A high-precision millinewton-level micro-propulsion thrust feedback measuring device

Abstract

The application discloses a high-precision millinewton-level micro-propulsion thrust feedback measuring device and relates to the technical field of micro-thrust testing. The device is provided with a torsional pendulum mechanism and an electromagnetic calibration device on a working platform, the torsional pendulum mechanism is arranged on the working platform, and a damping assembly and a laser displacement sensor are arranged at two ends of the torsional pendulum mechanism respectively; the electromagnetic calibration device is arranged on the torsional pendulum mechanism and is used for determining a system damping ratio, a vibration frequency and a moment of inertia. The device can solve the technical problem that the existing testing device has low micro-thrust testing precision.

Description

Technical Field

[0001] This invention relates to the field of micro-thrust testing technology, specifically to a high-precision millinewton-level micro-propulsion thrust feedback measurement device. Background Technology

[0002] With the aerospace technology trending towards lightweighting, miniaturization, and distributed deployment, micro-thrusters, with their significant advantages such as small size, low R&D cost, short development cycle, and flexible launch and deployment methods, have become core components in aerospace fields such as communication, remote sensing, navigation, and deep space scientific exploration. Their performance directly determines the orbit control and attitude adjustment capabilities of microsatellites and nanosatellites, as well as small spacecraft. Microsatellites that achieve precise orbit control capabilities using micro-thrusters have broken through the limitations of traditional large satellite development and application, becoming a cutting-edge research direction in the global satellite field. The formation and stable maintenance of the relative positions of microsatellite formations place extremely high demands on the thrust output accuracy of micro-thrusters, making the accurate and real-time measurement of micro-thrust a core key technology for the R&D, performance verification, and engineering application of micro-thrusters.

[0003] Precise measurement of micro-thrust relies on high-performance testing platforms. Currently, commonly used micro-thrust testing platforms in the industry are mainly divided into four categories: balance type, pendulum type, suspension wire type, and torsion pendulum type. These four types of platforms are designed based on different mechanical principles and have their own characteristics in terms of measurement performance and applicable scenarios. However, they all have unavoidable technical defects and cannot fully meet the high-precision testing requirements of micro-thrust devices at this stage. Among them, the pendulum type testing platform cannot eliminate the direct influence of gravity on the test results due to structural design limitations, resulting in large measurement data deviations and low overall resolution. It is only suitable for low-precision thrust testing scenarios. The balance type testing platform achieves the separation of thrust and gravity through structural balance, and the test structure in a dynamic equilibrium state gives it high sensitivity. However, its measurement resolution is significantly limited by the performance of the core sensing components, making it difficult to capture minute-level thrust changes. The suspension wire type testing platform achieves high-resolution measurement with its ingenious structural design. The device is small in size and easy to deploy, but its core sensing components are extremely sensitive to external interference such as environmental noise and airflow vibration, which can easily lead to measurement data distortion. It also has stringent requirements for the testing environment.

[0004] In comparison, the torsion pendulum test platform, with its design advantage of separating thrust and gravity, can not only adapt to the loading and testing of large-mass, large-volume micro-thrusters, but also has high measurement resolution, making it the mainstream technology in the field of micro-thrust testing. However, existing torsion pendulum micro-thrust test devices still have significant technical shortcomings. Their testing range is mostly limited to the mN to N range, making it difficult to accurately measure micro-thrust in the μN to mN range. Furthermore, they lack an effective thrust feedback measurement mechanism, making it impossible to provide real-time and accurate feedback and recording of the continuous thrust output of the micro-thruster. No torsion pendulum device has yet emerged that can achieve high-precision millinewton-level micro-thrust feedback measurement.

