Space refrigeration plant vibration composite control system and method

Abstract

The application provides a space refrigeration equipment vibration composite control system and method, comprising: a passive vibration isolation module and an actuation module; the passive vibration isolation module performs preliminary attenuation on the vibration of a compressor in the space refrigeration equipment in a passive vibration isolation mode, reduces the transmission of the vibration of the compressor from a base plate to a cold finger end detector; the actuation module performs attenuation on residual vibration transmitted from the compressor to the cold finger end through a connecting pipe in an active vibration suppression mode, so as to suppress the micro-vibration of the gas in the connecting pipe from the compressor to the cold finger end caused by uneven flow; and performs attenuation on residual vibration transmitted from the compressor to the cold finger end through the base plate in an active vibration suppression mode. The application is suitable for guaranteeing that the space vehicle load refrigeration equipment outputs minimal disturbance, and avoiding affecting the resolution and stability of the load.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of vibration control, and particularly relates to a vibration composite control system and method for a space refrigeration device. BACKGROUND

[0002] The main sensitive load of a high-resolution remote sensing satellite needs to work in a stable cold environment, which is generally provided by a space refrigeration device. During the operation of the space refrigeration device, the compressor of the space refrigeration device continuously outputs disturbance force due to asymmetric factors such as structure, production and process of the compressor. In particular, the space refrigeration device is often installed near the sensitive load, and the micro-vibration generated thereby affects the detection resolution and imaging performance of the load. If not controlled, it may affect the detection task, or even cause the space mission to fail due to structural resonance. Therefore, it is necessary to suppress the micro-vibration output of the space refrigeration device and reduce its impact on the detection performance of the load, which has become a key link in the design of a remote sensing satellite.

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

[0004] The journal article “Measurement and control method of micro-vibration output of a low-temperature refrigerator” provides a method for measuring the micro-vibration output by using a suspension method with springs and thin wires, and measures the maximum output disturbance force of a 2.8W / 80K Stirling refrigerator at 5 times the frequency under different input powers. The journal article “Theoretical research on nonlinear vibration characteristics of linear opposed compressor” provides a method for solving and analyzing the nonlinear vibration characteristics of the refrigerator by considering the nonlinear factors such as the gas spring force of the compression chamber and the gap flow resistance. From the above journal articles, it can be concluded that the vibration of the refrigerator has the characteristics of strong line spectrum and nonlinearity.

[0005] The journal articles “Vibration isolation design of a camera refrigeration device for astronomical survey” and “Design and experimental research on a dynamic vibration absorber for a free-piston Stirling refrigerator” respectively provide a flexible support isolator and a dynamic vibration absorber to suppress the vibration of the compressor of the refrigeration device, but neither of them considers the micro-vibration of the connecting pipe of the refrigerator to the cold finger due to uneven gas flow, which cannot completely reduce the disturbance output by the compressor.

[0006] Patent document CN115524010A discloses a highly reliable micro-vibration insulation system for a refrigerator. A support Dewar is mounted on the upper surface of the cold finger flange; a coupling substrate is placed on top of the support Dewar; the top of a support column is connected to the coupling substrate, and the bottom is connected to the cold finger flange; a pyrotechnic cutter and a conductive sensor are mounted on the support column; a detector Dewar cover is mounted on the coupling substrate; a splicing substrate is mounted on the coupling substrate; detector devices are 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; a flexible cold chain is located on top of the refrigerator cold head and connected to the coupling substrate; a vacuum pump is connected to the detector Dewar; and a water chiller is connected to the cold finger flange. This system ensures that the launch section effectively supports the detector assembly and also ensures physical isolation between the support end and the detector assembly during on-orbit operation, thus protecting the detector from micro-vibrations generated by the refrigerator during on-orbit operation. However, patent document CN115524010A also fails to consider the micro-vibrations caused by uneven gas flow in the connecting pipe from the refrigerator to the cold finger, which cannot completely reduce the disturbance in the compressor output.

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

[0008] To address the shortcomings of existing technologies, the purpose of this invention is to provide a vibration composite control system and method for space refrigeration equipment.

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

[0010] The passive vibration isolation module initially attenuates the vibration of the compressor itself in the space refrigeration equipment by passively isolating it, thereby reducing the transmission of compressor vibration from the substrate to the cold finger detector.

[0011] The actuation module actively attenuates the residual vibration transmitted from the compressor to the cold finger via the connecting pipe, thereby suppressing the micro-vibrations caused by uneven gas flow in the connecting pipe from the compressor to the cold finger; and actively attenuates the residual vibration transmitted from the compressor to the cold finger via the substrate.

