- Current Issue
- Online First
- Adopt Archive Virtual Album
-
HUANG Bohang, JIANG Tinghao, ZHAO Chunbo, WU Tengfei, HE Guangqiang
2025(6):10-28 ,DOI: 10.11823/j.issn.1674-5795.2025.06.01
Abstract:
The basic principles of precision ranging based on soliton microcombs and their advantages in chip-level integration, high precision, and high speed are introduced. The principles and implementations of single-microcomb frequency-modulated continuous wave, chaotic ranging, dispersive interferometry, synthetic-wavelength metrology, and dual-comb ranging are elaborated. The development paths such as repetition frequency locking, frequency scanning, and parallel imaging are discussed. It is pointed out that the research in this field has progressed from proof-of-concept demonstrations to a new stage focused on performance optimization and practical exploration. It is further proposed that the future development will be characterized by system-level full optoelectronic integration, multifunctional reconfigurability, and deep cross-disciplinary convergence, through which a large-scale deployment of chip-scale precision LiDAR in automotive perception, industrial metrology, space exploration, and related applications is expected to be enabled.
-
HAN Yixuan, GAO Doudou, DONG Dengfeng, WANG Bo, QIU Qifan
2025(6):29-40 ,DOI: 10.11823/j.issn.1674-5795.2025.06.02
Abstract:
To address the issues of accuracy degradation and computational delay in extracting small spot centers in the field of industrial high-speed visual measurement, a high-speed real-time spot localization method for small-sized spots is proposed. A Region of Interest (ROI) extraction algorithm based on sliding window brightness consistency is designed and implemented in a Field Programmable Gate Array (FPGA) to improve detection speed. A small spot center extraction algorithm combining distance-weighted least-square fitting and a Signal-to-Noise Ratio (SNR)-based adaptive weight adjustment mechanism is introduced to enhance the localization robustness of small spots under varying lighting and noise conditions. Experimental results show that the proposed method has achieved a spot center localization error of not more than 0.05 pixels, with a frame rate of 160 frames per second, significantly outperforming traditional methods in processing speed. This method to a great extent meets the high-precision real-time localization requirements of small spot centers in industrial high-speed visual measurement.
-
CHENG Xin, CONG Shanshan, XUE Zhipeng, LIU Jinquan, MIAO Zijian, WANG Sheng
2025(6):41-49 ,DOI: 10.11823/j.issn.1674-5795.2025.06.03
Abstract:
To address the bottlenecks of high cost and long development cycles in traditional aerospace product manufacturing, and to meet the urgent demand for batch production of space optical payloads in giant satellite constellations, this study adopts an integrated approach combining modular structural design, process optimization, and automated testing technology to develop a Maksutov-Cassegrain optical system with a small F-number and minute pixels. By enab-ling interchangeable assembly of lenses and focal plane components, along with integration into an automated assembly and testing line, the system achieves a ground pixel resolution of 4.5 m and a swath width of 13.5 km × 13.5 km at an orbital altitude of 500 km, with a total weight of only 1.1 kg. This approach has improved the overall development efficiency by 50%. The results provide crucial technical support for the low-cost, rapid, and batch-producible manufacturing of miniaturized space optical payloads.
-
DU Qiang, HAO Jianhai, BAI Jinhai, HU Dong, WANG Yu, XU Haotian, ZHANG Yeyuan
2025(6):50-64 ,DOI: 10.11823/j.issn.1674-5795.2025.06.04
Abstract:
This paper introduces the physical principles and typical methods of Rydberg atomic superheterodyne microwave measurement technology, elaborates on its research advancements in sensitivity enhancement, phase measurement, and dynamic range expansion, analyzes its potential value and current limitations in aviation equipment applications, and explores the developmental trajectory and key technical challenges involved in transitioning this technology from laboratory research to practical aviation applications. It points out that the current maturity level of this technology is in the transitional stage from theoretical breakthroughs to equipment integration. Furthermore, it proposes a three-phase roadmap for advancing this technology toward aviation applications: chip-scale integration of core units, enhanced environmental robustness at the system level, and mission-oriented networked collaborative sensing. It provides a prospective technology roadmap for constructing a new generation of highly sensitive, distributed, and intelligent aviation microwave measurement systems.
