A pendulum-type micro-thrust testing device

Abstract

This invention provides a pendulum-type micro-thrust testing device, belonging to the field of micro-thrust testing technology. The thrust testing range is in the mN to N range. The pendulum-type micro-thrust testing device includes a lifting platform, a pendulum, and a Hall sensor arranged sequentially on a working platform. This invention is a direct measurement type, employing a bearing structure at the pivot, effectively reducing sliding friction at the pivot connection of traditional pendulum devices and significantly improving testing accuracy. The lifting platform connects to the pendulum base, and a porous, strongly magnetic stage allows for the loading and testing of micro-thrusters of different sizes. The device has a simple structure, small size, and can be placed in a vacuum environment for testing, meeting practical applications in fields such as micro-nano satellite orbit control.

Description

Technical Field

[0001] This utility model relates to the field of micro-thrust testing technology, specifically to a pendulum-type micro-thrust testing device. Background Technology

[0002] In recent years, the development of highly integrated micro and nano satellites and the increasing demands for higher precision in positioning and attitude control in space missions have driven the development of micro propulsion systems. Due to their small size, light weight, and low moment of inertia, micro and nano satellites require less thrust for attitude control and orbit maintenance, and have higher requirements for thrust accuracy and adjustability. Micro-thrust is an important parameter reflecting the control technology and reliability of micro and nano satellites, making the development of micro-thrust testing technology particularly important.

[0003] The measurement methods vary depending on the thrust range. Currently, commonly used micro-thrust testing systems include torsion pendulum systems, balance systems, single pendulum systems, and double pendulum systems. Torsion pendulum systems can measure large-mass micro-thrusters with high resolution, primarily suitable for thrust testing in the μN range, but require highly accurate displacement sensors. Balance systems can separate thrust from gravity, eliminating the influence of gravity, but the high friction coefficient between contact points results in lower thrust measurement accuracy. Double pendulum systems can measure the micro-thrust of relatively heavy thrusters (up to 50kg) with high accuracy, but the significant friction causes rapid attenuation of the vibration displacement signal. Single pendulum systems are mainly used for thrust testing in the mN range, offering advantages such as easy mounting of various circuits and high resolution, and are currently a relatively mature thrust testing technology both domestically and internationally.

[0004] Domestic research on single-pendulum micro-thrust testing devices began in recent years. Li Chuangxin et al. from Nanjing University of Science and Technology mentioned a single-pendulum micro-thrust testing system in their paper "Micro-impulse Testing Technology for MEMS Solid Chemical Micro-propulsion Arrays." This system consists of a three-dimensional moving platform for the micro-propulsion unit, an impact pendulum subsystem, and a Hall displacement sensor. It easily achieves the measurement of the overall rotational inertia and features strong anti-interference capabilities and simple operation. However, the use of sliding friction at the pendulum connection significantly reduces the testing accuracy. Zhao Baorui et al. introduced a single-pendulum automatic micro-thrust measurement system in their paper "Research on Automatic Measurement System for Micro-thrust," which can achieve automatic and accurate measurement of the micro-thrust of electric rockets. However, this system has a limited scope of application and is greatly affected by the environment, exhibiting certain limitations.

[0005] Research on pendulum micro-thrust testing devices began earlier abroad. In 2004, TE Markusict et al. from NASA Marshall Space Center published a pendulum device for testing electric propulsion micro-thrust in "Thrust Stand for Electric Propulsion Performance Evaluation". The prototype of the thruster weighed up to 125 kg, and the thrust test range was 1 mN to 1 N. The device design used a traditional pendulum arm connected to a balancing mechanism to convert horizontal motion into amplified vertical motion. However, unlike the traditional pendulum testing device, the deflection of the pendulum arm was independent of the length of the pendulum arm, and the end of the pendulum did not require a corresponding auxiliary device, thus improving the sensitivity of the test displacement. However, the disadvantage of this device is that the fixed contact area between the pendulum arm and the central pivot is small, making it difficult to eliminate the error caused by the pendulum arm not being completely perpendicular to the pivot.

[0006] It can be seen that the single pendulum micro-thrust testing devices currently used both domestically and internationally all have certain shortcomings and limitations, which are not conducive to their application in actual measurement processes. Therefore, it is necessary to design a new type of single pendulum testing device to meet the requirements of practical applications. Summary of the Invention

[0007] The technical objective of this invention is to provide a pendulum-type micro-thrust testing device. Employing a direct measurement method, it replaces the pendulum bob in traditional pendulum devices with a lighter pendulum rod and a strongly magnetic stage, causing the pendulum to swing to a certain height under force. Bearings, bearing sleeves, a horizontal shaft, and a fixing clamp connect the pendulum rod and the pendulum base plate, effectively reducing sliding friction at the pivot connection point of traditional pendulum devices. The device is small in size, can be placed in a vacuum environment, and can achieve micro-thrust testing in the mN~N range, significantly improving testing accuracy.

