Pico / nano satellite propulsion system storage tank shake experiment platform

Abstract

The invention provides a liquid-filled pico-nano satellite propulsion system storage tank shake experiment platform, which specifically comprises a base, and the base is fixed at a required position; a turntable is arranged on the base and can translate and rotate on the base; a retainer is arranged on the turntable and is used for fixing a storage tank to be detected; the base is further provided with a piezoelectric sensor and a laser displacement sensor, and the positions of the piezoelectric sensor and the laser displacement sensor are variable. The piezoelectric sensor is used for measuring the pressure of the storage tank on the piezoelectric sensor when the turntable rotates to a required angle; a shading plate is arranged on the holder, and the laser displacement sensor is arranged opposite to the shading plate and used for measuring the distance change from the shading plate to the laser displacement sensor, so that the angle change of the storage tank is calculated; the turntable is driven by a magnet and a spring to move. The device has the advantages of being simple in structure, convenient to install, low in cost, stable in structure and capable of testing various motion states of the storage tanks in different shapes.

Description

Technical Field

[0001] The present invention relates to a picosatellite storage tank sloshing experiment platform, specifically a low-cost and simple experiment platform that can be used in aspects such as studying the vibration state of the internal liquid, liquid flow rate, and sloshing time when studying the storage tank sloshing. Background Art

[0002] In the field of small satellites, the liquid-filled storage tank, as an important part of the satellite fuel supply system, undertakes the function of providing necessary fuel and energy for the satellite. Due to the limited space of small satellites, the storage tank design usually needs to be efficient, compact and reliable. However, in small storage tanks, the sloshing phenomenon of the liquid poses challenges to the stability and control accuracy of the satellite. During the satellite's propulsion, attitude control, and orbit adjustment processes, the flow and sloshing of the liquid will cause unstable inertial moments, thus affecting the satellite's attitude and orbit accuracy. Therefore, testing and analyzing the sloshing behavior of the liquid-filled storage tank is crucial for ensuring the stable operation of small satellites. By designing effective testing methods, the sloshing characteristics of the storage tank liquid under different operating conditions can be evaluated, the storage tank design can be optimized, and the impact of the liquid on the satellite can be reduced. This plays an important role in improving the performance of the small satellite's power system, enhancing the attitude control accuracy, and extending the satellite's service life. At the same time, it provides more reliable technical support and innovative solutions for the future development of small satellite technology.

[0003] In the field of the internal liquid sloshing of storage tanks, existing technologies and papers mostly stay in the stage of mathematical modeling and simulation calculation. However, due to the limitation of computing power and the limited boundary conditions of simulation software, most simulation calculations have been simplified to a certain extent, and the obtained results can only reflect the state of the internal liquid sloshing of the storage tank to a certain extent, with a certain gap from the real situation, and experiments are still needed to prove the results. For the few devices that can conduct relevant experiments, they often have a high cost, and most studies focus on the dynamic response characteristics of liquid sloshing, and it is impossible to intuitively observe the influence of different structures and methods on reducing the internal liquid sloshing.

[0004] Therefore, how to reduce the cost of experimental equipment so that more small and medium-sized laboratories can use experimental results to corroborate their calculations is one of the key factors in promoting the popularization of this research field. In addition, how to efficiently and simply judge that a method can effectively reduce the internal liquid sloshing phenomenon, rather than detecting difficult-to-measure data such as the hydraulic pressure in the pipe and liquid torque, so as to improve the research efficiency, is also an important technical issue in this field. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to study the unpowered sloshing state of the storage tank of the Pina satellite propulsion system, detect the sloshing speed, time and impact force on the tank body, and use this data as a judgment standard to provide a method for judging the sloshing reduction effect in the study of comparing the performance of various sloshing reduction methods. In addition, this simple liquid sloshing experimental platform has a low cost and is easy to manufacture, enabling more research teams with limited funds to reduce the experimental cost when conducting research related to liquid sloshing.

