Propeller testing apparatus and method

Abstract

The application provides a propeller testing device and testing method, wherein the device comprises a vacuum chamber, a fixed rack, a measuring assembly, a main shaft, a middle connecting sleeve, a propeller clamp, a variable pitch mechanism and a power mechanism arranged in the vacuum chamber; the measuring assembly is arranged on the fixed rack, a sensor of the measuring assembly is connected with a data interface on the surface of the vacuum chamber, and the measuring assembly is used for collecting rotation data of the propeller; the main shaft is arranged on a connecting plate of the measuring assembly; the middle connecting sleeve is arranged on the main shaft and is rotationally connected; the propeller clamp is arranged at the end of the middle connecting sleeve and can rotate; the variable pitch mechanism is arranged on the main shaft and is used for driving the propeller clamp to rotate; and the power mechanism is arranged on the main shaft, and an output end of the power mechanism is connected with the middle connecting sleeve. Through the propeller testing device and testing method provided in the embodiment of the application, the vacuum chamber does not need to be opened and closed for multiple times, the rotation data under different attack angles can be quickly collected, the opening frequency of the chamber can be effectively reduced, and the testing efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of propeller testing, in particular to a propeller testing device and testing method. BACKGROUND

[0002] The physical properties of Mars are extremely similar to those of the Earth, both having atmosphere, liquid water, four seasons, five belt division, and hills and valleys. The exploration of Mars helps humans to strengthen the cognition of the origin of life, understand the evolution process of the planet, and thus better protect the environment of the Earth, and Mars can also be used as an alternative planet for human habitation. In recent years, the exploration of Mars has never stopped. Many countries have begun to turn their attention to Mars in order to further explore Mars and thus master more initiative. At present, the exploration of Mars mainly adopts a Mars rover and an orbiting probe, both of which have obvious advantages and disadvantages: the Mars rover can explore the surface of Mars in detail and has a high imaging rate, but is greatly limited by the terrain and can only travel on flat ground, has poor obstacle-crossing ability, and has a slow exploration speed; the orbiting probe, although having a fast exploration speed, can only conduct macroscopic exploration due to being too high from the surface of Mars and has a low imaging rate. In view of the limitations of the two, it is urgent to design a probe that can have the advantages of both, and therefore, the Mars unmanned aerial vehicle emerges as the times require.

[0003] The atmospheric environment of Mars is mainly composed of 90% carbon dioxide and only a small amount of oxygen, nitrogen and other rare gases. The air density of Mars is about one percent of that of the Earth, which leads to the operation of the Mars unmanned aerial vehicle in an ultra-low Reynolds number environment. The takeoff environment of the Mars unmanned aerial vehicle is equivalent to the atmospheric environment at an altitude of 30 km on the Earth, and the propeller system of the Mars unmanned aerial vehicle needs to run at a high speed to provide sufficient lift. However, the carbon dioxide-based atmosphere and the low sound speed (only two-thirds of the sound speed on the Earth) further limit the rotation speed of the propeller system of the Mars unmanned aerial vehicle, so that the propeller system of the Mars unmanned aerial vehicle operates in a relatively harsh atmospheric environment. Although the gravitational acceleration of Mars is about one-third of that of the Earth, it still cannot offset the influence of the low air density.

[0004] At present, the research on the propeller system of the Mars unmanned aerial vehicle is limited, and most of the research is only numerical simulation, and the numerical simulation results are too idealized and have certain differences from the actual propeller operating environment in the Martian atmospheric environment. The existing propeller testing devices are mostly based on the atmospheric environment of the Earth and are not suitable for testing the propeller developed for the Martian atmospheric environment. SUMMARY

[0005] To solve the above problems, the purpose of the embodiments of the present application is to provide a propeller testing device and testing method.

[0006] In a first aspect, the embodiment of the present application provides a testing device for a propeller, comprising a vacuum chamber, a fixed rack, a measuring assembly, a main shaft, a middle joint, a propeller clamp, a pitch changing mechanism and a power mechanism arranged in the vacuum chamber.

[0007] The fixed rack is fixedly arranged.

[0008] The measuring assembly is arranged on the fixed rack; a sensor of the measuring assembly is connected with a data interface on the surface of the vacuum chamber.

[0009] The main shaft is arranged on a connecting plate of the measuring assembly.

[0010] The middle joint is sleeved on the main shaft and rotationally connected with the main shaft.

[0011] The propeller clamp is arranged at the end of the middle joint and can rotate; the propeller clamp is used for arranging a propeller to be tested; the sensor of the measuring assembly is used for collecting rotation data of the propeller; the rotation data is dynamic data of a corresponding physical quantity when the propeller (200) rotates.

[0012] The pitch changing mechanism is arranged on the main shaft and used for driving the propeller clamp to rotate.

[0013] The power mechanism is arranged on the main shaft, and an output end of the power mechanism is connected with the middle joint.

[0014] In a possible implementation, the pitch changing mechanism comprises a fixed plate, a plurality of steering gears, an inclined disc, a first pull rod and a second pull rod.

[0015] The fixed plate is fixedly sleeved on the main shaft; the steering gears are arranged on the fixed plate.

[0016] The inclined disc is arranged on the main shaft.

