Four-degree-of-freedom attitude testing device of electromagnetic direct-drive attitude-adjusting aircraft and testing method thereof

Abstract

The application discloses a four-degree-of-freedom attitude testing device of an electromagnetic direct-drive attitude-adjusting aircraft and a testing method thereof. The four-degree-of-freedom attitude testing device comprises a coaxial aircraft (1), a support arm (2) and a general frame (3). The coaxial aircraft (1) is connected with the support arm (2) through a rod end bearing, simulates the roll, pitch and yaw movements of the aircraft, and the support arm (2) is installed on the general frame (3) through a slide rail (2-1), thereby simulating the lifting movement of the aircraft. The existing electromagnetic direct-drive attitude-adjusting system is based on a single-rotor configuration and is used for attitude testing, thereby restricting the yaw freedom of the rotor system, and the attitude control problem of the coaxial aircraft cannot be verified.

Description

Technical Field

[0001] This invention belongs to the field of attitude testing research and development of electromagnetic direct-drive attitude-adjusting aircraft, specifically involving a four-degree-of-freedom attitude testing device and its testing method for electromagnetic direct-drive attitude-adjusting aircraft. Background Technology

[0002] Rotorcraft can achieve vertical takeoff and landing (VTOL) and hovering. Coaxial rotorcraft, in particular, eliminate the need for a tail rotor to balance torque, resulting in a more compact structure and widespread application across various fields. Traditional rotorcraft employ swashplate-type periodic pitch control mechanisms for attitude adjustment. These mechanisms are complex and hinder miniaturization, making the optimization and innovation of attitude control structures a crucial research area. Electromagnetic direct-drive attitude control schemes, which simulate periodic pitch control via coils, simplify the mechanism and reduce power consumption, attracting increasing attention. However, existing electromagnetic direct-drive attitude control systems are all based on single-rotor configurations for attitude testing, constraining the yaw degree of freedom of the rotor system and failing to verify the attitude control of coaxial rotorcraft. Summary of the Invention

[0003] This invention provides a four-degree-of-freedom attitude testing device and method for an electromagnetic direct-drive attitude control aircraft. Existing electromagnetic direct-drive attitude control systems are all based on a single-rotor configuration, which constrains the yaw degree of freedom of the rotor system during attitude testing, and cannot verify the attitude control problem of coaxial aircraft.

[0004] This invention is achieved through the following technical solution:

[0005] A four-degree-of-freedom attitude testing device for an electromagnetic direct-drive attitude-adjusting aircraft includes a coaxial aircraft 1, a support arm 2, and an overall frame 3. The coaxial aircraft 1 is connected to the support arm 2 via a rod end bearing to simulate the roll, pitch, and yaw motions of the aircraft. The support arm 2 is mounted on the overall frame 3 via a slide rail 2-1 to simulate the rise and fall motions of the aircraft.

[0006] Furthermore, the coaxial aircraft 1 includes an upper rotor blade 1-1, an upper rotor blade clamp 1-2, an upper rotor washer 1-3, an upper rotor bearing 1-4, an upper rotor pin 1-5, an upper rotor magnet 1-6, an upper rotor bushing 1-7, an upper rotor hub 1-8, an upper rotor coil holder 1-9, an upper rotor coil 1-10, an upper rotor drive plate 1-11, an upper rotor motor rotor 1-12, an upper rotor motor 1-13, an upper rotor motor holder 1-14, a yaw limiter 1-15, a rod end bearing rotor 1-16, a rod end bearing stator 1-17, a flange 1-18, and a shaft elastic retaining ring 1-19;

[0007] The upper rotor blade 1-1 is fixed to the upper rotor clamp 1-2 by bolts. The upper rotor pin 1-5 is installed in the shaft hole of the upper rotor clamp 1-2. The upper rotor pin 1-5 uses the inner wall of the upper rotor blade 1-1 to limit its two ends. A pair of upper rotor washers 1-3 and an upper rotor bearing 1-4 are installed on the upper rotor pin 1-5. The upper rotor bearing 1-4 is embedded on both sides of the upper rotor hub 1-8. The upper rotor bearing 1-4, together with the upper rotor bushing 1-7, achieves bearing preload. An upper rotor magnet 1-6 is embedded on the lower side of the upper rotor clamp 1-2. The magnetization direction of the upper rotor magnet 1-6 is radial. The upper rotor hub 1-8 and the upper rotor motor rotor 1-12 are positioned by a boss to prevent axial movement and are tightened with bolts.

