Spacecraft launching process structure health monitoring system and method based on vibration signals

Abstract

The invention provides a spacecraft launching process structure health monitoring system and method based on a vibration signal, and the system comprises a high-frequency piezoelectric acceleration sensor which forms a sensor network and collects the vibration signal; the pre-amplifier is used for amplifying the vibration signal and then outputting the vibration signal; the data acquisition and storage unit is used for receiving and pre-storing the amplified signal output by the pre-amplifier and outputting a data signal to the vibration monitoring computer; the vibration monitoring computer acquires a vibration signal frequency spectrum; and obtaining the health state of the spacecraft launching process structure based on the analysis result of the vibration signal spectrum, and completing monitoring. According to the method, the state of the spacecraft can be measured and analyzed without human interference when the spacecraft normally works in orbit. When the structure of the spacecraft is slightly abnormal, an alarm can be given out, so that the fault can be quickly positioned, and the problem that the spacecraft can be monitored and analyzed in real time in real time without interference in the on-orbit normal working process of the spacecraft is solved.

Description

Technical Field

[0001] This invention relates to the field of spacecraft monitoring technology, specifically to a structural health monitoring system and method for spacecraft launch process based on vibration signals. Background Technology

[0002] Currently, the cost of spacecraft development and launch is high, and there is a trend towards mass development and launch. The launch process involves complex external loads on the structure, requiring monitoring of the structural health status for design optimization and determination of ground test conditions.

[0003] There are already some studies on structural health monitoring, and some specialized detection systems have been developed. Overall, research abroad started earlier, while domestic research needs improvement. NASA has developed a leak detector that uses ultrasonic detectors to probe the surface of spacecraft; Invocon has invented a spacecraft health monitoring system that can be used to detect debris impacts encountered by spacecraft in orbit; ESA uses fiber optic grating sensors to achieve strain-based structural health monitoring on spacecraft.

[0004] In Chinese patent document CN106813714A, American company SenseTech disclosed a device and system for structural health monitoring. The system uses an actuation unit to generate an acoustic or ultrasonic excitation signal that passes through the structure. Then, a sensor unit receives the structure's response to the excitation signal and generates corresponding sensor data. Finally, a processing unit uses an analysis algorithm to process the sensor data to determine the structural health of the structure. However, this method requires active excitation of the structure itself, which consumes a lot of spacecraft payload resources. Therefore, the system has not been further applied to structural health monitoring during spacecraft launch.

[0005] In Chinese patent document CN102809423, the Fifth Academy of Aerospace Science and Technology invented a method for detecting structural damage in on-orbit spacecraft. This method uses an ultrasonic sensor that can simultaneously excite or acquire ultrasonic vibration signals, acquires the ultrasonic sensor response signal, performs signal processing, and detects structural damage in spacecraft. However, this method requires manual operation.

[0006] In Chinese patent document CN102809423, the Shanghai Satellite Engineering Institute disclosed a satellite on-orbit micro-vibration measurement system that can comprehensively grasp the vibration state of the satellite in the active phase and on-orbit phase, providing a basis for subsequent satellite structure optimization, formulating appropriate vibration control strategies and environmental assessment indicators, but did not further apply the system to structural health monitoring during spacecraft launch.

[0007] In Chinese patent document CN1804612, Northwestern Polytechnical University disclosed a method for detecting structural damage based on cross-correlation function amplitude vectors under random vibration. This method meets the requirements for detecting structural damage under narrowband random excitation environments. It determines whether the structure is damaged by comparing the correlation coefficient of the cross-correlation function amplitude vectors of the intact structure and the current structure, and determines the location of the damage by analyzing the changes in the corresponding element components. However, this method is limited in engineering applications because the process of calculating modal parameters using random vibration is relatively complex and requires a lot of spacecraft computing resources.

[0008] In Chinese patent document CN104062446A, the China Aircraft Strength Institute disclosed an integrated system and method for monitoring the structural health of aircraft. This system and method integrates the hardware and software of multiple sensor monitoring technologies in the monitoring of the structural health of aircraft. It can uniformly schedule numerous sensors, fuse, process and manage their data to achieve remote monitoring. However, the multiple sensors involved in this system are subsystems for specific components of aircraft and cannot be directly applied to the structure of spacecraft. Therefore, it cannot be directly and simply used in parallel for the structural health monitoring of spacecraft during the launch process.

