A full-magnetic force supported rotor unmanned aerial vehicle and a flight control method thereof

Abstract

The application discloses a full-magnetic-force-supported rotor unmanned aerial vehicle and a flight control method thereof. The rotor unmanned aerial vehicle adopts a high-speed non-iron-core permanent magnet synchronous motor to realize driving rotation, eliminates iron core loss during high-frequency and high-speed operation of the motor, and directly connects the blade and the motor rotor. A Halbach permanent magnet array and an aluminum ring are respectively fixed in corresponding grooves of an outer ring frame of a shell and an outer ring frame of a rotor, so that axial suspension force and partial radial suspension force are generated, the main radial suspension force is provided by a radial passive permanent magnet ring, and the rotor blade system is fully suspended. The shell outer ring frame and the shell inner ring frame are fixed by spokes, so that the overall weight can be reduced while the mechanical strength is ensured. The motor rotating speed and the guide vane angle are adjusted by the flight control method, so that the vertical lifting, air hovering, horizontal flight and stable landing of the rotor unmanned aerial vehicle are realized. The full-magnetic-force-supported rotor unmanned aerial vehicle has small electromagnetic loss, no mechanical friction and high cooperativity, and can improve the system operation efficiency and stability.

Description

Technical Field

[0001] This invention belongs to the field of unmanned aerial vehicle (UAV) technology, specifically relating to a fully magnetically supported rotary-wing UAV and its flight control method. Background Technology

[0002] Unmanned aerial vehicles (UAVs) offer advantages such as low cost, high maneuverability, and ease of use. In the military field, UAVs have become a new type of weapon platform, capable of performing tasks such as armed patrols, electronic jamming, reconnaissance and surveillance, ground attack, communications relay, target location, and attack assessment. In the civilian field, UAVs are used for aerial photography, agricultural plant protection, air logistics, traffic monitoring, terrain surveying, and disaster relief and fire prevention.

[0003] For example, patent CN108382566A, entitled "A Magnetic Levitation Rotor Structure," discloses a drone with a magnetic levitation rotor structure. However, this structure uses too many stator cores, resulting in high core losses and excessive overall weight. In addition, the blades and rotor are only fixed at one end, and vibration still occurs during high-speed operation. Furthermore, there is no guide vane control system, which can only achieve simple ascent and descent.

[0004] Rotary-wing drones use propellers to generate thrust. To improve the flight time of drones, a highly efficient rotary-wing drone structure must be designed. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a fully magnetically supported rotary-wing UAV and its flight control method, solving the problems of UAV drive and support, and improving the operating efficiency and stability of the UAV.

[0006] The technical solution provided by this invention is as follows:

[0007] In a first aspect, the present invention provides a fully magnetically supported rotary-wing unmanned aerial vehicle (UAV), which includes an outer shell, a rotor, a suspension part, and a rotation drive module; wherein:

[0008] The outer casing includes an inner ring frame, spokes, and an outer ring frame; the spokes connect the inner ring frame and the outer ring frame.

[0009] The rotor section includes an inner rotor frame, blades, and an outer rotor frame; the blades connect the inner rotor frame and the outer rotor frame.

[0010] The suspension system includes an inner ring suspension assembly and an outer ring suspension assembly;

[0011] The inner ring suspension assembly includes a central shaft, a radial inner permanent magnet ring, and a radial outer permanent magnet ring. The central shaft is located at the center of the inner ring frame of the outer shell, the radial inner permanent magnet ring is located on the central shaft, and the radial outer permanent magnet ring is located around the radial inner permanent magnet ring and opposite to the radial inner permanent magnet ring. The rotor inner ring frame is connected to the radial outer permanent magnet ring to achieve inner ring suspension between the rotor inner ring frame and the outer shell.