[0008] The upper rotor motor 1-13 is mounted on the upper rotor motor base 1-14 via four evenly distributed bolts to the upper rotor drive plate 1-11. The upper rotor coil 1-10 is wound around the upper rotor coil base 1-9. The upper rotor coil base 1-9 is connected to the upper rotor motor 1-13 via bolts. The upper rotor motor base 1-14 is connected to the yaw limiter 1-15 on the side via bolts. The optical axis below the upper rotor motor base 1-14 and the rod end bearing rotor 1-16 are axially positioned using a stepped flange 1-18 and a shaft elastic retaining ring 1-19.

[0009] Furthermore, the coaxial aircraft 1 also includes a lower rotor motor mount 1-20, upper and lower rotor connecting bolts 1-21, a lower rotor motor 1-22, a lower rotor drive plate 1-23, a lower rotor motor rotor 1-24, a lower rotor coil 1-25, a lower rotor coil mount 1-26, a lower rotor hub 1-27, a lower rotor magnet 1-28, a lower rotor pin 1-29, a lower rotor bushing 1-30, a lower rotor bearing 1-31, a lower rotor retaining ring 1-32, a lower rotor blade clamp 1-33, and a lower rotor blade 1-34;

[0010] The lower rotor motor mount 1-20 and the upper rotor motor mount 1-14 are also positioned by bosses and tightened with bolts. The upper rotor blade 1-1 rotates in the opposite direction to the lower rotor blade 1-34.

[0011] The connection method between the lower rotor motor 1-22, lower rotor drive plate 1-23, lower rotor motor rotor 1-24, lower rotor coil 1-25, lower rotor coil seat 1-26, lower rotor hub 1-27, lower rotor magnet 1-28, lower rotor pin 1-29, lower rotor bushing 1-30, lower rotor bearing 1-31, lower rotor retaining ring 1-32, lower rotor blade clamp 1-33, and lower rotor blade 1-34 is symmetrical to that of the upper rotor.

[0012] Furthermore, the support arm 2 includes a slide rail 2-1, a rear side plate 2-2, a front side plate 2-3, a double slider rear connecting plate 2-4, a double slider front connecting plate 2-5, a support column 2-6, a rod end bearing connector 2-7, a rod end bearing locking nut 2-8, a rear yaw limit retaining ring 2-9, a front yaw limit retaining ring 2-10, an upper slider 2-11, an upper slider connector 2-12, a lower slider 2-13, a lower sliding fast connector 2-14, an upper cover plate 2-15, a laser height measurement module 2-16, and a lower cover plate 2-17;

[0013] The upper slider 2-11 and lower slider 2-13 are mounted on the slide rail 2-1, and can slide up and down along the slide rail 2-1. The upper slider connector 2-12 and the lower slider connector 2-14 are respectively bolted to the upper slider 2-11 and the lower slider 2-13. The front side plate 2-3 and the rear side plate 2-2 are mounted on the upper slider connector 2-12. The rear connecting plate 2-4 and the front connecting plate 2-5 of the double slider are both mounted on the lower slider connector 2-14. The rear side plate 2-2, the front side plate 2-3, the rear connecting plate 2-4, and the front connecting plate 2-5 of the double slider are all bolted together. The deformation of the rear side plate 2-2, front side plate 2-3, double slider rear connecting plate 2-4, and double slider front connecting plate 2-5 is reduced by the support column 2-6. The upper cover plate 2-15 and lower cover plate 2-17 are embedded in the grooves machined on the right side of the front side plate 2-3 and the rear side plate 2-2 and are connected by bolts. The laser height measurement module 2-16 is installed on the lower cover plate 2-17 by bolts. The laser height measurement module 2-16 calculates the height of the support arm 2 by measuring the return time of the infrared laser. The rod end bearing connector 2-7 is connected to the rod end bearing stator 1-17 by threads, and the double nuts 2-8 are used to lock the rod end bearings to prevent loosening.

