Journals >Optics and Precision Engineering
Contents
2024
Volume: 32 Issue 14
13 Article(s)
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[in Chinese]
Shafting design and dynamic deformation error correction of two-dimensional laser tracking turntable
Hanlin HUO, Jinsong WANG, Guoming WANG, Genzi LI, and Weihu ZHOU
The stability of shafting structure and the compensation accuracy of dynamic deformation error are the key factors for laser tracker to achieve high-precision dynamic coordinate measurement. To fulfill the stringent requirements of high precision and stability in dynamic coordinate measurement， a two-dimensional turntaThe stability of shafting structure and the compensation accuracy of dynamic deformation error are the key factors for laser tracker to achieve high-precision dynamic coordinate measurement. To fulfill the stringent requirements of high precision and stability in dynamic coordinate measurement， a two-dimensional turntable based on an over-positioned double angular contact bearing shafting system has been developed. Initially， the design and precision analysis of the two-dimensional turntable shafting were conducted based on the performance specifications of the turntable. Subsequently， based on the designed structure， existing assembly techniques and the theory of elasticity， the mechanism of the dynamic deformation error of the turntable was analyzed， and the rationality of the theory was verified through rigid flexible coupling dynamics simulation. Finally， a method for measuring shafting dynamic errors based on the symmetric differential optical self-collimation principle was proposed to achieve the measurement and compensation of shafting stability and dynamic deformation errors. The two-dimensional laser tracking turntable， as a crucial component of laser trackers to achieve high-precision dynamic coordinate measurements. Experimental results demonstrate that the repeatability of the turntable's dynamic deformation error is superior to ±0.6″， and the dynamic deformation error has been reduced from ±7″ to ±1″ after compensation. The stability and dynamic deformation error compensation accuracy of the designed turntable meet the requirements..
Optics and Precision Engineering
- Publication Date: Jul. 25, 2024
- Vol. 32, Issue 14, 2200 (2024)
Effect of tool wear and variable friction coefficient on cutting force
Jicai KUAI, Yunqian DUAN, Xin LI, Shian LIU, and Dmitrii Valerievich ARDASHEV
Tool wear and friction coefficients have a big impact on the cutting force and surface quality. To study the effect of tool wear and friction coefficients on cutting force， an cutting force model was developed， taking into account tool wear and variable friction coefficients. First， the edge radius for worn tool was loTool wear and friction coefficients have a big impact on the cutting force and surface quality. To study the effect of tool wear and friction coefficients on cutting force， an cutting force model was developed， taking into account tool wear and variable friction coefficients. First， the edge radius for worn tool was looked at. It was shown that the edge radius gets bigger as the tool wears down. Next， the minimum cutting thickness for worn tool was explained. It was thought that the minimum cutting thickness gets bigger as tool wear and edge radius get bigger. Lastly， the cutting of Al alloy was researched by single crystal diamond tool， and compared the variations in cutting force with respect to cutting depth， feed speed， tool edge radius， tool wear width， and constant and variable friction coefficients. It was shown that the normal and tangential cutting forces increase with increasing depth of cut and feed rate. When the edge radius went from 150 nm to 450 nm， the tangential force went up by 1.13 times and the normal force went up by 2.12 times. When the tool wear width went from 0 to 0.55 μm， the tangential force went up by 1 time and the normal force went up by about 7 times， and the constant friction coefficient model has a maximum error in cutting force of 41%， whereas the variable friction coefficient model has a maximum error within 11%. Hence， the cutting model， which accounts for both tool wear and changing friction coefficients， aligns more closely with the real cutting process..