[0017] The first pull rod is arranged along the axial direction of the main shaft; one end of the first pull rod is connected with a rotating arm of the steering gear, and the other end of the first pull rod is connected with a fixed ring of the inclined disc, and the first pull rod is used for driving the inclined disc to slide along the main shaft.

[0018] The second pull rod is arranged along the axial direction of the main shaft; one end of the second pull rod is connected with a movable ring of the inclined disc, and the other end of the second pull rod is connected with the propeller clamp, and the second pull rod is used for driving the propeller clamp to rotate.

[0019] In a possible implementation, the pitch changing mechanism further comprises a position limiter and a position limiting rod.

[0020] The position limiter is arranged on the fixed plate and is provided with a sliding groove arranged along the axial direction of the main shaft.

[0021] The limiting rod is arranged on the fixed ring of the tilt plate and is in sliding connection with the sliding groove.

[0022] In a possible implementation, the testing device further comprises a strain gauge, a signal transmitter and a signal receiver.

[0023] The strain gauge is arranged on the force receiving surface of the propeller.

[0024] The signal transmitter is arranged at the middle joint and is connected with the strain gauge.

[0025] The signal receiver is arranged on the fixed stand and is connected with the data interface on the surface of the vacuum chamber; the signal receiver is used to receive the data transmitted by the signal transmitter and transmit the data through the data interface.

[0026] In a possible implementation, the strain gauge is connected with the signal transmitter through a signal line; the signal line is arranged on the non-force receiving surface of the propeller.

[0027] The signal receiver is wirelessly connected with the signal transmitter.

[0028] In a possible implementation, the distance between the strain gauge and the root of the propeller accounts for 60% to 80% of the total length of the propeller.

[0029] In a possible implementation, the testing device further comprises a fine adjustment platform.

[0030] One end of the fine adjustment platform is connected with the end of the main shaft away from the measurement assembly, and the other end of the fine adjustment platform is connected with the fixed stand.

[0031] In a possible implementation, the main shaft is a hollow shaft.

[0032] The signal line of the measurement assembly and / or the power supply line of the power mechanism are arranged in the hollow shaft.

[0033] In the second aspect, the embodiments of the present application further provide a testing method based on the testing device provided in the first aspect, the propeller clamp of the testing device is provided with a propeller to be tested, and the method comprises the following steps.

[0034] After the vacuum chamber of the testing device is closed, the gas in the vacuum chamber is extracted until the environment of the vacuum chamber is consistent with the Mars environment;

[0035] The power mechanism of the testing device is controlled to drive the middle joint to rotate, and corresponding testing data are acquired through the data interface on the surface of the vacuum chamber; the testing data include rotating data collected by the measurement assembly of the testing device.

[0036] Send a pitch change instruction to the pitch change mechanism of the test device to adjust the attack angle of the propeller to a target attack angle to be tested, and obtain test data under each target attack angle through the data interface.

[0037] In a possible implementation, the sending of the pitch change instruction to the pitch change mechanism of the test device comprises:

[0038] Send the same first rotation instruction to the plurality of steering mechanisms of the test device, and the first rotation instruction is used to rotate the rotating arms of the steering mechanisms by the same angle.

[0039] Send different second rotation instructions to the plurality of steering mechanisms of the test device respectively, and the second rotation instructions are used to rotate the rotating arms of the steering mechanisms by periodically changed and mutually different angles.

[0040] In a possible implementation, the controlling of the power mechanism of the test device to rotate the middle link comprises:

[0041] Send a rotation speed control signal comprising a target rotation speed to the power mechanism through the data interface on the surface of the vacuum chamber, to drive the power mechanism to rotate at the target rotation speed.

[0042] In a possible implementation, the target rotation speed is a rotation speed gradually increasing from 0.

[0043] The controlling of the power mechanism of the test device to rotate the middle link further comprises:

[0044] Determine the actual rotation speed of the propeller according to the test data; and in the case that the actual rotation speed reaches a preset rotation speed, keep the target rotation speed unchanged.

[0045] In the scheme provided in the first aspect of the above embodiment, the environment in the vacuum chamber is changed, so that the propeller to be tested can be in a simulated environment similar to the Mars environment; in the testing process, the pitch change mechanism can drive the paddle clamp to rotate, so that the attack angle of the propeller can be changed while the vacuum chamber is kept closed, and the rotation data of the propeller at different attack angles can be collected by the measurement assembly, and then the aerodynamic performance of the propeller at different attack angles in the Mars environment can be analyzed, which can provide reliable data support for the subsequent design of the propeller of the Mars unmanned aerial vehicle. The test device does not need to open and close the vacuum chamber multiple times, so it does not need to pump the vacuum chamber multiple times, can quickly collect the rotation data at different attack angles, can effectively reduce the opening frequency, improve the testing efficiency, and can also save costs.

[0046] To make the above objectives, characteristics and advantages of the present application more obvious and easy to understand, the following preferred embodiments are described in detail below, and the accompanying drawings are described as follows. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 A structural diagram of a propeller testing device provided in an embodiment of the present invention is shown;

[0049] Figure 2 This diagram illustrates a structural view of the interior of the vacuum chamber in the testing apparatus provided in an embodiment of the present invention.

