Space refrigeration equipment vibration compound control system and method

Abstract

The invention provides a compound control system and method for vibration of space refrigeration equipment. The compound control system comprises a passive vibration isolation module and an actuation module. The passive vibration isolation module is used for primarily attenuating the vibration of a compressor in the space refrigeration equipment in a passive vibration isolation manner, so that the transmission of the vibration of the compressor from a substrate to a cold finger end detector is reduced; the actuation module attenuates residual vibration transmitted to the cold finger end from the compressor through the connecting pipe in an active vibration suppression mode so as to suppress micro vibration generated by non-uniform flow of gas in the connecting pipe, leading to the cold finger end, of the compressor. And the residual vibration transmitted to the cold finger end by the compressor through the substrate is attenuated in an active vibration suppression manner. The method is suitable for ensuring that refrigeration equipment of a spacecraft load outputs extremely small disturbance vibration, and the resolution ratio and stability of the load are prevented from being affected.

Description

Technical Field

[0001] The present invention belongs to the field of vibration control, and in particular, relates to a composite vibration control system and method for space refrigeration equipment. Background Art

[0002] The main sensitive payloads of high-resolution remote sensing satellites need to work in a stable cold environment, which is generally provided by space refrigeration equipment. During the operation of space refrigeration equipment, the compressor continuously outputs disturbance force due to asymmetric factors such as the structure, production, and process of the compressor. In particular, space refrigeration equipment is often installed close to sensitive payloads, and the micro-vibrations it produces affect the payload detection resolution and imaging performance. If not controlled, it will affect the detection mission at the least, and may even cause the space mission to fail due to structural resonance. For this reason, suppressing the micro-vibration output of space refrigeration equipment and reducing its detection performance of the payload have become key links in the design of remote sensing satellites.

[0003] At present, vibration control of space refrigeration equipment mainly includes passive vibration isolation of compressor and active vibration suppression of compressor.

[0004] The journal article "Measurement and Control Method of Micro-Vibration Output of Low-Temperature Refrigerator" provides a method to measure micro-vibration output by using spring and thin wire suspension, and the maximum output disturbance force of 2.8W / 80K Stirling refrigerator under different input powers is measured at 5 times the frequency; the journal article "Theoretical Study on Nonlinear Vibration Characteristics of Linear Opposed Compressor" provides a method to solve and analyze the nonlinear vibration characteristics of refrigerator by considering nonlinear factors such as gas spring force of compression chamber and gap airflow resistance. From the above journal articles, it can be concluded that the vibration of refrigerator has strong linear spectrum and nonlinear characteristics.

[0005] The journal articles “Vibration Isolation Design of Astronomical Survey Camera Refrigerator” and “Design and Experimental Study of Dynamic Vibration Absorber of Free-Piston Stirling Refrigerator” respectively provide the use of flexible support isolators and dynamic vibration absorbers to suppress the vibration of refrigeration equipment compressors. However, both of them do not take into account the micro-vibration caused by the uneven flow of gas in the connecting pipe from the refrigerator to the cold finger, and cannot completely reduce the disturbance of the compressor output.

[0006] Patent document CN115524010A discloses a high-reliability refrigerator micro-vibration insulation system, wherein the support dewar is mounted on the upper surface of the cold finger flange; the coupling substrate is placed on the top of the support dewar; the top of the support column is connected to the coupling substrate, and the bottom is connected to the cold finger flange; the pyrotechnic cutter and the conductive sensor are arranged on the support column; the detector dewar cover is mounted on the coupling substrate; the splicing substrate is mounted on the coupling substrate; the detector device is mounted on the splicing substrate; the refrigerator cold head extends from the bottom of the cold finger flange into the inner cavity of the support dewar; the flexible cold chain is arranged on the top of the refrigerator cold head and connected to the coupling substrate; the vacuum pump is connected to the detector dewar; the water cooler is connected to the cold finger flange; thereby ensuring that the launch section can effectively support the detector assembly and can also ensure that the support end and the detector assembly can be physically isolated during the on-orbit period, so as to ensure that the micro-vibration generated by the refrigerator working on-orbit is insulated from the detector. However, patent document CN115524010A also does not take into account the micro-vibration generated by the uneven flow of gas in the connecting pipe from the refrigerator to the cold finger, and cannot completely reduce the disturbance of the compressor output.

