Indoor research and development test platform for multi-rotor unmanned aerial vehicle

Abstract

The invention discloses an indoor research and development test platform for a multi-rotor unmanned aerial vehicle, and belongs to the technical field of unmanned aerial vehicle testing, the indoor research and development test platform comprises a test bench, a main control unit is arranged on the test bench, the main control unit is provided with a flight path resolving algorithm, and the test bench comprises a rectangular cubic frame. An annular outer ring is arranged in the rectangular cubic frame in a connected mode through a three-degree-of-freedom rotating shaft connecting piece and a frame body connecting plate, and an annular middle ring is arranged in the annular outer ring in a connected mode through a three-degree-of-freedom rotating shaft connecting piece and a ring connecting piece. The interior of the annular middle ring is connected with an annular inner ring and an annular outer ring which serve as unmanned aerial vehicle connecting plates through three-degree-of-freedom rotating shaft connecting pieces and fixing grooves, magnetic encoders are arranged on the middle ring and the inner ring, and meanwhile the cubic frame and the outer ring, the outer ring and the middle ring and the middle ring and the inner ring are connected through conductive sliding rings; according to the invention, an indoor unmanned aerial vehicle testing environment which is safe, reliable, accurate in data, simple to operate, friendly in interface, visual and efficient can be provided for users.

Description

Technical Field

[0001] The present invention relates to the technical field of UAV testing, and in particular to an indoor multi-rotor UAV indoor R & D and testing platform based on a three-degree-of-freedom mechanical structure and a real-time control algorithm. Background Art

[0002] An indoor R & D and testing platform for UAVs is a closed environment system designed for the R & D, debugging, and performance evaluation of UAVs. By integrating technologies such as high-precision positioning, simulation, and data monitoring, it provides support for the testing of UAVs under controllable conditions. Through the deep integration of software and hardware, such platforms provide full-process support for UAV technology innovation from simulation to actual flight, and are key infrastructures for accelerating the iteration of UAV products and the implementation of industry applications.

[0003] Existing test benches are restricted by the device structure and have various problems in actual tests. For example, the UAV test system disclosed in Document CN202411083309.1 and the UAV test bench disclosed in Document CN202321968945.3 have the problem of being able to detect only specific degrees of freedom. The multi-rotor UAV test device disclosed in Document CN202022997506.8 has the problem that the continuous rotation of the UAV is blocked and it is difficult to fully support the three-degree-of-freedom attitude movement of the UAV's unrestricted continuous rotation. The multi-degree-of-freedom quadrotor UAV attitude test device disclosed in Document CN201910293476.1 and the multi-functional test platform for quadrotor UAVs disclosed in Document CN202011070701.4 can only conduct attitude loop-related tests and lack tests for the position loop. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an indoor R & D and testing platform for multi-rotor UAVs. It supports the unrestricted continuous rotation of UAVs and is suitable for the basic performance tests of the dynamic and static performance of the attitude loop and position loop of UAVs, and can also be used for the comprehensive testing of other performances of UAVs. The platform aims to provide a safe, reliable, data-accurate, easy-to-operate, user-friendly, intuitive, and efficient indoor UAV testing environment for users.

[0005] To solve the above technical problems, the technical solution adopted by the present invention is as follows: A multi-rotor UAV indoor R & D test platform, including a test bench. A main control unit is arranged on the test bench, and a flight path calculation algorithm is set in the main control unit. The test bench includes a rectangular cube frame. Inside the rectangular cube frame, a ring-shaped outer ring is connected through a three-degree-of-freedom rotating shaft connecting piece and a frame connecting plate. Inside the ring-shaped outer ring, a ring-shaped middle ring is connected through a three-degree-of-freedom rotating shaft connecting piece and a ring connecting piece. Inside the ring-shaped middle ring, a ring-shaped inner ring serving as a UAV connecting plate is connected through a three-degree-of-freedom rotating shaft connecting piece and a fixed groove. Magnetic encoders are respectively arranged on the outer ring, middle ring, and inner ring to measure the yaw angle ψ, roll angle φ, and pitch angle θ in the motion attitude of the quad-rotor UAV. At the same time, between the cube frame and the outer ring, between the outer ring and the middle ring, and between the middle ring and the inner ring, conductive slip rings are used to maintain the normal conduction of the signal transmission line during high-speed rotation.

