Pure electric tandem dual-rotor unmanned helicopter platform

Abstract

The invention relates to a pure electric tandem double-rotor unmanned helicopter platform which comprises a rack, a rotor system, a transmission system, a power system and a control system, the rack is made of a carbon fiber material and comprises a triangular truss, rotor tower bases fixed to the front end and the rear end of the triangular truss and undercarriages fixed to bottom plates of the rotor tower bases; a rotor system is arranged on each rotor tower base, and the rotation directions of the two rotor systems are opposite and counteract the reverse torsional moment of the propeller disc; a transmission system is mounted on each rotor system; the power system comprises two sets of transmission electric power systems which are arranged on the rack and used for providing power for the transmission system; and the control system is used for providing flight control, navigation and data monitoring data information for the helicopter. According to the invention, the two sets of rotor systems depend on respective pure electric power systems to drive the rotors to rotate in opposite directions, and by adopting the structural design of the pure electric power systems, the machining difficulty and the maintenance difficulty are low.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft, and in particular to a pure electric tandem twin-rotor unmanned helicopter platform. Background Art

[0002] The main advantage of the tandem twin-rotor helicopter is that its rotors are arranged in tandem, and the front and rear rotors provide lift at the same time. The carrying capacity is significantly improved compared to the traditional single-rotor helicopter. The load can be arranged at multiple points between the two rotor shafts, which is suitable for tasks that change the center of gravity of the load midway. No special balancing is required, and the transportation efficiency is high and the requirements for take-off and landing sites are relatively low. The mainstream tandem twin-rotor drones at home and abroad mostly use oil-powered aviation engines. The advantages are that the load capacity and endurance are relatively good; but the disadvantages are complex structure, difficult maintenance, high control difficulty, and large engine vibration. In recent years, with the development of electric drones, unmanned helicopters using batteries as driving force have also been widely used and developed. In addition, at present, tandem twin-rotor unmanned helicopters at home and abroad are classified as medium-sized drones according to size and weight, while small tandem twin-rotor drones are rare on the market, which makes it difficult to study tandem twin-rotor models and flight control systems. Summary of the invention

[0003] Therefore, in response to the above problems, a small pure electric tandem twin-rotor unmanned helicopter platform is developed to meet the requirements of light weight, miniaturization and electric drive.

[0004] The purpose of the present invention and the solution to its technical problems are achieved by adopting the following technical solutions. A pure electric tandem twin-rotor unmanned helicopter platform proposed in the present invention includes a frame, a rotor system, a transmission system, a power system and a control system. The frame is made of carbon fiber material, including a triangular truss, a rotor tower fixed at the front and rear ends of the triangular truss, and a landing gear fixed on the bottom plate of the rotor tower; each rotor tower is provided with a rotor system, and the two rotor systems rotate in opposite directions to offset the anti-torque moment of the propeller disc; each rotor system is installed with a transmission system; the power system includes two sets of electric power transmission systems, which are arranged on the frame to provide power for the transmission system; the control system is used to provide flight control and navigation, data monitoring data information for the helicopter, and the control system includes a flight controller fixed on the frame, which obtains the attitude information of the drone through the inertial navigation system, and realizes attitude control through the PID controller.

[0005] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0006] The aforementioned pure electric tandem twin-rotor unmanned helicopter platform, the rotor system includes carbon fiber blades, a hub, an automatic tilt device and an anti-torsion arm, wherein the axis distance between the two rotor systems is greater than the propeller disc diameter, and the propeller discs of the two rotor systems have no overlapping area.

[0007] The aforementioned pure electric tandem twin-rotor unmanned helicopter platform, the transmission system includes a self-lubricating nylon reduction gear, a rotor main shaft and a one-way bearing; wherein the reduction gear is connected to the rotor main shaft, and the one-way bearing is installed on the rotor main shaft, so that the rotor main shafts of the two rotor systems rotate in opposite directions.

[0008] The aforementioned pure electric tandem twin-rotor unmanned helicopter platform, the control system also includes a GNSS positioning system, an obstacle avoidance radar and a data link fixed on the triangular truss.

[0009] The aforementioned pure electric tandem twin-rotor unmanned helicopter platform, the triangular truss includes three carbon fiber tubes distributed in a triangular shape and a plurality of carbon tube holders distributed along the axial direction of the carbon fiber tubes, the carbon tube holders provide support for the above-mentioned carbon fiber tubes and keep them in a stable relative position.