[0008] The specific technical solution of this invention is as follows:

[0009] A pendulum-type micro-thrust testing device, the device comprising:

[0010] A lifting platform, a pendulum, and a Hall sensor are sequentially arranged on the working platform.

[0011] The pendulum consists of a pendulum rod body, bearings, bearing fixing components, platform, base, and top plate;

[0012] The main body of the swing arm has a nested structure;

[0013] The main body of the swing arm includes an upper swing arm, a lower swing arm, a swing arm connector, and a bearing sleeve; the upper swing arm and the lower swing arm are connected by the swing arm connector, the upper swing arm is connected to the bearing through the bearing sleeve, and the lower swing arm is connected to the platform.

[0014] The bearing is connected to the top plate via a bearing fixing assembly, maintaining relative stillness.

[0015] Preferably, the top plate is fixed to the base, and the base is connected to the lifting platform.

[0016] Preferably, the top plate and the base are fastened with fastening screws, connected to the lifting platform with a threaded structure, and fastened to the working platform.

[0017] Preferably, the stage is connected to the lower swing arm by a thread, and will swing under force, and the testing direction of the testing device is horizontal.

[0018] Preferably, the bearing is nested and fixed within the arc-shaped groove of the pendulum top plate by a bearing fixing assembly to maintain a stable structure.

[0019] Preferably, the Hall sensor is a C12-10NO type sensor, which is fixed to the working platform by a sensor clamp. As the pendulum swings, it generates a certain displacement, and the spatial magnetic field will change. The Hall sensor senses the change in the magnetic field and converts it into a voltage signal, which is then displayed and output by an oscilloscope. Finally, the data is processed to obtain the displacement and swing angle information. When the stage swings, the Hall sensor senses the change in the surrounding magnetic field.

[0020] Preferably, the working platform adopts a PA14 type optical flat plate.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] (1) It can realize micro-thrust testing on the order of mN~N;

[0023] (2) The use of a bearing structure at the pivot connection effectively reduces the sliding friction at the pivot connection of the traditional pendulum device and greatly improves the test accuracy.

[0024] (3) The stage with a strong magnetic porous structure can realize the loading test of micro thrusters of different sizes.

[0025] (4) The pendulum base is connected by a lifting platform, which allows for adjustment of the height of the pendulum device at any time, thus improving the accuracy of the measurement results.

[0026] (5) The way the pivot and the pendulum are fixed in this device can ensure that the pendulum is horizontal in the vertical direction;

[0027] (6) The device has a simple structure and small size, and can be placed in a customized vacuum environment for testing. Attached Figure Description

[0028] Figure 1 This is an overall schematic diagram of the testing device according to this utility model.

[0029] Figure 2 This is a schematic diagram of the pendulum main body of the testing device according to this utility model.

[0030] Figure 3 This is a schematic diagram of the bearing used in the testing device of this utility model.

[0031] Figure 4 This is a schematic diagram of the bearing fixing assembly of the testing device according to this utility model.

[0032] Figure 5 This is a schematic diagram of the top plate of the testing device according to this utility model.

[0033] Figure 6 This is a schematic diagram of the base of the testing device according to this utility model.

[0034] Figure 7 This is a schematic diagram of the test stage of the testing device according to this utility model.

[0035] Figure 8 This is a schematic diagram of the sensor fixing base of the testing device according to this utility model.

[0036] Figure label annotations: 1 – Top plate; 2 – Base; 3 – Platform; 4 – Lifting platform; 5 – Upper swing arm; 6 – Lower swing arm; 7 – Swing arm connector; 8 – Bearing sleeve; 9 – Bearing; 10 – Horizontal axis; 11 – Fixing clamp; 12 – Hall sensor; 13 – Sensor fixing clamp; 14 – Working platform. Detailed Implementation

[0037] The following description, in conjunction with the accompanying drawings, further illustrates this utility model regarding the device itself and the operational steps for testing using the device:

[0038] This utility model provides a single-pendulum micro-thrust testing device, which includes...

[0039] A lifting platform 4, a pendulum and a Hall sensor 12 are sequentially arranged on the working platform 14.

[0040] The pendulum includes a pendulum rod body, bearing 9, bearing fixing assembly, platform 3, base 2, and top plate 1;

[0041] The main body of the swing arm has a nested structure;

[0042] The main body of the swing arm includes an upper swing arm 5, a lower swing arm 6, a swing arm connector 7, and a bearing sleeve 8; the upper swing arm 5 and the lower swing arm 6 are connected by the swing arm connector 7, the upper swing arm 5 is connected to the bearing 9 through the bearing sleeve 8, and the lower swing arm 6 is connected to the platform 3.