[0006] A further improvement of the technical solution of the present invention lies in: The rectangular cube frame is composed of several aluminum profile frames. Specifically, both the upper top surface and the lower bottom surface are composed of several horizontal transverse aluminum profile frames and 2 horizontal vertical aluminum profile frames. The side surface is composed of 4 vertical aluminum profile frames. Except that 4 L-shaped connecting pieces are used to connect between the 2 aluminum profile frames on the outermost side of the lower bottom surface and the 4 vertical aluminum profile frames, the remaining aluminum profile frames are connected by aluminum profile connecting angle pieces. Frame connecting plates for fitting and installing the ring-shaped outer ring are arranged on the transverse aluminum profile frames of the upper top surface and the lower bottom surface, and 4 foot cups are arranged on the lower bottom surface.

[0007] A further improvement of the technical solution of the present invention lies in: The aluminum profile frame is European standard aluminum profile 3030Q-1.8. The outer ring, middle ring, and inner ring are made of high-strength lightweight carbon fiber plates, and the magnetic encoder is MT6701.

[0008] A further improvement of the technical solution of the present invention lies in: The structure of the three-degree-of-freedom rotating shaft connecting piece includes: two bearings 10, and the two bearings 10 are respectively placed at the groove positions on both sides of the corresponding fixed connecting piece. One side of the rotating shaft 12 passes through the two bearings 10 and the corresponding fixed connecting piece, and the other side passes through the conductive slip ring 13 and is fixed on the flange 14, and the flange 14 is fixed on the connecting piece 15.

[0009] A further improvement of the technical solution of the present invention lies in: The structure of the main control unit includes a main control unit box cover. A screen and an LED lamp area are arranged on the main control unit box cover. LED lamp e, LED lamp f, LED lamp g, LED lamp h are arranged in sequence from left to right, and a control button area is arranged. Button a, button b, button c, button d are arranged in sequence from left to right. A USB interface and a power button are arranged on the right side of the main control unit box body, and a data line access port is arranged on the bottom surface. An STM32 main control board is fixed inside the main control unit.

[0010] A further improvement of the technical solution of the present invention lies in that: the test platform signal transmission and communication mode between the test bench and the main control unit is specifically as follows: RS232 serial communication is used between the main control unit and the UAV flight control; SPI communication is used between the main control unit and the magnetic encoder; communication is established between the main control unit and the upper computer through an RS232 serial port to USB module.

[0011] A further improvement of the technical solution of the present invention lies in that: the trajectory calculation algorithm is specifically as follows: using the θ, φ, ψ three-axis attitude angles obtained by the test bench, and the control quantity u i (PWM signal or Dshot signal), c i According to the following quadcopter UAV dynamics model, design a program to realize the UAV trajectory calculation:

[0012]

[0013] where m is the mass of the UAV, g is the acceleration due to gravity, x, y, z represent the position of the UAV in the inertial coordinate system, that is, the trajectory of the UAV; F i b is obtained from the following formula:

[0014] F i b = c i u i

[0015] where i represents the motor number; c i is the thrust coefficient, which varies depending on the power device; u i is the control quantity, which is obtained from the acquired PWM or Dshot signal here.