[0014] Furthermore, the overall frame 3 includes aluminum tube end caps 3-1, columns 3-2, upper hydraulic buffers 3-3, upper buffer connectors 3-4, T-bolts 3-5, large washers 3-6, lower buffer connectors 3-7, lower hydraulic buffers 3-8, corner brackets 3-9, footplates 3-10, transverse bases 3-11, front bases 3-12, and rear bases 3-13;

[0015] The aluminum tube end cap 3-1 is installed on the top of the column 3-2. The upper hydraulic buffer 3-3 is installed on the upper buffer connector 3-4 with a nut. The upper buffer connector 3-4 is installed on the right side of the column 3-2 with a T-bolt. The column 3-2 is connected to the slide rail 2-1 with bolts. The bolts at both ends of the slide rail 2-1 are installed on the surface of the slide rail 2-1 with large washers 3-6 to limit the slider. The lower side of the column 3-2 is also equipped with a lower hydraulic buffer 3-8 and a lower hydraulic buffer connector 3-7. The bottom of the column 3-2 is connected to the horizontal base 3-11, the front base 3-12 and the rear base 3-13 respectively with corner brackets 3-9. Four circumferentially arranged feet 3-10 are installed on both sides of the horizontal base 3-11, the front base 3-12 and the rear base 3-13.

[0016] Furthermore, the four-degree-of-freedom attitude testing device also includes a rotor drive board, which integrates a main control module, a voltage conversion module, a motor drive module, a coil drive module, an inertial measurement module, and a Hall effect detection module.

[0017] The main control module simultaneously drives the motor and coil, and processes feedback signals from the inertial measurement module, the Hall effect detection module, and the height measurement module on the outrigger.

[0018] The Hall detection module uses three Hall sensors evenly arranged around the center of the drive board, with an adjacent angle of 120°.

[0019] A test method for a four-degree-of-freedom attitude testing device for an electromagnetic direct-drive attitude-adjusting aircraft, the specific steps of which are as follows:

[0020] Step 1: The Hall effect sensor module measures the magnetic field generated by the coil and the magnet. Based on the magnetic field strength collected by the three Hall sensors, the azimuth angle and pitch angle of the blade are calculated using a lookup table method or an inverse function method.

[0021] Step 2: The main control module manipulates the coil drive module to perform state feedback control on the blade pitch angle, simulating periodic variable pitch motion;

[0022] Step 3: Calculate the motor speed based on the calculated blade azimuth angle, and combine it with the motor drive current collected by the motor drive module. Then, use the main control module to control the motor drive module to perform closed-loop control of the speed loop and current loop of the motor.

[0023] Step 4: The inertial measurement module measures the current attitude angle of the aircraft, and the altitude measurement module measures the current altitude of the aircraft. Based on the desired angle and desired altitude, the pitch angle of the upper and lower rotor blades and the motor speed are manipulated respectively.

[0024] The beneficial effects of this invention are:

[0025] The flange on the lower side of the rod end joint bearing of the present invention is machined with a step to constrain the roll and pitch angles of the aircraft within the range of –15° to 15°.

[0026] The yaw limiter of this invention, in conjunction with the yaw limiter retaining ring, constrains the yaw angle of the aircraft within the range of –40° to 40°.

[0027] The upper and lower hydraulic buffers of the present invention constrain the flight altitude of the aircraft and reduce the impact vibration caused when the aircraft ascends or descends to its extreme position.

[0028] This invention utilizes the Hall effect detection module on the drive board to calculate the blade pitch angle, thereby achieving closed-loop control of the pitch angle and increasing the stability and reliability of the aircraft's attitude control.

