Electrical thruster thrust measurement device for vertical upward ejection and measurement method thereof

Abstract

The application provides a vertical upward jetting electric thruster thrust measuring device and a measuring method thereof, comprising a thruster mounting base, a thruster gravity compensation device, a micro-thrust measuring device, a calibration device, a lead wire and a gas supply pipeline; the thruster gravity compensation device compensates the gravity of the thruster and the thruster mounting base through a spring; the micro-thrust measuring device is used for measuring the displacement change of the thruster mounting base in the vertical direction; and the calibration device is used for continuously calibrating the thrust of the thruster. The application compensates the gravity of the thruster through a spring, eliminates the interference of the gravity on the vertical micro-thrust measurement, and ensures the high-precision micro-thrust measurement; the micro-thrust is indirectly measured through a displacement sensor, the high-precision micro-thrust measurement is realized; the gas supply pipeline and the lead wire are spirally wound to avoid rigid interference, and the stability and accuracy of the measurement are further improved; the calibration device ensures the measurement accuracy in different thrust ranges; and the structure is simple and the operation is convenient.

Description

Technical Field

[0001] This invention relates to the field of micro-thrust measurement device technology, specifically to a thrust measurement device and method for an electric thruster used for vertical upward injection. Background Technology

[0002] With the increasing demand for high-precision, low-thrust propulsion systems in microsatellites and spacecraft, microthrust electric thrusters are playing an increasingly important role in space missions. Microthrusters are typically used for tasks such as orbital fine-tuning, attitude control, and long-duration continuous propulsion, applications that place extremely high demands on the accurate measurement of thrust. However, existing thrust measurement devices are mainly geared towards testing horizontal thrust; for measuring the thrust of vertically upward-ejecting thrusters, a precise and stable solution is still lacking.

[0003] A Chinese patent with publication number CN111964828B discloses a device and method for measuring the thrust and specific impulse of a micro-electric thruster. The measuring device includes a main suspension beam, two displacement sensors, two rotating elastic pivots, two electrostatic combs, and a support rod structure. The middle part of the main suspension beam is mounted on the support rod structure via the two rotating elastic pivots and is configured to rotate around the two rotating elastic pivots in the horizontal and vertical directions, respectively. The two displacement sensors measure the rotational displacement of the main suspension beam in the horizontal and vertical directions, respectively. After a DC high voltage is applied to the two electrostatic combs, the main suspension beam is reset in the horizontal and vertical directions, respectively.

[0004] Traditional thrust measurement devices typically employ force sensors or pendulum structures. While these methods can measure larger thrusts, they have significant limitations when dealing with micro-thrust measurements, especially in the vertical direction, where the thruster's own weight significantly affects the results. Furthermore, traditional measurement devices often rely on rigid tubing and wires in their mechanical structure, which interfere with the measurement of small thrusts in the vertical direction, making it difficult to meet practical requirements in terms of measurement accuracy.

[0005] To address the aforementioned issues, a thrust measurement device and method for an electric thruster used for vertical upward injection are needed. This device and method should eliminate gravitational interference, accurately calculate the minute thrust of the thruster, and avoid the influence of rigid piping on the thrust measurement accuracy, thus ensuring high stability and high precision in vertical thrust measurement. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a thrust measuring device and method for an electric thruster used for vertical upward injection.

[0007] According to the present invention, an electric thrust measuring device for vertically upward injection includes: a thruster mounting base, a thruster gravity compensation device, a micro-thrust measuring device, a calibration device, wires, and an air supply pipeline, wherein the thruster is mounted above the thruster mounting base;

[0008] The thruster gravity compensation device is located below the thruster mounting base. The thruster gravity compensation device is connected to the lower surface of the thruster gravity compensation device via a spring, and is used to compensate for the gravity of the thruster and the thruster mounting base.

[0009] The micro-thrust measuring device is located below the thruster mounting base and is used to measure the displacement change of the thruster mounting base in the vertical direction.