[0016] Due to the adoption of the above technical solution, the technical progress achieved by the present invention is as follows: by optimizing the existing test bench structure and designing a three-degree-of-freedom rotation structure, it realizes the support for the three-degree-of-freedom attitude movement of the UAV with unlimited continuous rotation. By adding a position loop test function and through the flight trajectory calculation model, real-time calculation of the UAV trajectory and speed is carried out to realize the accurate quantitative evaluation of the UAV spatial motion characteristics. It can display test data in real time and improve the R & D efficiency. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts;

[0018] Figure 1 It is a schematic diagram of the overall structure of the test bench;

[0019] Figure 2 It is an exploded view of the overall structure of the test bench;

[0020] Figure 3 It is an exploded view of the three-degree-of-freedom rotating shaft connector and magnetic encoder details between the outer ring and the middle ring;

[0021] Figure 4 It is an exploded view of the rotating shaft, connecting plate between the frame and the outer ring, ring connector, three-degree-of-freedom rotating shaft connector and magnetic encoder details;

[0022] Figure 5 It is an exploded view of the fixing groove, three-degree-of-freedom rotating shaft connector and magnetic encoder details between the middle ring and the inner ring;

[0023] Figure 6 It is an exploded view of the main control unit;

[0024] Figure 7 It is a communication mode diagram of the test bench;

[0025] Figure 8 It is a data transfer and electrical connection diagram;

[0026] Figure 9 It is a circuit schematic diagram of the magnetic encoder MT6701;

[0027] Figure 10 It is the top layer diagram of the magnetic encoder MT6701 PCB;

[0028] Figure 11 It is the bottom layer diagram of the magnetic encoder MT6701 PCB;

[0029] Figure 12 It is a schematic diagram of the user interface of the human-computer interaction upper computer software;

[0030] Figure 13 It is a flow chart of the test bench usage;

[0031] Among them, A is a cubic frame, B is an outer ring, C is a middle ring, D is an inner ring, E is a main control unit, F is a three-degree-of-freedom rotating shaft connecting piece, 1 is a frame connecting plate; 2 is an aluminum profile frame; 3 is an aluminum profile connecting angle piece; 4 is a magnetic encoder; 5 is a fixing groove; 6 is an L-shaped connecting piece; 7 is a ring; 8 is a foot cup; 9 is a magnet; 10 is a bearing; 11 is a ring connecting piece; 12 is a rotating shaft; 13 is a conductive slip ring; 14 is a flange; 15 is a ring connecting piece; 16 is a screen; 17 is an LED lamp area (from left to right are LED lamp e, LED lamp f, LED lamp g, LED lamp h); 18 is a main control unit box cover; 19 is a control button area (from left to right are button a, button b, button c, button d); 20 is an STM32 main control board; 21 is a data line access port; 22 is a main control unit box body; 23 is a USB interface; 24 is a power button; 25 is an upper and lower connecting piece of the outer ring. Detailed implementation mode

[0032] The present invention will be further described in detail below in conjunction with embodiments:

[0033] As Figure 1 shown, it is a structural schematic diagram of a multi-rotor UAV indoor R & D test platform, including a test bench. A main control unit E is arranged on the test bench, and the main control unit E is provided with a flight path calculation algorithm. The test bench is used to fix a multi-rotor (quad-rotor) UAV; support the unlimited continuous rotation of the UAV; measure the attitude angle of the UAV; ensure the normal conduction of the circuit during high-speed rotation. The main control unit is used to control the start and termination, initialization, mode switching, and data display of the test; calculate the state information such as the flight path and flight speed of the UAV; and feedback all state data to the human-computer interaction upper computer software. The human-computer interaction upper computer software is used for receiving, recording, processing, displaying, and storing test data.