Optics and Precision Engineering
- Publication Date: Jul. 25, 2024
- Vol. 32, Issue 14, 2211 (2024)
Optimized precision temperature control method and experimental validation for non-uniform discontinuous X-ray telescope
Xiaofeng ZHANG, Jianchao FENG, Jia MA, Xing LIAO, Yonghe ZHANG, and Yong CHEN
In this paper， we aim to realize the precision temperature control of EP satellite X-ray telescope. By establishing the mathematical heat transfer model of Wolter-I swept-incidence X-ray telescope， heat transfer law in the focusing mirror group is revealed， and two types of active temperature control heaters are designIn this paper， we aim to realize the precision temperature control of EP satellite X-ray telescope. By establishing the mathematical heat transfer model of Wolter-I swept-incidence X-ray telescope， heat transfer law in the focusing mirror group is revealed， and two types of active temperature control heaters are designed. In view of the difficulty in regulating the thermal field caused by the non-uniform and discontinuous configuration of the telescope， an optimized precision temperature control method was proposed， taking into account the temperature control index and the difficulty of process development， and a cost function was constructed on how to partition and deploy the heat compensation. By setting the weighting parameters of average deviation， maximum deviation， number of zones and minimum zone length， the optimal design of the first type of heater was obtained. The whole-satellite vacuum test results show that： the temperature range of 54 lenses is 19.1~20.9 ℃， and the time domain temperature stability is good， the fluctuation is less than 0.2 ℃， which meets the index requirement of （20±1）℃ for X-ray telescope， and the weighting parameters are reasonably designed. The method proposed in this study successfully copes with the problem of precision temperature control for non-uniform and discontinuous X-ray telescopes， and provides technical support for space science detectors with high temperature requirements..
Optics and Precision Engineering
- Publication Date: Jul. 25, 2024
- Vol. 32, Issue 14, 2225 (2024)
Study on the influence of temperature on the stability of aerostatic bearing with flexible structure
Xiaolong ZHAO, Weichao ZHANG, Guangwei SUN, Zhangyi MIAO, and Hao DONG
In order to study the influence of temperature on the deflection deformation， flow pattern and stability of the flexible structure of aerostatic bearing with flexible structure under the working state of aerostatic bearing， a three-dimensional （3D） model of aerostatic thrust bearing with flexible structure was establisIn order to study the influence of temperature on the deflection deformation， flow pattern and stability of the flexible structure of aerostatic bearing with flexible structure under the working state of aerostatic bearing， a three-dimensional （3D） model of aerostatic thrust bearing with flexible structure was established in this paper. Firstly， the influence of temperature change on the deflection deformation of the flexible structure of aerostatic bearing， the flow pattern of gas film flow field and the stability of gas film were analyzed by using the calculation method of fluid solid thermal multi physical field coupling. Then， through the design of aerostatic bearing test-bed， the vibration of the bearing under the impact of load is tested， and the test results are compared with the simulation analysis results to verify the reliability of the simulation calculation. The calculation results show that the deflection deformation of the annular flexible thin plate at the orifice increases with the increase of temperature， and when the film gap h=12 μm， the deflection deformation of T=100 ℃ is 43% higher than that of T=-20 ℃； Under the same other conditions， with the increase of temperature， the range of cyclone in the air film gradually decreases； The higher the working temperature， the smaller the vibration amplitude of the bearing after being loaded. The experimental results show that with the increase of working temperature， the stability of the bearing is higher， which is basically consistent with the simulation results. This study provides a theoretical reference for the application of aerostatic bearing in the field of ultra precision..
Optics and Precision Engineering
- Publication Date: Jul. 25, 2024
- Vol. 32, Issue 14, 2236 (2024)
Ion beam polishing process parameters optimization and polishing experiment of ZnS
Gen CAI, Beibei ZHU, Lin QIN, Chupeng ZHANG, and Xiao CHEN
Multispectral zinc sulfide is widely used in infrared optical guidance seeker， photoelectric detection radar and airborne photoelectric pod because of its high optical transmittance in near， middle and far infrared spectral bands. In order to obtain multi-spectral ZnS optical element with ultra-high surface shape accurMultispectral zinc sulfide is widely used in infrared optical guidance seeker， photoelectric detection radar and airborne photoelectric pod because of its high optical transmittance in near， middle and far infrared spectral bands. In order to obtain multi-spectral ZnS optical element with ultra-high surface shape accuracy and improve ion beam polishing efficiency， the orthogonal experiment method was used to carry out ion beam single point etching experiments on ZnS， and the removal function characteristics and volume removal efficiency were obtained under each process parameter. Through direct analysis of orthogonal experimental data and range analysis， the process parameters were optimized with the target of maximum volume removal rate. The optimized process parameters were obtained as follows： ion beam voltage 1 100 V， radio frequency power 110 W， acceleration voltage 200 V， argon flow rate 7 sccm， and processing distance 30 mm. By adjusting the process parameters， different ion beam spot diameters were obtained for combined polishing of 80 mm diameter zinc sulfide. After processing， the surface shape accuracy of zinc sulfide decreased from 467 nm to 71.506 nm and from 112 nm to 10.75 nm. The above experimental results show that the combination of large and small diameter ion beams can effectively improve the processing efficiency and surface shape accuracy of multi-spectral ZnS optical elements..