[0010] The calibration device is located at the lower center of the thruster mounting base, and is connected to the lower surface of the thruster mounting base via a connecting wire, for continuous calibration of the thrust of the thruster;

[0011] The air supply pipe and wire pass through the thruster mounting base from bottom to top and are connected to the thruster. Both the air supply pipe and wire below the thruster mounting base are spiral-shaped.

[0012] Preferably, the thruster is vertically mounted at the center of the thruster mounting base, and the thruster sprays rainwater vertically upwards.

[0013] Preferably, the thruster gravity compensation device includes: a guide shaft, an upper guide bearing, and a lower guide bearing. The upper guide bearing, spring, and lower guide bearing are sequentially sleeved on the guide shaft from top to bottom, and all four are arranged on the same central axis. The upper and lower ends of the spring are respectively pressed against the upper guide bearing and the lower guide bearing.

[0014] Preferably, the thruster mounting base has a through hole, the guide shaft extends through the through hole to the top of the thruster mounting base, the upper guide bearing is fastened to the lower surface of the thruster mounting base, and there are gaps between the through hole, the upper guide bearing and the guide shaft.

[0015] Preferably, the upper guide bearing and the lower guide bearing include magnetic levitation bearings or linear bearings.

[0016] Preferably, the micro-thrust measuring device includes a displacement sensor and a sensor mounting bracket, wherein the displacement sensor is placed on the sensor mounting bracket, and the vertical orthographic projection of the thruster mounting base completely covers the sensor mounting bracket.

[0017] Preferably, the calibration device includes a telescopic calibration platform and a weight set. The weight set is placed on the telescopic calibration platform and includes multiple weights connected in series from top to bottom in order of lightest to heaviest by a connecting thread. The upper end of the connecting thread is connected to the center of the lower surface of the thruster mounting base.

[0018] Preferably, the connecting wires between two adjacent weights in the weight set each have a tensioned state and a slack state, and the tensioned state and slack state are switched by the up and down movement of the telescopic calibration platform.

[0019] Preferably, a plurality of the thruster gravity compensation devices are evenly arranged around the circumference of the thruster mounting base, and a plurality of the micro-thrust measuring devices are evenly arranged around the circumference of the thruster mounting base.

[0020] A method for measuring the thrust of an electric thruster for vertical upward injection, provided by the present invention, is characterized in that, applied to the aforementioned electric thrust measuring device for vertical upward injection, it includes the following steps:

[0021] Step S1: Calibrate using a calibration device;

[0022] Step S2: Calibrate by adjusting the weight set, start the thruster, and detect the displacement of the thruster mounting base in the vertical direction by the micro-thrust measuring device;

[0023] Step S3: Adjust the weight set and perform multiple calibrations and measurements;

[0024] In step S4, the multiple sets of data detected by the micro-thrust measuring device are transmitted to the data processing system, and the thrust generated by the thruster is calculated by combining the spring stiffness coefficient.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] This invention eliminates the interference of gravity on vertical micro-thrust measurement by compensating for the thruster's own weight with a spring, ensuring high-precision micro-thrust measurement. It achieves high-precision measurement of minute thrust by indirectly measuring micro-thrust using a displacement sensor combined with Hooke's law. The spiral winding design of the air supply pipeline and wires avoids rigid interference, further improving the stability and accuracy of the measurement. The calibration device can continuously calibrate the thrust through a weight set and a telescopic calibration platform, ensuring measurement accuracy within different thrust ranges. The design of the guide shaft and guide bearing reduces the risk of overturning caused by uneven thrust, and the multiple bearing options effectively reduce the impact of friction. Attached Figure Description

[0027] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0028] Figure 1 This is a cross-sectional schematic diagram illustrating the structural principle of the micro-thrust measuring device for vertical upward injection under force measurement conditions, which is the main feature of this invention.

[0029] Figure 2 This is a cross-sectional schematic diagram illustrating the micro-thrust measuring device for vertical upward injection under calibration conditions, which is the main feature of this invention.