[0012] The outer ring suspension assembly includes a Halbach permanent magnet array and an aluminum ring; the Halbach permanent magnet array is located on the outer ring frame of the outer shell, and the aluminum ring is located on the outer ring frame of the rotor, thereby achieving outer ring suspension between the outer ring frame of the rotor and the outer ring frame of the outer shell;

[0013] The rotary drive module includes a stator back yoke, a stator winding frame, a stator coil, a rotor permanent magnet, and rotor silicon steel sheets. The stator coil is wound on the stator winding frame, which is fixedly connected to the stator back yoke. The stator back yoke, stator winding frame, and stator coil are all located on the outer ring frame of the outer casing. The rotor permanent magnet is located on the outer ring frame of the rotor via rotor silicon steel sheets and is opposite to the stator coil. Thus, the rotor permanent magnet on the outer ring frame of the rotor is driven by the stator coil on the outer ring frame of the outer casing, thereby realizing the rotation of the rotor section.

[0014] Furthermore, the outer ring frame of the outer shell is provided with a groove facing the outer ring frame of the rotor, and the outer ring frame of the rotor is located in the groove.

[0015] Furthermore, the rotor outer ring frame is provided with a protrusion that matches the groove in the direction of the outer ring frame of the outer shell.

[0016] Furthermore, the Halbach permanent magnet array includes an upper Halbach permanent magnet array and a lower Halbach permanent magnet array, and the aluminum ring includes an upper aluminum ring and a lower aluminum ring;

[0017] The outer ring frame of the outer shell has mounting slots on the upper and lower sides of the groove for mounting the upper Halbach permanent magnet array and the lower Halbach permanent magnet array, which are located in the mounting slots.

[0018] The upper and lower sides of the convex end of the rotor outer ring frame are provided with ring grooves for installing the upper aluminum ring and the lower aluminum ring, which are located in the ring grooves; and the upper Halbach permanent magnet array and the lower Halbach permanent magnet array are respectively opposite to the upper aluminum ring and the lower aluminum ring.

[0019] Furthermore, the groove is an inverted trapezoidal groove, with the edge of the groove forming a 60° angle with the central axis direction.

[0020] Furthermore, the inner ring suspension assembly also includes an axial protection bearing mover and an axial protection bearing stator;

[0021] The axial protection bearing mover is located on the upper and lower sides of the inner ring frame of the rotor, and the axial protection bearing stator is located on the inner ring frame of the outer shell and is opposite to the axial protection bearing mover.

[0022] Furthermore, the blades are bolted to the grooves of the inner rotor frame on one side and mounted on the outer rotor frame on the other side using dovetail grooves and bosses.

[0023] Furthermore, the rotary-wing UAV also includes a deflector; the deflector is located on the outer shell and below the propeller blades, and the angle between the deflector and the axial direction is adjustable to adjust the flight direction of the rotary-wing UAV.

[0024] Secondly, the present invention provides a flight control method for a fully magnetically supported rotary-wing unmanned aerial vehicle as described in any one of the above, the method comprising:

[0025] A Halbach permanent magnet array is used to achieve levitation between the outer shell and the rotor section;

[0026] The rotor section is driven to rotate, enabling the rotorcraft drone to fly up and down.

[0027] Furthermore, the method also includes:

[0028] The flight direction of the rotary-wing UAV can be adjusted by adjusting the angle of the guide vane located on the outer shell and below the propeller.

[0029] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0030] (1) A high-speed coreless permanent magnet synchronous motor is adopted. When running at high speed, the stator core loss is small and the motor efficiency is high. The motor has no magnetic teeth, which eliminates the cogging torque and makes the operation more stable.

[0031] (2) The use of all-magnetic bearings instead of traditional mechanical bearings eliminates friction loss; and the all-magnetic support system uses passive radial permanent magnet rings and axial EDS electric suspension bearings, without active electronic control system, thus consuming no overall system energy.

[0032] (3) The blades are fixed at both ends and form an integral part with the motor rotor. They are directly driven by the motor, resulting in less vibration when rotating at high speed, making the rotor drone structure more compact.