Optics and Precision Engineering
- Publication Date: Jul. 25, 2024
- Vol. 32, Issue 14, 2247 (2024)
[in Chinese]
Development and prospect of hyperspectral polarization
Changxiang YAN, Yuan ZHANG, Jian BO, Xueping JU, Bo YU, and Xianfeng LI
Hyperspectral polarization is a new technology that combines hyperspectral and polarization imaging. It has become a research hotspot in many scientific fields. The research progress of hyperspectral polarization technology is reviewed， and its future development direction is prospected. In this paper， we first introduHyperspectral polarization is a new technology that combines hyperspectral and polarization imaging. It has become a research hotspot in many scientific fields. The research progress of hyperspectral polarization technology is reviewed， and its future development direction is prospected. In this paper， we first introduced the basic principle of hyperspectral polarization technology， and explained the advantages of combining hyperspectral and polarization imaging. Then， the classification of polarization spectrum instruments was introduced according to different design principles. Next， the application of this technology in remote sensing， medicine， environmental monitoring， earth science and material science was discussed in detail. Through the review of case studied in different fields， the unique advantages of hyperspectral polarization technology in providing richer and more accurate information were demonstrated. Finally， the current challenges of hyperspectral polarization technology were analyzed， including the precision of instruments， the complexity of data processing， and the problem of effective integration with other sensing devices. In view of these challenges， the future technology development direction was discussed. Future research should focus on improving the hyperspectral and temporal resolution of the technology， improving the accuracy of data processing and analysis， and expanding the applicability of different application scenarios to better meet the needs of different fields. In summary， hyperspectral polarization technology， as a comprehensive and efficient means of information acquisition， had made remarkable research progress in many fields. By optimizing hyperspectral polarization technology to meet a wider range of applications， hyperspectral polarization technology was expected to become an important tool in future scientific research and practical applications..
Optics and Precision Engineering
- Publication Date: Jul. 25, 2024
- Vol. 32, Issue 14, 2141 (2024)
Research on measurement technology of rocket recovery height based on monocular vision
Rong LU, Gaopeng ZHANG, Jianzhong CAO, Weining CHEN, Huinan GUO, Haifeng ZHANG, Zhe ZHANG, Chao MEI, and Lei GUAN
Accurate measurement of rocket height is one of the important preconditions to complete the rocket recovery task. In o-rder to realize the real-time measurement of rocket height， the rocket recovery height measurement technology was studied based on monocular vision. Firstly， in view of the smoke scene in the process oAccurate measurement of rocket height is one of the important preconditions to complete the rocket recovery task. In o-rder to realize the real-time measurement of rocket height， the rocket recovery height measurement technology was studied based on monocular vision. Firstly， in view of the smoke scene in the process of rocket recovery， the transmission function was improved bas-ed on the He Kai light-dark channel de-fogging algorithm in combination with Retinex theory， so as to improve the adaptability o-f the de-fogging algorithm to different fog environments. Secondly， according to the characteristics of target in rocket recovery， an algorithm suitable for target feature extraction was proposed， and the feasibility and reliability of the algorithm were verified by e-xperiments. According to geometric characteristics of the rocket and the ground target， the mathematical model is built， and feasib-ility of the altitude algorithm is analyzed quantitatively by designing experiments. Finally， the influence of different defogging alg-orithms on the height measurement results under different fog concentrations is quantitatively analyzed. The simulation and exper-imental results show that the accuracy of rocket height calculated by the proposed method is within 0.5 m， which can meet the de-mand of height measurement in rocket recovery..