[0009] In summary, the methods currently used both domestically and internationally have significant limitations. Firstly, these systems have not been widely adopted due to poor sensitivity or operational complexity, limiting their application to ground-based testing. Secondly, these systems often require the generation of external excitation signals, which can affect the spacecraft's launch process. Therefore, a new detection system is urgently needed to meet the requirements for structural health monitoring during spacecraft launch. Summary of the Invention

[0010] In view of the deficiencies in the prior art, the purpose of this invention is to provide a structural health monitoring system and method for spacecraft launch process based on vibration signals.

[0011] A structural health monitoring system for spacecraft launch process based on vibration signals, according to the present invention, includes:

[0012] High-frequency piezoelectric accelerometer: Forms a sensor network to collect vibration signals;

[0013] Preamplifier: Amplifies and outputs the vibration signal;

[0014] Data acquisition and storage unit: Receives the amplified signal output from the preamplifier and pre-stores it, then outputs the data signal to the vibration monitoring computer;

[0015] Vibration monitoring computer: performs fast Fourier transform on the input signal to obtain the vibration signal spectrum; based on the analysis results of the vibration signal spectrum, it determines the health status of the spacecraft's structure during the launch process and completes the monitoring.

[0016] Preferably, the vibration signal includes the excitation signal generated by the launch vehicle transmitting to the spacecraft structure through the spacecraft docking interface during spacecraft launch.

[0017] Preferably, the sensor network acquires acceleration signals, including vibration signals of spacecraft components during launch.

[0018] Preferably, the vibration monitoring computer performs a fast Fourier transform on the input signal based on the vibration signal recorded periodically to obtain the vibration signal spectrum, and then analyzes the vibration signal spectrum using a neural network algorithm to obtain the analysis results.

[0019] Preferably, the vibration monitoring computer compares the analysis results with a set threshold to determine whether the sensor signal is abnormal, and identifies the area where the abnormality may occur as the damage site.

[0020] A method for monitoring the structural health of a spacecraft during launch based on vibration signals, according to the present invention, includes:

[0021] Step S1: Form a sensor network to collect vibration signals;

[0022] Step S2: Amplify the vibration signal and output it;

[0023] Step S3: Receive the amplified signal output from the preamplifier and pre-store it, then output the data signal to the vibration monitoring computer;

[0024] Step S4: Perform a fast Fourier transform on the input signal to obtain the vibration signal spectrum; based on the analysis results of the vibration signal spectrum, determine the health status of the spacecraft's structure during the launch process and complete the monitoring.

[0025] Preferably, the vibration signal includes the excitation signal generated by the launch vehicle transmitting to the spacecraft structure through the spacecraft docking interface during spacecraft launch.

[0026] Preferably, the sensor network acquires acceleration signals, including vibration signals of spacecraft components during launch.

[0027] Preferably, the vibration monitoring computer performs a fast Fourier transform on the input signal based on the vibration signal recorded periodically to obtain the vibration signal spectrum, and then analyzes the vibration signal spectrum using a neural network algorithm to obtain the analysis results.

[0028] Preferably, the vibration monitoring computer compares the analysis results with a set threshold to determine whether the sensor signal is abnormal, and identifies the area where the abnormality may occur as the damage site.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. This invention collects structural vibration signals of a spacecraft during launch, amplifies the signals, and processes them using an artificial neural network to determine whether the vibration signals are normal, thereby achieving the purpose of monitoring the structural health of the spacecraft in orbit. This process does not affect the normal launch process of the spacecraft, but can realize the monitoring of the structural health of the spacecraft, providing a breakthrough direction for the future development of structural health monitoring of spacecraft during the launch phase.

[0031] 2. This invention can use the vibration signal generated by the structure of a spacecraft under the influence of external loads during launch as an input signal for fault diagnosis. Since the system is completely external to the spacecraft system, it avoids interference to the normal operation of the spacecraft introduced during the monitoring process, and has the characteristics of non-interference and high precision.

[0032] 3. This invention uses an artificial neural network to diagnose the micro-vibration signals collected by a high-frequency piezoelectric accelerometer network. It can perform real-time diagnosis and has a fast analysis speed, and can promptly identify the characteristics of the fault area when a fault occurs. The artificial neural network has a simple structure and does not require human analysis of the noise characteristics in the sensor-collected signals. As long as sufficient feature sample signals are collected to train the neural system, a good diagnostic effect can be achieved.

[0033] 4. This invention enables uninterrupted state measurement and analysis of spacecraft while they are operating normally in orbit. It can issue alarms when even minor anomalies occur in the spacecraft structure, facilitating rapid fault location. This solves the problem of uninterrupted, real-time monitoring and fault analysis of spacecraft during normal operation in orbit, overcoming the shortcomings of existing technologies.