-
PAN Yan, WANG Nuanrang, WANG Yunjia, FENG Shilong, XUE Xiaobo, ZHANG Shengkang
2025(6):65-72 ,DOI: 10.11823/j.issn.1674-5795.2025.06.05
Abstract:
To accurately and efficiently control the probing sequence of the Hg? microwave atomic clock, a highly integrated custom timing control system was developed. This system adopts a layered architecture design, in which the host computer software enables parameter setting and sequence configuration distribution. The embedded software, in real-time, parses the received instructions and generates high-precision operation sequences, ultimately driving peripheral devices to precisely execute the corresponding operations. It achieves flexible configuration and dynamic reconfiguration of the timing logic. Experimental results show that the sequences generated by the system are consistent with the theoretically designed sequences, enabling convenient and efficient timing control for double-resonance probing, Rabi probing, and Ramsey probing. The system provides a reliable timing control solution for the integrated research of Hg? microwave atomic clocks.
-
ZHANG Yu, YANG Hongwei, LIU Fang, YANG Wengang, JIANG Hongchuan, DENG Xinwu
2025(6):73-85 ,DOI: 10.11823/j.issn.1674-5795.2025.06.06
Abstract:
O? and H?O significantly affect the hydrogen sensitivity of PdNi thin films. To monitor hydrogen concentration in high-humidity oxygen-containing environments such as electrolytic water hydrogen production, nuclear power plant storage, and deep-sea energy exploration, PdNi thin-film hydrogen sensors were fabricated using methods such as magnetron sputtering, photolithography, and plasma etching. By adjusting the Ni content and thickness of the PdNi thin films, the influence of Ni content and thickness on the stability of the PdNi thin-film hydrogen sensors under O? and H?O interference was systematically studied. Analytical methods such as XRD, SEM, and XPS were employed to characterize the crystallinity, elemental content, and elemental valence states of the PdNi thin films. The experimental results indicate that as the Ni content increases, the hydrogen response of the PdNi thin films becomes more affected by H?O and O?, while increasing the film thickness can reduce interference but weakens the hydrogen response sensitivity. Among them, the PdNi thin-film hydrogen sensor with a Ni content of 8.04% and a thickness of 24 nm, although affected by O? and H?O, can restore its response curve to the initial state after experiencing interference. This research provides important support for the development of the hydrogen sensor for applications under complex environment conditions.
-
JIN Ran, HUANG Yuqi, ZHU Liang
2025(6):86-94 ,DOI: 10.11823/j.issn.1674-5795.2025.06.07
Abstract:
To address the calibration demand for the response time constant of fast-response K-type thermocouples under gas medium conditions, a calibration device based on the gas temperature step method was developed. Key para-meters including heater power, orifice area, and nozzle flow rate were determined via theoretical calculations, and Ansys Fluent software was utilized for simulation to optimize the structure of the step temperature generation module. A calibration method based on synchronous dynamic pressure monitoring was proposed, which takes the pressure step moment as the reference to eliminate non-ideal excitation interference and ensure the calculation accuracy of the response time constant. Experimental tests were conducted using the developed device, and the results indicate that the gas temperature step amplitude generated by the device exceeds 200 ℃ with a temperature step excitation time of approximately 2.2 ms. The device can effectively calibrate the response time constant of K-type thermocouples with different wire diameters, demonstrating a significant engineering application value.
-
LIAO Yunhong, WANG Chenchen, FU Qiang
2025(6):95-104 ,DOI: 10.11823/j.issn.1674-5795.2025.06.08
Abstract:
Research was conducted for porous parameter inversion based on irregular acoustic incidence model to address the limitation of normal incidence case. A theoretical model was established for relating material porous parame- ters to the irregular incidence absorption coefficient. The acoustic response of porous materials under irregular incidence case was simulated to obtain the reference absorption data. The inversion study was conducted by using the established theoretical model and genetic algorithm, and the accuracy and astringency of inversed parameters was further analyzed. Results show a good agreement between theoretical and simulated outcomes and demonstrate high accuracy and astringency with relative errors of the inversed parameters below 9.0% and relative standard deviations less than 1 × 10?3. This study provides a novel theoretical approach for porous parameter inversion that presents considerable potential for both academic research and engineering applications.