[0012] Preferably, the actuation module comprises actuators, the actuators are installed at the geometric center of the cold finger of the space refrigeration device, the positions of different actuators are orthogonal to each other, and the actuation direction of one actuator is consistent with the movement direction of the piston in the compressor of the space refrigeration device.

[0013] Preferably, three actuators f1, f2 and f3 are installed at the end of the cold finger, the actuation direction of the actuator f1 is consistent with the movement direction of the piston in the compressor of the space refrigeration device, the actuation direction of the actuator f2 is perpendicular to the plane of the base plate 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, the plurality of passive vibration isolators form a convergent passive vibration isolation module, the included angle between adjacent two passive vibration isolators is equal, and the axis direction of each vibration isolator passes through the center of mass of the compressor.

[0015] Preferably, the plurality of passive vibration isolators comprise three slot spring damping vibration isolators, the vibration isolators are spaced 120° apart from each other, three hot knives are used to press the compressor, each hot knife is arranged between two vibration isolators, and the pressing and unlocking of the passive vibration isolators are realized.

[0016] Preferably, it further comprises a control module and a monitoring module.

[0017] The control module outputs white noise to excite the cold finger end of the space refrigeration device, and obtains a dynamic characteristic, wherein the dynamic characteristic is a pulse response sequence of the actuation module and the cold finger end of the refrigeration device, reflecting the dynamic characteristics of the actuation module and the cold finger end of the refrigeration device; after obtaining the dynamic characteristic, the space refrigeration device is driven at different frequencies and powers to generate additional vibration; after generating the additional vibration, the passive vibration isolation module of the compressor of the space refrigeration device is unlocked, it is judged whether the vibration response of the cold finger end of the space refrigeration device satisfies a response index, and the actuation module is triggered to perform active vibration suppression when the corresponding index is not satisfied, wherein the response index is the maximum vibration response that can be tolerated by the load served by the cold finger in the refrigeration device.

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

[0019] Preferably, the monitoring module comprises an acceleration sensor, which is respectively installed at the compressor measuring point, the base plate measuring point and the cold finger end measuring point of the space refrigeration device.

[0020] Preferably, it further comprises a physical filter conditioning module.

[0021] The physical filter conditioning module serves as an interface for input and output of signals of the control module, amplifies sensor signals of the monitoring module as required, filters out high-frequency interference of the system through low-pass filtering, inputs the amplified and filtered signals to the control module, and simultaneously filters out high-frequency interference through low-pass filtering of output signals of the control module, so that the driving signals transmitted to the actuating module are stable.

[0022] The control module receives the input signals processed by the physical filter conditioning module, selects a control bandwidth, adjusts control parameters, generates control instructions for driving the actuating module as driving signals, and outputs the driving signals to the physical filter conditioning module.

[0023] The actuating module actively suppresses vibration according to the driving signals.

[0024] According to the vibration composite control method of the space refrigeration device provided by the application, the following steps are included.

[0025] Step (1): white noise is output to excite the cold finger end of the space refrigeration device to obtain dynamic characteristics as control parameters for active vibration suppression.

[0026] Step (2): the space refrigeration device is driven at different frequencies and powers to generate additional vibration.

[0027] Step (3): the passive vibration isolation module of the compressor of the space refrigeration device is unlocked, and it is judged whether the vibration response of the cold finger end of the space refrigeration device 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 started, and it is continuously judged 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, the monitoring data is recorded; if the response index of step (4) is not met, the control parameters of the control module are adjusted until the index is met.

[0030] Preferably, the vibration composite control is performed by using the vibration composite control system of the space refrigeration device.

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

[0032] 1. The application comprehensively considers the micro-vibration output of each link of the space refrigeration device, ensures that the vibration control of the space refrigeration device in orbit is effective at the right time, and more efficiently and reliably reduces the influence of the vibration of the space refrigeration device on the load.

[0033] 2. The application preliminarily attenuates the vibration of the compressor in the space refrigeration device through passive vibration isolation, and reduces the transmission of the vibration of the compressor from the base plate to the cold finger end detector.

