmanned aerial vehicle, and posture information of the unmanned aerial vehicle.

13. The unmanned aerial photography system according to claim 12, characterized in that: A cargo compartment is provided inside the fuselage of the unmanned aerial vehicle, and the cargo compartment is used to at least carry the aerial photography information module and the wireless communication module. The image recording module is installed on the central axis of the lower part of the fuselage.

14. The unmanned aerial photography system according to claim 12, characterized in that: The image recording module includes an oblique photography device, which includes at least one vertical camera and multiple oblique cameras.

15. An unmanned aerial photography method, characterized in that: The unmanned aerial photography method is implemented based on the unmanned aerial photography system according to any one of claims 12 to 14, and comprises the following steps: S1: The control unit determines the starting point of the aerial photography mission and designs the flight path for the UAV; S2: After the UAV reaches the starting point of the aerial photography mission, the image recording module starts to work and captures the required image data, and the aerial photography information module starts to record the corresponding aerial photography work data, and transmits the image data and the aerial photography work data to the control unit via the wireless communication module, and the control unit then processes the image data and the aerial photography work data to obtain the required image format; S3: After all aerial photography tasks are completed, the image recording module and the aerial photography information module stop working, and the unmanned aerial vehicle returns to the specified landing point and lands vertically at the specified location.

16. The unmanned aerial photography method according to claim 15, characterized in that: Step S2 also includes: in the process of performing the aerial photography task, in order to obtain clear image data of a selected location, the unmanned aerial vehicle is decelerated and hovered above the selected location, and then the unmanned aerial vehicle is vertically descended to a set height, and then the image recording module is used to capture the required image data. After completing the shooting task of the selected location, the unmanned aerial vehicle is vertically ascended to the original planned height and subsequent shooting tasks are carried out.

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