[0029] This invention is scientifically and rationally designed. The electromagnetic direct-drive attitude adjustment aircraft adopts a coaxial design with a highly symmetrical structure, so that the center of gravity of the aircraft coincides with the rotation center of the stick end bearing. It can simulate the roll, pitch and yaw motion of the aircraft. Combined with the vertical sliding of the support arm relative to the overall frame, it can simulate the rise and fall motion of the aircraft. It can realize the design and verification of the attitude control method of the electromagnetic direct-drive attitude adjustment aircraft. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0031] Figure 2 This is a schematic diagram of the coaxial aircraft structure of the present invention.

[0032] Figure 3 This is a schematic diagram of the support arm structure of the present invention.

[0033] Figure 4 yes Figure 3 AA section view of the outrigger.

[0034] Figure 5 This is a schematic diagram of the framework structure of the present invention.

[0035] Figure 6 yes Figure 3 BB section view of the frame. Detailed Implementation

[0036] 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 only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Combination Figure 1 – Figure 6 As shown, a four-degree-of-freedom attitude testing device for an electromagnetic direct-drive attitude-adjusting aircraft is disclosed. The four-degree-of-freedom attitude testing device includes a coaxial aircraft 1, a support arm 2, and an overall frame 3. The coaxial aircraft 1 is connected to the support arm 2 via a rod end bearing to simulate the roll, pitch, and yaw motions of the aircraft. The support arm 2 is mounted on the overall frame 3 via a slide rail 2-1 to simulate the rise and fall motions of the aircraft.

[0038] Furthermore, the coaxial aircraft 1 includes an upper rotor blade 1-1, an upper rotor blade clamp 1-2, an upper rotor washer 1-3, an upper rotor bearing 1-4, an upper rotor pin 1-5, an upper rotor magnet 1-6, an upper rotor bushing 1-7, an upper rotor hub 1-8, an upper rotor coil holder 1-9, an upper rotor coil 1-10, an upper rotor drive plate 1-11, an upper rotor motor rotor 1-12, an upper rotor motor 1-13, an upper rotor motor holder 1-14, a yaw limiter 1-15, a rod end bearing rotor 1-16, a rod end bearing stator 1-17, a flange 1-18, and a shaft elastic retaining ring 1-19;

[0039] The upper rotor blade 1-1 is fixed to the upper rotor clamp 1-2 by bolts. The upper rotor pin 1-5 is installed in the shaft hole of the upper rotor clamp 1-2. The upper rotor pin 1-5 uses the inner wall of the upper rotor blade 1-1 to limit its two ends. A pair of upper rotor washers 1-3 and an upper rotor bearing 1-4 are installed on the upper rotor pin 1-5. The upper rotor bearing 1-4 is embedded on both sides of the upper rotor hub 1-8. The upper rotor bearing 1-4, together with the upper rotor bushing 1-7, achieves bearing preload. An upper rotor magnet 1-6 is embedded on the lower side of the upper rotor clamp 1-2. The magnetization direction of the upper rotor magnet 1-6 is radial. The upper rotor hub 1-8 and the upper rotor motor rotor 1-12 are positioned by a boss to prevent axial movement and are tightened with bolts.

[0040] The upper rotor motor 1-13 is mounted on the upper rotor motor base 1-14 via four evenly distributed bolts to the upper rotor drive plate 1-11. The upper rotor coil 1-10 is wound around the upper rotor coil base 1-9. The upper rotor coil base 1-9 is connected to the upper rotor motor 1-13 via bolts. The upper rotor motor base 1-14 is connected to the yaw limiter 1-15 on the side via bolts. The optical axis below the upper rotor motor base 1-14 and the rod end bearing rotor 1-16 are axially positioned using a stepped flange 1-18 and a shaft elastic retaining ring 1-19.