[0050] Figure 3 This invention illustrates a structural diagram of a propeller system in a testing apparatus provided in an embodiment of the invention.

[0051] Figure 4 This diagram shows a partial enlarged view of the propeller system in the testing apparatus provided in an embodiment of the present invention;

[0052] Figure 5 A schematic flowchart of a testing method provided by an embodiment of the present invention is shown.

[0053] Explanation of reference numerals in the attached figures:

[0054] 10. Vacuum chamber; 101. Data interface; 20. Fixed platform; 30. Measurement component; 301. Connecting plate; 40. Spindle; 401. Spindle adapter; 50. Connector; 60. Propeller clamp; 70. Pitch mechanism; 701. Fixed plate; 702. Servo; 703. Swashplate; 7031. Fixed ring; 7032. Moving ring; 704. First tie rod; 705. Second tie rod; 706. Limiter; 707. Limit rod; 80. Power mechanism; 81. Motor adapter; 901. Strain gauge; 100. Fine-tuning platform; 200. Propeller. Detailed Implementation

[0055] By utilizing the ability of a vacuum chamber to alter atmospheric density, propellers can be placed in a vacuum chamber similar to the Martian environment to test the propellers of Mars drones. However, the propeller testing process requires multiple changes to the propeller angle of attack, necessitating repeated steps such as "opening the vacuum chamber → adjusting the angle of attack → closing the vacuum chamber → evacuating the vacuum chamber." This is time-consuming, labor-intensive, and inefficient, and the evacuation process also adds extra costs.

[0056] The testing device of the propeller provided by the embodiment of the present application can adjust the pitch of the propeller, thereby adjusting the attack angle of the propeller, without repeatedly opening and closing the vacuum chamber, so that the testing efficiency is improved and the testing cost is saved.

[0057] Referring to Figures 1 to 4 As shown in the figure, the testing device of the propeller provided by the embodiment of the present application comprises a vacuum chamber 10, a fixed rack 20, a measuring assembly 30, a main shaft 40, a middle joint 50, a propeller clamp 60, a pitch changing mechanism 70 and a power mechanism 80 which are arranged in the vacuum chamber 10.

[0058] The fixed rack 20 is fixedly arranged and serves as a support base for the middle joint 50 and the like. As shown in the figure, Figure 1 The vacuum chamber 10 can be in a cylindrical shape, and the inner cavity of the vacuum chamber 10 is provided with a stepped platform, and the fixed rack 20 can be fixedly arranged on the platform. As shown in the figure, Figure 1 and Figure 2 The main body of the fixed rack 20 is a frame which is composed of a plurality of section bars (for example, aluminum alloy section bars) through corner racks, so that sufficient rigidity is ensured and the frame is convenient to disassemble.

[0059] The measuring assembly 30 is a component for realizing the function of measuring and collecting, and comprises a plurality of sensors, such as tension sensors, torque sensors, temperature sensors, voltage and current sensors, rotation speed sensors and the like, so as to collect the tension, torque, temperature, voltage and current, rotation speed and the like of the propeller 200 when the propeller 200 rotates. Referring to Figure 2 The measuring assembly 30 is arranged on the fixed rack 20; for example, the measuring assembly 30 is fixed on the fixed rack 20 through screw connection. The surface of the vacuum chamber 10 is provided with a data interface 101, as shown in the figure, Figure 1 The data interface 101 can be externally expanded through a data line; the sensors of the measuring assembly 30 are connected to the data interface 101, so that the equipment located outside the vacuum chamber 10 can collect the rotation data transmitted by the sensors through the data interface 101. The rotation data is dynamic data of the corresponding physical quantity when the propeller 200 rotates, and specifically can include the tension, torque, rotation speed, required voltage, current and temperature and the like which are generated when the propeller 200 runs at high speed in the vacuum chamber 10.

[0060] The testing device further comprises a propeller system for testing the propeller, and the propeller system specifically comprises the main shaft 40, the middle joint 50, the propeller clamp 60, the pitch changing mechanism 70 and the power mechanism 80 and the like. As shown in the figure, Figure 3 The side of the measuring assembly 30 close to the propeller system is a plate-shaped connecting plate 301, and the propeller system can be arranged on the connecting plate 301.

[0061] Specifically, referring to Figure 4As shown, the spindle 40 is mounted on the connecting plate 301 of the measuring assembly 30. Figure 4 (The connecting plate 301 is not shown); the intermediate link 50 is sleeved on the main shaft 40 and rotatably connected to the main shaft 40; the power mechanism 80 is mounted on the main shaft 40, and the output end of the power mechanism 80 is connected to the intermediate link 50. Under the action of the power mechanism 80, the intermediate link 50 can rotate around the main shaft 40. Specifically, the power mechanism 80 can be a motor, with the motor stator fixed on the main shaft 40 and the rotor connected to the intermediate link 50 through a motor adapter 81, thereby driving the intermediate link 50 to rotate.