[0010] The aforementioned pure electric tandem twin-rotor unmanned helicopter platform, the carbon tube retainer includes an upper retainer and a lower retainer, wherein the upper retainer is a triangular frame, the top corner of the triangular frame is provided with a limiting hole for circumferentially limiting the uppermost carbon fiber tube, and a first arc groove is provided below the two bottom corners; the lower retainer is fixed to the bottom of the upper retainer, and the upper two sides thereof are respectively provided with a second arc groove for cooperating with the first arc groove to achieve circumferential limiting of the carbon fiber tube located below.

[0011] The aforementioned pure electric tandem twin-rotor unmanned helicopter platform also has weight-reducing structures on each side of the retaining frame.

[0012] In the aforementioned pure electric tandem twin-rotor unmanned helicopter platform, the front and rear ends of the two carbon fiber tubes located at the bottom of the triangular truss are provided with connecting blocks for fixing the rotor tower; the two ends of the carbon fiber tube located at the top are respectively connected and fixed to a rotor tower.

[0013] The aforementioned pure electric tandem twin-rotor unmanned helicopter platform, the triangular truss is also provided with a flight controller mounting plate, the flight controller is fixed on the flight controller mounting plate, and the flight controller mounting plate is also provided with tandem twin-rotor UAV flight control firmware and cables.

[0014] The aforementioned pure electric tandem twin-rotor unmanned helicopter platform also has a GNSS positioning system mounting plate and two battery pack mounting racks on the triangular truss; the rotor tower is provided with a digital image transmission module mounting bracket for installing a camera, a data transmission link or an obstacle avoidance radar.

[0015] Compared with the prior art, the present invention has obvious advantages and beneficial effects. By means of the above technical solution, the present invention can achieve considerable technical advancement and practicality, and has wide industrial utilization value, and has at least the following advantages:

[0016] 1. The pure electric power system has better structural design, machining difficulty and maintenance difficulty than fuel engines, and is more environmentally friendly;

[0017] 2. Two rotor systems with opposite rotation directions are installed on two rotor towers respectively, which can offset the anti-torque generated by each other, without the need to design a separate tail rotor;

[0018] 3. Compared with other tandem twin-rotor drones, the rotor discs rotate without overlapping areas, the synchronous transmission mechanical structure is eliminated, and the rotor main axis distance is large, so the hovering efficiency is higher;

[0019] 4. If the power system fails, the main shaft of the rotor system is equipped with a one-way bearing, which can achieve a safe forced landing without power based on inertia, making it safer;

[0020] 5. It has excellent ability to resist crosswind disturbances when hovering, has a large control margin, and has low requirements for the take-off and landing environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 1. is an axonometric view of the structure of a pure electric tandem twin-rotor unmanned helicopter platform according to an embodiment of the present invention;

[0022] Figure 2 2. It is a cross-sectional view of the transmission system of a pure electric tandem twin-rotor unmanned helicopter platform in an embodiment of the present invention;

[0023] Figure 3 1 is a front view of a pure electric tandem twin-rotor unmanned helicopter platform according to an embodiment of the present invention;

[0024] Figure 4 This is a left view of a pure electric tandem twin-rotor unmanned helicopter platform according to an embodiment of the present invention;

[0025] Figure 5 1. It is a composition diagram of a pure electric tandem twin-rotor unmanned helicopter platform system in an embodiment of the present invention.

[0026]

Main component symbol description

[0027] 1-digital image transmission module mounting bracket, 2-front rotor tower, 3-front rotor system, 4-GNSS positioning system, 5-triangular truss, 6-rear rotor system, 7-rear rotor tower, 8-landing gear, 9-battery pack, 10-flight controller, 11-rotor main shaft, 12-reduction gear, 13-one-way bearing, 14-carbon fiber tube, 15-upper holder, 16-lower holder, 17-first arc groove, 18-second arc groove, 19-through hole, 20-connecting block, 21-connecting base plate, 22-connecting seat, 23-flight controller mounting plate. DETAILED DESCRIPTION

[0028] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation method, structure, characteristics and effects of the pure electric tandem twin-rotor unmanned helicopter platform proposed by the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0029] See also Figure 1-5 , which is a schematic diagram of the structure of each part of the pure electric tandem twin-rotor unmanned helicopter platform of the present invention, the helicopter includes a frame, a rotor system, a transmission system, a power system and a control system, wherein the frame is made of carbon fiber material, and includes a triangular truss 5, a front rotor tower 2 fixed to the front end of the triangular truss 5, a rear rotor tower 7 fixed to the rear end of the triangular truss 5, and a landing gear 8 fixed to the bottom plates of the front rotor tower 2 and the rear rotor tower 7. The frame has the characteristics of stable structure, small size and light weight.

