Non-contact multi-source information sensing system in strong random environment

Abstract

The invention discloses a non-contact multi-source information sensing system in a strong random environment. The system comprises an RF ID sensing system, reliability optimization deployment in the strong random environment, and vibration signal recovery and reconstruction. The RF ID sensing system can be used for collecting original signal data of an engine under the non-contact condition. Secondly, reliability optimization deployment is carried out in a strong random environment, and deployment of system tags, antennas and sensing parameters is optimized under the condition that influences of various interference factors in the working environment of the engine are comprehensively considered, so that the performance of the sensing system is improved. The method can be used for realizing accurate recovery of vibration characteristic signals, ensuring quick and accurate sensing of key parameters of an engine, and realizing quick detection of typical fault modes. The technology has wide application potential and can play an important role in the fields of engine vibration monitoring, engine fault analysis, engine health management and the like.

Description

Technical Field

[0001] The invention belongs to the field of liquid rocket engine turbine pump vibration monitoring, and in particular refers to a non-contact multi-source information perception system in a strongly random environment. Background Art

[0002] In recent years, with the rapid development of the field of space transportation, the domestic and foreign aerospace fields have gradually promoted the upgrading of the space transportation system for the purpose of reusability, prompting the system to evolve in the direction of reusability. Space powers represented by the United States have carried out exploration and research on reusable earth-to-space transportation systems, and have achieved phased results, realizing the recovery of the rocket sub-stage, which has greatly stimulated the research boom in this field. However, to achieve the goal of reusable rocket engines, further research is still needed on the detection of spacecraft and engine health parameters and health management technology.

[0003] To achieve health parameter detection and health management, it is necessary to collect reusable rocket engine health characteristics. Vibration signals are typical signals for health management data monitoring. By analyzing the time and frequency domains of vibration signals, it is possible to quickly extract the parameter characteristics of the engine in an unhealthy state and reflect the health status of the engine. However, due to the influence of engine space and complex working conditions, traditional vibration monitoring systems are difficult to apply to the harsh environment of rocket engines.

[0004] To solve the above problems, the present invention proposes a non-contact multi-source information perception system in a strongly random environment. The system can be installed in the narrow space and irregular surface of the engine. With the advantages of non-contact form, small size, light weight and extremely low cost, it can carry multiple measuring points at the same time to realize multi-tag signal collection, signal transmission and signal storage functions of vibration and temperature. Summary of the invention

[0005] The purpose of the present invention is to provide a non-contact multi-source information perception system in a strongly random environment, which solves the problem of inconvenient engine detection in the prior art.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A non-contact multi-source information perception system in a strongly random environment, including an RFID perception system, a strongly random environment optimization deployment strategy, and a vibration signal recovery and reconstruction technology; wherein;

[0008] The RFID sensing system is used to collect the original signal data of the engine in a non-contact manner, and includes a flexible anti-metal tag antenna, an integrated tag and a communication software system;

[0009] The integrated tag includes an energy acquisition module, a digital module, and a radio frequency module;

[0010] The energy acquisition module adopts a microstrip antenna structure, the digital module adopts a low-dropout regulator, and the RF module uses a microstrip antenna with good anti-metal interference characteristics as a communication antenna;

[0011] The optimization deployment strategy for a strongly random environment includes factors such as channel path interference, strong earthquakes, high and low temperature, and shielding environments. Under the combined influence of the above factors, the appropriate deployment method for sensing equipment is determined;

[0012] Vibration signal recovery and reconstruction technology is used to achieve accurate recovery of vibration characteristic signals, ensuring fast and accurate perception of key engine parameters.

[0013] On the basis of the above technical solution, the present invention also provides the following optional technical solution:

[0014] In an optional solution: the RFID sensing system can collect raw signal data of the engine in a non-contact manner.

[0015] In an optional solution: the vibration signal recovery and reconstruction technology is implemented based on the principle of compressed sensing;

[0016] The principle of compressed sensing can be expressed as the following relationship;

[0017] y=ΦΨ -1 X=ΘX

[0018] Where Ψ is the sparse basis matrix in the selected transform domain, Φ is the measurement matrix unrelated to Ψ, X is the sparse signal of the original signal x in the transform domain, y is the observed value of the sparse signal, and Θ is the sensor matrix.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention proposes a non-contact multi-source information perception system in a strongly random environment. The system can be carried in a small space or irregular surface of an engine. With the advantages of non-contact form, small size, light weight and extremely low cost, it can carry multiple measuring points at the same time to realize multi-label signal collection, signal transmission and signal storage functions of vibration and temperature. The system is small in size, light in weight, and can realize long-distance wireless transmission of monitoring signals. Compared with traditional perception systems, it is more suitable to be carried on spacecraft and aerospace engines to monitor health parameters. The system can realize vibration and temperature monitoring of multiple measuring points at the same time. Compared with traditional monitoring systems, the monitoring data is richer and the health characteristics that can be extracted are more comprehensive. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the development technology route of the present invention.