[0006] The present invention is implemented by the following technical solutions:

[0007] A sloshing experimental platform for the storage tank of the Pina satellite propulsion system, the platform includes:

[0008] A base for supporting the overall structure; four fixed feet are provided at the edge of the base, and the fixed feet are thin plates with holes for fixing the base at the required position; a turntable is provided on the base, and the turntable can perform translational and rotational motions on the base at the same time;

[0009] A radial slideway provided on the base, the base and the turntable are connected by a "convex" slider matching the radial slideway, and the turntable performs translational motion along the radial slideway; the radial slideway is a convex smooth slideway, and the friction coefficient is designed to be as low as possible to reduce the influence of friction on the swing of the slider during the experiment; one end of the radial slideway passes through the edge of the base for the installation of the slider and other components, and a slideway buckle is provided at the end position of the radial slideway for closing the radial slideway;

[0010] A slider (i.e., the above-mentioned "convex" slider) for connecting the lower base and the upper turntable; the bottom of both sides of the slider is slightly convex for fixing with the slideway, and the slider can perform translational motion along the radial slideway; a circular depression is provided at the top of the slider for fixing the bearing and the spring, and the spring is located outside the bearing; the turntable is connected to the slider through a bearing, and the turntable rotates around the circular depression at the top of the slider through the bearing; the other end of the spring is fixedly connected to the turntable for controlling the reset of the upper turntable after each rotation, so as to realize the rotation of the turntable;

[0011] Magnets fixed at both ends of the radial slideway and on both sides of the slider respectively, the magnets on the radial slideway and the magnets on the slider are opposite to each other; and the magnets can be adjusted by replacing different models, sizes, etc. to adjust the thrust of the translational motion of the slider; in the initial state, the slider is located at the center position of the base, and the opposite two magnets have the same polarity and the same repulsive force; if an initial displacement is given to the slider, a repulsive force difference will be generated between the two pairs of magnets, and the repulsive force difference between the two pairs of magnets provides the power for the slider to slide along the radial slideway, so as to realize the translational motion of the turntable (the turntable reciprocates along the radial slideway);

[0012] Two slider fixing plates are used to control the sliders from moving in the radial direction when testing the sloshing state of the liquid during the rotation of the storage tank;

[0013] An inwardly concave circular sensor fixing groove is provided at the edge of the base, which is used to fix the sensor in different directions and facilitate adjusting the relative angle between the sensor and the storage tank;

[0014] The sensor is fixed to the base through a sensor bracket. The sensor bracket and the base are fixed by a threaded rod and a nut clamp, making the structure simple to disassemble and assemble and firmly fixed; the sensor includes a piezoelectric sensor and a laser displacement sensor;

[0015] The upper cross bar and the vertical bar for support of the sensor bracket of the piezoelectric sensor are fixed in an articulated manner, which is convenient for adjusting the height of the piezoelectric sensor so as to align it with the plane of the storage tank;

[0016] Four cage positioning grooves are evenly distributed along the circumference on the turntable, which are used to fix the cage. The position of the cage on the cage positioning groove is adjustable, so as to achieve the purpose of fixing storage tanks of different sizes; the cage and the turntable are fixed by screws and nuts, simplifying the structure and facilitating processing; a light shielding plate is provided at the upper end of one of the cages. The laser displacement sensor is arranged opposite to the light shielding plate. The light shielding plate is used to reflect the light of the laser displacement sensor to ensure that the laser displacement sensor can operate stably when testing an irregular storage tank, and the size of the light shielding plate can be replaced according to the size of the deflection angle.