[0033] (4) The flight control method can effectively coordinate the motor drive and the deflector angle to achieve vertical take-off, hovering, horizontal flight and stable landing of the rotor drone. Attached Figure Description

[0034] Figure 1 This is a frontal cross-sectional view of a rotary-wing unmanned aerial vehicle (UAV).

[0035] Figure 2This is a top-view cross-sectional view of the outer shell of a rotary-wing drone.

[0036] Figure 3 Axonometric drawing of the rotor section of a rotary-wing UAV;

[0037] Figure 4 Diagram showing the installation of rotor blades for a rotary-wing drone;

[0038] Figure 5 Power-torque diagram of a high-speed coreless permanent magnet synchronous motor;

[0039] Figure 6 Power-current diagram of a high-speed coreless permanent magnet synchronous motor;

[0040] Figure 7 Speed-efficiency diagram for a high-speed coreless permanent magnet synchronous motor;

[0041] Figure 8 The magnetic field distribution diagram of the Halbach permanent magnet array of the axial EDS electric levitation module;

[0042] Figure 9 This is a graph showing the radial repulsion force of a permanent magnet ring.

[0043] Figure 10 This is a flowchart of the flight control method.

[0044] In the diagram: 1-Stator back yoke, 2-Stator winding frame, 3-Rotor permanent magnet, 4-Rotor silicon steel sheet, 5-Upper Halbach permanent magnet array, 6-Upper aluminum ring, 7-Stator coil, 8-Blade, 9-Inner rotor ring frame, 10-Axial protection bearing mover, 11-Axial protection bearing stator, 12-Central shaft, 13-Radial inner permanent magnet ring, 14-Radial outer permanent magnet ring, 15-Outer rotor ring frame, 16-Lower aluminum ring, 17-Lower Halbach permanent magnet array, 18-Outer outer ring frame, 19-Inner outer ring frame, 20-Spoke, 21-Guide plate. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0046] This invention discloses a fully magnetically supported rotorcraft unmanned aerial vehicle (UAV) structure and its flight control method. A high-speed, coreless permanent magnet synchronous motor is used for drive rotation, eliminating core losses during high-frequency, high-speed motor operation. The rotor blades are directly connected to the motor rotor. A Halbach permanent magnet array and an aluminum ring are fixed in corresponding grooves on the outer shell frame and the rotor outer shell frame, respectively, generating axial levitation force and partial radial levitation force. The radial passive permanent magnet ring provides the main radial levitation force, thus achieving full levitation of the rotor blade system. An axially mounted mechanical protective bearing prevents collisions during the UAV's ascent and descent. Spokes are used to fix the outer and inner shell frames, reducing overall weight while maintaining mechanical strength. The motor speed and guide vane angle are adjusted using the flight control method to achieve vertical takeoff, hovering, horizontal flight, and stable landing of the rotorcraft UAV. This structure has low electromagnetic loss, no mechanical friction, and high synergy, improving system operating efficiency and stability.

[0047] This invention employs a high-speed coreless permanent magnet synchronous motor that eliminates the guide teeth, offering the following characteristics and advantages compared to traditional permanent magnet motors: (1) It eliminates or significantly reduces stator iron losses and eddy current losses, resulting in no cogging torque and near-zero torque pulsation; (2) It exhibits extremely low rotor losses, especially under sinusoidal current excitation, where rotor permanent magnet losses are almost negligible; (3) It is difficult to induce magnetic saturation under large armature current excitation, and under conditions where stator winding heat dissipation is permissible, the motor possesses strong overload capacity, reaching 5 to 10 times. It is highly suitable for all-electric propulsion systems and boasts excellent operating efficiency.