[0062] The inline link 50 is a mechanism connecting the power mechanism 80 and the propeller 200. The inline link 50 is equipped with a propeller clamp 60 for holding the propeller 200. Specifically, the propeller clamp 60 is located at the end of the inline link 50 along the radial direction of the main shaft 40 and is rotatable; the rotation axis of the propeller clamp 60 is parallel to the radial direction of the main shaft 40. The propeller clamp 60 is used to hold the propeller 200 to be tested. By rotating the propeller clamp 60, the pitch of the propeller 200 can be changed, thereby changing the angle of attack of the propeller 200. During the rotation of the propeller 200 around the main shaft 40, corresponding rotation data can be generated. As described above, the rotation data of the propeller 200 can be collected by the sensors of the measuring component 30.

[0063] In this embodiment of the invention, the propeller system is further provided with a pitch-changing mechanism 70, which can drive the propeller clamp 60 to rotate. When the propeller clamp 60 rotates, the pitch of the propeller 200 changes, thereby changing the angle of attack of the propeller 200. When testing the propeller 200, while keeping the vacuum chamber 10 closed, the angle of attack of the propeller can be changed by controlling the pitch-changing mechanism 70, thereby enabling rapid testing and collection of rotational data of the propeller 200 at different angles of attack.

[0064] This invention provides a propeller testing device that, by altering the environment within the vacuum chamber 10, places the tested propeller 200 in a simulated environment similar to that of Mars. During testing, a pitch-changing mechanism 70 drives the propeller clamp 60 to rotate, thereby changing the angle of attack of the propeller 200 while keeping the vacuum chamber 10 closed. A measurement component 30 collects rotational data of the propeller 200 at different angles of attack, allowing analysis of the aerodynamic performance of the propeller 200 under different angles of attack in a Martian environment. This provides reliable data support for the design of propellers for subsequent Mars drones. This testing device eliminates the need for repeated opening and closing of the vacuum chamber 10, thus avoiding repeated evacuation. It enables rapid acquisition of rotational data at different angles of attack, effectively reducing the frequency of chamber opening, improving testing efficiency, and saving costs.

[0065] Optionally, see Figure 3As shown, the test device further comprises a strain gauge 901, a signal transmitter and a signal receiver. The strain gauge 901 is arranged on the force receiving surface of the propeller 200; the signal transmitter is arranged at the middle joint 50 and connected to the strain gauge 901; the signal receiver is arranged on the fixed stand 20 and connected to the data interface 101 on the surface of the vacuum chamber 10; the signal receiver is used to receive the data transmitted by the signal transmitter and transmit the data through the data interface 101.

[0066] In the embodiment of the application, the strain gauge 901 is arranged on the force receiving surface of the propeller 200 to collect the strain of the propeller 200 during rotation. Figure 3 As shown, each propeller 200 can be provided with the strain gauge 901. In order to more accurately collect the strain of the propeller 200, the strain gauge 901 is arranged at a position close to the blade tip of the propeller 200. Specifically, the distance between the strain gauge 901 and the root of the propeller 200 accounts for 60% to 80% of the total length of the propeller 200; for example, at the position of 75%.

[0067] In addition, the signal transmitter and the signal receiver are arranged to facilitate the transmission of the strain data collected by the strain gauge 901. The signal transmitter is arranged at the middle joint 50, for example, mounted on the hub, and the signal receiver is arranged on the fixed stand 20. The signal transmitter and the signal receiver are not shown in the figure. After the strain data collected by the strain gauge 901 is transmitted to the signal transmitter, the signal transmitter sends the strain data to the signal receiver. Similar to the transmission of the rotation data by the sensor, the signal receiver is also connected to the data interface 101, so that the strain data can be transmitted to the outside of the vacuum chamber 10 through the data interface 101.

[0068] When the propeller 200 rotates at high speed, the deformation of the blade of the propeller 200 is caused by the vibration of the motor and the aerodynamic force acting on the propeller 200. The strain gauge 901 can collect the strain data containing the corresponding strain value by sensing the size of the deformation, and transmit the strain data to the external device through the data interface 101 of the vacuum chamber 10. In the case where the elastic modulus E and the shear modulus G of the material of the tested blade part are known, the stress value at the part can be calculated from the strain data obtained by the test according to Hooke's law. The greater the stress or strain value, the greater the deformation of the propeller 200 during high-speed operation, and the better the strength and stiffness of the propeller 200.

[0069] In the embodiment of the present application, the sensors of the measuring assembly 30 and the strain gauges 901 can collect rotation data representing the aerodynamic performance of the propeller 200 and strain data representing the strength of the propeller 200; the rotation data and the strain data collected in the vacuum chamber 10 can be transmitted to the equipment outside the vacuum chamber 10 through the data interface 101, so that the aerodynamic performance of the propeller 200 at different attack angles can be determined, and the strain state of the propeller 200 at high speed rotation can be detected, so as to verify whether the strength and rigidity of the propeller 200 meet the requirements.

[0070] Optionally, since the propeller 200 is in a rotating state, it is difficult to realize data transmission through ordinary wiring, so in the embodiment of the present application, the strain gauges 901 and the signal transmitter are connected through signal lines; the signal lines are arranged on the non-stressed surface of the propeller 200; the signal receiver and the signal transmitter are wirelessly connected.