[0030] Figure 3 This is a top view schematic diagram of the micro-thrust measuring device for vertical upward injection under calibration conditions, which is the main feature of this invention.

[0031] The figure shows: 1. Thruster mounting base; 2. Wire; 3. Guide shaft; 4. Thruster; 5. Rainflow; 6. Air supply line; 7. Upper guide bearing; 8. Lower part of air supply line; 9. Lower guide bearing; 10. Telescopic calibration platform; 11. Weight group; 12. Spring; 13. Connecting wire; 14. Sensor mounting base; 15. Displacement sensor; 16. Lower part of wire; 17. Weights within the calibration thrust range; 18. Weights outside the calibration thrust range. Detailed Implementation

[0032] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0033] Example 1

[0034] like Figure 1-3As shown, a thrust measuring device for an electric thruster used for vertical upward injection according to the present invention includes: a thruster mounting base 1, a thruster gravity compensation device, a micro-thrust measuring device, a calibration device, a wire 2, and an air supply line 6. The thruster 4 is mounted above the thruster mounting base 1; the thruster gravity compensation device is disposed below the thruster mounting base 1, and the thruster gravity compensation device is connected to the lower surface of the thruster gravity compensation device via a spring 12, for performing gravity compensation on the thruster 4 and the thruster mounting base 1. Compensation; a micro-thrust measuring device is set below the thruster mounting base 1 to measure the displacement change of the thruster mounting base 1 in the vertical direction; a calibration device is set at the lower center of the thruster mounting base 1, and the calibration device is connected to the lower surface of the thruster mounting base 1 through a connecting thin wire 13, for continuous calibration of the thrust of the thruster 4; the air supply line 6 and the wire 2 pass through the thruster mounting base 1 from bottom to top and are connected to the thruster 4, and both the air supply line 6 and the wire 2 below the thruster mounting base 1 are spiral-shaped.

[0035] This application is mainly used in the case where the thruster 4 is ejected vertically upwards. The spring 12 compensates for the weight of the thruster 4 itself, and the high-precision displacement sensor 15 measures the micro-displacement of the spring 12, thereby accurately measuring the micro-thrust. It has high precision and strong stability, and is widely applicable to ground testing of space propulsion systems and performance evaluation of micro-thrusters.

[0036] The thruster 4 is vertically installed at the center of the thruster mounting base 1, and the thruster 4 sprays rain stream 5 vertically upward.

[0037] The thruster gravity compensation device mainly uses the elastic force of spring 12 to compensate for the gravity of the installed thruster 4 and thruster mounting base 1. The thruster gravity compensation device includes: guide shaft 3, upper guide bearing 7 and lower guide bearing 9. The upper guide bearing 7, spring 12 and lower guide bearing 9 are sequentially sleeved on the guide shaft 3 from top to bottom, and the four are set on the same central axis. The upper and lower ends of spring 12 are respectively pressed against the upper guide bearing 7 and the lower guide bearing 9.

[0038] A through hole is provided on the thruster mounting base 1. The guide shaft 3 extends through the through hole to the top of the thruster mounting base 1. The upper guide bearing 7 is fastened to the lower surface of the thruster mounting base 1. There are gaps between the hole walls of the through hole and the upper guide bearing 7 and the guide shaft 3.

[0039] The upper guide bearing 7 and the lower guide bearing 9 can be either magnetic levitation bearings or linear bearings. The selection of magnetic levitation bearings or linear bearings for the upper guide bearing 7 and the lower guide bearing 9 depends on the estimated thrust of the thruster 4. When the estimated thrust is large, a linear bearing can be installed; when the estimated thrust is small, a magnetic levitation bearing can be installed. The guide shaft 3 reduces the risk of the thruster mounting base 1 tilting due to the thrust of the thruster 4 not being centered. The upper guide bearing 7 and the lower guide bearing 9 reduce the friction between the thruster mounting base 1 and the guide shaft 3, thereby reducing the thrust measurement error caused by friction. Through the ingenious design of the guide shaft 3 and the guide bearings, the risk of base tilting caused by uneven thrust of the thruster is effectively reduced, and the flexible selection of magnetic levitation bearings and linear bearings reduces the impact of friction on the thrust measurement accuracy.

