Multi-source information sensing system based on radio frequency sensing

Abstract

The invention discloses a multi-source information sensing system based on radio frequency sensing. The multi-source information sensing system comprises an RFID sensing system, reliability optimization deployment in a strong random environment and vibration signal recovery and reconstruction. The RFID 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 present invention belongs to the field of liquid rocket engine turbopump vibration monitoring, and in particular relates to a multi-source information perception system based on radio frequency sensing. Background Art

[0002] In recent years, with the rapid development of space transportation, both domestic and international aerospace sectors have been steadily upgrading their space transportation systems with the goal of achieving reusability, driving this evolution. Space powers, particularly the United States, have explored and researched reusable space transportation systems, achieving initial success, including the recovery of a rocket's sub-stage, sparking a surge in research in this field. However, achieving the reusability of reusable rocket engines requires further research into spacecraft and engine health parameter monitoring and health management technologies.

[0003] Health parameter detection and health management require the collection of reusable rocket engine health characteristics. Vibration signals are a typical signal for health management data monitoring. By analyzing vibration signals in the time and frequency domains, it is possible to quickly extract parameter characteristics when the engine is in an unhealthy state, reflecting the engine's health status. However, due to the influence of the engine's space and complex operating conditions, traditional vibration monitoring systems are difficult to adapt to the harsh environment of rocket engines.

[0004] To solve the above problems, the present invention proposes a multi-source information perception system based on radio frequency sensing. 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 simultaneously carry multiple measuring points 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 multi-source information perception system based on radio frequency sensing, 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 multi-source information perception system based on radio frequency sensing, 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 raw engine signal data 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 harvesting module uses a microstrip antenna structure, the digital module uses a low-dropout voltage regulator, and the RF module uses a microstrip antenna with good anti-metal interference characteristics as a communication antenna;

[0011] The optimized deployment strategy for a strongly random environment includes factors such as channel path interference, strong earthquakes, high and low temperature, and obstruction. Taking these factors into account, the appropriate deployment method for sensing equipment is determined.

[0012] Vibration signal recovery and reconstruction technology is used to accurately recover vibration characteristic signals and ensure fast and accurate perception of key engine parameters.

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

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

[0015] In one 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 observation value of the sparse signal, and Θ is the sensing matrix.

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

[0020] The present invention proposes a multi-source information perception system based on radio frequency sensing. The system can be carried 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. The system is small in size and light in weight, and can realize long-distance wireless transmission of monitoring signals. Compared with traditional perception systems, it is more suitable for being 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 development technology route structure of the present invention.

[0022] Figure 2This is a flow chart of the RFID tag antenna design of the present invention.

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

[0024] Figure 4 Schematic diagram of the vibration signal recovery and reconstruction technology of the present invention. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention 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 radio frequency 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 a tag antenna and a tag chip. The tag antenna receives the RF signal transmitted by the reader and converts it into energy, which is then supplied to 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 a passive RF tag antenna is as follows: Figure 2 shown.

[0031] The choice of substrate material is also crucial for the design and fabrication of RFID sensor tags. The tag's operating frequency and radiation frequency are influenced by the substrate material's dielectric constant and loss tangent, respectively. A higher dielectric constant increases signal loss, while a larger loss tangent increases feed loss. Tag performance is also influenced by the substrate material's Young's modulus, which determines how well the tag conforms to curved surfaces. 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] Adjustment is achieved by changing the width of the antenna and the depth of the feed embedment. The wider the microstrip antenna, the lower the impedance; the deeper the embedment, the lower the impedance. For UHF RFID anti-metal tag antennas, short-circuiting the stub increases the antenna's reactance, and adjusting its length adjusts the imaginary part 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 changes in the electromagnetic wave frequency band. This change requires full consideration of the interaction 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, ultimately improving the antenna's radiation efficiency and overall performance.

[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 implements 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 the vibration signal. The architecture of the integrated vibration sensing tag is as follows Figure 3 shown.