[0071] In the embodiment of the present application, the strain gauges 901 and the signal transmitter rotate synchronously with the central shaft 50, and the two can be connected through signal lines. In order to avoid that the signal lines have a great influence on the strain, the signal lines are arranged on the non-stressed surface of the propeller 200, for example, the signal lines are laid along the trailing edge of the non-stressed surface of the blade to the hub. It can be understood that the main part (more than 50%) of the signal lines is located on the non-stressed surface, and a small part of the end of the signal lines is located on the stressed surface, so as to be connected with the strain gauges 901. The signal receiver is located on the fixed rack, and its position can be fixed, and it is connected with the signal transmitter in a wireless communication manner, so as to facilitate receiving the strain data.

[0072] Optionally, as described above, one end of the propeller system is arranged on the connecting plate 301 of the measuring assembly 30, and the other end of the propeller system can be connected with the fixed rack 20, so as to ensure the stability of the propeller system during operation, thereby avoiding cantilever effect, effectively preventing the imbalance of centrifugal force generated by the propeller 200 at high speed rotation from aggravating the cantilever effect, and further causing the fracture of the main shaft 40. Specifically, as shown in Figure 4 the end of the main shaft 40 away from the measuring assembly 30 is a plate-shaped main shaft adapter 401, which can be fixedly arranged on the fixed rack 20.

[0073] In the embodiment of the present application, the strain gauges 901 and the signal transmitter rotate synchronously with the central shaft 50, and the two can be connected through signal lines. In order to avoid that the signal lines have a great influence on the strain, the signal lines are arranged on the non-stressed surface of the propeller 200, for example, the signal lines are laid along the trailing edge of the non-stressed surface of the blade to the hub. It can be understood that the main part (more than 50%) of the signal lines is located on the non-stressed surface, and a small part of the end of the signal lines is located on the stressed surface, so as to be connected with the strain gauges 901. The signal receiver is located on the fixed rack, and its position can be fixed, and it is connected with the signal transmitter in a wireless communication manner, so as to facilitate receiving the strain data. Figure 4As shown, the test device further comprises a fine adjustment platform 100, which can be an XY plane fine adjuster for example. Wherein, one end of the fine adjustment platform 100 is connected to the main shaft 40 away from the measuring assembly 30, for example, connected to the main shaft adapter 401; the other end of the fine adjustment platform 100 is connected to the fixed gantry 20, so as to fix the end of the main shaft 40 away from the measuring assembly 30 on the fixed gantry 20, which can greatly avoid the cantilever beam effect. Moreover, the fine adjustment platform 100 can eliminate the initial stress in the main shaft 40, which can further avoid the damage of the cantilever beam effect to the main shaft 40, and prevent the main shaft 40 from breaking during the test.

[0074] Optionally, referring to Figure 4 As shown, the variable-pitch mechanism 70 comprises a fixed plate 701, a steering engine 702, an inclined disc 703, a first pull rod 704 and a second pull rod 705; the number of the steering engine 702 is multiple, Figure 4 Taking three steering engines 702 as an example.

[0075] Wherein, the fixed plate 701 is fixedly sleeved on the main shaft 40; the steering engine 702 is arranged on the fixed plate 701. The inclined disc 703 is arranged on the main shaft 40; the first pull rod 704 is arranged along the axial direction of the main shaft 40; one end of the first pull rod 704 is connected to the rotating arm of the steering engine 702, and the other end is connected to the fixed ring 7031 of the inclined disc 703, which is used to drive the inclined disc 703 to slide along the main shaft 40; the second pull rod 705 is arranged along the axial direction of the main shaft 40; one end of the second pull rod 705 is connected to the movable ring 7032 of the inclined disc 703, and the other end is connected to the paddle clamp 60, which is used to drive the paddle clamp 60 to rotate.

[0076] In the embodiment of the application, the steering engine 702 and the inclined disc 703 are used to realize variable-pitch; wherein, the inclined disc 703 comprises a fixed ring 7031 which cannot rotate around the main shaft 40 and a movable ring 7032 which can rotate around the main shaft 40, and both the fixed ring 7031 and the movable ring 7032 can slide along the main shaft 40. The plurality of steering engines 702 are fixedly arranged on the main shaft 40 through the fixed plate 701, and the plurality of steering engines 702 can be uniformly distributed; for example, Figure 4 As shown, three steering engines 702 are uniformly arranged on the fixed plate 701, and the included angle between any two of the three steering engines 702 is 120 degrees. The rotating arm of the steering engine 702 is connected to the first pull rod 704, and when the rotating arm of the steering engine 702 rotates, it can drive the first pull rod 704 to move along the axial direction of the main shaft 40 as a whole; and the other end of the first pull rod 704 is connected to the fixed ring 7031, so as to drive the inclined disc 703 to slide along the main shaft 40.

[0077] The inclined disc 703 drives the paddle clamp 60 to rotate through the second pull rod 705. Specifically, as Figure 4As shown, one end of the second pull rod 705 is connected with the moving ring 7032 of the tilt disc 703, and the other end is connected with the paddle clamp 60. When the tilt disc 703 as a whole slides along the main shaft 40, the moving ring 7032 also slides synchronously, thereby driving the second pull rod 705 as a whole to move along the axial direction of the main shaft 40, and further driving the paddle clamp 60 to rotate, so as to change the attack angle of the propeller 200. It can be understood that when the middle connecting rod 50 rotates, the moving ring 7032 can also be driven to rotate around the main shaft 40.