[0034] The test bench includes a rectangular cubic frame A. Inside the rectangular cubic frame A, a ring-shaped outer ring B is connected and arranged through a three-degree-of-freedom rotating shaft connecting piece F and a frame connecting plate 1. Inside the ring-shaped outer ring B, a ring-shaped middle ring C is connected and arranged through a three-degree-of-freedom rotating shaft connecting piece F and a ring connecting piece 15. Inside the ring-shaped middle ring C, a ring-shaped inner ring D serving as a UAV connecting plate is connected and arranged through a three-degree-of-freedom rotating shaft connecting piece F and a fixing groove 5. Magnetic encoders 4 are arranged on the outer ring B, the middle ring C, and the inner ring D respectively for measuring the yaw angle ψ, roll angle φ, and pitch angle θ in the motion attitude of the quad-rotor UAV. At the same time, between the cubic frame A and the outer ring B, between the outer ring B and the middle ring C, and between the middle ring C and the inner ring D, conductive slip rings are used to maintain the normal conduction of the signal transmission line during high-speed rotation.

[0035] As Figure 2The figure shows an exploded view of the overall structure of the test bench. The mechanical structure of the test bench mainly consists of a cubic support frame A, a circular outer ring B, a circular middle ring C, an inner ring D serving as the connecting plate for the drone, and a main control unit E. Among them, between the outer ring B and the middle ring C, and between the middle ring C and the inner ring D, they are all connected by two three-degree-of-freedom rotating shaft connectors F.

[0036] Its main part is as Figure 2 , and the support frame A is composed of 12 horizontal aluminum profile frames 2 (8 transverse and 4 longitudinal) on the upper top surface and the lower bottom surface, 4 vertical aluminum profile frames 2, and four foot cups 8. Except that 4 L-shaped connectors 6 are used between the 2 aluminum profile frames 2 on the outermost side of the lower bottom surface and the 4 longitudinal aluminum profile frames 2, the rest of the aluminum profile frames 2 are connected by aluminum profile connecting angle pieces 3. The support frame A and the outer ring B are connected by a rotating shaft and a frame connecting plate 1 and a three-degree-of-freedom rotating shaft connector F. The outer ring B and the middle ring C are connected by a three-degree-of-freedom rotating shaft connector F and a ring connector 15. The middle ring C and the inner ring D are connected by a three-degree-of-freedom rotating shaft connector F and a fixed groove 5.

[0037] The specific structure of the three-degree-of-freedom rotating shaft connector F is as Figures 3 - 5 shown.

[0038] The structure between the connectors between the outer ring B and the middle ring C is as Figure 3 , and two bearings 10 are respectively placed in the groove positions on both sides of the ring connector 11. The left side of the rotating shaft 12 passes through the two bearings 10 and the ring connector 11, and the right side passes through the conductive slip ring 13 and is fixed on the flange 14. The flange 14 is fixed on the connector 15. Among them, the upper and lower groove positions of the ring connector 11 are respectively used to fix the ring circles 7 of the upper and lower outer rings, and the front and rear groove positions of the connector 15 are used to fix the ring circles 7 of the front and rear middle rings.

[0039] The connection structure between the support frame A and the outer ring B is as Figure 4 , and two bearings 10 are respectively placed in the groove positions on both sides of the upper and lower connectors 25 of the outer ring. One side of the rotating shaft 12 passes through the two bearings 10 and the upper and lower connectors 25 of the outer ring, and the other side passes through the conductive slip ring 13 and is fixed on the flange 14. The flange 14 is fixed on the connector 15. Among them, the bottom of the upper and lower connectors 25 of the outer ring is fixed on the rotating shaft and the frame connecting plate 1, and the left and right groove positions of the connector 15 are used to fix the ring circles 7 of the left and right outer rings.

[0040] The connection structure between the middle ring C and the inner ring D is as Figure 5, two bearings 10 are respectively placed at the groove positions on both sides of the connecting piece 11. The right side of the rotating shaft 12 passes through the two bearings 10 and the ring connecting piece 11, and the left side passes through the conductive slip ring 13 and is fixed on the flange 14. The flange 14 is fixed on the fixing groove 5 and can be adjusted up and down on the fixing groove 5. Among them, the front and rear groove positions on both sides of the ring connecting piece 11 are respectively used to fix the rings 7 of the front and rear middle rings, and the 5 is fixed on the inner ring D. The aluminum profile frame 2 is the European standard aluminum profile 3030Q - 1.8. The outer ring B, the middle ring C, and the inner ring D are made of high-strength lightweight carbon fiber plates, and the magnetic encoder 4 is MT6701.