[0007] The journal article "Adaptive Active Vibration Control Method for Space Refrigeration Compressor" provides a method of using the drive motor inside the compressor of the refrigeration equipment and adopting the feedforward control method to drive the refrigeration equipment to work normally while eliminating the generated micro-vibration. However, this method can only suppress the vibration output when the feedforward control channel is normal and fault-free. If a link fails, the vibration control measures will fail, and it cannot meet the design principles of safety, reliability, and redundancy in space orbit. Summary of the invention

[0008] In view of the defects in the prior art, an object of the present invention is to provide a vibration composite control system and method for space refrigeration equipment.

[0009] A composite vibration control system for space refrigeration equipment provided by the present invention includes: a passive vibration isolation module and an actuation module;

[0010] The passive vibration isolation module performs preliminary attenuation on the vibration of the compressor itself in the space refrigeration equipment in a passive vibration isolation manner, thereby reducing the transmission of the vibration of the compressor from the base plate to the cold finger detector;

[0011] The actuation module attenuates the residual vibration transmitted from the compressor to the cold finger end through the connecting pipe in an active vibration suppression manner, so as to suppress the micro-vibration caused by the uneven flow of gas in the connecting pipe from the compressor to the cold finger end; and attenuates the residual vibration transmitted from the compressor to the cold finger end through the base plate in an active vibration suppression manner.

[0012] Preferably, the actuation module includes an actuator, which is installed at the geometric center of the cold finger passing through the space refrigeration equipment. The positions of different actuators are orthogonal to each other, and the actuation direction of an actuator is ensured to be consistent with the movement direction of the piston in the compressor in the space refrigeration equipment.

[0013] Preferably, the three actuators f1, f2, and f3 are orthogonally installed at the cold finger end, the actuation direction of the actuator f1 is consistent with the movement direction of the piston in the compressor in the space refrigeration equipment, the actuation direction of the actuator f2 is perpendicular to the substrate plane and perpendicular to the actuation direction of the actuator f1, and the actuation direction of the actuator f3 is orthogonal to the actuation directions of the actuators f1 and f2, respectively.

[0014] Preferably, the passive vibration isolation module comprises a plurality of passive vibration isolators, which form a convergent passive vibration isolation module, wherein the angles between two adjacent passive vibration isolators are equal, and the axial direction of each vibration isolator passes through the center of mass of the compressor.

[0015] Preferably, the plurality of passive vibration isolators include three slotted spring damping vibration isolators, the vibration isolators are spaced 120° apart from each other, and the compressor is compressed by three hot knives, each of which is arranged between two vibration isolators, to achieve compression and unlocking of the passive vibration isolators.

[0016] Preferably, it also includes: a control module and a monitoring module;

[0017] The control module outputs white noise to excite the cold finger end of the space refrigeration equipment to obtain dynamic characteristics, wherein the dynamic characteristics are pulse response sequences of the actuation module and the cold finger end of the refrigeration equipment, reflecting the dynamic characteristics of the actuation module and the cold finger end of the refrigeration equipment; after obtaining the dynamic characteristics, the space refrigeration equipment is driven at different frequencies and powers to generate additional vibrations; after the additional vibrations are generated, the passive vibration isolation module of the compressor of the space refrigeration equipment is unlocked to determine whether the vibration response of the cold finger end of the space refrigeration equipment meets the response index, and the actuation module is triggered to perform active vibration suppression when the corresponding index is not met, wherein the response index is the maximum vibration response that can be tolerated by the load served by the cold finger in the refrigeration equipment;

[0018] The monitoring module records monitoring data for vibration signal monitoring and vibration control performance verification.

[0019] Preferably, the monitoring module includes acceleration sensors, which are respectively installed at the compressor measuring point, the substrate measuring point, and the cold finger end measuring point of the space refrigeration equipment;

[0020] Preferably, it also includes: a physical filtering and conditioning module;

[0021] The physical filtering and conditioning module serves as the interface for inputting and outputting signals of the control module, amplifies the sensor signal of the monitoring module as required, and filters out the high-frequency interference of the system through low-pass filtering, and inputs the amplified and filtered signal to the control module; at the same time, the output signal of the control module is low-pass filtered to filter out high-frequency interference, so that the driving signal transmitted to the actuation module is stable;

[0022] The control module receives the input signal processed by the physical filter conditioning module, completes the selection of the control bandwidth, adjusts the control parameters, generates the control instruction of the driving actuation module as the driving signal, and outputs it to the physical filter conditioning module;

[0023] The actuation module actively suppresses vibration according to the driving signal.