[0048] The all-magnetic support system uses passive magnetic bearings, which are small, consume no power, and have a simple structure. The biggest difference between passive and active magnetic bearings is that the former does not have an active electronic control system and does not consume overall system energy. Instead, it uses the properties of the magnetic field itself to levitate the shaft. The axial EDS electric suspension bearing uses blades to drive the aluminum ring to rotate at high speed, and interacts with the changing magnetic field of the Halbach permanent magnet array to generate a repulsive force to achieve levitation.

[0049] The blades are fixed at both ends, which reduces blade vibration and improves the flight stability of the rotary-wing UAV under high-speed operation.

[0050] The fully magnetically supported rotorcraft drone structure of the present invention, such as Figure 1As shown, it includes a stator back yoke 1, a stator winding frame 2, a rotor permanent magnet 3, a rotor silicon steel sheet 4, an upper Halbach permanent magnet array 5, an upper aluminum ring 6, a stator coil 7, a blade 8, a rotor inner ring frame 9, an axial protection bearing mover 10, an axial protection bearing stator 11, a central shaft 12, a radial inner permanent magnet ring 13, a radial outer permanent magnet ring 14, a rotor outer ring frame 15, a lower aluminum ring 16, a lower Halbach permanent magnet array 17, an outer outer ring frame 18, an inner outer ring frame 19, spokes 20, and a guide plate 21.

[0051] In this embodiment, the whole is divided into an outer shell and a rotor section, such as Figure 2 and Figure 3 As shown. The rotor section consists of an outer rotor frame 15, blades 8, and an inner rotor frame 9, which are fixed together using bolts and grooves. The outer shell section consists of an inner outer shell frame 19, spokes 20, and an outer outer shell frame 18, which are connected by spokes 20.

[0052] In this embodiment, the rotary drive module adopts a high-speed coreless permanent magnet synchronous motor, which consists of a stator back yoke 1, a stator winding frame 2, a stator coil 7, a rotor permanent magnet 3, and a rotor silicon steel sheet 4. The stator coil 7 is wound on the stator winding frame 2, and the stator winding frame 2 is fixedly connected to the stator back yoke 1. The stator back yoke 1, the stator winding frame 2, and the stator coil 7 are fixed on the outer ring frame 19 of the outer casing. The rotor permanent magnet 3 and the outer surface of the rotor silicon steel sheet 4 are fixedly connected and mounted on the rotor outer ring frame 15.

[0053] In this embodiment, a Halbach permanent magnet array is used in conjunction with an aluminum ring and is axially bonded at 60° to the corresponding grooves of the outer ring frame 18 of the outer shell and the outer ring frame 15 of the rotor to provide the main axial levitation force and part of the radial levitation force. The radial passive permanent magnet bearing provides the main radial levitation force, thereby achieving full levitation of the rotor blade system. The axially installed mechanical protection bearing prevents overload collisions during the rotor's lifting and lowering process.

[0054] In this embodiment, the blade 8 is fixed at both ends, such as... Figure 4 As shown, one side is bolted into the groove of the inner ring frame 9 of the rotor, while the other side is mounted on the outer ring frame 15 of the rotor using a dovetail groove and a boss.

[0055] In this embodiment, the flight control method adjusts the motor speed and the angle of the guide vane 21. During the vertical ascent of the rotorcraft drone, the motor speed and torque are increased to obtain greater thrust and axial suspension force. The translation of the rotorcraft drone is achieved by adjusting the angle of the guide vane.

[0056] In this invention, the rotary drive module is a high-speed coreless permanent magnet synchronous motor, and its structure is as follows: Figures 1 to 4 As shown, the motor output performance is as follows: Figures 5 to 7 As shown, where, Figure 5This is the power-torque diagram for a high-speed coreless permanent magnet synchronous motor. Figure 6 This is a power-current diagram for a high-speed coreless permanent magnet synchronous motor. Figure 7 This is a speed-efficiency diagram for a high-speed coreless permanent magnet synchronous motor. Figure 8 This is a diagram showing the magnetic field distribution of the Halbach permanent magnet array in the axial EDS electric levitation module. It features low iron loss and high efficiency during high-speed operation. The stator coils are wound on the stator winding frame, which is fixedly connected to the stator back yoke. The stator back yoke, stator winding frame, and stator coils are fixed to the outer ring frame of the rotor housing. The rotor permanent magnets and the outer surface of the rotor silicon steel sheets are fixedly connected and mounted on the outer ring frame of the rotor. Its basic parameters are shown in Table 1.