[0041] The main control unit E is as Figure 6 shown. On the cover 18 of the main control unit, there are a screen 16, an LED lamp area 17 (from left to right, there are LED lamp e, LED lamp f, LED lamp g, and LED lamp h in sequence), and a control button area 19 (from left to right, there are button a, button b, button c, and button d in sequence). On the right side of the main control unit box body 22, there is a USB interface 23 and a power button 24, and on the bottom surface, there is a data line access port 21. Inside the main control unit, the STM32 main control board is fixed. The power button 24 is used to control the start and termination of the test bench. The 4 control buttons 18 control the initialization and mode switching of the test process, and the corresponding 4 LED lamps 17 provide button signals. The screen 16 is a serial port screen and is used to display the data of the state information such as the flight path and flight speed of the unmanned aerial vehicle. The STM32 single-chip microcomputer is used as the main control board, and a multi-rotor (quad-rotor) digital prototype is embedded to calculate the state information such as its flight path and flight speed in real time.

[0042] 1) The control buttons are used

[0043] a) Data initialization

[0044] Press button d, and LED lamp h lights up constantly, entering the initialization mode.

[0045] Press button a, and LED lamp e flashes once, clearing the pitch angle (θ) data;

[0046] Press button b, and LED lamp f flashes once, clearing the roll angle (φ) data;

[0047] Press button c, and LED lamp g flashes once, clearing the yaw angle (ψ) data.

[0048] Press button d, and LED lamp h goes out, exiting the initialization mode.

[0049] b) Screen data display switching

[0050] Press button a, and LED lamp e flashes once, and the screen flips forward;

[0051] Press button b, and LED lamp f flashes once, and the screen flips backward.

[0052] The communication mode of signal transmission on the test platform is as Figure 7 shown. RS232 serial communication is used between the main control unit and the UAV flight control; SPI communication is used between the main control unit and the magnetic encoder; communication is established between the main control unit and the host computer through an RS232 serial port to USB module.

[0053] Among them, the detailed data transfer and electrical connection between the UAV flight control, outer loop B, middle loop C, inner loop D and the main control unit E are as Figure 8 shown. The UAV flight control transmits the control quantity (PWM signal or Dshot signal) and the built-in sensor data (θ b , φ b , the three-axis attitude angles of θ, φ, ψ and ω x , ω y , ω z the three-axis attitude angular velocities) to form signal ① through the slip ring of the inner loop D; signal ① and the yaw angle (ψ) obtained by the inner loop magnetic encoder form signal ②, which passes through the slip ring of the middle loop C; signal ② and the roll angle (φ) obtained by the middle loop magnetic encoder form signal ③, which passes through the slip ring of the outer loop B; signal ③ and the pitch angle (θ) obtained by the outer loop magnetic encoder are transmitted into the main control unit together.

[0054] The circuit schematic diagram and PCB layout of the designed magnetic encoder MT6701 are as Figures 9 - 11 shown, as Figure 3 shown. Taking the magnetic encoder of the middle loop C as an example, when the middle loop rotates, it drives the magnet 9 to rotate, and the magnetic field generated by the magnet 9 changes. The magnetic encoder MT6701 reads this magnetic field change and outputs the corresponding signal.

[0055] The specific flight path calculation algorithm is as follows: using the three-axis attitude angles of θ, φ, ψ obtained by the test bench, and the control quantity u i (PWM signal or Dshot signal), c i coefficient data, according to the following dynamics model of the quadrotor UAV, design a program to realize the flight path calculation of the UAV:

[0056]

[0057] Among them, m is the mass of the UAV, g is the acceleration due to gravity, x, y, z represent the position of the UAV in the inertial coordinate system, that is, the flight path of the UAV; F i b is obtained from the following formula:

[0058] F i b = c i u i

[0059] where i represents the motor number; c i is the thrust coefficient, which varies with different power devices; u i is the control variable, which is obtained from the acquired PWM or Dshot signals here.