[0022] Figure 2The flowchart of the RFID tag antenna design of the present invention is shown in FIG.

[0023] Figure 3 Schematic diagram of the integrated vibration sensing tag architecture of the present invention.

[0024] Figure 4 It is a schematic diagram of the vibration signal recovery and reconstruction technology of the present invention. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] like Figure 1 As shown, this implementation case involves a passive radio frequency RFID sensing system, strong random environment reliability optimization deployment and vibration signal recovery. The specific implementation steps are as follows

[0027] Passive RFID sensing system

[0028] The passive radio frequency RFID sensing system includes a flexible anti-metal tag antenna, an integrated tag and a communication software system.

[0029] Flexible anti-metal tag antenna design

[0030] Tags are generally composed of tag antennas and tag chips. The tag antenna receives the RF signal emitted by the reader and converts it into energy to supply the tag chip. When the energy obtained reaches a certain level, the tag chip is activated and performs corresponding operations according to the query instructions of the reader, reflecting the stored tag information back to the reader through backscatter modulation. The design process of the passive RF tag antenna is as follows: Figure 2 shown.

[0031] The selection of substrate materials is also particularly important for the design and preparation of RFID sensor tags. The operating frequency and radiation frequency of the tag are affected by the dielectric constant and loss tangent of the substrate material respectively. The larger the dielectric constant, the higher the signal loss, and the larger the loss angle, the higher the feed loss. The working performance of the tag is also affected by the Young's modulus of the substrate material. The size of the Young's modulus determines whether the prepared tag is well conformal to the curved surface. The Young's modulus, dielectric constant and loss tangent of the tag substrate material should be comprehensively considered during the design process.

[0032] The input impedance of the tag antenna is conjugate with the tag chip to achieve maximum energy transfer between the chip and the tag. The input impedance of the tag chip can be expressed as follows:

[0033] Z=R-jX

[0034] The input impedance of the tag antenna is expressed as follows

[0035] Z=R+jX

[0036] It can be adjusted by changing the width of the antenna and the embedding depth of the feeder. The wider the microstrip antenna, the smaller the impedance; the deeper the embedding depth, the smaller the impedance. For UHF RFID anti-metal tag antennas, short-circuit stubs can increase the reactance of the antenna, and adjusting their length can adjust the imaginary value of the impedance. In practical applications, the antenna performance of passive RFID tags directly affects the efficiency of signal transmission and reception, and the impedance characteristics of RF chips often change with the change of electromagnetic wave frequency bands. This change requires full consideration of the mutual influence between the circuit and the electromagnetic field during the design process. Through field-circuit collaborative simulation, the resonant frequency can be accurately calculated, thereby achieving more accurate impedance matching, and ultimately improving the radiation efficiency and overall performance of the antenna.

[0037] Integrated label design

[0038] The integrated tag has a built-in MCU and a sensor chip, in which the sensor chip is responsible for collecting vibration signals. The collected vibration signal is transmitted to the MCU for preliminary processing and AD conversion, and finally the RF chip backscatters the RF signal containing the vibration signal through the tag antenna to the reader antenna. The passive RF patch vibration sensor is mainly composed of an energy module, a digital module and a RF module. The energy management module obtains the energy in the signal emitted by the reader into space through the antenna, stores energy and boosts the voltage to provide power for the digital module and the RF module. The digital module includes an MCU processor and an acceleration sensor chip, in which the acceleration sensor chip is responsible for collecting the original vibration signal, and the MCU processes the signal from the acceleration sensor chip and transmits it to the RF module. In addition, the MCU also executes the low-power operation strategy of the entire passive RF tag. The RF module is mainly composed of an RF chip, which is responsible for modulating and sending vibration signals. The architecture of the integrated vibration sensing tag is as follows Figure 3 shown.

[0039] Energy acquisition module: This project selects a microstrip antenna structure to ensure reliable energy acquisition in a complex metal environment. To achieve maximum energy transmission efficiency, high-quality factor adjustable RF inductors and high-frequency capacitors are used for impedance matching. A secondary boost rectifier circuit is designed to convert the RF energy obtained by the antenna into a DC voltage higher than 1.5V to meet the minimum input requirements of the subsequent low-power boost voltage regulator chip. In addition, to further improve the operational reliability of the tag, a supercapacitor is selected as an auxiliary energy source.