[0041] Furthermore, the coaxial aircraft 1 also includes a lower rotor motor mount 1-20, upper and lower rotor connecting bolts 1-21, a lower rotor motor 1-22, a lower rotor drive plate 1-23, a lower rotor motor rotor 1-24, a lower rotor coil 1-25, a lower rotor coil mount 1-26, a lower rotor hub 1-27, a lower rotor magnet 1-28, a lower rotor pin 1-29, a lower rotor bushing 1-30, a lower rotor bearing 1-31, a lower rotor retaining ring 1-32, a lower rotor blade clamp 1-33, and a lower rotor blade 1-34;

[0042] The lower rotor motor mount 1-20 and the upper rotor motor mount 1-14 are also positioned by bosses and tightened with bolts. The upper rotor blade 1-1 rotates in the opposite direction to the lower rotor blade 1-34.

[0043] The connection method between the lower rotor motor 1-22, lower rotor drive plate 1-23, lower rotor motor rotor 1-24, lower rotor coil 1-25, lower rotor coil seat 1-26, lower rotor hub 1-27, lower rotor magnet 1-28, lower rotor pin 1-29, lower rotor bushing 1-30, lower rotor bearing 1-31, lower rotor retaining ring 1-32, lower rotor blade clamp 1-33, and lower rotor blade 1-34 is symmetrical to that of the upper rotor.

[0044] The upper and lower propellers of the coaxial aircraft 1 rotate in opposite directions, and the anti-torque generated during rotation is in opposite directions, thereby controlling the yaw angle of the aircraft.

[0045] The rotor 1-16 and stator 1-17 with rod end bearings are manufactured by SKF Group of France, and the production model is SI 17 C.

[0046] The upper rotor blade 1-1 and lower rotor blade 1-34 are manufactured by China T-motor Group Corporation, and the production model is MS1302.

[0047] Furthermore, the support arm 2 includes a slide rail 2-1, a rear side plate 2-2, a front side plate 2-3, a double slider rear connecting plate 2-4, a double slider front connecting plate 2-5, a support column 2-6, a rod end bearing connector 2-7, a rod end bearing locking nut 2-8, a rear yaw limit retaining ring 2-9, a front yaw limit retaining ring 2-10, an upper slider 2-11, an upper slider connector 2-12, a lower slider 2-13, a lower sliding fast connector 2-14, an upper cover plate 2-15, a laser height measurement module 2-16, and a lower cover plate 2-17;

[0048] The upper slider 2-11 and the lower slider 2-13 are mounted on the slide rail 2-1, and can slide up and down along the slide rail 2-1. The upper slider connector 2-12 and the lower slider connector 2-14 are respectively bolted to the upper slider 2-11 and the lower slider 2-13. The front side plate 2-3 and the rear side plate 2-2 are mounted on the upper slider connector 2-12. The rear connecting plate 2-4 and the front connecting plate 2-5 of the double slider are both mounted on the lower slider connector 2-14. The rear side plate 2-2, the front side plate 2-3, the rear connecting plate 2-4, and the front connecting plate of the double slider are all mounted on the lower slider connector 2-14. All parts 2-5 are connected by bolts, and the deformation of the rear side plate 2-2, front side plate 2-3, double slider rear connecting plate 2-4, and double slider front connecting plate 2-5 is reduced by the support column 2-6. The upper cover plate 2-15 and the lower cover plate 2-17 are embedded in the grooves machined on the right side of the front side plate 2-3 and the rear side plate 2-2 and are connected by bolts. The laser height measurement module 2-16 is installed on the lower cover plate 2-17 by bolts. The laser height measurement module 2-16 calculates the height of the support arm 2 by measuring the return time of the infrared laser. The rod end bearing connector 2-7 is connected to the rod end bearing stator 1-17 by threads.

[0049] The support arm 2 is connected to the slide rail fixed on the column through two upper and lower sliders, and the rod end bearing is arranged between the two sliders, which can reduce the frictional force generated by the bending moment of the slider when the aircraft rises and falls.

[0050] The rod end bearing connector 2-7 and the rod end bearing stator 1-17 are connected by two rod end bearing locking thin nuts 2-8 to prevent loosening.