[0078] Wherein, by utilizing the cooperative action of the plurality of rudders 702, the total pitch and the periodic pitch of the propeller 200 can be changed.

[0079] Specifically, when the total pitch needs to be changed, the rotating arms of the plurality of rudders 702 have the same angle, and under the action of the plurality of rudders 702, the tilt disc 703 can slide along the main shaft 40, so as to change the pitch of the propeller 200; and since the rotating arms of the plurality of rudders 702 have the same angle, the tilt disc 703 as a whole is parallel, or in other words, the main shaft 40 is perpendicular to the tilt disc 703, at this time the total pitch of the propeller 200 changes synchronously, thereby realizing the change of the total pitch.

[0080] When the periodic pitch needs to be changed, the rotating arms of the plurality of rudders 702 are controlled to periodically change different angles, at this time the tilt disc 703 is inclined to the main shaft 40, different pitches can be applied to different propellers 200, thereby realizing the change of the periodic pitch.

[0081] In the embodiment of the present application, the pitch changing mechanism 70 can change the total pitch or the periodic pitch of the propeller 200 as required, so as to facilitate the rapid and efficient measurement of the aerodynamic performance of the propeller 200 under different attack angles in the vacuum chamber 10. Moreover, by utilizing the pitch changing mechanism 70, the aerodynamic performance of the propeller 200 under various working conditions can be accurately tested, which greatly avoids the cost increase caused by repeated opening of the chamber, and also can reduce the error accumulation caused by manual adjustment of the attack angle.

[0082] Optionally, referring to Figure 4 As shown, the pitch changing mechanism 70 further comprises a limiting device 706 and a limiting rod 707. The limiting device 706 is arranged on the fixed plate 701 and is provided with a sliding groove arranged along the axial direction of the main shaft 40; the limiting rod 707 is arranged on the fixed ring 7031 of the tilt disc 703 and is in sliding connection with the sliding groove. By utilizing the limiting device 706 with the sliding groove, the fixed ring 7031 of the tilt disc 703 can only slide along the main shaft 40, and cannot rotate around the main shaft 40.

[0083] Optionally, in order to facilitate the arrangement of the cable, the main shaft 40 is a hollow shaft; the signal line of the measurement assembly 30 and / or the power line of the power mechanism 80 is arranged in the hollow shaft. In the case that the strain gauge 901 exists, the signal line of the signal receiver can also be arranged in the hollow shaft.

[0084] The embodiment of the present application also provides a testing method, which is realized based on any testing device provided in the above embodiments. Specifically, when the performance of a certain propeller 200 needs to be tested, the propeller 200 is arranged on the hub clamp 60, and the testing is realized based on the following steps S501 to S503. As shown in the figure, the testing method comprises the following steps. Figure 5

[0085] Step S501: After the vacuum chamber 10 of the testing device is closed, the gas in the vacuum chamber 10 is extracted until the environment of the vacuum chamber 10 is consistent with the environment of Mars.

[0086] In the embodiment of the present application, after the propeller 200 is installed, the vacuum chamber 10 is closed, and the internal environment of the vacuum chamber 10 is initialized, that is, the gas in the vacuum chamber 10 is extracted until the environment of the vacuum chamber 10 is consistent with the environment of Mars. Before entering the vacuum chamber 10, the propeller system can also be pre-adjusted to ensure that the static balance and dynamic balance of the propeller system have good performance.

[0087] By extracting the gas in the vacuum chamber 10, the atmospheric density and Reynolds number in the vacuum chamber 10 can be changed, so that the environment of Mars can be simulated.

[0088] Step S502: The power mechanism 80 of the testing device is controlled to drive the hub 50 to rotate, and the corresponding test data is acquired through the data interface 101 on the surface of the vacuum chamber 10; the test data includes the rotation data collected by the measurement assembly 30 of the testing device.

[0089] In the embodiment of the present application, when the performance of the propeller 200 needs to be tested, the state of the vacuum chamber 10 is maintained unchanged, and a control instruction can be sent to the power mechanism 80 to control the power mechanism 80 to rotate at a set speed, so as to drive the hub 50 and the propeller 200 on the hub 50 to rotate synchronously.

[0090] During the rotation of the propeller 200, the sensor of the measurement assembly 30 can collect the rotation data of the propeller 200, which can include the tension, torque and rotation speed of the propeller 200; the rotation data is all or part of the test data. Moreover, if the testing device is provided with a strain gauge 901, the strain data of the propeller 200 can also be collected by the strain gauge 901, and the strain data can also be part of the test data, that is, the test data can include the rotation data and the strain data.

[0091] The test data can be transmitted to the outside of the vacuum chamber 10 through the data interface 101 on the surface of the vacuum chamber 10, so that the external equipment can receive the test data.