-
WANG Siyu, CUI Yuguo, WEI Chunfeng, CHEN Jichi
2025(6):105-115 ,DOI: 10.11823/j.issn.1674-5795.2025.06.09
Abstract:
To improve the quality and efficiency of Digital Elevation Model (DEM) construction in complex terrain, this study proposes a multi-source DEM acquisition and fusion method that integrates high-resolution optical imagery and interferometric Synthetic Aperture Radar (SAR) imagery. Using an unmanned aerial vehicle and satellite remote sensing system as a platform, this method constructs a multi-view data acquisition chain to generate optical imagery DEM and interferometric imagery SAR-DEM, respectively. By introducing a point cloud classification algorithm based on texture and structural features and a regional adaptive weight estimation model, weighted fusion of multi-source elevation data has been achieved. The fusion process employs error constraints and seamline control strategies to address typical challenges such as terrain occlusion, data holes, and elevation jumps. Experiments in representative landforms, including forests, glaciers, deserts, cities, and water bodies, demonstrates that this method has the characteristics of high elevation restoration accuracy and good boundary continuity, and can meet the three dimensions modeling needs of various landform types. Among them, the relative elevation mean error in hilly areas is 0.5 m. The research findings provide stable and reliable technical support for fields such as high-resolution topographic mapping, landform evolution monitoring, and disaster early warning, and are of great significance for promoting the automation and intelligence of remote sensing mapping.
-
MENG Wei, SHI Wei, CHEN Shilin
2025(6):116-127 ,DOI: 10.11823/j.issn.1674-5795.2025.06.10
Abstract:
To systematically solve the application problems of Measurement System Analysis (MSA) in the automatic hardness detection system, the particularity of its MSA is expounded, and points out the limitations of the traditional Gauge Repeatability and Reproducibility (GRR) method in the identification of variation sources and experimental design. On this basis, a "process decoupling hybrid GRR" experimental strategy is proposed, which decouples the hardness testing process into two sub processes: indentation generation (destructive) and indentation measurement (non-destructive). Nested design and cross design are used to separate and quantify the variation sources, respectively. Through the construction of an automation platform with double detection units, the systematic MSA experiment was conducted, and the analysis of variance was used to evaluate the influence of equipment repeatability, reproducibility and interaction. The results show that the proposed method can effectively identify the dominant variation sources, and provide a feasible analysis framework for the performance evaluation and optimization of the automatic hardness testing system, which has strong engineering applicability and popularization value.
-
SHI Chunying, ZHANG Yixiang, HU Wanxin, XING Runjia
2025(6):128-140 ,DOI: 10.11823/j.issn.1674-5795.2025.06.11
Abstract:
To accurately evaluate the metrological performance of airborne sensors under the prolonged, gradual, and cumulative influence of the natural environment, this study examines key technical aspects of the testing process — including preliminary preparations, test design, execution, result analysis, and reporting — based on the characteristics of both airborne sensors and natural environments. This exploration has resulted in the development of a relatively universal methodology for conducting natural environmental tests. These tests generate fundamental data on the changes in sensor metrological indicators, providing essential support for subsequent research on the performance degradation and the calibration cycle of airborne sensors.