[0030] The rotor system includes a front rotor system 3 and a rear rotor system 6, both of which include carbon fiber blades, a hub, an automatic tilt device, and an anti-torsion arm, wherein the front rotor system 3 is mounted on the front rotor tower 2, and the rear rotor system is mounted on the rear rotor tower 7, and the rotation directions of the front rotor system 3 and the rear rotor system 6 are opposite, and can offset the anti-torsion moment of the propeller disc. In addition, the axial spacing between the front rotor system 3 and the rear rotor system 6 of the present invention is greater than the propeller disc diameter, the propeller discs of the front and rear rotor systems have no overlapping area, the propeller disc lift is not consumed by the front and rear rotors, and the whole machine has a more excellent hovering performance.

[0031] The transmission system is a reduction gear mechanism installed on two rotor towers respectively, each equipped with a one-way bearing to ensure that when the rotor system loses power, it can safely land by rotating itself. Specifically, the transmission system includes two sets of self-lubricating nylon reduction gears 12, two sets of rotor main shafts 11 and two one-way bearings 13 with opposite directions. The reduction gear 12 is connected to the rotor main shaft 11, and the one-way bearing 13 is installed on the rotor main shaft 11, so that the two sets of rotor main shafts 11 rotate in opposite directions. The rotor system of the present invention also includes a servo steering gear for controlling the cyclic pitch change and the total pitch of the rotor disc.

[0032] The power system is a pure electric power system, which is fixed on the triangular truss, and there are two sets, which are respectively installed in cooperation with the reduction mechanism in the front rotor system 3 and the rear rotor system 6 to provide power for the rotor system. In this embodiment, the power system includes two sets of battery packs 9, a power management system, a brushless drive motor and a brushless electronic speed regulator.

[0033] The control system is fixed on the triangular truss, including a flight controller 10, a tandem dual-rotor UAV flight control firmware, a GNSS positioning system 4, an obstacle avoidance radar, a data link, etc., to provide flight control and navigation, data monitoring data information for the unmanned helicopter. The flight controller obtains the attitude information of the UAV through the inertial navigation system and realizes attitude control through the PID controller. The GNSS positioning system 4 is also equipped with a barometer sensor.

[0034] The battery pack 9 is a high-energy-density lithium battery pack. The power management system is respectively connected to the high-energy-density lithium battery pack, the flight controller, and the electronic speed regulator of the front and rear rotor drive motors to monitor the working status of the battery pack and allocate efficient and reliable power to each electrical device. The triangular truss 5 includes three carbon fiber tubes 14 and a plurality of carbon tube holders distributed along the axial direction of the carbon fiber tubes 14. One of the three carbon fiber tubes 14 is located at the top, and the other two are distributed in parallel at the bottom, forming an isosceles triangle. The carbon tube holder provides support for the three carbon fiber tubes 14 and keeps them in the above relative position.

[0035] In this embodiment, the carbon tube holder is formed by docking an upper holder 15 and a lower holder 16, wherein the upper holder 15 is a triangular frame structure, and a limiting hole for circumferentially limiting the uppermost carbon fiber tube 14 is provided at the top corner of the triangular frame, and a first arc groove 17 adapted to the outer periphery of the upper ends of the two carbon fiber tubes 14 located below is provided at the two bottom corners of the triangular frame. The lower holder 16 is fixed to the bottom of the upper holder 15, and a second arc groove 18 adapted to the outer periphery of the lower end of the carbon fiber tube 14 is provided on both sides of the upper end surface. When the upper holder 15 and the lower holder 16 are docked and fixed, the corresponding first arc groove 17 and the second arc groove 18 are opposite to each other, and together form a limiting hole for constraining the outer periphery of the carbon fiber tube 14, so as to support and position the two carbon fiber tubes 14 below. In this embodiment, the upper holder 15 and the lower holder 16 are connected and fixed by screws. Preferably, each side of the holder is also provided with a hollow or groove structure for weight reduction.

[0036] In this embodiment, in order to achieve a stable connection between the carbon fiber tube 14 and the carbon tube holder, the carbon fiber tube 14 and the carbon tube holder are also connected by a limit member, one end of the limit member passes through the through hole 19 on the carbon tube holder, and the other end is inserted into the groove or through hole on the carbon fiber tube 14, so that the carbon fiber tube 14 and the carbon tube holder maintain axial and radial stop fit.