[0092] ​Optionally, the above step of "controlling the power mechanism 80 of the testing device to drive the Zoomlion 50 to rotate" may include: sending a speed control signal including the target speed to the power mechanism 80 through the data interface 101 on the surface of the vacuum chamber 10, so as to drive the power mechanism 80 to rotate at the target speed. For example, the equipment outside the vacuum chamber 10 is equipped with testing software. The set speed, i.e., the target speed, is input using the testing software, and the set target speed is sent to the power mechanism 80 through the data interface 101 of the vacuum chamber 10, so that the power mechanism 80 can drive the propeller 200 to rotate at the target speed.

[0093] The target rotational speed is a gradually increasing speed starting from 0. Furthermore, the step of "controlling the power mechanism 80 of the testing device to drive the Zoomlion 50 to rotate" may also include: determining the actual rotational speed of the propeller 200 based on test data; and maintaining the target rotational speed unchanged when the actual rotational speed reaches the preset speed.

[0094] In this embodiment of the invention, a control method that gradually increases the rotational speed is used to control the propeller 200 to reach the required rotational speed. If the actual rotational speed of the propeller 200 reaches the preset rotational speed, it indicates that the current rotational speed meets the requirements. At this time, the target rotational speed is kept unchanged to ensure that the propeller 200 rotates at the actual rotational speed. For example, if the Mach number of the propeller 200 in the Martian environment reaches a preset value (e.g., 0.85), its actual rotational speed can be considered to have reached the preset rotational speed.

[0095] Step S503: Send a pitch control command to the pitch control mechanism 70 of the test device to adjust the angle of attack of the propeller 200 to the target angle of attack to be tested, and obtain test data at the target angle of attack through the data interface 101.

[0096] In this embodiment of the invention, when the propeller 200 is at a certain angle of attack, test data at that angle of attack can be collected according to step 502 described above, facilitating the subsequent determination of the corresponding aerodynamic performance of the propeller 200 based on the test data at that angle of attack. Furthermore, by sending a pitch control command to the pitch control mechanism 70, the angle of attack of the propeller 200 can be adjusted to the target angle of attack to be tested, thereby collecting test data at that target angle of attack. By continuously changing the target angle of attack, multiple sets of test data corresponding to the target angle of attack can be efficiently collected without opening the propeller housing. The thrust and torque of the propeller 200 are generally different at different target angles of attack.

[0097] Optionally, when the pitch mechanism 70 can perform both total pitch and periodic pitch changes, the above step of "sending a pitch change command to the pitch mechanism 70 of the testing device" may specifically include:

[0098] Step A1: send the same first rotation instruction to the plurality of rudders 702 of the test device, and the first rotation instruction is used to rotate the rotating arm of the rudder 702 by the same angle.

[0099] Step A2: send different second rotation instructions to the plurality of rudders 702 of the test device respectively, and the second rotation instruction is used to rotate the rotating arm of the rudder 702 by the periodically changed and mutually different angles.

[0100] In the embodiment of the present application, when the total pitch needs to be changed, the same first rotation instruction is sent to the plurality of rudders 702, so that the rotating arms of the plurality of rudders 702 are rotated by the same angle. Similar to sending the rotation speed control signal to the power mechanism 80, the corresponding rotation instruction can be sent to the plurality of rudders 702 through the data interface 101 of the vacuum chamber 10, so as to control the rotating arm of the rudder 702 to rotate as required.

[0101] When the periodic pitch change is needed, different second rotation instructions are sent to the plurality of rudders 702 respectively, so that the rotating angle of each rudder 702 is periodically changed, and then the periodic pitch change of the propeller 200 can be realized.

[0102] The propeller 200 under different total pitches and periodic pitch changes has different attack angles, so that the test data under different attack angles can be collected.

[0103] The test method provided by the embodiment of the present application can change the total pitch and the periodic pitch of the propeller 200, and the aerodynamic performance of the propeller 200 under different attack angles can be obtained. By changing the atmospheric density of the vacuum chamber 10, the Reynolds number, or controlling the rotation speed of the propeller 200, the aerodynamic performance of the propeller 200 under different atmospheric densities, different Reynolds numbers, different rotation speeds and different blade attack angles can be tested and data collected, which provides data support for subsequent structure design and controller design of the Mars unmanned aerial vehicle.

[0104] In addition, the strain data under different attack angles can be obtained by using the strain gauge 901, so that the deformation of the propeller 200 when rotating in the Mars environment can be detected while the aerodynamic performance experiment is performed, and whether the strength of the propeller 200 meets the requirements can be verified.

