Thrust measuring device and method of electric thruster for vertical upward injection

Abstract

The invention provides an electric thruster thrust measuring device for vertical upward injection and a measuring method thereof. The electric thruster thrust measuring device comprises a thruster mounting base, a thruster gravity compensation device, a micro thrust measuring device, a calibration device, a wire and a gas supply pipeline, the thruster gravity compensation device performs gravity compensation on 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 gravity of the thruster is compensated through the spring, interference of the gravity on vertical micro-thrust measurement is eliminated, and high-precision micro-thrust measurement is ensured; the micro thrust is indirectly measured through the displacement sensor, and high-precision measurement of the micro thrust is achieved; the air supply pipeline and the wire are spirally wound to avoid rigid interference, so that the stability and the accuracy of measurement are further improved; the calibration device ensures the measurement precision in different thrust ranges; the structure is simple and operation is convenient.

Description

Technical Field

[0001] The invention relates to the technical field of micro-thrust measurement devices, and in particular to a thrust measurement device of an electric thruster for vertical upward injection and a measurement method thereof. Background Art

[0002] With the increasing demand for high-precision, low-thrust propulsion systems for microsatellites and spacecraft, micro-thrust electric thrusters are playing an increasingly important role in space missions. Micro-thrusters are usually used for tasks such as orbit fine-tuning, attitude control, and long-term continuous propulsion. Such applications place extremely high demands on the precise measurement of thrust. However, existing thrust measurement devices are mainly aimed at testing horizontal thrust, and there is still a lack of accurate and stable solutions for the micro-thrust measurement of vertically upward ejecting thrusters.

[0003] The existing Chinese patent with publication number CN111964828B discloses a thrust and specific impulse measurement device and method of a micro-electric thruster. The measurement device includes a main suspension beam, two displacement sensors, two rotating elastic pivots, two electrostatic comb teeth and a support rod structure. The middle part of the main suspension beam is installed on the support rod structure through two rotating elastic pivots, and is configured to rotate around the two rotating elastic pivots in the horizontal direction and the vertical direction respectively; the two displacement sensors measure the rotational displacement of the main suspension beam in the horizontal direction and the vertical direction respectively; after the two electrostatic comb teeth are applied with DC high voltage, they reset the main suspension beam in the horizontal direction and the vertical direction respectively.

[0004] Traditional thrust measurement devices usually use force sensors or pendulum structures. Although these methods can measure large thrusts, they have obvious shortcomings when dealing with micro-thrust measurements, especially in vertical measurements, where the thruster's own gravity has a significant impact on the measurement results. In addition, traditional measurement devices usually rely on rigid pipes and wires in mechanical structure, which interfere with the measurement of tiny thrusts in the vertical direction, making it difficult for the measurement accuracy to meet actual needs.

[0005] In order to solve the above problems, it is necessary to provide a thrust measurement device and a measurement method for an electric thruster for vertical upward injection, which can eliminate gravity interference, accurately calculate the tiny thrust of the thruster, and avoid the influence of rigid pipelines on the thrust measurement accuracy, thereby ensuring high stability and high precision in vertical thrust measurement. Summary of the invention

[0006] In view of the defects in the prior art, an object of the present invention is to provide a thrust measurement device and a measurement method of an electric thruster for vertical upward injection.

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

[0008] The thruster gravity compensation device is arranged below the thruster mounting base, and the thruster gravity compensation device is connected to the lower surface of the thruster gravity compensation device through a spring, and is used to perform gravity compensation on the thruster and the thruster mounting base;

[0009] The micro-thrust measuring device is arranged 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 arranged at the central lower part of the thruster mounting base, and the calibration device is connected to the lower surface of the thruster mounting base through a connecting fine line, and is used for continuous calibration of the thrust of the thruster;

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

[0012] Preferably, the thruster is vertically mounted at the center of the thruster mounting base, and the thruster sprays rain flow vertically upward.