[0040] The micro-thrust measuring device measures the vertical displacement of the thruster mounting base 1 and then indirectly measures the magnitude of the micro-thrust of the thruster 4 using Hooke's Law. The micro-thrust measuring device includes a displacement sensor 15 and a sensor mounting support 14. The displacement sensor 15 is placed on the sensor mounting support 14, and the vertical orthographic projection of the thruster mounting base 1 completely covers the sensor mounting support 14.

[0041] To eliminate the influence of the thruster 4's own weight on the measurement results, the spring 12 in the thruster gravity compensation device balances the weight of the thruster 4 via the guide shaft 3. This allows thrust measurement to be performed under gravity-free conditions, thereby improving measurement accuracy. With the micro-thrust generated by the thruster 4, the thruster mounting base 1 undergoes a slight displacement change in the vertical direction. This displacement is detected and recorded by the displacement sensor 15. According to Hooke's Law, the displacement of the spring 12 is proportional to the force acting on it. Therefore, by measuring the displacement change of the thruster mounting base 1, the thrust generated by the thruster 4 can be indirectly calculated.

[0042] The calibration device can continuously calibrate the thrust of the thruster 4 using a certain combination of weights. The calibration device includes a telescopic calibration platform 10 and a weight set 11. The weight set 11 is placed on the telescopic calibration platform 10. The weight set 11 includes multiple weights connected in series from top to bottom in order of lightest to heaviest by a connecting thread 13. The upper end of the connecting thread 13 is connected to the center of the lower surface of the thruster mounting base 1.

[0043] The connecting wires 13 between adjacent weights in the weight set 11 each have a tensioned state and a slack state. The tensioned and slack states of the connecting wires 13 are switched by the up-and-down movement of the telescopic calibration platform 10. The telescopic calibration platform 10 can be automatically or manually adjusted continuously in height, and by supporting the weights 18 outside the calibration thrust range, it maintains the slack state of the lightweight connecting wires 13 of those weights, thereby ensuring the tensioned state of the lightweight connecting wires 13 of the weights 17 within the calibration thrust range, thus accurately calibrating the required thrust. The calibration device of this application can adapt to a wide range of measurement needs from extremely small to large thrust, has high practicality, and is particularly suitable for ground testing and performance evaluation of micro-thrust electric thrusters.

[0044] The lower part 8 of the gas supply line 6 and the lower part 16 of the wire 2 are both wound in a spiral shape to avoid the gas supply line 6 and the wire 2 from generating additional interference force on the thrust measuring device due to rigid tension, thereby ensuring the stability and reliability of the measurement.

[0045] Multiple thruster gravity compensation devices are evenly arranged along the circumference of the thruster mounting base 1, preferably four. Multiple micro-thrust measuring devices are evenly arranged along the circumference of the thruster mounting base 1, preferably two.

[0046] This application compensates for the weight of the thruster 4 by using spring 12, eliminating the interference of gravity on the vertical micro-thrust measurement, ensuring high-precision micro-thrust measurement, and solving the error problem caused by gravity in traditional devices; it indirectly measures micro-thrust by using displacement sensor 15 in combination with Hooke's law, realizing high-precision measurement of micro-thrust; the air supply pipeline 6 and the wire 2 adopt a spiral winding design to avoid rigid interference, further improving the stability and accuracy of the measurement.

[0047] The calibration device of this application can achieve continuous calibration of thrust through the weight set 11 and the telescopic calibration stage 10, ensuring measurement accuracy within different thrust ranges and solving the problem of insufficient calibration accuracy in traditional measuring devices. The design of the guide shaft 3 and guide bearing reduces the risk of overturning caused by uneven thrust, and the multiple selections of bearings effectively reduce the impact of friction.