[0051] Furthermore, the overall frame 3 includes aluminum tube end caps 3-1, columns 3-2, upper hydraulic buffers 3-3, upper buffer connectors 3-4, T-bolts 3-5, large washers 3-6, lower buffer connectors 3-7, lower hydraulic buffers 3-8, corner brackets 3-9, footplates 3-10, transverse bases 3-11, front bases 3-12, and rear bases 3-13;

[0052] The aluminum tube end cap 3-1 is installed on the top of the column 3-2. The upper hydraulic buffer 3-3 is installed on the upper buffer connector 3-4 with a nut. The upper buffer connector 3-4 is installed on the right side of the column 3-2 with a T-bolt. The column 3-2 is connected to the slide rail 2-1 with bolts. The bolts at both ends of the slide rail 2-1 are installed on the surface of the slide rail 2-1 with large washers 3-6 to limit the slider. The lower side of the column 3-2 is also equipped with a lower hydraulic buffer 3-8 and a lower hydraulic buffer connector 3-7. The bottom of the column 3-2 is connected to the horizontal base 3-11, the front base 3-12 and the rear base 3-13 respectively with corner brackets 3-9. Four circumferentially arranged feet 3-10 are installed on both sides of the horizontal base 3-11, the front base 3-12 and the rear base 3-13.

[0053] The upper hydraulic buffer 3-3 and the lower hydraulic buffer 3-8 are adjustable hydraulic buffers, and the oil pressure is adjusted according to the total mass of the support arm and the aircraft.

[0054] Furthermore, the four-degree-of-freedom attitude testing device also includes a rotor drive board, which integrates a main control module, a voltage conversion module, a motor drive module, a coil drive module, an inertial measurement module, and a Hall effect detection module.

[0055] The main control module simultaneously drives the motor and coil, and processes feedback signals from the inertial measurement module, the Hall effect detection module, and the height measurement module on the outrigger.

[0056] The Hall detection module uses three Hall sensors evenly arranged around the center of the drive board, with an adjacent angle of 120°.

[0057] A test method for a four-degree-of-freedom attitude testing device for an electromagnetic direct-drive attitude-adjusting aircraft, the specific steps of which are as follows:

[0058] Step 1: The Hall effect sensor module measures the magnetic field generated by the coil and the magnet. Based on the magnetic field strength collected by the three Hall sensors, the azimuth angle and pitch angle of the blade are calculated using a lookup table method or an inverse function method.

[0059] Step 2: The main control module manipulates the coil drive module to perform state feedback control on the blade pitch angle, simulating periodic variable pitch motion;

[0060] Step 3: Calculate the motor speed based on the calculated blade azimuth angle, and combine it with the motor drive current collected by the motor drive module. Then, use the main control module to control the motor drive module to perform closed-loop control of the speed loop and current loop of the motor.

[0061] Step 4: The inertial measurement module measures the current attitude angle of the aircraft, and the altitude measurement module measures the current altitude of the aircraft. Based on the desired angle and desired altitude, the pitch angle of the upper and lower rotor blades and the motor speed are manipulated respectively.