[0040] Digital module: A low dropout regulator is used to obtain a stable 1.8V DC voltage output. The selected microcontroller is the 16-bit MSP430F5172, which has an operating voltage of 1.8V and is equipped with 32kB flash memory, 2kB SRAM and 8 10-bit ADC channels. The accelerometer uses the ADXL346 ultra-low power three-axis accelerometer, which also has an operating voltage of 1.8V DC.

[0041] RF module: Considering that the sensor tag is used in a metal environment, a microstrip antenna with good anti-metal interference characteristics is used as the communication antenna. The RFID chip is Monza X-2K, which has 2176B non-volatile storage capacity and an I2C interface. The data measured by the sensor can be transmitted to the chip through the I2C interface. When the tag is activated by the reader, the tag transmits the data to the corresponding reader in a backscattering manner.

[0042] Communication software design

[0043] The development of the communication software is based on C#. In order to realize the functions of the RFID system software, it is necessary to establish a connection with the RFID reader through a specific SDK or API. First, set the communication parameters, such as COM port and baud rate, to ensure stable communication; secondly, carefully select the appropriate antenna and antenna channel according to the actual application scenario and environmental conditions to ensure the effectiveness of reading; after completing the antenna configuration, adjust the reader's power and communication frequency band; implement the communication mechanism between the reader and the tag through an event-driven method; finally, use a structured storage method to realize signal storage for subsequent data processing and analysis.

[0044] Reliability optimization deployment in a strong random environment

[0045] During the operation of rocket engines, there are many factors in the environment, such as strong vibration, temperature fluctuations, and electromagnetic interference. These factors interact with each other, exacerbating the randomness and uncertainty of the signal. When specifying the system deployment strategy, it is necessary to consider the impact of channel path interference factors, strong earthquake interference factors, high and low temperature factors, and occlusion environmental factors on the performance of the perception system, and optimize the deployment of perception tags and perception chips.

[0046] Vibration signal recovery and reconstruction

[0047] Vibration signal recovery and reconstruction technology Figure 4 As shown in the figure, this technology is implemented based on the theory of compressed sensing. The theory of compressed sensing points out that when a signal is sparse in a certain transform domain, a measurement matrix that is unrelated to the transform domain can be used to observe the sparse signal of the original signal in the transform domain, and the original signal can be reconstructed based on the observed value. The principle of compressed sensing can be expressed as the following relationship.

[0048] y=ΦΨ-1 X=ΘX

[0049] Where Ψ is the sparse basis matrix in the selected transform domain, Φ is the measurement matrix unrelated to Ψ, x is the sparse signal of the original signal x in the transform domain, y is the observed value of the sparse signal, and Θ is the sensing matrix.

[0050] In the application scenario of the present invention, the engine vibration signal is transformed into a sparse coefficient matrix through Fourier basis transformation, and the dense signal in the time domain is transformed into a sparse signal in the frequency domain. The measurement matrix is ​​divided into time slots and reading frames according to the time granularity of microseconds. Each row includes only one reading frame and the adjacent frames are in two staggered rows to meet the irrelevant condition. The signal recovery problem is expressed as solving X based on the known observation value y and the sensor matrix Θ. In the signal recovery process, the reconstruction of the high-frequency signal is achieved by converting the zero-norm minimization problem into the one-norm minimization problem.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A non-contact multi-source information perception system in a strongly random environment, characterized by: Including RFID sensing system, strong random environment optimization deployment strategy and vibration signal recovery and reconstruction technology; in; The RFID sensing system is used to collect the original signal data of the engine in a non-contact manner, and includes a flexible anti-metal tag antenna, an integrated tag and a communication software system; The integrated tag includes an energy acquisition module, a digital module, and a radio frequency module; The energy acquisition module adopts a microstrip antenna structure, the digital module adopts a low-dropout regulator, and the RF module uses a microstrip antenna with good anti-metal interference characteristics as a communication antenna; The optimization deployment strategy for a strongly random environment includes factors such as channel path interference, strong earthquakes, high and low temperature, and shielding environments. Under the combined influence of the above factors, the appropriate deployment method for sensing equipment is determined; Vibration signal recovery and reconstruction technology is used to achieve accurate recovery of vibration characteristic signals, ensuring fast and accurate perception of key engine parameters.

2. The non-contact multi-source information perception system in a strongly random environment according to claim 1 is characterized in that: The RFID sensing system can collect original signal data of the engine in a non-contact manner.

3. The non-contact multi-source information perception system in a strongly random environment according to claim 1 is characterized in that: The vibration signal recovery and reconstruction technology is based on the principle of compressed sensing; The principle of compressed sensing can be expressed as the following relationship; y=ΦΨ -1 X=ΘX Where Ψ is the sparse basis matrix in the selected transform domain, Φ is the measurement matrix unrelated to Ψ, X is the sparse signal of the original signal x in the transform domain, y is the observed value of the sparse signal, and Θ is the sensor matrix.

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