[0005] With the continuous development of micro-nano satellite formation technology and deep space micro-miniature detector technology, the aerospace field's requirements for the thrust output accuracy of micro-thrusters are constantly increasing. High-precision testing of millinewton-level micro-thrust in the μN to mN range has become an industry necessity. The technical deficiencies of existing testing platforms, especially the shortcomings of torsion-type testing platforms in measuring and feedback of micro-thrust at the micro-scale, have become key bottlenecks restricting the technological iteration and engineering application of micro-thrusters. Therefore, a torsion-type micro-thrust testing device capable of achieving high-precision feedback measurement in the μN to mN range and adapted to large-scale micro-thrusters is needed, making it an important research direction and urgent requirement in the field of micro-thrust testing. Summary of the Invention

[0006] This invention addresses the shortcomings of existing technologies by providing a high-precision millinewton-level micro-thrust feedback measurement device, thus solving the technical problem of low accuracy in millinewton-level micro-thrust testing using existing testing devices.

[0007] To achieve the above objectives, the technical solution adopted by the present invention to solve its technical problem is as follows: a high-precision millinewton-level micro-propulsion thrust feedback measurement device, comprising a torsion pendulum mechanism and an electromagnetic calibration device, wherein the torsion pendulum mechanism is disposed on a working platform, and a damping component and a laser displacement sensor are respectively disposed at both ends of the torsion pendulum mechanism; the electromagnetic calibration device is disposed on the torsion pendulum mechanism and is used to determine the system damping ratio, vibration frequency and moment of inertia.

[0008] Preferably, the torsion mechanism includes a torsion body, a support frame, a fixed frame, a base frame, and a pad. The torsion body is mounted on the support frame, the support frame is mounted on the fixed frame, the fixed frame is mounted on the side of the base frame, the base frame is mounted on the work platform, and the pad is mounted at the bottom of the fixed frame.

[0009] Preferably, a micro-thruster is installed at one end of the torsion pendulum body to provide millinewton-level micro-thrust during testing, and a counterweight is placed at the other end of the torsion pendulum body to ensure the mechanical balance of the torsion pendulum and stabilize the torsion pendulum motion.

[0010] Preferably, the holes in the fixing frame and the support frame are provided with twisted wires, which are used to provide elastic restoring force.

[0011] Preferably, the torsion pendulum body is an H-shaped pendulum arm structure, and the end of the torsion pendulum body used to install the micro thruster is set as a rectangular platform.

[0012] Preferably, the damping assembly includes a damping bracket, a damping plate, and two electromagnets. The damping bracket is disposed on the working platform, the damping plate is disposed in the middle of the damping bracket, and the two electromagnets are disposed at both ends of the damping plate and are axially connected to the damping bracket.

[0013] Preferably, the laser displacement sensor is mounted on the working platform to measure the displacement change of the torsional pendulum and is electrically connected to the computer.

[0014] Preferably, the electromagnetic calibration device includes a support, a coil cylinder, and a coil. The support is set on a working platform, the coil cylinder is set on the support, and the coil is wound and fixed on the coil cylinder.

[0015] The beneficial effects that this invention can achieve are as follows: This invention proposes a high-precision millinewton-level micro-thrust feedback measurement device. It uses a horizontally movable torsion pendulum mechanism as its main body, with damping components and laser displacement sensors at both ends. It is also equipped with an electromagnetic calibration device for calibrating system parameters. The overall structure is scientifically designed, and the components work together seamlessly. The damping components effectively suppress the irregular vibration of the torsion pendulum mechanism, ensuring its motion stability. The laser displacement sensors accurately capture the displacement changes of the torsion pendulum mechanism, and the electromagnetic calibration device accurately determines core parameters such as the system's damping ratio, vibration frequency, and moment of inertia, providing precise data for thrust calculation. The coordinated operation of these components achieves high-precision feedback measurement of millinewton-level micro-thrust. The device has strong overall adaptability and high measurement accuracy, effectively meeting the thrust testing requirements of micro-thrusters and solving the technical problems of insufficient measurement accuracy and inability to achieve high-precision millinewton-level measurement in existing testing devices. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the micro-thrust testing device; Figure 2 This is a schematic diagram of the electromagnetic calibration device of the micro-thrust testing device; Figure 3 This is a schematic diagram of the mounting bracket of the testing device according to the present invention; Figure 4 This is a schematic diagram of the support frame of the testing device according to the present invention; Figure 5 This is a schematic diagram of the torsion wire of the testing device according to the present invention; Figure 6 It is the response of the torsional yaw system under step force; Figure 7 It is the response of a torsional pendulum system under free vibration; Figure 8It is the vibration displacement curve of the laser displacement sensor during the electromagnetic calibration process.