-
ZHENG Jianhua, ZHAO Jian, WANG Xiaolu, HU Lintao, KONG Xiangxue, ZHAO Yijun
2025(6):141-152 ,DOI: 10.11823/j.issn.1674-5795.2025.06.12
Abstract:
Accurate heat flux measurement is essential for developing hypersonic vehicles and their thermal protection systems. The intense aerodynamic heating generated during high-speed flight of aerospace vehicles is primarily dominated by convective heat transfer. However, existing heat flux gauges struggle to accurately measure surface thermal loads under extreme high-temperature and high-speed conditions, resulting in low measurement accuracy and significantly constraining the performance evaluation of thermal protection systems and material development. To address the lack of reliable calibration methods for heat flux sensors under high-temperature and high-speed conditions, this study introduces a dual-plate transient calibration method. This method adopts a highly accurate thin-film platinum resistance sensor as a reference, installs a Gardon gauge to be calibrated with the sensor together on a displacement ejection mechanism, and simulates the high-speed flight scenario of the aircraft in the wind tunnel to achieve the calibration to the Gardon heat flux gauge under airflow conditions. Calibration experiments were conducted at a flight Mach number of 0.3 and temperatures from 100 °C to 300 °C for the developed convective heat flux measurement device. The results demonstrate that the relative expanded uncertainty is 4.2% (k = 2), and this method can effectively obtain the convective heat flux sensitivity coefficient of the Gardon heat flux meter. The dual plate transient calibration method proposed in this paper provides new ideas and approaches for high-temperature and high-speed convective heat flux calibration, significantly improving the reliability of convective heat flux measurement data and providing strong technical support for the development of hypersonic aircraft and accurate measurement of thermal loads in thermal protection systems.
-
WANG Yida, TIAN Qingyun, CHEN Yong, KONG Xiangxue, MANG Kexin, WANG Sujie, SHI Jiyuan
2025(6):153-160 ,DOI: 10.11823/j.issn.1674-5795.2025.06.13
Abstract:
Traditional test equipment struggles to meet the high-precision and efficient static temperature testing requirements of thin-film thermocouples in high-temperature environments. To address this issue, a chamber furnace with large-space and precise temperature control functions has been developed. The furnace body adopts a split-type multi-layer structure design. Its side thermal insulation components can be flexibly disassembled to eliminate installation obstructions, satisfying the testing needs of thin-film thermocouples with different shapes. High-efficiency heating is achieved using three-section molybdenum disilicide heating elements, combined with a water-cooling system to realize precise temperature control and generate a stable and reliable temperature field. A three-dimensional thermodynamic model was established and simulated using ANSYS Workbench 2019R3 software. The simulation results show that the temperature field at the measuring end and the temperature at the reference end of the sample meet the design expectations. Practical tests conducted with the developed box-type furnace indicate that the temperature fluctuation in the furnace's test coordinate system is 0.47 ℃ / 6 min, and the temperature field uniformity is better than 3 ℃ / 50 mm, which complies with the testing requirements for thin-film thermocouples. Tests on Au-Pt thin-film thermocouples were conducted using this box-type furnace, further verifying its application effectiveness. It provides important technical support for the static temperature characteristic detection of thin-film thermocouples.
Volume ,2025 Issue 6
-
Dual-Mixing Time-Delay detection of weak frequency signals enabled by local-oscillator optical enhancement
Zhang Yunrui, Gao Hao, Luo bin, Yu song
Abstract:
Frequency transfer is a key technology that supports long-distance frequency comparison, and its performance directly affects the establishment of a global unified timescale, the interconnection of optical atomic clock networks, and the further development of quantum metrology systems. To address the limitations in resolution and sensitivity at the receiver side caused by power attenuation during ultra-long-haul fiber frequency transfer and the additional noise introduced by active components, this paper proposes a weak frequency signal detection scheme enhanced by local oscillator light. The scheme employs a coherent laser to amplify the power of the weak carrier signal, utilizes a dual heterodyne delay detection structure to improve sensitivity, and integrates a balanced photodetector for high signal-to-noise ratio (SNR) extraction. Compared with conventional intensity modulation/direct detection (IM/DD) methods, the proposed approach improves the receiver sensitivity by approximately 10 dB, the RF power is increased by 25 dB under the same input optical power conditions. Experimental results demonstrate that the system achieves Allan deviations of 2×10-13 @1 s and 2.1×10-15 @10000 s, verifying that the local-oscillator-enhanced detection method achieves a receiver sensitivity of -49 dBm. Meanwhile, the constructed dual-mixing time-delay detection system achieves a stability of 3×10-17 @1 s and 3×10-19 @10,000 s under a beat frequency of 10 kHz, demonstrating its feasibility and significant advantages in high-precision optical frequency transfer.