[0037] The front and rear ends of the carbon fiber tube 14 are also respectively provided with connection blocks 20 for fixing the front rotor tower 2 to the front end of the triangular truss 5 and the rear rotor tower 7 to the rear end of the triangular truss 5. Specifically, a connection block is fixedly provided at each end of the two carbon fiber tubes 14 located at the bottom of the triangular truss 5, and the front rotor tower 2 and the rear rotor tower 7 are both fixed on the triangular truss 5 through the two connection blocks 20.

[0038] In this embodiment, the connection block includes a connection base plate 21 and at least two connection seats 22 fixed on the connection base plate 21. The connection seats 22 also achieve positioning after the two are connected by cooperating with the positioning pieces embedded thereon and the peripheral holes or grooves of the carbon fiber tube 14.

[0039] In order to further enhance the stability of the rotor tower fixed on the triangular truss 5 and prevent it from swinging, the two ends of the uppermost carbon fiber tube 14 in the triangular truss 5 of the present invention are also connected to the front rotor tower 2 and the rear rotor tower 7 respectively. Preferably, the end faces of both ends of the carbon fiber tube 14 are provided with anti-rotation grooves, which are used to cooperate with the corresponding protrusions on the rotor tower to achieve an anti-rotation connection between the two. In other embodiments of the present invention, a protrusion structure can also be provided on the front and rear end faces of the carbon fiber tube 14, and the protrusion structure cooperates with the corresponding grooves on the rotor tower to achieve a concave-convex anti-rotation fit.

[0040] The triangular truss 5 is also provided with a flight controller mounting plate 23, which is used to install the flight controller 10 and flight control hardware such as the flight control firmware of the tandem twin-rotor drone and cables. In this embodiment, the flight controller mounting plate 23 is also provided with a flight control damping plate and a cable clamp. In this embodiment, the flight controller mounting plate 23 is Z-shaped, the horizontal portion at the upper end of the Z-shaped is fixedly connected to the topmost carbon fiber tube 11, the lower horizontal portion is provided with a cable clamping block and is used to carry the flight control firmware, the vertical portion is provided with a flight control damping plate, and the horizontal portion below the flight controller mounting plate is also connected to the rotor tower at its end.

[0041] A GNSS positioning system mounting plate is also fixed on the triangular truss 5, and the GNSS positioning system 4 is fixed in the GNSS positioning system mounting plate. Preferably, the GNSS positioning system mounting plate is fixed on the flight controller mounting plate 23, but it is not limited thereto.

[0042] Two battery pack mounting frames are also fixed on the triangular truss 5 to realize the fixed installation of two battery packs 9. Specifically, the battery pack mounting frames are fixed at the bottom of the carbon tube holder.

[0043] A digital image transmission module mounting bracket 1 is respectively provided on the bottom plate of the front rotor pylon 2 and the rear rotor pylon 7, and the digital image transmission module mounting bracket 1 can be installed with a small camera, a data transmission link or an obstacle avoidance radar. The digital image transmission module mounting bracket 1 is located in front of the front landing gear or behind the rear landing gear.

[0044] In the embodiment of the present invention, the two landing gears 8 are respectively located below the connection blocks at the front and rear ends of the triangular truss 5, and are directly connected to the bottom plates of the front rotor tower 2 and the rear rotor tower 7, without occupying the belly space of the frame. In this embodiment, the landing gear 8 is in an inverted U shape with an opening gradually expanding from top to bottom, which can ensure the stability of the frame.

[0045] The pure electric tandem twin-rotor unmanned helicopter platform of the present invention adopts two sets of independent drive motor structures. The front and rear rotor systems provide lift at the same time, and can obtain the best performance under low propeller disk load. The longitudinal center of gravity range is large and the hovering efficiency is higher. The fuselage and external attachment points are not affected by the changes in the center of gravity of the structure and external cargo, and are not disturbed by the landing mechanism. The carrying capacity and hovering efficiency are significantly improved compared with traditional single-rotor helicopters. The tandem twin-rotor helicopter has strong crosswind resistance and still has a large control margin in a level 5 wind environment.

[0046] Further,

[0047] The working process and principle of a pure electric tandem twin-rotor unmanned helicopter platform provided in this embodiment are as follows:

[0048] 1. The two rotor systems rely on their own pure electric power systems to drive the front and rear rotors to rotate in opposite directions. The pure electric power system can be equipped with a brushless motor with a power battery and an electronic speed regulator;

[0049] 2. The main rotor rotates at a constant speed. When the speed reaches the preset value, it remains unchanged. The total pitch of the main rotor is changed by the up and down movement of the swash plate, resulting in a change in lift, thus achieving the rise and fall of the UAV.