[0039] Energy Harvesting Module: This project utilizes a microstrip antenna structure to ensure reliable energy harvesting in complex metallic environments. To maximize energy transmission efficiency, a high-quality factor, adjustable RF inductor and high-frequency capacitors are used for impedance matching. A two-stage boost rectifier circuit is designed to convert the RF energy harvested by the antenna into a DC voltage exceeding 1.5V, meeting the minimum input requirements of the subsequent low-power boost regulator chip. Furthermore, to further enhance the tag's operational reliability, a supercapacitor is used as an auxiliary energy source.

[0040] The digital module uses a low-dropout voltage regulator to achieve a stable 1.8V DC output. The microcontroller selected is the 16-bit MSP430F5172, which operates at 1.8V and features 32kB of flash memory, 2kB of SRAM, and eight 10-bit ADC channels. The accelerometer uses the ADXL346 ultra-low-power triaxial accelerometer, also operating at 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. Figure 2 The RFID chip shown in the figure 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 via the I2C interface. When the tag is activated by the reader, the tag transmits the data to the corresponding reader in the form of backscatter.

[0042] Communication software design

[0043] The communication software was developed in C#. To implement the RFID system software's functionality, a connection to the RFID reader must be established through a specific SDK or API. First, communication parameters, such as the COM port and baud rate, must be set to ensure stable communication. Secondly, the appropriate antenna and antenna channel must be carefully selected based on the actual application scenario and environmental conditions to ensure effective reading. After antenna configuration, the reader's power and communication frequency band must be adjusted. Communication between the reader and the tag is implemented through an event-driven approach. Finally, structured storage is used to store signals for subsequent data processing and analysis.

[0044] Reliability optimization deployment in a strong random environment

[0045] During rocket engine operation, numerous environmental factors exist, such as strong vibration, temperature fluctuations, and electromagnetic interference. These factors interact with each other, exacerbating the randomness and uncertainty of signals. When designing a system deployment strategy, it is important to consider the impact of channel path interference, strong earthquake interference, high and low temperature conditions, and environmental obstruction on perception system performance, 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 Figure 2, this technology is based on the theory of compressed sensing. This theory states that when a signal is sparse in a certain transform domain, a measurement matrix unrelated to the transform domain can be used to observe the sparse signal of the original signal in that transform domain and reconstruct the original signal based on the observed values. 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 observation value of the sparse signal, and Θ is the sensing matrix.

[0050] In the application scenario of this invention, the engine vibration signal is transformed into a sparse coefficient matrix using a Fourier basis transform, converting the dense signal in the time domain into a sparse signal in the frequency domain. The measurement matrix is ​​divided into time slots and reading frames at a time granularity of microseconds. Each row contains only one reading frame, and adjacent frames are placed in two staggered rows to meet the uncorrelated condition. The signal recovery problem is formulated as solving for X based on the known observation value y and the sensor matrix Θ. During the signal recovery process, the high-frequency signal is reconstructed by converting the zero-norm minimization problem into a 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 principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A multi-source information perception system based on radio frequency sensing, 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 raw engine signal data 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 harvesting module uses a microstrip antenna structure, the digital module uses a low-dropout voltage regulator, and the RF module uses a microstrip antenna with good anti-metal interference characteristics as a communication antenna; The optimized deployment strategy for a strongly random environment includes factors such as channel path interference, strong earthquakes, high and low temperature, and obstruction. Taking these factors into account, the appropriate deployment method for sensing equipment is determined. Vibration signal recovery and reconstruction technology is used to accurately recover vibration characteristic signals and ensure fast and accurate perception of key engine parameters.

2. The multi-source information perception system based on radio frequency sensing according to claim 1, characterized in that: The RFID sensing system can collect original engine signal data in a non-contact manner.

3. The multi-source information perception system based on radio frequency sensing according to claim 1, characterized in that: 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 observation value of the sparse signal, and Θ is the sensing matrix.

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