[0034] 3、The present application considers that the micro-vibration caused by uneven flow of gas in the connecting pipe leading to the cold finger is attenuated by active vibration suppression of the residual vibration transmitted from the compressor to the cold finger end through the copper pipe as the connecting pipe; the present application attenuates the residual vibration transmitted from the compressor to the cold finger end through the substrate by active vibration suppression; the residual vibration of the cold finger end detector is greatly reduced, and the ultra-static working environment of the detector is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0035] Other features, objects, and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments thereof, read in conjunction with the accompanying drawings:

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

[0037] Figure 2 is a schematic diagram of the vibration composite control method flow of the space refrigeration equipment;

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

[0039] The present application will be described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present application, but do not limit the present application in any form. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present application. These all belong to the protection scope of the present application.

[0040] The present application reduces the disturbance force output of the refrigeration equipment by the composite control of passive vibration isolation of the compressor in the space refrigeration equipment and active vibration suppression of the cold finger, and provides an ultra-static dynamic environment for the load.

[0041] As shown in Figure 1 , according to the vibration composite control system of the space refrigeration equipment provided by the present application, comprising:

[0042] The compressor passive vibration isolation module mainly composed of multiple passive vibration isolators; for example, the passive spring vibration isolation module uses springs for passive vibration isolation; the present application preliminarily attenuates the vibration of the compressor itself in the space refrigeration equipment through passive vibration isolation, and reduces the transmission of the vibration of the compressor to the cold finger end detector from the substrate. Among them, multiple passive vibration isolators are used to form a convergent passive vibration isolation module, the included angle between adjacent two passive vibration isolators is equal, and the axis direction of each vibration isolator passes through the center of mass of the compressor. The compressor passive vibration isolation module is installed on the substrate, supporting the compressor while isolating the vibration transmitted from the compressor to the substrate;

[0043] A physical filtering and conditioning module is used for feedback signal input and control signal output. This module serves as the interface for the control module's signal input and output, amplifying the sensor signal as needed and filtering out high-frequency interference through a low-pass filter before inputting the amplified and filtered signal to the control module. Simultaneously, the control module's output signal is low-pass filtered to remove high-frequency interference, stabilizing the drive signal transmitted to the actuation module.

[0044] The control module is used for feedback signal calculation and control command generation. It receives the input signal processed by the physical filtering and conditioning module, selects the control bandwidth, adjusts the control parameters, generates control commands using the Fx-RLS algorithm (Fast Recursive Least Squares algorithm), and outputs them to the physical filtering and conditioning module.

[0045] An actuation module for energy input and control signal drive; wherein, the actuation module includes actuators, which are 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 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 through the copper tube, and attenuating the residual vibration transmitted from the compressor to the cold finger through the substrate. This greatly reduces the residual vibration of the cold finger detector and ensures the ultra-quiet working environment of 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 cooling equipment, and uses them for real-time display and early warning of working status monitoring and vibration control effect.

[0047] like Figure 2 As shown, a composite vibration control method for a space refrigeration device according to the present invention includes the following steps:

[0048] Step (1): The control module outputs white noise to excite the cold finger of the space cooling device and obtains the dynamic characteristics as the control parameters for active vibration suppression;

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

[0050] Step (3): Unlock the passive vibration isolation module of the space refrigeration equipment compressor and determine 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 satisfied, record the monitoring data; if the response index of step (3) is not satisfied, start the cold finger active vibration suppression, and continue to judge whether the vibration response of the cold finger end satisfies the response index; wherein the control parameters of the active vibration suppression obtained from the dynamic characteristics are used as the input parameters of the active vibration suppression control algorithm, so as 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 satisfied, record the monitoring data; if the response index of step (4) is not satisfied, adjust the control parameters of the control module until the index is satisfied.

[0053] The vibration composite control system and method of the space refrigeration equipment provided by the application are suitable for guaranteeing that the space refrigeration equipment of the spacecraft load outputs minimum disturbance, and avoiding affecting the resolution and stability of the load.

[0054] The application will be described in more detail below. In the preferred example, the vibration of a certain space refrigeration equipment is controlled by using the application, and the example is as follows.

[0055] The passive vibration isolation module of the compressor in the space refrigeration equipment mainly comprises three slot spring damper vibration isolators, the vibration isolators are spaced 120° from each other, the axial direction of each vibration isolator passes through the center of mass of the compressor, and three hot knives are used to press the compressor, and each hot knife is arranged between two vibration isolators to realize the pressing and unlocking of the passive vibration isolator.

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

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

[0058] The basic parameters are as follows:

[0059] (1) The set space refrigeration equipment driving voltage is 7V, the driving power is 23W, and the driving frequency is 42Hz.