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

[0014] Preferably, a through hole is provided on the thruster mounting base, the guide shaft passes through the through hole and extends to above the thruster mounting base, the guide upper bearing is fastened to the lower surface of the thruster mounting base, and there is a gap between the hole walls of the through hole and the guide upper bearing and the guide shaft.

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

[0016] Preferably, the micro-thrust measurement device comprises a displacement sensor and a sensor mounting support, the displacement sensor is placed on the sensor mounting support, and the orthographic projection of the thruster mounting base in the vertical direction completely covers the sensor mounting support.

[0017] Preferably, the calibration device includes a telescopic calibration platform and a weight group, the weight group is placed on the telescopic calibration platform, the weight group includes a plurality of weights connected in series in order from light to heavy from top to bottom through a connecting wire, and the upper end of the connecting wire is connected to the center of the lower surface of the thruster mounting base.

[0018] Preferably, the connecting thin wires between two adjacent weights of the weight group include a tensioned state and a relaxed state, and the connecting thin wires are switched between the tensioned state and the relaxed state by moving up and down the telescopic calibration platform.

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

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

[0021] Step S1, calibrating by a calibration device;

[0022] Step S2, calibrating by adjusting the weight set, starting the thruster, and detecting the displacement of the thruster mounting base in the vertical direction by a micro-thrust measuring device;

[0023] Step S3, adjusting the weight set to perform multiple calibrations and multiple measurements;

[0024] Step S4, multiple groups 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 in combination with the stiffness coefficient of the spring.

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

[0026] The present invention compensates for the thruster's own gravity through a spring, eliminates the interference of gravity on vertical micro-thrust measurement, and ensures high-precision micro-thrust measurement; indirectly measures micro-thrust through a displacement sensor combined with Hooke's law, and realizes high-precision measurement of tiny thrust; adopts a spiral winding design for the air supply pipeline and the wire to avoid rigid interference and further improve the stability and accuracy of the measurement; the calibration device can realize continuous calibration of the thrust through a weight set and a telescopic calibration platform, and ensures the measurement accuracy within different thrust ranges; the design of the guide shaft and the guide bearing reduces the risk of overturning caused by uneven thrust, and the multiple choices of bearings effectively reduce the influence of friction. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0028] Figure 1 This is a schematic cross-sectional view of the structure of a micro-thrust measuring device for vertical upward injection in a force measuring state, which is mainly embodied in the present invention;

[0029] Figure 2 The present invention mainly embodies the structural section schematic diagram of a micro-thrust measurement device for vertical upward injection in a calibration state;

[0030] Figure 3 The present invention mainly embodies a top view schematic diagram of a micro-thrust measurement device for vertical upward injection in a calibration state.

[0031] As shown in the figure:

[0032] Thruster mounting base wire guide shaft

[0033] Thruster jet rain flow air supply line

[0034] Guide upper bearing Air supply pipeline Lower guide lower bearing

[0035] Telescopic calibration table weight spring

[0036] Connect the thin wire sensor to install the seat shift sensor

[0037] Weights within the calibration thrust range at the bottom of the conductor Weights outside the calibration thrust range DETAILED DESCRIPTION

[0038] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0039] Example 1

[0040] like Figure 1-3As shown, according to the present invention, an electric thruster thrust measuring device for vertical upward injection 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 pipeline 6. The 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 gravity compensation device through a spring 12, which is used to gravity-compensate the thruster 4 and the thruster mounting base 1. compensation; a micro-thrust measuring device is arranged below the thruster mounting base 1, and is used to measure the displacement change of the thruster mounting base 1 in the vertical direction; a calibration device is arranged 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 fine wire 13, and is used to continuously calibrate the thrust of the thruster 4; an air supply pipeline 6 and a conducting 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 pipeline 6 and the conducting wire 2 below the thruster mounting base 1 are spiral.