[0043] Bearing 9 is connected to top plate 1 via bearing fixing assembly, maintaining relative stillness;

[0044] The top plate 1 is fixed to the base 2, and the base 2 is connected to the lifting platform 4.

[0045] The present invention provides a specific implementation as follows: the top plate 1 and the base 2 are fastened by fastening screws, and are connected to the lifting platform 4 by a threaded structure, and are fastened to the working platform 14.

[0046] The present invention provides a specific implementation as follows: the stage 3 is connected to the lower swing rod 6 by a thread, and will swing when subjected to force, and the testing direction of the testing device is horizontal.

[0047] The present invention provides a specific embodiment as follows: the bearing 9 is nested and fixed in the arc-shaped groove of the pendulum top plate 1 by the bearing fixing assembly to maintain a stable structure.

[0048] The present invention provides a specific implementation as follows: The Hall sensor 12 adopts a C12-10NO type sensor, which is fixed on the working platform 14 by the sensor fixing clip 13. As the pendulum swings, a certain displacement is generated, and the spatial magnetic field will change. The Hall sensor 12 senses the change in the magnetic field and converts it into a voltage signal, which is then displayed and output by the oscilloscope. Finally, the data is processed to obtain the displacement and swing angle information. When the stage 3 swings, the Hall sensor senses the change in the surrounding magnetic field.

[0049] The lifting platform 4 is a 100X50 laboratory lifting platform manufactured by Hangzhou Youken Chemical Instrument Co., Ltd.

[0050] The Hall sensor 12 is a C12-10NO type sensor manufactured by Foshan Bangtuo Technology Co., Ltd. It has a detection distance of 10mm and a positioning accuracy of 1% to 5%. The outer shell is made of nickel-plated brass tubing and is installed 30mm away from the wall of the stage. The sensor is connected to computer software to measure the displacement of the pendulum in real time.

[0051] Stage 3 is made of strong magnetic stainless steel (such as...) customized from Wuxi Shengzan Stainless Steel Co., Ltd. Figure 7 As shown in the figure, its length and width are 75mm and 47.5mm respectively, and its wall thickness is 7mm. It has a multi-hole threaded structure and can be used for micro thrusters of different sizes and masses.

[0052] Bearing 9 is an IKO-K 6X9X8 deep groove ball bearing manufactured by Shanghai Jupeng Bearing Co., Ltd., and the material is stainless steel.

[0053] The structure will be explained in detail below with reference to the accompanying drawings.

[0054] The main body of the swing arm consists of the upper swing arm 5, the lower swing arm 6, the swing arm connector 7, and the bearing sleeve 8. Figure 2As shown, the upper rocker arm 5 is 109.6 mm long and 6 mm in diameter, with an M4 thread structure of 4.6 mm long at the upper end and an M12 thread structure of 17 mm long at the lower end, and an internal conical hole structure of 6 mm in diameter and 11.2 mm in height; the lower rocker arm 6 is 118 mm long and 10 mm in diameter, with an M6 thread structure of 15 mm long at the lower end and a nested structure at the upper end; the bearing sleeve 8 has an inner diameter of 15 mm and an outer diameter of 25 mm, and has an M4 fine thread hole structure at the bottom for connecting the upper rocker arm 5; the rocker arm connector 7 is 33.2 mm long, with an M12 thread structure of 15 mm long at the lower end, and the rocker arm connector 7 connects the upper rocker arm 5 and the lower rocker arm 6 to maintain a stable structure;

[0055] Bearing fixing components such as Figure 4 As shown, it consists of a horizontal shaft 10 and two fixing clips 11. The horizontal shaft 10 is 36mm long and 6mm in diameter, with grooves 7mm long and 2mm deep cut at both ends. The fixing clips 11 adopt a nested structure, are 17mm long, and have positioning holes with a diameter of 6.5mm inside.

[0056] The structure of top plate 1 is as follows Figure 5 As shown, it has a fixing clip groove and a connection hole with the base.

[0057] The structure of base 2 is as follows Figure 6 As shown, the length and width are 120mm and 50mm respectively, and the height is 150mm.

[0058] Sensor mounting clip 11 Figure 8 As shown, the height is 32.8mm, the diameter of the fixing hole at the lower end is 5.5mm, and the diameter of the positioning hole for the Hall sensor 12 is 8mm.