[0024] A composite vibration control method for space refrigeration equipment provided by the present invention includes:

[0025] Step (1): output white noise to excite the cold finger of the space cooling equipment to obtain dynamic characteristics as control parameters for active vibration suppression;

[0026] Step (2): driving the space cooling equipment at different frequencies and powers to generate additional vibrations;

[0027] Step (3): unlocking the passive vibration isolation module of the compressor of the space refrigeration equipment, and determining whether the vibration response of the cold finger end of the space refrigeration equipment meets the response index;

[0028] Step (4): if the response index of step (3) is met, the monitoring data is recorded; if the response index of step (3) is not met, the cold finger active vibration suppression is turned on to continue to determine whether the vibration response of the cold finger end meets the response index;

[0029] Step (5): If the response index of step (4) is met, record the monitoring data; if the response index of step (4) is not met, adjust the control parameters of the control module until the index is met.

[0030] Preferably, the composite vibration control system of the space refrigeration equipment is used to perform composite vibration control.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. The present invention comprehensively considers the micro-vibration output of each link of the space refrigeration equipment, ensures that the vibration control of the on-orbit space refrigeration equipment is always effective, and more efficiently and reliably reduces the impact of the vibration of the space refrigeration equipment on the load.

[0033] 2. The present invention preliminarily attenuates the vibration of the compressor itself in the space refrigeration equipment through passive vibration isolation, thereby reducing the transmission of the vibration of the compressor from the base plate to the cold finger detector.

[0034] 3. The present invention takes into account the micro-vibration caused by the uneven flow of gas in the connecting pipe from the refrigerator to the cold finger, and attenuates the residual vibration transmitted from the compressor to the cold finger end through the copper tube serving as the connecting pipe through active vibration suppression; the present invention attenuates the residual vibration transmitted from the compressor to the cold finger end through the baseboard through active vibration suppression; the residual vibration of the detector at the cold finger end is greatly reduced, ensuring an ultra-quiet working environment for the detector. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] 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:

[0036] Figure 1 It is a schematic diagram of the composition of the vibration composite control system of the space refrigeration equipment of the present invention;

[0037] Figure 2 It is a flow chart of a composite vibration control method for space refrigeration equipment;

[0038] Figure 3 This is a schematic diagram of the response of the cold finger tip measurement point #3 under certain working conditions. DETAILED DESCRIPTION

[0039] 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.

[0040] The present invention reduces the disturbing force output of the refrigeration equipment through the composite control of passive vibration isolation of the compressor and active vibration suppression of the cold finger in the space refrigeration equipment, and provides a super-static dynamic environment for the load.

[0041] like Figure 1 As shown, a vibration composite control system for space refrigeration equipment provided by the present invention comprises:

[0042] A passive vibration isolation module for a compressor mainly composed of a plurality of passive vibration isolators; for example, the passive vibration isolation module is a passive spring vibration isolation module that uses springs for passive vibration isolation; the present invention preliminarily attenuates the vibration of the compressor itself in the space refrigeration equipment through passive vibration isolation, thereby reducing the transmission of the vibration of the compressor from the substrate to the cold finger detector. Among them, a convergent passive vibration isolation module is composed of a plurality of passive vibration isolators, the angles between two adjacent passive vibration isolators are equal, and the axial direction of each vibration isolator passes through the center of mass of the compressor. The passive vibration isolation module for the compressor is installed on the substrate to support the compressor while isolating the vibration transmitted from the compressor to the substrate;

[0043] A physical filter conditioning module for feedback signal input and control signal output; the physical filter conditioning module serves as the interface for the control module signal input and output, amplifies the sensor signal as required, and filters out the high-frequency interference of the system through low-pass filtering, and inputs the amplified and filtered signal to the control module. At the same time, the output signal of the control module is low-pass filtered to filter out high-frequency interference, so that the drive signal transmitted to the actuation module is stable.

[0044] A control module for feedback signal calculation and control instruction generation; wherein, it receives the input signal processed by the physical filtering and conditioning module, completes the selection of the control bandwidth, adjusts the control parameters, uses the Fx-RLS algorithm (fast recursive least squares algorithm) to generate control instructions, and outputs them to the physical filtering and conditioning module.

[0045] An actuation module for energy input and control signal driving; wherein the actuation module includes an actuator, the actuator is installed through the geometric center of the cold finger of the space refrigeration equipment, the positions of different actuators are orthogonal to each other, and the direction of one actuator is ensured to be consistent with the direction of piston movement in the compressor of the space refrigeration equipment; the actuation module performs active vibration suppression, including attenuating the residual vibration transmitted from the compressor to the cold finger end through the copper tube through active vibration suppression, and attenuating the residual vibration transmitted from the compressor to the cold finger end through the substrate through active vibration suppression; the residual vibration of the cold finger end detector is greatly reduced, ensuring an ultra-quiet working environment for the detector.