[0041] The present application is mainly used for the working condition where the thruster 4 plume is ejected vertically upward. The spring 12 is used to compensate for the thruster 4's own gravity, and a high-precision displacement sensor 15 is used to measure the micro-displacement of the spring 12, thereby accurately measuring tiny thrusts. The application has high accuracy and strong stability, and is widely applicable to ground testing of space propulsion systems and performance evaluation of micro-thrusters.

[0042] The thruster 4 is vertically mounted at the center of the thruster mounting base 1 , and the thruster 4 sprays the rain flow 5 vertically upward.

[0043] The thruster gravity compensation device mainly performs gravity compensation on the installed thruster 4 and the thruster mounting base 1 through the elastic force of the spring 12. 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 coaxially. The upper and lower ends of the spring 12 are respectively pressed against the guide upper bearing 7 and the guide lower bearing 9.

[0044] A through hole is provided on the thruster mounting base 1, and the guide shaft 3 extends through the through hole to the top of the thruster mounting base 1. The guide upper bearing 7 is tightly connected to the lower surface of the thruster mounting base 1, and there is a gap between the hole walls of the through hole and the guide upper bearing 7 and the guide shaft 3.

[0045] The upper guide bearing 7 and the lower guide bearing 9 include magnetic bearings or linear bearings. The upper guide bearing 7 and the lower guide bearing 9 can select magnetic bearings or linear bearings according to the estimated thrust size of the thruster 4. When the estimated thrust of the thruster is large, a linear bearing can be installed. When the estimated thrust is small, a magnetic bearing can be installed. The guide shaft 3 reduces the risk of the thruster mounting base 1 tilting due to the non-centering thrust of the thruster 4; 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 of the thruster 4 caused by friction. Through the ingenious design of the guide shaft 3 and the guide bearing, the risk of base tilting caused by uneven thrust of the thruster is effectively reduced, and through the flexible selection of magnetic bearings and linear bearings, the influence of friction on the thrust measurement accuracy is reduced.

[0046] The micro-thrust measuring device measures the displacement change of the thruster mounting base 1 in the vertical direction, and then indirectly measures the micro-thrust of the thruster 4 according to 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. The vertical projection of the thruster mounting base 1 completely covers the sensor mounting support 14.

[0047] In order to eliminate the influence of the thruster 4's own gravity on the measurement results, the spring 12 in the thruster gravity compensation device balances the thruster 4's gravity through the guide shaft 3. This enables the thrust measurement to be performed without gravity interference, thereby improving the 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. The 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 it receives. Therefore, by measuring the displacement change of the thruster mounting base 1, the thrust generated by the thruster 4 can be indirectly calculated.

[0048] The calibration device can realize continuous calibration of the thrust of the thruster 4 through a certain weight combination. The calibration device includes a telescopic calibration platform 10 and a weight group 11, the weight group 11 is placed on the telescopic calibration platform 10, and the weight group 11 includes a plurality of weights connected in series from top to bottom in a light to heavy order through a connecting wire 13, and the upper end of the connecting wire 13 is connected to the center of the lower surface of the thruster mounting base 1.

[0049] The connecting wire 13 between two adjacent weights of the weight group 11 includes a tensioned state and a relaxed state, and the connecting wire 13 switches between the tensioned state and the relaxed state by moving up and down the telescopic calibration platform 10. The telescopic calibration platform 10 can automatically or manually adjust the height continuously, and by supporting the weights 18 outside the calibration thrust range, the lightweight connecting wire 13 of this part of the weights is maintained in a relaxed state, thereby ensuring the tensioned state of the lightweight connecting wire 13 of the weights 17 within the calibration thrust range, and then accurately calibrating the required thrust. The calibration device of the present application can adapt to a wide range of measurement requirements from extremely small to large thrusts, has a high degree of practicality, and is particularly suitable for ground testing and performance evaluation of micro-thrust electric thrusters.

[0050] The lower part 8 of the air supply line 6 and the lower part 16 of the wire 2 are both wound in a spiral shape to prevent the air supply line 6 and the wire 2 from generating additional interference force on the thrust measurement device due to rigid pulling, thereby ensuring the stability and reliability of the measurement.