[0060] The user interface of the human-machine interaction host computer software is as Figure 12 shown. The host computer software receives the test data and performs further processing, presenting it in various ways such as attitude cubes, speed gauges, average thrust dynamometers, waveform diagrams, etc., automatically recording and storing the test data, and supporting the export of.csv format data.

[0061] Principle of operation or method of use: As Figure 13 shown,

[0062] 1. Fix the multi-rotor (quad-rotor) UAV: Fix the multi-rotor (quad-rotor) UAV on the inner ring.

[0063] 2. Power supply and communication test of the test bench: Press the power button of the main control unit to power on the test bench; Connect the flight controller of the UAV to the RS232 serial port provided by the test bench, check the data on the display screen of the main control unit. If the data changes, the data communication between the test bench and the UAV has been achieved; Open the host computer software, select the corresponding communication interface, connect the main control unit and the host computer with a USB data cable, and observe the displayed data. If it changes, the communication between the main control unit and the host computer software has been achieved.

[0064] 3. Data initialization: Place a circular spirit level on the multi-rotor (quad-rotor) UAV, adjust the position of the UAV. After the circular spirit level is in a stable equilibrium state, operate the buttons on the main control unit to initialize the data stored in the main control unit.

[0065] 4. Start the test: After the above steps are completed, the formal test can be started. Observe the test data through the main control unit and the host computer.

[0066] 5. Shutdown: After the test is completed, save the data in the host computer software or export it as a file, exit the host computer software; Press the power button of the main control unit to cut off the power; Disconnect all communication wires; Remove the UAV to end the use of the test bench.

[0067] The present invention is based on a mechanical structure with three degrees of freedom of rotation axes (θ, φ, ψ axes), combined with a magnetic encoder and a conductive slip ring, breaking through the bottleneck of limited rotation degrees of freedom of traditional test benches and supporting unlimited continuous rotation of unmanned aerial vehicles; the stable transmission of sensor power supply and data signals in the unlimited rotation state is ensured through the conductive slip ring. Real-time flight path calculation technology: Based on the STM32 main control board, integrating the dynamic model of a quadrotor unmanned aerial vehicle, the flight path and flight speed are calculated in real time to achieve the full closed-loop test function of the position loop. Dynamic visual human-computer interaction and efficient test technology: Through the graphical upper computer interface, multi-dimensional data such as the attitude angle, flight path and flight speed of the unmanned aerial vehicle are displayed in real time, supporting functions such as dynamic data display, multi-view comparative analysis and one-key data export.

[0068] The embodiments described above are only used to describe the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention should fall within the protection scope determined by the claims of the present invention.

Claims

1. A multi-rotor UAV indoor R & D test platform, including a test bench. A main control unit (E) is arranged on the test bench, and a trajectory calculation algorithm is set in the main control unit (E). It is characterized in that: The test bench includes a rectangular cubic frame (A). Inside the rectangular cubic frame (A), a ring-shaped outer ring (B) is connected and arranged through a three-degree-of-freedom rotating shaft connector (F) and a frame connection plate (1). Inside the ring-shaped outer ring (B), a ring-shaped middle ring (C) is connected and arranged through a three-degree-of-freedom rotating shaft connector (F) and a ring connection member (15). Inside the ring-shaped middle ring (C), a ring-shaped inner ring (D) serving as a UAV connection plate is connected and arranged through a three-degree-of-freedom rotating shaft connector (F) and a fixing groove (5). Magnetic encoders (4) are arranged on the outer ring (B), the middle ring (C), and the inner ring (D) respectively for measuring the yaw angle ψ, roll angle φ, and pitch angle θ in the motion attitude of the quadrotor UAV. At the same time, between the cubic frame (A) and the outer ring (B), between the outer ring (B) and the middle ring (C), and between the middle ring (C) and the inner ring (D), conductive slip rings are used to maintain the normal conduction of the signal transmission line during high-speed rotation.