[0034] Other beneficial effects of the present invention will be explained in detail through the introduction of specific technical features and technical solutions in specific embodiments. Those skilled in the art should be able to understand the beneficial technical effects brought about by these technical features and technical solutions through the introduction of these technical features and technical solutions. Attached Figure Description

[0035] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0036] Figure 1 This is a schematic diagram of the system of the present invention.

[0037] Figure 2 This is a flowchart of the method of the present invention. Detailed Implementation

[0038] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0039] Example 1

[0040] Reference Figure 1 As shown, a spacecraft launch process structural health monitoring system based on vibration signals includes: a high-frequency piezoelectric accelerometer network, a preamplifier, a data acquisition and storage unit, and a vibration monitoring computer;

[0041] A high-frequency piezoelectric accelerometer network consists of several high-frequency piezoelectric accelerometers.

[0042] The vibration signal is the excitation signal generated by the launch vehicle transmitting to the spacecraft structure through the spacecraft docking interface during the spacecraft launch process.

[0043] The acceleration signals collected by the sensor network are vibration signals of components on the spacecraft during launch. The collected vibration signals are first amplified by a preamplifier.

[0044] The data acquisition and storage unit pre-stores the amplified signal output by the preamplifier and sends the output data signal to the vibration monitoring computer.

[0045] The vibration monitoring computer records vibration signals periodically and performs a fast Fourier transform on the input signal to obtain the vibration signal spectrum. The micro-vibration signal spectrum is analyzed by a neural network algorithm and compared with a set threshold to determine whether the sensor signal is normal, and the area where the abnormality may occur is identified as the damage site.

[0046] This invention utilizes vibration signals generated by external loads on a spacecraft's structure during launch as input signals for fault diagnosis. Because the system is entirely external to the spacecraft system, it avoids interference with the spacecraft's normal operation introduced during monitoring, offering the advantages of non-interference and high precision. Furthermore, by employing an artificial neural network to diagnose the micro-vibration signals collected by a high-frequency piezoelectric accelerometer network, real-time diagnosis is possible, with rapid analysis and timely identification of the fault region when a fault occurs. The artificial neural network has a simple structure and does not require manual analysis of noise characteristics in the sensor-collected signals; sufficient feature sample signals are collected to train the neural system, achieving good diagnostic results. This invention allows for uninterrupted state measurement and analysis of the spacecraft while it operates normally in orbit. It can issue alarms when minor anomalies occur in the spacecraft structure, facilitating rapid fault location and solving the problem of non-interference, real-time monitoring and fault analysis of spacecraft during normal operation in orbit, thus overcoming the shortcomings of existing technologies.

[0047] Example 2

[0048] Reference Figure 2 As shown, a method for structural health monitoring during spacecraft launch based on vibration signals includes:

[0049] First, high-frequency piezoelectric accelerometers are distributed and installed at monitoring points on the spacecraft structure, forming a sensor network. This network collects vibration signals generated by external loads on the spacecraft structure during launch.

[0050] Next, the preamplifier amplifies and processes the collected vibration signal, which is then transferred to the data acquisition and storage unit for storage. The data acquisition and storage unit then outputs a data signal to the vibration monitoring computer.

[0051] Finally, the vibration monitoring computer performs a fast Fourier transform on the input signal based on the vibration signal recorded periodically to obtain the vibration signal spectrum; the vibration signal spectrum is analyzed by a neural network algorithm and compared with a set threshold to determine whether the sensor signal is normal, and the area where the abnormality may occur is given as the damage site.

[0052] Example 3

[0053] Reference Figure 2 As shown, a method for structural health monitoring during spacecraft launch based on vibration signals includes the following steps:

[0054] Step 1: Connect the high-frequency piezoelectric accelerometers placed on the spacecraft structure into a sensor network using cables. Connect the sensor network to the preamplifier using cables to output vibration signals from the spacecraft structure.

[0055] Step 2: The preamplifier is connected to the data acquisition and storage unit to transmit and store the micro-vibration signal. The data acquisition and storage unit outputs vibration signal data and sends it to the vibration monitoring computer. The vibration monitoring computer performs a Fast Fourier Transform on the input signal based on the vibration signal data recorded periodically to obtain the micro-vibration signal spectrum.

[0056] Step 3: Finally, the neural network algorithm is used to analyze the spectrum of the micro-vibration signal and compare it with the set threshold to determine whether the sensor signal is normal and to give the area where the abnormality may occur.

[0057] When using this invention, it is necessary to first collect various normal or abnormal micro-vibration signal data of the spacecraft structure according to the typical operating conditions of the spacecraft in orbit, and store them inside the vibration monitoring computer.