[0057] Table 1 Basic Parameters of High-Speed ​​Coreless Permanent Magnet Synchronous Motor

[0058] Stator outer diameter 380mm Stator inner diameter 340mm Rotor outer diameter 337mm Rotor inner diameter 300mm Number of slots 18 Extreme logarithm 2 Axial length 30mm Permanent magnet thickness 2.5mm Back yoke material DW310_35 Winding frame material polyimide Permanent magnet materials NdFe30 Winding material copper Rated speed 10000rpm Rated power 800w Rated voltage 48V Rated efficiency 88％

[0059] The structure of the axial EDS electric suspension module is as follows: Figure 1 and Figure 2 As shown, its magnetic field distribution is as follows Figure 8 As shown in the figure. The Halbach permanent magnet array mates with the aluminum ring and is installed at a 60° angle to the axis. The Halbach permanent magnet array and the aluminum ring are respectively installed in the corresponding grooves of the outer ring frame of the outer shell and the outer ring frame of the rotor, and are connected by adhesive bonding. Its basic parameters are shown in Table 2.

[0060] Table 2 Parameter Table of Axial EDS Electric Suspension Module

[0061] Halbach array length 10mm Halbach array width 8mm Halbach array thickness 2mm Halbach array group number 10 Permanent magnet materials NdFe30 Aluminum ring thickness 1.5mm outer diameter of aluminum ring 332mm Aluminum ring inner diameter 308mm Single Halbach repulsion 21N Unilateral axial force 210N

[0062] The radial inner and outer magnetic rings repel each other, and axial magnetization is used. The outer ring of the magnetic ring is mounted on the inner ring frame of the rotor, and the inner ring is mounted on the inner ring frame of the outer shell. Its basic parameters are shown in Table 3, and the radial permanent magnet ring repulsion curve is shown in... Figure 9 As shown.

[0063] Table 3. Structural Parameters of Radial Permanent Magnet Bearing

[0064] Outer diameter of the outer magnetic ring 40mm Outer magnetic ring inner diameter 32mm Inner magnetic ring outer diameter 30mm Inner diameter of the inner magnetic ring 20mm Axial length 30mm air gap 1mm Material NdFe30 Magnetization method Axial magnetization

[0065] This invention also provides a flight control method, such as... Figure 10 As shown, by adjusting the motor speed and the guide vane angle, the motor speed and torque are increased during the vertical ascent of the rotorcraft drone to obtain greater thrust and axial suspension force. The translation of the rotorcraft drone is achieved by adjusting the angle of the guide vane.

[0066] It should be noted that, depending on the implementation needs, the various steps / components described in this application can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this invention.