[0017] In the diagram: 1-Working platform; 2-Torsional pendulum body; 3-Laser displacement sensor; 4-Base frame; 5-Fixed frame; 6-Support frame; 7-Counterweight; 8-Padded block; 9-Damping plate; 10-Damping bracket; 11-Electromagnet; 12-Electromagnetic calibration device; 13-Coil; 14-Coil cylinder; 15-Bracket.

[0018] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0021] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0022] See Figures 1 to 8 This invention provides a high-precision millinewton-level micro-propulsion thrust feedback measurement device, including a torsion pendulum mechanism and an electromagnetic calibration device 12. The torsion pendulum mechanism is the main body of the device and is set on the working platform 1, moving in the horizontal direction. Damping components and laser displacement sensors 3 are respectively set at both ends of the torsion pendulum mechanism. The electromagnetic calibration device 12 is set on the torsion pendulum mechanism and is used to determine the system damping ratio, vibration frequency and rotational inertia.

[0023] In this embodiment, the torsion pendulum mechanism serves as the core force-bearing and motion carrier, converting the millinewton-level micro-thrust output by the micro-thruster into horizontal torsional displacement. The damping component effectively suppresses the irregular vibration of the torsion pendulum mechanism, allowing it to quickly return to a steady state. The laser displacement sensor 3 accurately captures the displacement change of the torsion pendulum mechanism, and the electromagnetic calibration device 12 pre-calibrates the core parameters of the system, providing a precise basis for thrust calculation. All components work together to achieve high-precision feedback measurement of micro-thrust in the μN to mN range, meeting the testing requirements of actual application scenarios for micro-thrusters.

[0024] As an optional implementation, the torsion mechanism includes a torsion body 2, which is mounted on a support frame 6. The support frame 6 is mounted on a fixed frame 5, which is mounted on the side of a base frame 4. The base frame 4 is mounted on a work platform 1, and a pad 8 is mounted on the bottom of the fixed frame 5.

[0025] In this embodiment, the base frame 4 is directly fixed to the working platform 1, providing a stable foundation support for the entire torsion mechanism and preventing the device from shifting as a whole; the fixed frame 5 is rigidly connected to the base frame 4, serving as the static support end of the torsion mechanism; the support frame 6 connects the fixed frame 5 and the torsion body 2, providing load-bearing capacity for the torsion body 2 and performing horizontal torsion motion synchronously with it; the pad block 8 is placed at the bottom of the fixed frame 5 to form a vertical auxiliary support, preventing the fixed frame 5 from deforming or shifting due to the weight of the device itself, ensuring the matching accuracy of each component of the torsion mechanism, and ensuring that the torsion body 2 always performs regular torsion motion in the horizontal direction.

[0026] As an optional implementation, a micro-thruster is installed at one end of the torsion pendulum body 2 to provide millinewton-level micro-thrust during testing, and a counterweight 7 is placed at the other end to ensure the mechanical balance of the torsion pendulum and stabilize the torsion pendulum motion.

[0027] In this embodiment, one end of the torsion pendulum body 2 is the mounting end of the micro-thruster, where the micro-thruster to be tested is fixed. When it is working, the millinewton-level micro-thruster output provides torsional power to the torsion pendulum mechanism and is the core force source to be measured in the device. The other end of the torsion pendulum body 2 is the placement end of the counterweight 7. The matching counterweight 7 offsets the mass off-center load caused by the installation of the micro-thruster, so that the torsion pendulum maintains an initial equilibrium state of horizontal stillness when there is no thrust output. At the same time, the counterweight 7 can constrain the torsional motion trajectory of the torsion pendulum body 2, avoid irregular swinging, and ensure that the displacement signal collected by the laser displacement sensor 3 is the real torsional displacement generated by the micro-thruster, thereby reducing measurement error from the perspective of structural balance.