[0105] In the description of the present application, it is to be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0106] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0107] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0108] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any skilled in the art can easily think of changes or alternative technical solutions within the technical scope disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A testing device for a propeller, characterized in that The device comprises a vacuum chamber (10), a fixed rack (20), a measuring assembly (30), a main shaft (40), a middle joint (50), a paddle clamp (60), a pitch changing mechanism (70) and a power mechanism (80) arranged in the vacuum chamber (10); the vacuum chamber (10) is configured to be sealed after single vacuumization to the pressure of the Mars environment; The fixed rack (20) is fixedly arranged; The measuring assembly (30) is arranged on the fixed rack (20); a sensor of the measuring assembly (30) is connected with a data interface (101) on the surface of the vacuum chamber (10); The main shaft (40) is arranged on a connecting plate (301) of the measuring assembly (30); The middle joint (50) is sleeved on the main shaft (40) and rotationally connected with the main shaft (40); The paddle clamp (60) is arranged at the end of the middle joint (50) and can rotate; the paddle clamp (60) is used for arranging a propeller (200) to be tested; a sensor of the measuring assembly (30) is used for collecting rotation data of the propeller (200), and the rotation data is dynamic data of corresponding physical quantities when the propeller (200) rotates; The pitch changing mechanism (70) is arranged on the main shaft (40) and used for driving the paddle clamp (60) to rotate in the sealed state of the vacuum chamber (10) so as to change the attack angle of the propeller (200) under different total pitches and periodic pitch changes; the pitch changing mechanism (70) comprises a fixed plate (701), a steering wheel (702), an inclined disc (703), a position limiter (706) and a position limiting rod (707); the number of the steering wheels (702) is multiple; the fixed plate (701) is fixedly sleeved on the main shaft (40); the inclined disc (703) is arranged on the main shaft (40); the position limiter (706) is arranged on the fixed plate (701) and is provided with a sliding groove arranged along the axial direction of the main shaft (40); the position limiting rod (707) is arranged on a fixed ring (7031) of the inclined disc (703) and is in sliding connection with the sliding groove; The power mechanism (80) is arranged on the main shaft (40), and an output end of the power mechanism (80) is connected with the middle joint (50); The device further comprises a fine adjustment platform (100); one end of the fine adjustment platform (100) is connected with one end of the main shaft (40) away from the measuring assembly (30), and the other end of the fine adjustment platform (100) is connected with the fixed rack (20). The pitch changing mechanism (70) comprises a first pull rod (704) and a second pull rod (705); 2. The test device of claim 1, wherein, The steering wheel (702) is arranged on the fixed plate (701); The first pull rod (704) is arranged along the axial direction of the main shaft (40); one end of the first pull rod (704) is connected with a rotating arm of the steering wheel (702), and the other end is connected with the fixed ring (7031) of the inclined disc (703) and used for driving the inclined disc (703) to slide along the main shaft (40); ​ The second pull rod (705) is arranged along the axial direction of the main shaft (40); one end of the second pull rod (705) is connected with the moving ring (7032) of the tilt disc (703), and the other end is connected with the paddle clamp (60) for driving the paddle clamp (60) to rotate.

3. The test device of claim 1, wherein, Further comprising: A strain gauge (901), a signal transmitter and a signal receiver; The strain gauge (901) is arranged on the force receiving surface of the propeller (200); The signal transmitter is arranged at the middle link (50) and connected with the strain gauge (901); The signal receiver is arranged on the fixed rack (20) and connected with the data interface (101) on the surface of the vacuum chamber (10); the signal receiver is used for receiving the data transmitted by the signal transmitter and transmitting the data through the data interface (101).

4. The test device of claim 3, wherein, The signal transmitter and the signal receiver are wirelessly connected. The distance between the strain gauge (901) and the root of the propeller (200) accounts for 60%-80% of the total length of the propeller (200).

5. The test device of claim 3, wherein, The main shaft (40) is a hollow shaft; 6. The test device of claim 1, wherein, The signal line of the measuring assembly (30) and / or the power line of the power mechanism (80) are arranged in the hollow shaft. The paddle clamp (60) of the test device is provided with the propeller (200) to be tested, and the method comprises:

7. A test method based on the test device according to any one of claims 1 to 6, characterized in that, After closing the vacuum chamber (10) of the test device, the gas in the vacuum chamber (10) is extracted until the environment of the vacuum chamber (10) is consistent with the Mars environment; The power mechanism (80) of the test device drives the middle link (50) to rotate, and the corresponding test data is obtained through the data interface (101) on the surface of the vacuum chamber (10); the test data includes the rotation data collected by the measuring assembly (30) of the test device; A pitch changing instruction is sent to the pitch changing mechanism (70) of the test device to adjust the attack angle of the propeller (200) to the target attack angle to be measured, and the test data under each target attack angle is obtained through the data interface (101). The pitch changing instruction sent to the pitch changing mechanism (70) of the test device comprises:

8. The test method of claim 7, wherein, The same first rotation instruction is sent to the plurality of steering gears (702) of the test device, and the first rotation instruction is used to rotate the rotating arm of the steering gear (702) by the same angle; Different second rotation instructions are respectively sent to the plurality of steering gears (702) of the test device, and the second rotation instructions are used to rotate the rotating arm of the steering gear (702) by periodically changing angles which are different from each other. The control of the power mechanism (80) of the test device to drive the middle link (50) to rotate comprises:

9. The test method of claim 7, wherein, A rotation speed control signal including a target rotation speed is sent to the power mechanism (80) through the data interface (101) on the surface of the vacuum chamber (10) to drive the power mechanism (80) to rotate at the target rotation speed. ​ 10. The test method of claim 9, wherein, The target rotating speed is gradually increased from 0; The control of the power mechanism (80) of the testing device drives the rotating of the connecting rod (50), and further comprises: According to the test data, the actual rotating speed of the propeller (200) is determined; in the case that the actual rotating speed reaches the preset rotating speed, the target rotating speed is kept unchanged.

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