- 1
-
Electro-Optic Frequency Combs: Theory and Applications
Chen Caixin; Li Sixuan, Yan Ming
Abstract:
Electro-optic frequency combs (EOFCs), produced by electro-optic modulation, are optical frequency combs with tunable spacing, high comb-tooth power, and strong coherence. They bridge microwave and optical domains and find applications in spectroscopy, precision ranging, and optical communications. Conventional EOFCs depend on bulky, power-intensive devices, which hinder practical use. Advances in thin-film lithium niobate (TFLN) and silicon nitride (SiN) have driven the rise of chip-scale integrated EOFCs as a major research focus. Recent progress using Mach–Zehnder modulators, phase modulators, and microring resonators has improved spectral flatness, modulation efficiency, and bandwidth coverage. This paper reviews EOFC generation mechanisms and representative designs, compares implementations on different material platforms, and highlights prospects in spectroscopy, ranging, and communications. Finally, current challenges and future research directions are outlined.
- 1
-
Research on Spherical Collimator Frequency Sweeping Laser Interferometry for Distance Measurement in Accelerator Alignment
ZHANG Luyan, 张福民, MEN Lingling
Abstract:
The frequency sweeping interferometer enables high-precision absolute distance measurement over large scales, demonstrating significant research and application value in the field of accelerator alignment, where stringent requirements for measurement accuracy, stability, and environmental adaptability are imposed. A frequency sweeping interferometer system incorporating an HCN (H13C14N) gas absorption cell and an optical switch was developed to achieve multi-channel laser ranging functionality. Since laser trackers are widely used for equipment calibration and installation during accelerator alignment, a spherical collimator compatible with the target mount of laser tracker retroreflectors was designed. To validate system performance, distance measurement accuracy tests were conducted in an experimental environment simulating accelerator alignment. The results indicate that the designed system meets accelerator alignment requirements, with a ranging error not exceeding 30 μm within a 30?m measurement range. This system provides a high-precision, highly adaptable measurement solution for accelerator alignment, offering substantial practical engineering significance.
- 1
-
Ammonia Measurement by Femtosecond Laser Filament-Triggered Discharge
ZHU Zhifeng, LI Xiaofeng, 武腾飞, FENG Zhanyu, GAO Qiang, LI Bo
Abstract:
For the precise ammonia (NH3) measurement, an ammonia measurement technique using femtosecond laser filament-triggered discharge is proposed. Discharge is triggered by long filaments formed in air by femtosecond laser pulses. The plasma emission spectra of NH3 under different conditions were obtained by using a spectral acquisition system. The calibration curve for NH3 concentration was obtained by utilizing the ratio of peak areas of characteristic spectral lines in the emission spectra. The one-dimensional spatial distribution of spectral line intensity was analyzed. Experimental results demonstrate that the ratio of characteristic spectral line peak areas exhibits excellent linear response to NH3 concentration. The one-dimensional spatial distribution of characteristic spectral line intensities exhibits good stability. Femtosecond laser filament-triggered discharge for NH3 concentration measurement enables real-time quantitative NH3 detection with one-dimensional measurement capability. This technique provides a novel approach for real-time in situ measurement of NH3.