Claims

1. A four-degree-of-freedom attitude testing device for an electromagnetic direct-drive attitude-adjusting aircraft, characterized in that, The four-degree-of-freedom attitude testing device includes a coaxial aircraft (1), a support arm (2), and an overall frame (3); the coaxial aircraft (1) is connected to the support arm (2) through a rod end bearing to simulate the roll, pitch, and yaw motion of the aircraft; the support arm (2) is installed on the overall frame (3) through a slide rail (2-1) to simulate the rise and fall motion of the aircraft. The coaxial aircraft (1) includes an upper rotor blade (1-1), an upper rotor blade clip (1-2), an upper rotor washer (1-3), an upper rotor bearing (1-4), an upper rotor pin (1-5), an upper rotor magnet (1-6), an upper rotor bushing (1-7), an upper rotor hub (1-8), an upper rotor coil holder (1-9), an upper rotor coil (1-10), an upper rotor drive plate (1-11), an upper rotor motor rotor (1-12), an upper rotor motor (1-13), an upper rotor motor holder (1-14), a yaw limiter (1-15), a rod end bearing rotor (1-16), a rod end bearing stator (1-17), a flange (1-18), and a shaft elastic retaining ring (1-19). The upper rotor blade (1-1) is bolted and fixed to the upper rotor clamp (1-2). The upper rotor pin (1-5) is installed in the shaft hole of the upper rotor clamp (1-2). The upper rotor pin (1-5) is limited at both ends by the inner wall of the upper rotor blade (1-1). A pair of upper rotor washers (1-3) and an upper rotor bearing (1-4) are installed on the upper rotor pin (1-5). 1-4) The upper rotor bearing (1-4) is embedded on both sides of the upper rotor hub (1-8). The upper rotor bearing (1-4) and the upper rotor bushing (1-7) achieve bearing preload. The upper rotor clamp (1-2) is inlaid with an upper rotor magnet (1-6) on the lower side. The magnetization direction of the upper rotor magnet (1-6) is radial. The upper rotor hub (1-8) and the upper rotor motor rotor (1-12) are positioned by a boss to prevent axial movement and are tightened with bolts. The upper rotor motor (1-13) is mounted on the upper rotor motor mount (1-14) via four evenly distributed bolts to the upper rotor drive plate (1-11). The upper rotor coil (1-10) is wound around the upper rotor coil mount (1-9). The upper rotor coil mount (1-9) is connected to the upper rotor motor (1-13) via bolts. The upper rotor motor mount (1-14) is connected to the yaw limiter (1-15) on the side via bolts. The optical axis below the upper rotor motor mount (1-14) and the rod end bearing rotor (1-16) are axially positioned using a stepped flange (1-18) and a shaft elastic retaining ring (1-19).

2. The four-degree-of-freedom attitude testing device for an electromagnetic direct-drive attitude-adjusting aircraft according to claim 1, characterized in that, The coaxial aircraft (1) also includes a lower rotor motor mount (1-20), upper and lower rotor connecting bolts (1-21), a lower rotor motor (1-22), a lower rotor drive plate (1-23), a lower rotor motor rotor (1-24), a lower rotor coil (1-25), a lower rotor coil mount (1-26), a lower rotor hub (1-27), a lower rotor magnet (1-28), a lower rotor pin (1-29), a lower rotor bushing (1-30), a lower rotor bearing (1-31), a lower rotor retaining ring (1-32), a lower rotor blade clamp (1-33), and a lower rotor blade (1-34). The lower rotor motor mount (1-20) and the upper rotor motor mount (1-14) are also positioned by bosses and tightened with bolts. The upper rotor blade (1-1) and the lower rotor blade (1-34) rotate in opposite directions. The connection method between the lower rotor motor (1-22), lower rotor drive plate (1-23), lower rotor motor rotor (1-24), lower rotor coil (1-25), lower rotor coil seat (1-26), lower rotor hub (1-27), lower rotor magnet (1-28), lower rotor pin (1-29), lower rotor bushing (1-30), lower rotor bearing (1-31), lower rotor retaining ring (1-32), lower rotor blade clamp (1-33), and lower rotor blade (1-34) is symmetrical to that of the upper rotor.

3. The four-degree-of-freedom attitude testing device for an electromagnetic direct-drive attitude-adjusting aircraft according to claim 1, characterized in that, The support arm (2) includes a slide rail (2-1), a rear side plate (2-2), a front side plate (2-3), a double slider rear connecting plate (2-4), a double slider front connecting plate (2-5), a support column (2-6), a rod end bearing connector (2-7), a rod end bearing locking nut (2-8), a rear yaw limit retaining ring (2-9), a front yaw limit retaining ring (2-10), an upper slider (2-11), an upper slider connector (2-12), a lower slider (2-13), a lower slider connector (2-14), an upper cover plate (2-15), a laser height measurement module (2-16), and a lower cover plate (2-17). The upper slider (2-11) and lower slider (2-13) are mounted on the slide rail (2-1), and can slide up and down along the slide rail (2-1). The upper slider connector (2-12) and lower slider connector (2-14) are respectively bolted to the upper slider (2-11) and lower slider (2-13). The front side plate (2-3) and rear side plate (2-2) are mounted on the upper slider connector (2-12). The rear connecting plate (2-4) and front connecting plate (2-5) of the double slider are both mounted on the lower slider connector (2-14). The rear side plate (2-2), front side plate (2-3), rear connecting plate (2-4), and front connecting plate (2-5) of the double slider are all connected by bolts. The bolted connection reduces the deformation of the rear side plate (2-2), front side plate (2-3), double slider rear connecting plate (2-4), and double slider front connecting plate (2-5) through the support column (2-6). The upper cover plate (2-15) and lower cover plate (2-17) are embedded in the grooves machined on the right side of the front side plate (2-3) and rear side plate (2-2) and connected by bolts. The laser height measurement module (2-16) is installed on the lower cover plate (2-17) by bolts. The laser height measurement module (2-16) calculates the height of the support arm (2) by measuring the return time of the infrared laser. The rod end bearing connector (2-7) and rod end bearing stator (1-17) are connected by threads and double nuts are used to lock the thin nuts (2-8) for double nut anti-loosening.