[0046] A monitoring module for vibration signal monitoring and vibration control performance verification; it receives vibration sensor monitoring data, actuator current monitoring data and actuator temperature monitoring data attached to the space refrigeration equipment, and is used for real-time display and early warning of working status monitoring and vibration control effects.

[0047] like Figure 2 As shown, a vibration composite control method for space refrigeration equipment provided by the present invention comprises the following steps:

[0048] Step (1): the control module is instructed to output white noise to excite the cold finger of the space cooling equipment, and the dynamic characteristics are obtained as the control parameters of active vibration suppression;

[0049] Step (2): driving the space cooling equipment at different frequencies and powers to generate additional vibrations;

[0050] Step (3): unlocking the passive vibration isolation module of the compressor of the space refrigeration equipment, and determining whether the vibration response of the cold finger end of the space refrigeration equipment meets the response index;

[0051] Step (4): if the response index of step (3) is met, the monitoring data is recorded; if the response index of step (3) is not met, the cold finger active vibration suppression is started, and it is further determined whether the vibration response of the cold finger end meets the response index; wherein the control parameters of the active vibration suppression obtained from the dynamic characteristics are used as input parameters of the active vibration suppression control algorithm to accelerate the control convergence time, enhance the stability of the active vibration suppression system, and improve the efficiency and effect of the active vibration suppression;

[0052] Step (5) If the response index of step (4) is met, record the monitoring data; if the response index of step (4) is not met, adjust the control parameters of the control module until the index is met.

[0053] The space refrigeration equipment vibration composite control system and method provided by the present invention are suitable for ensuring that the refrigeration equipment of the spacecraft load outputs extremely small disturbances, thereby avoiding affecting the resolution and stability of the load.

[0054] The present invention is described in more detail below. In a preferred example, the present invention is used to perform composite control on the vibration of a space refrigeration device, as shown below.

[0055] The passive vibration isolation module of the compressor in this space refrigeration equipment is mainly composed of three slotted spring damping isolators, which are spaced 120° apart. The axial direction of each isolator passes through the center of mass of the compressor. At the same time, three hot knives are used to press the compressor, and each hot knife is arranged between two isolators to achieve the pressing and unlocking of the passive isolator.

[0056] The three actuators f1, f2, and f3 are orthogonally installed at the cold finger end as an actuation module. The direction of actuator f1 is consistent with the piston movement direction in the compressor of the space refrigeration equipment. Actuator f2 is perpendicular to the substrate plane and perpendicular to actuator 1. The direction of actuator f3 is orthogonal to actuator 1 and actuator 2. Feedback acceleration sensors a1, a2, and a3 are respectively installed in the same position close to actuators f1, f2, and f3.

[0057] The sensors of the monitoring module adopt acceleration sensors, which are respectively installed at the compressor measuring point #1, substrate measuring point #2, and cold finger end measuring point #3 of the space refrigeration equipment.

[0058] The basic parameters are:

[0059] (1) Set the space cooling equipment drive voltage to 7V, drive power to 23W, and drive frequency to 42Hz.

[0060] (2) The control bandwidth is 30 to 200 Hz, the physical low-pass filter cutoff frequency is 210 Hz, the physical high-pass filter cutoff frequency is 28 Hz, the width of the identification system impulse response is 200, and the data width of the adaptive filter is 200;

[0061] Complete steps (1) to (5) of the composite vibration control method for space refrigeration equipment. The vibration acceleration time domain response of the cold finger end measurement point #3 is as follows: Figure 3 As shown by Figure 3 It can be seen that the present invention can ensure that the vibration control of the on-orbit space refrigeration equipment is always effective, and can more efficiently and reliably reduce the impact of the vibration of the space refrigeration equipment on the load.

[0062] 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.

[0063] 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 vibration composite control system for space refrigeration equipment, characterized in that: include: Passive vibration isolation module, actuation module; The passive vibration isolation module performs preliminary attenuation on the vibration of the compressor itself in the space refrigeration equipment in a passive vibration isolation manner, thereby reducing the transmission of the vibration of the compressor from the base plate to the cold finger detector; The actuation module attenuates the residual vibration transmitted from the compressor to the cold finger end through the connecting pipe in an active vibration suppression manner, so as to suppress the micro-vibration caused by the uneven flow of gas in the connecting pipe from the compressor to the cold finger end; The residual vibration transmitted from the compressor to the cold finger end through the base plate is attenuated by active vibration suppression.