- 1
-
Time delay estimation method of ultrasonic thickness measurement signal based on fuzzy variable step size LMS
Abstract:
Accurate acquisition of time of flight (TOF) is essential for high-precision ultrasonic thickness measurement. A time delay estimation method for ultrasonic thickness measurement signal based on fuzzy variable-step least mean square (LMS) was proposed, addressing the issues that the inherent contradiction between the convergence speed and the steady-state error of the fixed-step LMS algorithm in the traditional ultrasonic signal time delay estimation, and the poor adaptability of the existing variable-step algorithm under non-stationary echo signals due to the dependence on the fixed function model. The time-varying characteristics of ultrasonic echo signal were analyzed, and the single error feedback mechanism was abandoned. The local correlation coefficient error and its variation between the output signal and the desired signal were extracted as the dual input characteristics of the fuzzy controller. The zero-order Sugeno fuzzy inference system was designed, and the nonlinear mapping rule between the input feature and the step size factor was established to realize the adaptive dynamic adjustment of the step size factor. The simulated echo signals were used to carry out simulation tests under different signal-to-noise ratios. The results show that compared with the fixed step size LMS algorithm, the hyperbolic tangent function variable step size LMS algorithm and the fuzzy variable step size LMS algorithm based on instantaneous error, the comprehensive performance of the proposed method is better. The steady-state offset error is significantly reduced while ensuring rapid convergence, with higher measurement accuracy and anti-noise performance. The experimental platform of ultrasonic thickness measurement was built, and the thickness measurement experiments were performed on gauge blocks. The results show that the relative errors of the proposed method for different thickness gauge blocks are all smaller than that of the other three LMS algorithms, and the maximum relative error is 0.71 %. The fuzzy variable step size LMS time delay estimation method can provide feasible scheme selection and technical support for high-precision ultrasonic TOF calculation, which is conducive to promoting the development of ultrasonic nondestructive testing technology and has certain engineering application value.
- 1
-
Research on the Motion Characteristics and Clearance Control Technology of Reciprocating Piston Flowmeters
YU Xiaoli, ZHANG Yongsheng, LIU Yanjun, ZHANG Lei
Abstract:
To solve the technical difficulties in the collaborative design of wide range, high accuracy, and smooth operation of domestic reciprocating piston flowmeters, a four piston linkage kinematic model based on crank slider mechanism was established, and the piston motion law and dynamic characteristics were systematically analyzed; By utilizing gap optimization control technology, the influence mechanism of motion pair gap on piston resistance and leakage was studied, breaking through the key technical difficulties of gap matching and dynamic sealing under high-precision working conditions, and ultimately achieving the structural optimization design of a four piston linkage piston flowmeter. Experimental tests have shown that the flow measurement range of the developed prototype can reach (5-10000) mL/min, and the accuracy within a 200:1 range can reach ± 0.54%. It can effectively meet the technical requirements of industrial sites for wide range and high-precision flow measurement, and has good engineering applicability. It plays a technical support role in promoting independent innovation and domestic substitution in the field of high-end flow measurement instruments in China.
- 1
-
Optimization of Magnetic Field Uniformity for the C-Field Coil in Rubidium Atomic Optical Clock Based on COMSOL Multiphysics
LIU Shijia, HUANG Junchao, XUE Yicong, CHEN Chen, ZHANG Yafei
Abstract:
In atomic clocks, the uniformity of the static magnetic field generated by the C-field coil directly influences the measurement accuracy of atomic energy level transition frequencies and the stability of the clock. To address the issue of insufficient field uniformity in finite-length solenoids under spatial constraints, this paper conducts a parametric modeling and optimization study on a multi-segment C-field coil structure placed inside a magnetic shielding tube, based on the COMSOL Multiphysics simulation software. The results demonstrate that by adopting a multi-segment coil structure and optimizing winding parameters such as the number of segments and turns density, the magnetic field uniformity within the target region along the central axis can be significantly improved. Specifically, under optimal parameters, a five-segment coil reduces the magnetic field non-uniformity to 0.078% over a 40 mm range, while a seven-segment coil further optimizes the magnetic field non-uniformity to 0.033% over the same range. In this research, a compact multi-segment coil structure is optimally designed for the high-uniformity C-field of rubidium atomic optical clock in a limited space, and an efficient parameter determination method is provided.