[0058] Then, using the acquired typical signals, a Fast Fourier Transform is performed to obtain the vibration signal spectrum. Afterwards, a neural network algorithm is used to train the acquired vibration signal spectrum, establishing a data feature database. Once training is complete, health monitoring of typical operating conditions of spacecraft in orbit can be achieved through an artificial neural network.

[0059] During training, the number of input nodes in the artificial neural network should equal the number of characteristic frequency bands in the vibration signal spectrum, and the number of output nodes should be the number of normal operating conditions plus one, corresponding to various normal spacecraft states. During anomaly diagnosis, the characteristic frequency band values ​​are input into the neural network, and the network output will provide the current signal state of each high-frequency piezoelectric accelerometer and its membership degree to the normal or abnormal state. If the membership degree of a certain abnormal state is greater than a preset threshold, it indicates that an abnormal fault has occurred in the vicinity of that high-frequency piezoelectric accelerometer, and the computer will issue an alarm.

[0060] Those skilled in the art will understand that, besides implementing the system and its various devices, modules, and units provided by this invention in the form of purely computer-readable program code, the same functions can be achieved entirely through logical programming of the method steps, making the system and its various devices, modules, and units of this invention function in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers. Therefore, the system and its various devices, modules, and units provided by this invention can be considered as a hardware component, and the devices, modules, and units included therein for implementing various functions can also be considered as structures within the hardware component; alternatively, the devices, modules, and units for implementing various functions can be considered as both software modules implementing the method and structures within the hardware component.

[0061] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0062] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A structural health monitoring system for spacecraft launch process based on vibration signals, characterized in that, include: High-frequency piezoelectric accelerometer: Forms a sensor network to collect vibration signals; Preamplifier: Amplifies and outputs the vibration signal; Data acquisition and storage unit: Receives the amplified signal output from the preamplifier and pre-stores it, then outputs the data signal to the vibration monitoring computer; Vibration monitoring computer: performs fast Fourier transform on the input signal to obtain the vibration signal spectrum; based on the analysis results of the vibration signal spectrum, it determines the health status of the spacecraft's structure during the launch process and completes the monitoring.

2. The spacecraft launch process structural health monitoring system based on vibration signals according to claim 1, characterized in that, The vibration signal includes the excitation signal generated by the launch vehicle transmitting to the spacecraft structure through the spacecraft docking interface during spacecraft launch.

3. The spacecraft launch process structural health monitoring system based on vibration signals according to claim 2, characterized in that, The sensor network collects acceleration signals, including vibration signals of spacecraft components during launch.

4. The spacecraft launch process structural health monitoring system based on vibration signals according to claim 1, characterized in that, The vibration monitoring computer performs a fast Fourier transform on the input signal based on the vibration signal recorded periodically to obtain the vibration signal spectrum. The vibration signal spectrum is then analyzed using a neural network algorithm to obtain the analysis results.

5. The spacecraft launch process structural health monitoring system based on vibration signals according to claim 4, characterized in that, The vibration monitoring computer compares the analysis results with a set threshold to determine whether the sensor signal is abnormal, and identifies the area where the abnormality may occur as the damage site.

6. A method for structural health monitoring during spacecraft launch based on vibration signals, characterized in that, include: Step S1: Form a sensor network to collect vibration signals; Step S2: Amplify the vibration signal and output it; Step S3: Receive the amplified signal output from the preamplifier and pre-store it, then output the data signal to the vibration monitoring computer; Step S4: Perform a fast Fourier transform on the input signal to obtain the vibration signal spectrum; based on the analysis results of the vibration signal spectrum, determine the health status of the spacecraft's structure during the launch process and complete the monitoring.

7. The method for structural health monitoring during spacecraft launch based on vibration signals according to claim 6, characterized in that, The vibration signal includes the excitation signal generated by the launch vehicle transmitting to the spacecraft structure through the spacecraft docking interface during spacecraft launch.

8. The method for structural health monitoring during spacecraft launch based on vibration signals according to claim 7, characterized in that, The sensor network collects acceleration signals, including vibration signals of spacecraft components during launch.

9. The method for structural health monitoring during spacecraft launch based on vibration signals according to claim 6, characterized in that, The vibration monitoring computer performs a fast Fourier transform on the input signal based on the vibration signal recorded periodically to obtain the vibration signal spectrum. The vibration signal spectrum is then analyzed using a neural network algorithm to obtain the analysis results.

10. The method for structural health monitoring during spacecraft launch based on vibration signals according to claim 9, characterized in that, The vibration monitoring computer compares the analysis results with a set threshold to determine whether the sensor signal is abnormal, and identifies the area where the abnormality may occur as the damage site.

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