[0051] A plurality of thruster gravity compensation devices are evenly arranged along the circumference of the thruster mounting base 1, preferably 4. A plurality of micro-thrust measurement devices are evenly arranged along the circumference of the thruster mounting base 1, preferably 2.

[0052] The present application compensates for the thruster 4's own gravity through the spring 12, eliminates the interference of gravity on the vertical micro-thrust measurement, ensures high-precision micro-thrust measurement, and solves the error problem caused by the influence of gravity in traditional devices; indirectly measures the micro-thrust through the displacement sensor 15 combined with Hooke's law, thereby achieving high-precision measurement of tiny 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.

[0053] The calibration device of the present application can realize continuous calibration of thrust through the weight set 11 and the telescopic calibration platform 10, ensuring the 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 the guide bearing reduces the risk of overturning caused by uneven thrust, and the multiple choices of bearings effectively reduce the influence of friction.

[0054] The present application provides an accurate and stable solution to the gravity compensation problem of vertical micro-thrust measurement. It has a simple structure, is easy to operate, can measure micro-thrust with high precision, and is widely applicable to ground testing and micro-thrust measurement of electric thrusters.

[0055] Example 2

[0056] Based on Example 1, a measurement method of a thrust measurement device for an electric thruster for vertical upward injection provided by the present invention comprises the following steps:

[0057] Step S1, calibrating by a calibration device;

[0058] Step S2, calibrating 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 a micro-thrust measuring device;

[0059] Step S3, adjusting the weight set 11 to perform multiple calibrations and multiple measurements;

[0060] Step S4 , 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 in combination with the stiffness coefficient of the spring 12 .

[0061] Before performing micro-thrust measurement, the device is first calibrated by a calibration device. The calibration process controls the load of the weight group 11 by adjusting the height of the telescopic calibration platform 10. When the thruster mounting base 1 is in the calibration state, only the weights 17 within the calibration thrust range are activated, and the weights 18 outside the calibration thrust range remain in a relaxed state. By adjusting the combination of weights of different weights, the measuring device can be calibrated continuously step by step to ensure that it has sufficient measurement accuracy in different thrust ranges. After the calibration is completed, the device can be used for actual measurement.

[0062] During the thrust measurement process, the thruster 4 is vertically mounted on the thruster mounting base 1, and the thruster 4 is started. The thrust generated by the thruster 4 acts on the micro-thrust measuring device through the thruster mounting base 1. In order to eliminate the influence of the thruster 4's own gravity on the measurement result, the spring 12 in the thruster gravity compensation device balances the gravity of the thruster 4 through the guide shaft 3. This enables the thrust measurement to be carried out without gravity interference, thereby improving the 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. The 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 it receives. Therefore, by measuring the displacement change of the thruster mounting base 1, the thrust generated by the thruster 4 can be indirectly calculated.

[0063] The data recorded by the displacement sensor 15 is transmitted to the data processing system in real time. The system calculates the micro-thrust generated by the thruster 4 based on the measured displacement value and the stiffness coefficient of the spring 12. Since the device can eliminate the influence of gravity and avoid rigid interference through the spiral air supply pipeline 6 and the wire 2 design, the measurement result has a high degree of accuracy and stability.

[0064] The present application effectively eliminates the interference of the thruster 4's own gravity on the vertical micro-thrust measurement through the spring compensation device, greatly improving the measurement accuracy. The present application uses a displacement sensor 15 combined with Hooke's law to indirectly measure the thrust, and accurately calculates the thrust value by detecting the tiny displacement of the base. This method has higher sensitivity and accuracy under extremely small thrust measurement conditions, which is superior to traditional force sensors.