- 1
-
Analysis of Condensate Growth Law Based on Mirror Image Characteristics
Abstract:
The chilled mirror precision dew point meter is a device for measuring the dew point temperature of gas, and it plays an important role in the humidity measurement system. However, the important parameter for measuring the dew point, the photoelectric signal, is insensitive to the change of the mirror temperature of the chilled mirror precision dew point meter, which makes it difficult to determine the optimal voltage change value at different dew point temperatures, resulting in low accuracy of the dew point temperature finally measured. In order to determine the optimal voltage change value at different dew point temperatures, solve the problem that the photoelectric signal is insensitive to the change of mirror temperature, and find the mirror state closest to the dew point moment, a mirror image feature analysis test based on the growth law of mirror condensation was designed. The test studies the relationship between the voltage change value of the photoelectric signal and different dew point temperatures, and analyzes the law under different dew point temperatures. At the same time, an electron microscope was used to analyze the mirror image at different voltage change values. The image features were extracted by calculating the number and density of condensates. The growth law of mirror condensate at the same dew point temperature and different voltage change values was summarized, and the selection range of the optimal voltage change value for different dew point temperatures was clarified. The problem that the photoelectric signal of the chilled mirror precision dew point meter is insensitive to the mirror temperature change is solved, and the accuracy of dew point measurement of the chilled mirror precision dew point meter is improved.
- 1
-
Research Progress and Prospects of Ultrasonic Velocimetry Reconstruction Algorithms for Complex Flow Fields
Abstract:
Ultrasonic velocity measurement technology has become a research focus due to its non-invasive and pressure-loss-free advantages in addressing the measurement challenges of complex distorted flow fields, such as those in aero-engine intakes and industrial pipelines. This review introduces mainstream ultrasonic velocimetry methods, detailing the fundamental principles and calculation formulas of the transit-time method and the Doppler method. It focuses particularly on the ill-posed inverse problem inherent in ultrasonic velocity field reconstruction, providing an in-depth analysis of the mechanisms, strengths, and inherent ill-posedness of classical inversion algorithms including the least squares method, Tikhonov regularization, and truncated singular value decomposition (TSVD). The article summarizes key physical-signal joint processing strategies for mitigating significant ultrasonic beam drift and low signal-to-noise ratio (SNR). Looking ahead, it highlights the integration of physics-informed algorithms, multi-physical field coupling, and system-on-chip implementation as pivotal pathways for advancing the technology toward enhanced precision, adaptability, and miniaturization. This work serves as a reference for future breakthroughs and the engineering application of ultrasonic velocimetry technology.
- 1
-
Research on Peak Detection and Correction Method for Periodic Fatigue Test Data of Aviation Structural Components
Abstract:
The fatigue test of aviation structural components is one of the key links to verify the fatigue strength and durability of the structure. How to accurately detect and correct the peak value of test data with periodic and large data characteristics is directly related to the effectiveness of aviation structural life prediction and damage assessment. This article uses fiber Bragg grating strain sensors to monitor the health of a certain type of aviation structural component. Based on the data obtained during fatigue testing, the problem of data errors caused by spectral distortion is first solved. Subsequently, a method for detecting and correcting peak values of periodic fatigue test data is proposed, which achieves rapid detection and correction of peak and valley values of test data. This method is superior to traditional methods in terms of efficiency, accuracy, and robustness, and is suitable for key scenarios such as aircraft structural health monitoring and fatigue life assessment.
- 1
-
Fatigue Testing and Life Prediction Modeling of Silicon-Based Piezoresistive Pressure Sensors
Abstract:
Silicon-based piezoresistive pressure sensors suffer from insufficient reliability and reduced service life due to issues such as output drift and sensitivity degradation in harsh environments. This study aims to systematically elucidate the physical mechanisms behind their stability degradation and to develop a high-precision life prediction model. Utilizing the physics of failure analysis theory, the research employed variable-amplitude cyclic loading and accelerated fatigue testing. Accelerated tests were conducted by applying alternating pressure with different amplitudes. A dataset of sensor failure degradation was established through microscopic examination and performance monitoring. This approach overcame the challenge of analyzing the coupled effects of multiple mechanisms, including diaphragm cracking, piezoresistor creep, and packaging stress failure, ultimately enabling the construction of a life prediction model under uniaxial pressure loading conditions. Accelerated life testing demonstrated that under a pressure load of 140% of the full-scale range, the sensor's linearity increased by over 50% after approximately 2.2 million cycles, which was defined as failure. The developed model achieved an error of less than 15% between the predicted and measured lifespan, enabling effective prediction of the sensor's failure cycle. The fatigue experiments conducted and the life prediction model developed in this study effectively meet the engineering requirements for reliability assessment and life extension of pressure sensors. This work holds significant theoretical and practical application value, providing crucial support for advancing the design optimization and lifetime prediction of highly reliable silicon-based pressure sensors.