[0017] In the above technical solution, further, the experimental platform has a simple structure, is convenient to install, and has a low cost. The specific method for the magnet to drive the turntable to move translationally is: applying an initial displacement to the slider, and the magnetic force difference (repulsion difference) generated by the distance difference between the two pairs of magnets will drive the slider to do reciprocating motion along the radial slideway; the specific method for the spring to drive the turntable to rotate is: first rotating the turntable to an initial angle, and then the turntable will make a rotary motion under the action of the spring. The radial slideway has a small friction force, and the spring has damping. Therefore, both motion modes will gradually return to the initial position under energy dissipation. During the experiment, the anti-disturbance performance of the storage tank can be judged according to the time to return to the stationary position, and physical quantities such as angle, speed, and force during the measurement process can also be measured by the sensor.

[0018] Further, the light shielding plate is replaceable. A small light shielding plate is used when the rotation angle is small, minimizing the influence of the mass of the light shielding plate on the movement of the storage tank.

[0019] Further, a laser displacement sensor is used to measure the rotation angle and angular velocity of the storage tank, with small errors and low costs.

[0020] Further, a piezoelectric sensor is used to measure the impact force inside the tank body, with a simple structure and being convenient for disassembling, assembling, and replacing parts.

[0021] Furthermore, four cages are adopted to fix the storage tank, which can fix irregular storage tanks and has a wide range of applications.

[0022] The beneficial effects of the present invention are as follows:

[0023] The sloshing experimental platform of the present invention can detect the time, displacement, angle, and impact force of the movement of storage tanks with different shapes under various working conditions. When the slider fixing plate is installed on the radial slideway of the base to restrict the position of the slider, the three-axis rotation state of the storage tank can be detected. By measuring the change in the distance from the light-shielding plate to the sensor with a laser displacement sensor, the angle change during the sloshing process can be converted through trigonometric relationships. The piezoelectric sensor can detect the impact force of the storage tank at different rotation angles. By comparing the magnitudes of the impact forces of the empty storage tank at the same position, the sloshing situation and impact force of the liquid in the tank can be indirectly analyzed. Similarly, after removing the slider fixing plate, the time, displacement, and impact force of the reciprocating movement (i.e., radial sliding) of the storage tank during translational motion can be detected. At the same time, there are no electronic devices inside the present invention, which is a pure mechanical structure, simple to manufacture, convenient to disassemble and assemble, reliable in structure, and low in cost. The sloshing experimental platform of the present invention has a stable structure and can test various motion states. Description of the Drawings

[0024] Figure 1 It is a schematic diagram of the experimental platform of the present invention without a storage tank installed.

[0025] Figure 2 It is a front view of the experimental platform of the present invention without a storage tank installed.

[0026] Figure 3 It is a schematic diagram of the experimental platform of the present invention after fixing the upper storage tank.

[0027] Figure 4A and Figure 4B They are respectively cross-sectional views of the base and the slider of the present invention with the slideway not inserted and with the slider fixing plate inserted.

[0028] Figure 5 It is a cross-sectional view of the "convex" slideway of the present invention;

[0029] Among them, the base 1, the turntable 2, the cage 3, the piezoelectric sensor 4, the laser displacement sensor 5, the light-shielding plate 6, the magnet A 7-1, the magnet B 7-2, the magnet C 7-3, the magnet D 7-4, the radial slideway 8, the sensor fixing groove 9, the slider 10, the slider fixing plate 11, the bearing 12, the spring 13, the slideway buckle 14, the sensor bracket A 15-1, the sensor bracket B 15-2, the fixed support foot 16, the cage positioning groove 17, the positioning scale 18. Detailed Embodiments

[0030] The specific implementation process of the present invention will be described below with reference to the accompanying drawings.

[0031] As Figures 1-5 shown, an embodiment of the present invention provides a sloshing experiment platform for a pico-satellite propulsion system storage tank.