[0065] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0066] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A thrust measuring device for an electric thruster for vertical upward injection, characterized in that: include: A thruster mounting base (1), a thruster gravity compensation device, a micro-thrust measurement device, a calibration device, a wire (2) and an air supply pipeline (6), wherein the thruster (4) is mounted above the thruster mounting base (1); The thruster gravity compensation device is arranged below the thruster mounting base (1), and is connected to the lower surface of the thruster gravity compensation device via a spring (12), and is used to perform gravity compensation on the thruster (4) and the thruster mounting base (1); The micro-thrust measurement device is arranged below the thruster mounting base (1) and is used to measure the displacement change of the thruster mounting base (1) in the vertical direction; The calibration device is arranged at the central 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 fine line (13), and is used for continuously calibrating the thrust of the thruster (4); The air supply pipeline (6) and the wire (2) pass through the thruster mounting base (1) from bottom to top and are connected to the thruster (4); the air supply pipeline (6) and the wire (2) below the thruster mounting base (1) are both spiral-shaped.

2. The thrust measuring device for electric thruster for vertical upward injection according to claim 1, characterized in that: The thruster (4) is vertically mounted at the center of the thruster mounting base (1), and the thruster (4) sprays a rain flow (5) vertically upward.

3. The thrust measuring device for electric thruster for vertical upward injection according to claim 1, characterized in that: The thruster gravity compensation device comprises: a guide shaft (3), an upper guide bearing (7) and a lower guide bearing (9); the upper guide bearing (7), a spring (12) and a lower guide bearing (9) are sequentially sleeved on the guide shaft (3) from top to bottom, and the four are arranged on the same central axis; the upper and lower ends of the spring (12) are respectively pressed against the upper guide bearing (7) and the lower guide bearing (9).

4. The thrust measuring device for electric thruster for vertical upward injection as claimed in claim 3, characterized in that: The thruster mounting base (1) is provided with a through hole, the guide shaft (3) passes through the through hole and extends to the top of the thruster mounting base (1), the guide upper bearing (7) is tightly connected to the lower surface of the thruster mounting base (1), and there is a gap between the hole walls of the through hole and the guide upper bearing (7) and the guide shaft (3).

5. The thrust measuring device for electric thruster for vertical upward injection as claimed in claim 3, characterized in that: The guide upper bearing (7) and the guide lower bearing (9) include magnetic bearings or linear bearings.

6. The thrust measuring device for electric thruster for vertical upward injection according to claim 1, characterized in that: The micro-thrust measurement 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).

7. The thrust measuring device for electric thruster for vertical upward injection according to claim 1, characterized in that: The calibration device comprises a telescopic calibration platform (10) and a weight group (11), wherein the weight group (11) is placed on the telescopic calibration platform (10), and the weight group (11) comprises a plurality of weights connected in series in order from light to heavy from top to bottom via a connecting thin wire (13), wherein the upper end of the connecting thin wire (13) is connected to the center of the lower surface of the thruster mounting base (1).

8. The thrust measuring device for electric thruster for vertical upward injection according to claim 7, characterized in that: The connecting thin wire (13) between two adjacent weights of the weight group (11) includes a tensioned state and a relaxed state, and the connecting thin wire (13) switches between the tensioned state and the relaxed state by moving up and down through the telescopic calibration platform (10).

9. The thrust measuring device for electric thruster for vertical upward injection according to claim 1, characterized in that: A plurality of the thruster gravity compensation devices are evenly arranged along the circumference of the thruster mounting base (1), and a plurality of the micro-thrust measurement devices are evenly arranged along the circumference of the thruster mounting base (1).

10. A method for measuring the thrust of an electric thruster for vertical upward injection, characterized in that: The thrust measuring device for an electric thruster for vertical upward injection as claimed in any one of claims 1 to 9 comprises the following steps: Step S1, calibrating by a calibration device; Step S2, calibration is performed 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 using a micro-thrust measuring device; Step S3, adjusting the weight set (11) to perform multiple calibrations 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 thrust generated by the thruster (4) is calculated in combination with the stiffness coefficient of the spring (12).

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