2. The space refrigeration equipment vibration composite control system according to claim 1, characterized in that: The actuation module includes an actuator, which is installed at the geometric center of a cold finger passing through the space refrigeration equipment. The positions of different actuators are orthogonal to each other, and the actuation direction of an actuator is ensured to be consistent with the movement direction of the piston in the compressor of the space refrigeration equipment.

3. The space refrigeration equipment vibration composite control system according to claim 2, characterized in that: The three actuators f1, f2, and f3 are orthogonally installed at the cold finger end. The actuation direction of the actuator f1 is consistent with the movement direction of the piston in the compressor of the space refrigeration equipment. The actuation direction of the actuator f2 is perpendicular to the substrate plane and perpendicular to the actuation direction of the actuator f1. The actuation direction of the actuator f3 is orthogonal to the actuation directions of the actuators f1 and f2, respectively.

4. The space refrigeration equipment vibration composite control system according to claim 1, characterized in that: The passive vibration isolation module comprises a plurality of passive vibration isolators, which form a convergent passive vibration isolation module. The angles between two adjacent passive vibration isolators are equal, and the axial direction of each vibration isolator passes through the centroid of the compressor.

5. The space refrigeration equipment vibration composite control system according to claim 4, characterized in that: The multiple passive vibration isolators include three slotted spring damping vibration isolators, each of which is spaced 120 degrees apart. The compressor is compressed by three hot knives, each of which is arranged between two vibration isolators to achieve compression and unlocking of the passive vibration isolators.

6. The space refrigeration equipment vibration composite control system according to claim 1, characterized in that: Also includes: Control module, monitoring module; The control module outputs white noise to excite the cold finger end of the space refrigeration equipment to obtain dynamic characteristics, wherein the dynamic characteristics are pulse response sequences of the actuation module and the cold finger end of the refrigeration equipment, reflecting the dynamic characteristics of the actuation module and the cold finger end of the refrigeration equipment; after obtaining the dynamic characteristics, the space refrigeration equipment is driven at different frequencies and powers to generate additional vibrations; after the additional vibrations are generated, the passive vibration isolation module of the compressor of the space refrigeration equipment is unlocked to determine whether the vibration response of the cold finger end of the space refrigeration equipment meets the response index, and the actuation module is triggered to perform active vibration suppression when the corresponding index is not met, wherein the response index is the maximum vibration response that can be tolerated by the load served by the cold finger in the refrigeration equipment; The monitoring module records monitoring data for vibration signal monitoring and vibration control performance verification.

7. The space refrigeration equipment vibration composite control system according to claim 1, characterized in that: The monitoring module includes acceleration sensors, which are respectively installed at the compressor measuring point, the base plate measuring point, and the cold finger end measuring point of the space refrigeration equipment;.

8. The space refrigeration equipment vibration composite control system according to claim 6, characterized in that: Also includes: Physical filtering and conditioning module; The physical filtering and conditioning module serves as the interface for inputting and outputting signals of the control module, amplifies the sensor signal of the monitoring module as required, and filters out the high-frequency interference of the system through low-pass filtering, and inputs the amplified and filtered signal to the control module; at the same time, the output signal of the control module is low-pass filtered to filter out high-frequency interference, so that the driving signal transmitted to the actuation module is stable; The control module receives the input signal processed by the physical filter conditioning module, completes the selection of the control bandwidth, adjusts the control parameters, generates the control instruction of the driving actuation module as the driving signal, and outputs it to the physical filter conditioning module; The actuation module actively suppresses vibration according to the driving signal.

9. A composite vibration control method for space refrigeration equipment, characterized in that: include: Step (1): output white noise to excite the cold finger of the space cooling equipment to obtain dynamic characteristics as control parameters for active vibration suppression; Step (2): driving the space cooling equipment at different frequencies and powers to generate additional vibrations; Step (3): unlocking the passive vibration isolation module of the compressor of the space refrigeration equipment, and determining whether the vibration response of the cold finger end of the space refrigeration equipment meets the response index; Step (4): if the response index of step (3) is met, the monitoring data is recorded; if the response index of step (3) is not met, the cold finger active vibration suppression is turned on to continue to determine whether the vibration response of the cold finger end meets the response index; Step (5) If the response index of step (4) is met, record the monitoring data; if the response index of step (4) is not met, adjust the control parameters of the control module until the index is met.

10. The space refrigeration equipment vibration composite control method according to claim 9, characterized in that: The space refrigeration equipment vibration composite control system according to any one of claims 1 to 8 is used to perform vibration composite control.

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