[0032] As Figure 1 shown, the base 1 is fixed to the experimental table through four fixed feet 16. A recessed track is provided on the side of the base 1 as a sensor fixing groove 9 for changing and fixing the positions of two sensor brackets. The laser displacement sensor 5 and the piezoelectric sensor 4 are respectively fixed to the base through the sensor bracket A 15-1 and the sensor bracket B 15-2. The sensor bracket A 15-1 and the sensor bracket B 15-2 are both fixed to the base by a threaded rod and a nut clamp. The upper cross bar and the vertical rod for support of the sensor bracket A 15-1 are fixed in a hinged manner, facilitating the adjustment of the height of the piezoelectric sensor so that it is aligned with the plane of the storage tank. A Figure 5 shown radial slideway 8 (i.e., a "convex" slideway) is opened in the middle of the base 1. The base 1 and the turntable 2 are connected by a slider 10 (shaped like a "convex") that matches the radial slideway 8. For the convenience of installation and maintenance, one end of the radial slideway 8 is provided with an opening for installing the slider 10, and the radial slideway 8 is closed by a slideway buckle 14. Magnets C 7-3 and D 7-4 are installed at both ends of the slider 10, and magnets A 7-1 and B 7-2 are arranged at both ends of the slideway. Among them, the same poles of magnets A 7-1 and C 7-3 are opposite to each other, and the same poles of magnets B 7-2 and D 7-4 are opposite to each other. The repulsive force difference between the magnets provides the power for the slider 10 to slide along the radial slideway 8 (i.e., the turntable 2 to translate). The turntable 2 is connected to the slider 10 through a bearing 12, and a spring 13 is further provided in the middle to provide the power for the turntable 2 to rotate. A circle of positioning scales 18 is provided around the turntable 2 for positioning the rotation angle at the start of the experiment. Four cage positioning grooves 17 are evenly distributed along the circumferential direction on the turntable 2 for fixing the cage 3. The form of installing the storage tank is as Figure 3 shown. The turntable 2 fixes the storage tank through four cages 3. The four cage positioning grooves of the turntable 2 enable the device to fix storage tanks of different sizes. When fixing the storage tank for the accuracy of the experiment, it is necessary to align the rotation center of the storage tank with the center of the turntable 2.

[0033] When testing the sloshing state of the liquid inside the storage tank during turning, Figure 4A and 4BFix the slider 10 in such a way as to restrict the translational movement of the turntable 2 and the storage tank thereon. Rotate the turntable 2 to give the storage tank an initial rotation angle. Under the action of the spring 13, the storage tank and the turntable 2 will perform a rotary motion along the bearing 12. At this time, the change in the distance between the light shielding plate 6 and the laser displacement sensor 5 can be collected by using the laser displacement sensor 5. Through trigonometric conversion, the angle and angular velocity changes of the storage tank sloshing and the sloshing time can be obtained. According to these data, the anti-disturbance ability of the storage tank structure against liquid sloshing can be judged. If it is necessary to measure the impact force of the liquid inside the storage tank on the tank body, a piezoelectric sensor 4 can be set at the required angle to measure the pressure of the tank body on the piezoelectric sensor 4 when the turntable 2 rotates to this angle, and then compare it with the force of the empty storage tank under the same conditions. This additional force is the impact force of the liquid on the tank wall due to the superposition of factors such as inertia and liquid surface tension. When only the sloshing data in the translational state needs to be measured, the turntable 2 can be lifted, the bearing 12 therein can be taken out to restrict the rotation of the turntable 2, and the slider fixing plate 11 can be taken out so that the slider 10 can translate along the radial slideway 8, and the data collection method is as described above.

[0034] In the relevant research on the sloshing analysis of the pico-satellite storage tank, since the difficulty and cost of the zero-gravity environment test are too high, but the data obtained solely by simulation calculation are too one-sided and lack stability. Therefore, the present invention can be used for the sloshing experiment of the micro-nano satellite storage tank. The main maneuvering methods of the satellite in orbit are three-axis rotation and orbit-changing and speed-changing maneuvers. During the maneuvering process, the liquid inside the storage tank will be disturbed by inertia and surface tension to affect the satellite attitude. Although the ground test brings in the influence of gravity, it can still reflect the sloshing characteristics of the storage tank and the anti-disturbance ability of the structure to a certain extent.