[0028] As an optional implementation, the fixing frame 5 and the support frame 6 are provided with twisted wires in their holes, which are used to provide elastic restoring force.

[0029] In this embodiment, coaxial mating holes are provided at corresponding mating positions of the fixed frame 5 and the support frame 6. The torsion wire passes through the hole and achieves a tight connection, serving as the only mechanical link connecting the fixed frame 5 (static component) and the support frame 6 (moving component). When the torsion pendulum body 2 drives the support frame 6 to twist around the torsion wire under a slight thrust, the torsion wire undergoes elastic deformation. When the slight thrust disappears, the torsion wire relies on its own elastic restoring force to drive the support frame 6 and the torsion pendulum body 2 to quickly return to their initial equilibrium positions, achieving automatic reset of the torsion pendulum mechanism. This supports multiple repeated tests and ensures that the initial reference is consistent for each test. At the same time, the torsion wire can precisely constrain the torsion pendulum mechanism to twist only in the horizontal direction, eliminating motion interference from unnecessary degrees of freedom.

[0030] As an optional implementation, the torsion pendulum body 2 is an H-shaped pendulum arm structure, and the end of the torsion pendulum body 2 used to install the micro thruster is set as a rectangular platform.

[0031] In this embodiment, the torsion pendulum body 2 adopts an H-shaped swing arm structure. While ensuring the overall structural strength and being able to support micro-thrusters of different specifications, it has good horizontal torsional flexibility, effectively reducing the influence of the swing arm's own weight on the torsional motion, so that even a small thrust can drive the torsion pendulum to produce a precisely measurable displacement. The micro-thruster mounting end of the torsion pendulum body 2 is set as a rectangular platform, which increases the contact area with the micro-thruster, can adapt to the installation requirements of micro-thrusters of different sizes and volumes, improves the stability of the micro-thruster after installation, avoids the micro-thruster from loosening or shifting during the test, and ensures that the micro-thrust can be completely transmitted to the torsion pendulum body 2, further ensuring the accuracy of the measurement.

[0032] As an optional implementation, the damping assembly includes a damping bracket 10, a damping plate 9, and two electromagnets 11. The damping bracket 10 is disposed on the working platform 1, the damping plate 9 is disposed in the middle position of the damping bracket 10, and the two electromagnets 11 are respectively disposed at both ends of the damping plate 9 and are axially connected to the damping bracket 10.

[0033] In this embodiment, the damping bracket 10 is fixedly connected to the working platform 1, providing basic support for the entire damping assembly. Its position precisely corresponds to the end of the torsion pendulum mechanism. The damping plate 9 is vertically arranged in the middle of the damping bracket 10, and its end contacts the end of the torsion pendulum mechanism. It can swing adaptively with the torsion of the pendulum and is the core component for transmitting damping force. Two electromagnets 11 are symmetrically arranged at both ends of the damping plate 9 and axially connected to the damping bracket 10. The electromagnets 11 and the damping plate 9 work together to generate a stable damping force, effectively suppressing the free vibration and irregular swaying of the torsion pendulum mechanism during the torsion process. At the same time, it reduces the interference of external factors such as environmental vibration and airflow, so that the torsion pendulum mechanism can quickly return to a steady state after the thrust is applied. This avoids the distortion of the displacement signal collected by the laser displacement sensor 3 due to vibration and ensures the accuracy of displacement detection.

[0034] As an optional implementation, the laser displacement sensor 3 is mounted on the working platform 1 to measure the displacement change of the torsional pendulum and is electrically connected to the computer.