[0067] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A fully magnetically supported rotary-wing unmanned aerial vehicle, characterized in that, The rotary-wing drone comprises an outer shell, a rotor section, a suspension section, and a rotation drive module; wherein: The outer casing includes an inner ring frame, spokes, and an outer ring frame; the spokes connect the inner ring frame and the outer ring frame. The rotor section includes an inner rotor frame, blades, and an outer rotor frame; the blades connect the inner rotor frame and the outer rotor frame. The outer ring frame of the outer shell has an inverted trapezoidal groove facing the outer ring frame of the rotor, and the outer ring frame of the rotor is located in the inverted trapezoidal groove; the outer ring frame of the rotor has a protrusion that matches the inverted trapezoidal groove facing the outer ring frame of the outer shell; The suspension system includes an inner ring suspension assembly and an outer ring suspension assembly; The inner ring suspension assembly includes a central shaft, a radial inner permanent magnet ring, and a radial outer permanent magnet ring. The central shaft is located at the center of the inner ring frame of the outer shell, the radial inner permanent magnet ring is located on the central shaft, and the radial outer permanent magnet ring is located around the radial inner permanent magnet ring and opposite to the radial inner permanent magnet ring. The rotor inner ring frame is connected to the radial outer permanent magnet ring to achieve inner ring suspension between the rotor inner ring frame and the outer shell. The outer ring suspension assembly includes a Halbach permanent magnet array and an aluminum ring. The Halbach permanent magnet array includes an upper Halbach permanent magnet array and a lower Halbach permanent magnet array, and the aluminum ring includes an upper aluminum ring and a lower aluminum ring. The upper and lower sides of the inverted trapezoidal groove of the outer ring frame of the outer shell are provided with mounting grooves for installing the upper Halbach permanent magnet array and the lower Halbach permanent magnet array, which are located in the mounting grooves. The upper and lower sides of the convex end of the rotor outer ring frame are provided with annular grooves for installing the upper aluminum ring and the lower aluminum ring, which are located in the annular grooves. The upper Halbach permanent magnet array and the lower Halbach permanent magnet array are respectively opposite to the upper aluminum ring and the lower aluminum ring, realizing the outer ring suspension between the rotor outer ring frame and the outer ring frame of the outer shell. The inner ring suspension assembly provides the main radial suspension force, while the outer ring suspension assembly provides the axial suspension force and part of the radial suspension force, achieving full suspension of the rotor section; The rotary drive module includes a stator back yoke, a stator winding frame, a stator coil, a rotor permanent magnet, and rotor silicon steel sheets. The stator coil is wound on the stator winding frame, which is fixedly connected to the stator back yoke. The stator back yoke, stator winding frame, and stator coil are all located on the outer ring frame of the outer casing. The rotor permanent magnet is located on the outer ring frame of the rotor via rotor silicon steel sheets and is opposite to the stator coil. Thus, the rotor permanent magnet on the outer ring frame of the rotor is driven by the stator coil on the outer ring frame of the outer casing, thereby realizing the rotation of the rotor section.

2. The fully magnetically supported rotary-wing UAV according to claim 1, characterized in that, The edge of the inverted trapezoidal groove forms a 60° angle with the central axis.

3. The fully magnetically supported rotary-wing UAV according to claim 1, characterized in that, The inner ring suspension assembly also includes an axial protection bearing mover and an axial protection bearing stator; The axial protection bearing mover is located on the upper and lower sides of the inner ring frame of the rotor, and the axial protection bearing stator is located on the inner ring frame of the outer shell and is opposite to the axial protection bearing mover.

4. The fully magnetically supported rotary-wing UAV according to claim 1, characterized in that, The blade is bolted to the inverted trapezoidal groove of the inner ring frame of the rotor, and mounted on the outer ring frame of the rotor using a dovetail groove and a boss.

5. The fully magnetically supported rotary-wing UAV according to claim 1, characterized in that, The rotary-wing UAV also includes a deflector; the deflector is located on the outer shell and below the propeller blades, and the angle between the deflector and the axial direction is adjustable to adjust the flight direction of the rotary-wing UAV.

6. A flight control method for a fully magnetically supported rotary-wing unmanned aerial vehicle as described in any one of claims 1 to 5, characterized in that, The method includes: A Halbach permanent magnet array is used to achieve levitation between the outer shell and the rotor section; The rotor section is driven to rotate, enabling the rotorcraft drone to fly up and down.

7. The flight control method according to claim 6, characterized in that, The method also includes: The flight direction of the rotary-wing UAV can be adjusted by adjusting the angle of the guide vane located on the outer shell and below the propeller.

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