Claims

1. A Pina satellite propulsion system tank sloshing test platform, characterized in that: include: A base is fixed at a desired position; a turntable is provided on the base, and the turntable can perform translation and rotation on the base, the translation of the turntable is driven by a magnet, and the rotation of the turntable is achieved based on a spring; a retaining frame is provided on the turntable, which is used to fix the storage tank to be tested; a piezoelectric sensor and a laser displacement sensor are also provided on the base, and the positions of the piezoelectric sensor and the laser displacement sensor are changeable; the piezoelectric sensor is used to measure the pressure of the storage tank on the piezoelectric sensor when the turntable is rotated to a desired angle; a shading plate is provided on the retaining frame, and the laser displacement sensor is arranged opposite to the shading plate, and is used to measure the change in the distance from the shading plate to the laser displacement sensor, thereby calculating the angular change of the storage tank.

2. The Pina satellite propulsion system tank sloshing experimental platform according to claim 1 is characterized in that: The base is provided with a radial slideway and a sensor fixing groove; the radial slideway is smooth, and the turntable performs translational motion along the radial slideway; the sensor fixing groove is arranged in an annular direction and is used to install the piezoelectric sensor and the laser displacement sensor, and the positions of the two sensors are variable.

3. The Pina satellite propulsion system tank sloshing experimental platform according to claim 2 is characterized in that: The interior of the radial slide is smooth, and a slider is provided in the radial slide; the radial slide is convex, and protrusions are provided at the bottom of both sides of the slider, and the slider is fixed to the radial slide; the slider is used in conjunction with a slider fixing plate, and the slider fixing plate is placed in the radial slide to fix the position of the slider, so that when the liquid is in a sloshing state during the rotation of the test tank, the slider is controlled not to move in the radial direction; a circular depression is provided on the top of the slider for fixing the bearing and the spring; the turntable is connected to the slider through a bearing, and the turntable rotates around the circular depression on the top of the slider through the bearing; the other end of the spring is connected to the turntable, and is used to provide a rotational force for the turntable, thereby realizing the rotation of the turntable.

4. The Pina satellite propulsion system tank sloshing experimental platform according to claim 2 is characterized in that: A slideway buckle for blocking the slideway is provided at the opening of the radial slideway, which is used to close the radial slideway.

5. The Pina satellite propulsion system tank sloshing experimental platform according to claim 2 is characterized in that: Magnets are provided at both ends of the radial slideway and on both sides of the slider. The magnets on the slideway and the magnets on the slider are opposite to each other, and the ferromagnetism is replaceable. The repulsive force difference between the two pairs of magnets provides the power for the slider to slide along the radial slideway, thereby realizing the translation of the turntable.

6. The Pina satellite propulsion system tank sloshing experimental platform according to claim 1 is characterized in that: Four retainers are arranged on the turntable, and four retainer positioning grooves are evenly arranged on the turntable along the circumferential direction. A retainer is arranged in each retainer positioning groove, and the position of the retainer in the retainer positioning groove is variable, so as to fix storage tanks of different sizes.

7. The Pina satellite propulsion system tank sloshing experimental platform according to claim 1 is characterized in that: The piezoelectric sensor and the laser displacement sensor are both fixed on the base through a sensor bracket, and the sensor bracket and the base are fixed by a threaded rod and a nut clamp.

8. The Pina satellite propulsion system tank sloshing experimental platform according to claim 7 is characterized in that: The sensor bracket of the piezoelectric sensor comprises an upper cross bar and a vertical bar for support, and the cross bar and the vertical bar are fixed in a hinged manner, so as to facilitate the adjustment of the height of the piezoelectric sensor so as to align it with the storage tank.

9. The Pina satellite propulsion system tank sloshing experimental platform according to claim 1, characterized in that: The rotating disk is provided with a circle of positioning scales around it, which is used to locate the rotation angle at the beginning of the experiment.

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