[0048] This application provides a precise and stable solution to the gravity compensation problem in vertical micro-thrust measurement. It has a simple structure, is easy to operate, and can measure micro-thrust with high precision. It is widely applicable to ground testing and micro-thrust measurement of electric thrusters.

[0049] Example 2

[0050] Based on Embodiment 1, a method for measuring the thrust of an electric thruster for vertically upward injection, according to the present invention, includes the following steps:

[0051] Step S1: Calibrate using a calibration device;

[0052] Step S2: Calibrate by adjusting the weight group 11, start the thruster 4, and detect the displacement of the thruster mounting base 1 in the vertical direction by the micro-thrust measuring device;

[0053] Step S3: Adjust the weight group 11 and perform multiple calibrations and measurements;

[0054] In step S4, the multiple sets of data detected by the micro-thrust measuring device are transmitted to the data processing system, and the thrust generated by the thruster 4 is calculated by combining the stiffness coefficient of the spring 12.

[0055] Before performing micro-thrust measurements, the device is first calibrated using a calibration apparatus. The calibration process involves adjusting the height of the telescopic calibration platform 10 to control the load on the weight set 11. When the thruster mounting base 1 is in calibration mode, only the weights 17 within the calibrated thrust range are activated, while the weights 18 outside the calibrated thrust range remain in a relaxed state. By adjusting combinations of weights of different weights, the measuring device can be continuously calibrated step-by-step to ensure sufficient measurement accuracy across different thrust ranges. After calibration, the device is ready for actual measurements.

[0056] During thrust measurement, thruster 4 is vertically mounted on thruster mounting base 1 and activated. The thrust generated by thruster 4 acts on the micro-thrust measuring device through thruster mounting base 1. To eliminate the influence of thruster 4's own weight on the measurement results, spring 12 in the thruster gravity compensation device balances the weight of thruster 4 via guide shaft 3. This allows thrust measurement to be performed under gravity-free conditions, thereby improving measurement accuracy. With the micro-thrust generated by thruster 4, thruster mounting base 1 undergoes a small displacement change in the vertical direction. This displacement is detected and recorded by displacement sensor 15. According to Hooke's Law, the displacement of spring 12 is proportional to the force acting on it. Therefore, by measuring the displacement change of thruster mounting base 1, the thrust generated by thruster 4 can be indirectly calculated.

[0057] The data recorded by displacement sensor 15 is transmitted to the data processing system in real time. The system calculates the micro-thrust generated by thruster 4 based on the measured displacement value and the stiffness coefficient of spring 12. Because the device can eliminate the influence of gravity and avoids rigid interference through the spiral air supply line 6 and wire 2 design, the measurement results have high accuracy and stability.

[0058] This application effectively eliminates the interference of the thruster 4's own weight on the vertical micro-thrust measurement through a spring compensation device, significantly improving measurement accuracy. This application uses a displacement sensor 15 combined with Hooke's law to indirectly measure thrust, accurately calculating the thrust value by detecting minute displacements of the base. This method has higher sensitivity and accuracy under extremely small thrust measurement conditions, superior to traditional force sensors.