[0059] The present invention provides a method for performing micro-thrust testing using a micro-thrust testing device, comprising the following steps:

[0060] (1) Turn on the Hall sensor to prepare;

[0061] (2) Adjust the position of the micro-thruster according to the test requirements, fix it, and keep it in a relatively static state;

[0062] (3) Adjust the height of the lifting platform so that the center of the platform is opposite to the Hall sensor;

[0063] (4) Determine the overall moment of inertia of the simple pendulum through experimental methods or theoretical calculations;

[0064] (5) The micro-thruster is triggered to generate a micro-thrust, causing the pendulum to swing, and the sensor records real-time data.

[0065] (6) Turn off the micro-thruster and let the pendulum return to the equilibrium position by gravity;

[0066] (7) Repeat steps (5) and (6) to perform multiple tests;

[0067] (8) After the test, restore the pendulum to the equilibrium position, turn off the test instrument, and process the data.

[0068] The above description represents a widely applicable embodiment of this utility model, and while the description is relatively specific and detailed, it should not be construed as limiting the scope of this invention. Any simple modifications, alterations, or equivalent changes made to the above embodiments based on the essence of this invention shall fall within the protection scope of this invention.

Claims

1. A single pendulum micro-thrust test device, characterized in that: The device includes A lifting platform (4), a pendulum and a Hall sensor (12) are sequentially arranged on the working platform (14); The pendulum includes a pendulum rod body, a bearing (9), a bearing fixing assembly, a platform (3), a base (2), and a top plate (1); The main body of the swing arm has a nested structure; The main body of the swing arm includes an upper swing arm (5), a lower swing arm (6), a swing arm connector (7) and a bearing sleeve (8); the upper swing arm (5) and the lower swing arm (6) are connected by the swing arm connector (7), the upper swing arm (5) is connected to the bearing (9) through the bearing sleeve (8), and the lower swing arm (6) is connected to the platform (3); The bearing (9) is connected to the top plate (1) through the bearing fixing assembly and remains relatively stationary; The top plate (1) is fixed to the base (2), and the base (2) is connected to the lifting platform (4).

2. The pendulum micro-thrust test device according to claim 1, wherein: The top plate (1) and the base (2) are fastened by fastening screws, and are connected to the lifting platform (4) by a threaded structure and fastened to the working platform (14).

3. The pendulum micro-thrust test device according to claim 1, wherein: The stage (3) is connected to the lower swing arm (6) by a thread. When subjected to force, it will swing. The test direction of the test device is horizontal.

4. The pendulum micro-thrust test device of claim 1, wherein: The upper swing arm (5) is 109.6 mm long and 6 mm in diameter. The upper end has an M4 thread structure with a length of 4.6 mm and the lower end has an M12 thread structure with a length of 17 mm. It has a conical hole structure with a diameter of 6 mm and a height of 11.2 mm inside. The lower swing arm (6) is 118 mm long and 10 mm in diameter. The lower end has an M6 thread structure with a length of 15 mm and the upper end has a nested structure.

5. The pendulum micro-thrust test device of claim 1, wherein: The bearing sleeve (8) has an inner diameter of 15mm and an outer diameter of 25mm. It has an M4 fine thread hole structure at the bottom for connecting the upper rocker arm (5). The rocker arm connector (7) is 33.2mm long and has an M12 thread structure at the bottom with a length of 15mm. The rocker arm connector (7) connects the upper rocker arm (5) and the lower rocker arm (6) to maintain a stable structure.

6. The pendulum-type micro-thrust testing device according to claim 1, characterized in that: The bearing fixing assembly includes a horizontal shaft (10) and two fixing clips (11). The horizontal shaft (10) is 36mm long and 6mm in diameter, with grooves 7mm long and 2mm deep cut at both ends. The fixing clips (11) adopt a nested structure, are 17mm long, and have a positioning hole with a diameter of 6.5mm inside.

7. The pendulum micro-thrust test device of claim 1, wherein: The bearing (9) is fixed in the arc groove of the pendulum top plate (1) by the bearing fixing assembly to maintain a stable structure.

8. According to the single pendulum micro-thrust testing device of claim 6, the Hall sensor (12) adopts a C12-10NO type sensor, which is fixed on the working platform (14) by the sensor fixing clip (13). As the pendulum swings, a certain displacement is generated, and the spatial magnetic field will change. The Hall sensor senses the change in the magnetic field and converts it into a voltage signal, which is then displayed and output by the oscilloscope. Finally, the displacement and swing angle information are obtained by data processing. When the stage (3) swings, the Hall sensor senses the change in the surrounding magnetic field.

9. The simple pendulum type micro-thrust test device according to claim 1, characterized in that: The lifting platform (4) is a 100X50 type laboratory lifting platform.

10. The pendulum micro-thrust test device of claim 1, wherein: The working platform (14) adopts the PA14 type optical flat plate.

Images