- 1
-
Research Status and Prospects of LiDAR Point Cloud and Visible-Light Image Fusion Technology
Abstract:
Lidar point cloud and visible image fusion technology, by integrating three-dimensional point clouds with two-dimensional texture and color information, can provide a richer and more accurate data foundation for environmental perception. Compared to conventional LiDAR, single-photon LiDAR offers advantages such as photon-level sensitivity and picosecond-level timing precision, enabling high-precision three-dimensional point cloud imaging over long distances and in low-observability scenarios. The fusion technology of single-photon LiDAR with visible images provides a new pathway for addressing target recognition and localization challenges in complex environments. This paper introduces the fundamental principles of conventional/single-photon LiDAR systems and image fusion technology, analyzes the feature differences between conventional/single-photon LiDAR and visible images as well as the issue of image registration, elaborates on the research and application status of fusion technology between conventional/single-photon LiDAR and visible images, and finally summarizes and prospects the current state of conventional/single-photon LiDAR and visible image fusion technology.
- 1
-
Two-dimensional wind retrieval for wind lidar based on relative total variation model
Abstract:
Wind lidar can only directly measure the radial components of wind vectors. So two-dimensional（2D）wind retrieval is crucial for reconstructing wind structure. To address the issue of wind-speed distortion in the 2D wind retrieval using traditional Velocity Azimuth Processing（VAP）algorithm, the relative total variation（RTV）model is incorporated to improve the algorithm. Based on the correlation between wind-speed distortion and radial wind speed, a threshold is established to identify distorted regions ,enabling subsequent correction. Then the RTV model is employed to eliminate irregular textures generated during the correction process and extract the 2D overall wind structure . And local texture features are reconstructed by the texture information from the actual radial wind speed. Experimental results demonstrate that the improved algorithm effectively mitigates the wind-speed distortion issue in VAP algorithm. Compared to the preliminary results retrieved by VAP algorithm, the improved algorithm reduces root mean square error by 0.42 m/s for wind speed and 4.85 for wind direction, significantly improving the accuracy of wind retrieval.
- 1
-
Research on Automatic Positioning and Scanning Technology of Laser Tracker for Curved Surface Measurement
LI Yan, 孙安斌, FAN Shuaixin, 孟宇航
Abstract:
In response to the requirements for automatic positioning and scanning of component curved surfaces during aircraft assembly, relevant research was conducted using the Leica ATS600 laser tracker. Based on the SpatialAnalyzer (SA) software, secondary development was carried out using Measure Plan and SA SDK, and a research method for automatic positioning and scanning technology of laser trackers was proposed. The research process is as follows: first, connect the measurement equipment and import the curved surface digital model and theoretical positioning point information; then, measure the positioning features and curved surfaces; subsequently, perform digital model alignment and relationship matching between the actual measured information of the curved surface and the theoretical information, and automatically generate a report based on the matching results. Finally, a set of automatic positioning and scanning system for curved surface measurement was built, and a large-scale curved surface standard device was used as the experimental object for measurement. The results show that the program runs stably, effectively addresses the inherent shortcomings of SA, and significantly improves the efficiency and automation level of curved surface scanning.
- 1
-
Optimization Algorithm for the Deployment of Heterogeneous Nodes in Energy-Isoform Sensor Networks
Abstract:
The wireless sensor network is a crucial component of the Internet of Things (IoT), and ensuring its efficient operation has become one of the prominent research challenges today. By incorporating energy-replenishable heterogeneous nodes into the network, it is possible to effectively extend the network's lifespan. This paper establishes criteria for selecting the locations of heterogeneous nodes based on characteristics such as network coverage and data transmission distance. We propose an optimization deployment algorithm specifically designed for positioning heterogeneous nodes within heterogeneous wireless sensor networks, and we conduct a simulation analysis comparing our proposed algorithm with existing methods. The results indicate that our proposed algorithm demonstrates superior performance in terms of data transmission volume and energy consumption.
- 1