[0059] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0060] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. An electric thruster thrust measurement device for vertical up-ward ejection, characterized by, The device comprises a thruster mounting base (1), a thruster gravity compensation device, a micro-thrust measuring device, a calibration device, a wire (2) and a gas supply pipeline (6), and a thruster (4) is mounted above the thruster mounting base (1). The thruster gravity compensation device is arranged below the thruster mounting base (1), and the thruster gravity compensation device is connected to the lower surface of the thruster mounting base (1) through a spring (12) for gravity compensation of the thruster (4) and the thruster mounting base (1). The micro-thrust measuring device is arranged below the thruster mounting base (1) for measuring the displacement change of the thruster mounting base (1) in the vertical direction. The calibration device is arranged at the center of the lower part of the thruster mounting base (1), and the calibration device is connected to the lower surface of the thruster mounting base (1) through a connecting thin wire (13) for continuous calibration of the thrust of the thruster (4). The gas supply pipeline (6) and the wire (2) pass through the thruster mounting base (1) and are connected to the thruster (4) from bottom to top, and both the gas supply pipeline (6) and the wire (2) below the thruster mounting base (1) are in a spiral shape. The thruster (4) is vertically mounted at the center of the thruster mounting base (1), and the thruster (4) sprays rain flow (5) vertically upward. The thruster gravity compensation device comprises a guide shaft (3), a guide upper bearing (7) and a guide lower bearing (9), the guide upper bearing (7), the spring (12) and the guide lower bearing (9) are sequentially sleeved on the guide shaft (3) from top to bottom, and the four are arranged on the same central axis, and the upper and lower ends of the spring (12) are respectively abutted against the guide upper bearing (7) and the guide lower bearing (9).

2. An electrical thrust motor thrust measurement device for vertical up-jet as in claim 1, wherein, A through hole is formed in the thruster mounting base (1), the guide shaft (3) extends to the upper side of the thruster mounting base (1) through the through hole, the guide upper bearing (7) is tightly connected with the lower surface of the thruster mounting base (1), and gaps exist between the hole walls of the through hole and the guide upper bearing (7) and the guide shaft (3).

3. An electrical thrust motor thrust measurement device for vertical up-ward ejection as in claim 2, wherein, The guide upper bearing (7) and the guide lower bearing (9) comprise magnetic suspension bearings or linear bearings.

4. An electrical thrust motor thrust measurement apparatus for vertical up-jet as in claim 2, wherein, The micro-thrust measuring device comprises a displacement sensor (15) and a sensor mounting support (14), the displacement sensor (15) is placed on the sensor mounting support (14), and the vertical projection of the thruster mounting base (1) completely covers the sensor mounting support (14).

5. The electric thruster thrust measurement apparatus for vertical upward ejection as recited in claim 1, characterized by, The calibration device comprises a telescopic calibration table (10) and a weight set (11), the weight set (11) is placed on the telescopic calibration table (10), the weight set (11) comprises a plurality of weights which are sequentially connected by a connecting thin wire (13) from top to bottom in the order of light to heavy, and the upper end of the connecting thin wire (13) is connected with the center of the lower surface of the thruster mounting base (1).

6. An electrical thrust motor thrust measurement device for vertical up-jet as in claim 1, wherein, ​ 7. An electrical thrust motor thrust measurement device for vertical up-jet as in claim 6, wherein, The connecting thin line (13) between two adjacent weights of the weight set (11) includes a tension state and a relaxation state, and the connecting thin line (13) switches between the tension state and the relaxation state by moving up and down on the telescopic calibration platform (10).

8. An electrical thrust motor thrust measurement device for vertical up-jet as in claim 1, wherein, A plurality of the thruster gravity compensation devices are uniformly arranged along the circumference of the thruster mounting base (1), and a plurality of the micro-thrust measuring devices are uniformly arranged along the circumference of the thruster mounting base (1).

9. A method of measurement for an electric thruster thrust measurement device for vertical up-ward ejection, characterized by, The application is applied to the electric thruster thrust measuring device for vertical upward injection as claimed in any one of claims 1-8, and comprises the following steps: Step S1, calibration by the calibration device; Step S2, calibration by adjusting the weight set (11), starting the thruster (4), and detecting the displacement of the thruster mounting base (1) in the vertical direction by the micro-thrust measuring device; Step S3, multiple calibrations by adjusting the weight set (11) and multiple measurements; Step S4, multiple groups of data detected by the micro-thrust measuring device are transmitted to the data processing system, and the generated thrust of the thruster (4) is calculated in combination with the stiffness coefficient of the spring (12).

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