[0050] 3. The main rotor swash plates of the two rotor systems move toward each other to change the lift direction of the main rotor, thereby controlling the UAV to complete pitch and roll movements and achieve heading control;

[0051] 4. The inertial navigation system of the flight control unit is used to obtain the attitude data of the UAV in real time, and the PID controller is used to control the aircraft to achieve self-stabilization; the altitude parameters are obtained through the barometer sensor to achieve altitude maintenance of the UAV; the positioning coordinates and geomagnetic heading of the UAV are obtained through the GNSS positioning system to achieve functions such as fixed-point hovering, one-key takeoff and landing, one-key return and track planning of the UAV; the laser obstacle avoidance radar is equipped to dynamically perceive the surrounding obstacle information to achieve physical obstacle avoidance of the UAV.

[0052] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with the profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A pure electric tandem twin-rotor unmanned helicopter platform, comprising a frame, a rotor system, a transmission system, a power system and a control system, characterized in that: The frame is made of carbon fiber material, including a triangular truss, a rotor tower fixed at the front and rear ends of the triangular truss, and a landing gear fixed on the bottom plate of the rotor tower; each rotor tower is provided with a rotor system, and the two rotor systems rotate in opposite directions to offset each other's anti-torque torque of the propeller disc; each rotor system is installed with a transmission system; the power system includes two sets of electric power transmission systems, which are arranged on the frame to provide power for the transmission system; the control system is used to provide flight control and navigation, data monitoring data information for the helicopter, and the control system includes a flight controller fixed on the frame, which obtains the attitude information of the drone through the inertial navigation system and realizes attitude control through the PID controller.

2. The pure electric tandem twin-rotor unmanned helicopter platform according to claim 1 is characterized by: The rotor system includes carbon fiber blades, a hub, an automatic tilt device and an anti-torsion arm, wherein the axis distance between the two rotor systems is greater than the diameter of the propeller disc, and the propeller discs of the two rotor systems have no overlapping area.

3. The pure electric tandem twin-rotor unmanned helicopter platform according to claim 2 is characterized by: The transmission system includes a self-lubricating nylon reduction gear, a rotor main shaft and a one-way bearing; the reduction gear is connected to the rotor main shaft, and the one-way bearing is installed on the rotor main shaft, so that the rotor main shafts of the two rotor systems rotate in opposite directions.

4. The pure electric tandem twin-rotor unmanned helicopter platform according to claim 1 is characterized by: The control system also includes a GNSS positioning system, an obstacle avoidance radar and a data link fixed on the triangular truss.

5. The pure electric tandem twin-rotor unmanned helicopter platform according to any one of claims 1 to 4, characterized in that: The triangular truss comprises three carbon fiber tubes distributed in a triangular shape and a plurality of carbon tube holders distributed along the axial direction of the carbon fiber tubes. The carbon tube holders provide support for the carbon fiber tubes and keep them in a stable relative position.

6. The pure electric tandem twin-rotor unmanned helicopter platform according to claim 5 is characterized by: The carbon tube holder comprises an upper holder and a lower holder, wherein the upper holder is a triangular frame, a limiting hole for circumferentially limiting the uppermost carbon fiber tube is provided at the top corner of the triangular frame, and a first arc groove is provided below the two bottom corners; the lower holder is fixed to the bottom of the upper holder, and a second arc groove is provided on both sides thereof for cooperating with the first arc groove to achieve circumferential limiting of the carbon fiber tube located below.

7. The pure electric tandem twin-rotor unmanned helicopter platform according to claim 6 is characterized by: Each side of the retaining frame is also provided with a weight-reducing structure.

8. The pure electric tandem twin-rotor unmanned helicopter platform according to claim 5 is characterized by: The front and rear ends of the two carbon fiber tubes at the bottom of the triangular truss are both provided with connection blocks for fixing the rotor tower; the two ends of the carbon fiber tube at the top are respectively connected and fixed to a rotor tower.

9. The pure electric tandem twin-rotor unmanned helicopter platform according to claim 5, characterized in that: The triangular truss is also provided with a flight controller mounting plate, the flight controller is fixed on the flight controller mounting plate, and the flight controller mounting plate is also provided with a tandem twin-rotor UAV flight control firmware and cables.

10. The pure electric tandem twin-rotor unmanned helicopter platform according to claim 5, characterized in that: The triangular truss is also provided with a GNSS positioning system mounting plate and two battery pack mounting racks; the rotor tower is provided with a digital image transmission module mounting bracket for installing a camera, a data transmission link or an obstacle avoidance radar.

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