2. The indoor R & D and test platform for a multi-rotor unmanned aerial vehicle according to claim 1, characterized in that: The rectangular cubic frame (A) is composed of several aluminum profile frames (2). Specifically, both the upper top surface and the lower bottom surface are composed of several horizontal transverse aluminum profile frames (2) and 2 horizontal vertical aluminum profile frames (2). The side surface is composed of 4 vertical aluminum profile frames (2). Except that 4 L-shaped connectors (6) are used to connect the 2 aluminum profile frames (2) on the outermost side of the lower bottom surface and the 4 vertical aluminum profile frames (2), the remaining aluminum profile frames (2) are connected by aluminum profile connection angle pieces (3). Frame connection plates (1) for fitting and installing the ring-shaped outer ring (B) with the three-degree-of-freedom rotating shaft connector (F) are arranged on the transverse aluminum profile frames (2) of the upper top surface and the lower bottom surface. 4 foot cups (8) are arranged on the lower bottom surface.

3. The indoor R & D and test platform for a multi-rotor unmanned aerial vehicle according to claim 2, wherein: The aluminum profile frame (2) is European standard aluminum profile 3030Q-1.

8. The outer ring (B), the middle ring (C), and the inner ring (D) are made of high-strength lightweight carbon fiber plates. The magnetic encoder (4) is MT6701.

4. A multi-rotor UAV indoor R & D test platform according to claim 1, characterized in that: The structure of the three-degree-of-freedom rotating shaft connector (F) includes: two bearings (10). The two bearings (10) are respectively placed at the grooves on both sides of the corresponding fixed connector. One side of the rotating shaft (12) passes through the two bearings (10) and the corresponding fixed connector, and the other side passes through the conductive slip ring (13) and is fixed on the flange plate (14). The flange plate (14) is fixed on the connector (15).

5. A multi-rotor UAV indoor R & D test platform according to claim 1, characterized in that: The structure of the main control unit (E) includes a main control unit box cover (18). On the main control unit box cover (18), there is a screen (16) and an LED lamp area (17). From left to right, there are LED lamps (e), LED lamps (f), LED lamps (g), LED lamps (h) in sequence, and a control button area (19). From left to right, there are buttons (a), buttons (b), buttons (c), buttons (d) in sequence. On the right side of the main control unit box body 22, there is a USB interface (23) and a power button (24). On the bottom surface, there is a data line access port (21). Inside the main control unit, an STM32 main control board is fixed.

6. A multi-rotor UAV indoor R & D test platform according to claim 1, characterized in that: The test platform signal transmission and communication mode between the test bench and the main control unit (E) is specifically as follows: RS232 serial communication is used between the main control unit (E) and the UAV flight control; SPI communication is used between the main control unit (E) and the magnetic encoder (4); communication is established between the main control unit (E) and the upper computer through an RS232 serial port to USB module.

7. A multi-rotor UAV indoor R & D test platform according to claim 1, characterized in that: The specific track calculation algorithm is as follows: Using the θ, φ, ψ three-axis attitude angles obtained by the test bench, as well as the control quantity u i (PWM signal or Dshot signal), c i Coefficient data. According to the following quadrotor UAV dynamics model, design a program to implement UAV track calculation: Wherein, m is the mass of the drone, g is the acceleration due to gravity, and x, y, and z represent the position of the drone in the inertial coordinate system, that is, the flight path of the drone; Obtained from the following formula: where i represents the motor number; c i is the thrust coefficient, which varies depending on the power device; u i is the control quantity, which is obtained from the acquired PWM or Dshot signal here.

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