4. The four-degree-of-freedom attitude testing device for an electromagnetic direct-drive attitude-adjusting aircraft according to claim 1, characterized in that, The overall frame (3) includes aluminum tube end caps (3-1), columns (3-2), upper hydraulic buffers (3-3), upper buffer connectors (3-4), T-bolts (3-5), large washers (3-6), lower buffer connectors (3-7), lower hydraulic buffers (3-8), corner brackets (3-9), foot brackets (3-10), horizontal bases (3-11), front bases (3-12), and rear bases (3-13). The aluminum tube end cap (3-1) is installed on the top of the column (3-2). The upper hydraulic buffer (3-3) is installed on the upper buffer connector (3-4) by a nut. The upper buffer connector (3-4) is installed on the right side of the column (3-2) by a T-bolt. The column (3-2) is connected to the slide rail (2-1) by bolts. The bolts at both ends of the slide rail (2-1) are installed on the surface of the slide rail (2-1) by large washers (3-6), thereby limiting the slider. The column (3-2) is also equipped with a lower hydraulic buffer (3-8) and a lower hydraulic buffer connector (3-7) on its lower side. The bottom of the column (3-2) is connected to the horizontal base (3-11), the front base (3-12) and the rear base (3-13) respectively through corner brackets (3-9). Four circumferentially arranged feet (3-10) are installed on both sides of the horizontal base (3-11), the front base (3-12) and the rear base (3-13).

5. The four-degree-of-freedom attitude testing device for an electromagnetic direct-drive attitude-adjusting aircraft according to claim 1, characterized in that, The four-degree-of-freedom attitude testing device also includes a rotor drive board, which integrates a main control module, a voltage conversion module, a motor drive module, a coil drive module, an inertial measurement module, and a Hall effect detection module. The main control module simultaneously drives the motor and coil, and processes feedback signals from the inertial measurement module, the Hall effect detection module, and the height measurement module on the outrigger. The Hall detection module uses three Hall sensors evenly arranged around the center of the drive board, with an adjacent angle of 120°.

6. The test method of the four-degree-of-freedom attitude testing device for an electromagnetic direct-drive attitude-adjusting aircraft according to any one of claims 1-5, characterized in that, The specific steps of the testing method are as follows: Step 1: The Hall effect sensor module measures the magnetic field generated by the coil and the magnet. Based on the magnetic field strength collected by the three Hall sensors, the azimuth angle and pitch angle of the blade are calculated using a lookup table method or an inverse function method. Step 2: The main control module manipulates the coil drive module to perform state feedback control on the blade pitch angle, simulating periodic variable pitch motion; Step 3: Calculate the motor speed based on the calculated blade azimuth angle, and combine it with the motor drive current collected by the motor drive module. Then, use the main control module to control the motor drive module to perform closed-loop control of the speed loop and current loop of the motor. Step 4: The inertial measurement module measures the current attitude angle of the aircraft, and the altitude measurement module measures the current altitude of the aircraft. Based on the desired angle and desired altitude, the pitch angle of the upper and lower rotor blades and the motor speed are manipulated respectively.

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