[0035] In this embodiment, the laser displacement sensor 3 is fixed on the working platform 1, with its detection end facing the detection position of the torsion mechanism and maintaining parallel alignment. It can capture the horizontal displacement change generated by the torsion mechanism under micro-thrust in real time and accurately, and is the core data acquisition component for micro-thrust measurement of the device. The laser displacement sensor 3 is electrically connected to an external computer through a dedicated data transmission line. The collected displacement data can be transmitted to the computer in real time for recording, feedback and digital processing, providing core data support for subsequent deduction of the micro-thrust magnitude and total impact based on system parameters.

[0036] As an optional implementation, the electromagnetic calibration device 12 includes a bracket 15, a coil cylinder 14, and a coil 13. The bracket 15 is disposed on the working platform 1, the coil cylinder 14 is disposed on the bracket 15, and the coil 13 is wound and fixed on the coil cylinder 14.

[0037] In this embodiment, the bracket 15 is directly fixed to the working platform 1, and its position precisely corresponds to the calibration end of the torsion pendulum mechanism, providing stable support for the entire electromagnetic calibration device 12 and ensuring that the electromagnetic force can be accurately applied to the torsion pendulum mechanism. The coil tube 14 is fixed to the upper end of the bracket 15, providing a dedicated winding and fixing carrier for the coil 13, and its axial direction is adapted to the torsion direction of the torsion pendulum mechanism. The coil 13 is tightly wound and fixed to the outer wall of the coil tube 14, and the number and method of winding are precisely designed to ensure that a stable electromagnetic force can be generated after energization. The coil 13 is connected to a constant current power supply system, and the magnitude of the electromagnetic force can be precisely controlled by adjusting the input current. After the electromagnetic force acts on the torsion pendulum mechanism, combined with the displacement response curve collected by the laser displacement sensor 3, the core parameters such as the system damping ratio, vibration frequency, and moment of inertia can be accurately calculated. This provides key parameter basis for the subsequent construction of the unit pulse force response function and the derivation of the micro-thrust magnitude, ensuring the measurement accuracy of the millinewton-level micro-thrust from the system calibration level.

[0038] The specific operation steps of the high-precision millinewton-level micro-propulsion thrust feedback measurement device provided in this embodiment of the invention are as follows: First, install and debug the laser displacement sensor 3. Fix the laser displacement sensor 3 at the designated position on the working platform 1, ensuring that the detection end is accurately aligned with the micro-thruster mounting end of the torsion pendulum body 2. Then connect the sensor data transmission line to the external computer and debug the torsion pendulum to a horizontal equilibrium state, ensuring that the reading of the laser displacement sensor 3 is zero at this time. This establishes an accurate benchmark for subsequent displacement data acquisition and avoids the initial deviation from affecting the measurement results.

[0039] Then, electromagnetic force calibration was carried out using a high-precision electronic balance as the core calibration device. First, the permanent magnet was fixed in the center of the electronic balance. The distance between the coil 13 of the electromagnetic calibration device 12 and the permanent magnet was adjusted to zero. After the electronic balance reading was zeroed, the calibration process was started. Different gradients of current were applied to the coil 13 using a constant current power supply. After the electronic balance reading stabilized, nine sets of electromagnetic force values ​​corresponding to different currents were recorded. The calibration operation was repeated six times for each set of currents, including three current loading processes and three current unloading processes. Based on the obtained measurements, the overall mean and variance were calculated. Finally, a linear relationship curve between current and electromagnetic force was fitted, completing the electromagnetic force calibration and providing accurate known force values ​​for subsequent system parameter calculations.