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

[0061] The vibration acceleration time domain response of the cold finger end measuring point #3 in steps (1)-(5) of the vibration composite control method of the space refrigeration device is shown in the following table. Figure 3 Figure 3 It can be seen that the present application can ensure the vibration control time of the space refrigeration device in orbit, and more efficiently and reliably reduce the influence of the vibration of the space refrigeration device on the load.

[0062] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0063] The specific embodiments of the present application are described above. It should be understood that the present application is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essential content of the present application. The embodiments of the present application and the features in the embodiments can be arbitrarily combined without conflict.​

Claims

1. A vibration compound control system for a space refrigeration plant, characterized by, Comprise: Passive vibration isolation module, actuator module; The passive vibration isolation module preliminarily attenuates the vibration of the compressor in the space cooling device in a passive vibration isolation mode, reduces the transmission of the vibration of the compressor from the base plate to the cold finger end detector; The actuator module attenuates the residual vibration transmitted from the compressor to the cold finger end through the connecting pipe in an active vibration suppression mode, so as to suppress the micro-vibration of the gas in the connecting pipe from the compressor to the cold finger end due to uneven flow; And attenuates the residual vibration transmitted from the compressor to the cold finger end through the base plate in an active vibration suppression mode; Further comprising: a control module, a monitoring module; The control module outputs white noise to excite the cold finger end of the space cooling device, and obtains the dynamic characteristics, wherein the dynamic characteristics are the impulse response sequence of the actuator module and the cold finger end of the cooling device, reflecting the dynamic characteristics of the actuator module and the cold finger end of the cooling device; After obtaining the dynamic characteristics, the space cooling device is driven at different frequencies and powers to generate additional vibration; After generating additional vibration, the passive vibration isolation module of the compressor of the space cooling device is unlocked, whether the vibration response of the cold finger end of the space cooling device meets the response index is judged, and the actuator 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 the load served by the cold finger in the cooling device can tolerate; The monitoring module records monitoring data for vibration signal monitoring and vibration control performance verification.

2. The vibration compound control system of the space refrigeration plant according to claim 1, wherein, The actuator module comprises actuators, the actuators are installed through the geometric center of the cold finger of the space cooling device, the positions of different actuators are orthogonal to each other, and the actuation direction of one actuator is consistent with the movement direction of the piston in the compressor of the space cooling device.

3. The vibration compound control system of the space refrigeration plant according to claim 2, wherein, 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 cooling device, the actuation direction of the actuator f2 is perpendicular to the plane of the base plate 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 actuator f1 and the actuator f2.

4. The vibration compound control system of the space refrigeration plant according to claim 1, wherein, The passive vibration isolation module comprises a plurality of passive vibration isolators, the plurality of passive vibration isolators form a convergent passive vibration isolation module, the included angle between adjacent two passive vibration isolators is equal, and the axis direction of each vibration isolator passes through the center of mass of the compressor.

5. The vibration compound control system of the space refrigeration plant according to claim 4, wherein The plurality of passive vibration isolators comprise three slot spring damping vibration isolators, the vibration isolators are spaced 120° apart from each other, three hot knives are used to press the compressor, each hot knife is arranged between two vibration isolators, and the pressing and unlocking of the passive vibration isolators are realized.

6. The vibration compound control system of a space refrigeration plant according to claim 1, wherein The monitoring module comprises 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 cooling device.

7. The vibration compound control system of the space refrigeration plant of claim 1, wherein, Further comprising: Physical filter conditioning module; The physical filter conditioning module serves as the interface for signal input and output of the control module, amplifies the sensor signals of the monitoring module as required, filters out high-frequency interference of the system through low-pass filtering, inputs the amplified and filtered signals 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 actuator 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 actuation module as the driving signal, and outputs to the physical filter conditioning module; The actuation module actively suppresses vibration according to the driving signal.

8. A method for vibration compound control of a space refrigeration device, characterized in that, The vibration composite control system for the space refrigeration equipment according to any one of claims 1 to 7 is used for vibration composite control, comprising: Step (1): output white noise to stimulate the cold finger end of the space refrigeration equipment, and obtain the dynamic characteristics as the control parameters of active vibration suppression; Step (2): drive the space refrigeration equipment at different frequencies and powers to generate additional vibration; Step (3): unlock the passive vibration isolation module of the compressor of the space refrigeration equipment, and determine 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, record the monitoring data; if the response index of step (3) is not met, start the active vibration suppression of the cold finger, and 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.

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