[0040] Subsequently, the core parameters of the torsion pendulum system were calibrated. The permanent magnet was fixed to the front end of the torsion pendulum balance frame, and the distance between coil 13 and the permanent magnet was adjusted to zero. The damping bracket 10 was opened to bring the torsion pendulum to a steady state before calibration began. Different currents were applied to coil 13 using a constant current power supply. After the torsion pendulum reached a steady state, the electromagnetic force was unloaded, and the step response and free vibration displacement curves collected by the laser displacement sensor 3 were recorded simultaneously. Based on the displacement data and the torsion pendulum angle calculation formula, the torsion pendulum angle was converted, and key points such as the maximum torsion angle and steady-state torsion angle were extracted from the curves. The system's torsional stiffness coefficient, vibration frequency, damping ratio, natural frequency, and moment of inertia were calculated sequentially. The nine sets of calibration data were preprocessed, and the maximum and minimum values ​​of each set were removed before averaging to determine the final core parameters of the system. Based on these parameters, a response function for the unit pulse force was constructed.

[0041] Finally, a micro-thrust test was conducted. The micro-thruster under test was activated to output pulse thrust, which acted on the torsional pendulum body 2, causing it to produce horizontal torsional motion. The laser displacement sensor 3 captured the displacement changes of the torsional pendulum in real time and generated a displacement response curve. The measured displacement curve was matched with the previously constructed analytical expression of the unit pulse force response function. The total impulse generated by the pulse thrust was calculated through data fitting, and the specific magnitude of the pulse thrust output by the micro-thruster was further derived from the total impulse, completing a single micro-thrust test. The entire test process is repeatable, enabling multiple measurements and performance verifications of the micro-thruster, ensuring the accuracy and reliability of the test results.

[0042] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A high-precision millinewton-level micro-propulsion thrust feedback measurement device, characterized in that, include: A torsion pendulum mechanism is mounted on a working platform, and a damping component and a laser displacement sensor are respectively mounted at both ends of the torsion pendulum mechanism. An electromagnetic calibration device is mounted on a torsion pendulum mechanism and is used to determine the system's damping ratio, vibration frequency, and moment of inertia.

2. The high-precision millinewton-level micro-propulsion thrust feedback measurement device according to claim 1, characterized in that, The torsion mechanism includes a torsion body, a support frame, a fixed frame, a base frame, and a pad. The torsion body is mounted on the support frame, the support frame is mounted on the fixed frame, the fixed frame is mounted on the side of the base frame, the base frame is mounted on the working platform, and the pad is mounted at the bottom of the fixed frame.

3. The high-precision millinewton-level micro-propulsion thrust feedback measurement device according to claim 2, characterized in that, One end of the torsion pendulum body is equipped with a micro-thruster to provide millinewton-level micro-thrust during testing, and the other end of the torsion pendulum body is equipped with a counterweight to ensure the mechanical balance of the torsion pendulum and stabilize the torsion pendulum motion.

4. The high-precision millinewton-level micro-propulsion thrust feedback measurement device according to claim 2, characterized in that, The fixing frame and the support frame are provided with twisted wires in the holes, which are used to provide elastic restoring force.

5. The high-precision millinewton-level micro-propulsion thrust feedback measurement device according to claim 3, characterized in that, The main body of the torsion swing is an H-shaped swing arm structure, and the end of the torsion swing body used to install the micro thruster is set as a rectangular platform.

6. The high-precision millinewton-level micro-propulsion thrust feedback measurement device according to claim 1, characterized in that, The damping assembly includes a damping bracket, a damping plate, and two electromagnets. The damping bracket is mounted on a working platform, the damping plate is positioned in the middle of the damping bracket, and the two electromagnets are respectively positioned at both ends of the damping plate and are axially connected to the damping bracket.

7. The high-precision millinewton-level micro-propulsion thrust feedback measurement device according to claim 1, characterized in that, The laser displacement sensor is mounted on the working platform and is used to measure the displacement change of the torsional pendulum. It is electrically connected to the computer.

8. The high-precision millinewton-level micro-propulsion thrust feedback measurement device according to claim 1, characterized in that, The electromagnetic calibration device includes a support, a coil cylinder, and a coil. The support is mounted on a working platform, the coil cylinder is mounted on the support, and the coil is wound and fixed on the coil cylinder.

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