Optics and Precision Engineering
- Publication Date: Jul. 25, 2024
- Vol. 32, Issue 14, 2166 (2024)
Design of automatic image measuring system Research on dynamic and high-sensitive detection of SF6 discharge decomposition products by fluorescence-suppressed fiber-enhanced Raman spectroscopy
Tongqin RAN, Fu WAN, Quan ZHOU, Weiping KONG, Qiang LIU, Yingkai LONG, and Weigen CHEN
Analyzing the dynamic change of composition and concentration of SF6 discharge decomposition products is the key to SF6 Gas-Insulated Switchgear （GIS） state diagnosis. This paper proposed a dynamic and high-sensitive detection method based on fluorescence-suppressed Fiber-Enhanced Raman Spectroscopy （FERS）. Firstly， a Analyzing the dynamic change of composition and concentration of SF6 discharge decomposition products is the key to SF6 Gas-Insulated Switchgear （GIS） state diagnosis. This paper proposed a dynamic and high-sensitive detection method based on fluorescence-suppressed Fiber-Enhanced Raman Spectroscopy （FERS）. Firstly， a fluorescence-suppressed FERS gas detection system of SF6 discharge decomposition products is established. With a Synergistic Fluorescence Filtering method combining CCD digital noise filtering and iris noise reduction， the signal-to-noise ratio of the system is increased by 228.4%. Based on Allan variance analysis， the optimal integration time of the system is determined to be 220 s. Next， by analyzing standard mixed gas samples under 2 bar pressure and 220 s integration time， the characteristic Raman peaks for qualitative and quantitative analysis of SF6 discharge decomposition products SOF2， SO2F2， COS， CF4， SO2， CO2 and CO are determined， and the lower limits of detection are calculated to be 1.95， 1.78， 0.83， 2.41， 0.93， 2.51， 6.69 ppm， respectively. Finally， by a 168-hour continuous partial discharge experiment in a reduced scale GIS model， the fluorescence-suppressed FERS gas detection system is proved capable of dynamic and high-sensitive detection of SF6 discharge decomposition products， and the deviation from gas chromatography result is within ±5%. Experimental results demonstrate that the proposed detection method can provide technical support for the safe operation of GIS..
Optics and Precision Engineering
- Publication Date: Jul. 25, 2024
- Vol. 32, Issue 14, 2189 (2024)
[in Chinese]
Visual inspection of soldering defects on board surfaces against complex backgrounds
Liying ZHU, Sen WANG, Aiping SHEN, and Xuangang LI
To resolve the current stage of printed circuit board （PCB） defect detection， it is necessary to consider both the detail and global information of the defects simultaneously. The downsampling operation of cross-pixel convolution or pooling results in the loss of both global and detailed information on the surface defeTo resolve the current stage of printed circuit board （PCB） defect detection， it is necessary to consider both the detail and global information of the defects simultaneously. The downsampling operation of cross-pixel convolution or pooling results in the loss of both global and detailed information on the surface defects of printed circuit boards （PCBs）. Although some of the methods above employ attention mechanisms for intra-layer information， the issue of insufficient attention to the weight bias problem resulting from conventional convolution after feature extraction persists. The PCB defect detection Network （PCBNet） proposed in this paper employed the inflated Dilation and extrusion convolution （DeConv） to extract both global and detailed information about PCB surface defects. Downsampling was performed using Spatial Passage Directed Focused Convolution （SPD-Conv） to minimize the loss of information. The Subtle Feature Enhancement Module （SFEM） had been designed to adjust the intra-layer relationship of PCB surface defect features and reduce the weight bias while enhancing the algorithm's ability to perceive the subtle features. The experimental results obtained by comparing the PCB surface soldering defects dataset and the PCB Defect-Augmented dataset， which were collected in the field using multiple state-of-the-art methods， demonstrate that PCBNet is not only capable of accurately identifying PCB surface soldering defects at a rate of 83 frames per second on the PCB surface soldering defects dataset but also achieves the following results on the PCB Defect-Augmented dataset： the highest accuracy of mAP0.5， which is the evaluation metric of the COCO dataset. This indicates that our method has the potential to be implemented on embedded devices..
Optics and Precision Engineering
- Publication Date: Jul. 25, 2024
- Vol. 32, Issue 14, 2256 (2024)
UAV target positioning integrating multi-dimensional attitude adaptive sensing
Zhicheng LING, Zhongkui LEI, Daqing HUANG, Cheng XU, and Yanan HU
Aiming to address the challenge of identifying and eliminating systematic errors in various attitudes during target positioning of UAV optoelectronic reconnaissance platforms， a study was conducted on a target positioning system that integrates multi-dimensional attitude adaptive sensing algorithms. This paper presenteAiming to address the challenge of identifying and eliminating systematic errors in various attitudes during target positioning of UAV optoelectronic reconnaissance platforms， a study was conducted on a target positioning system that integrates multi-dimensional attitude adaptive sensing algorithms. This paper presented a comprehensive target position calculation model that was based on the principles of target positioning. It utilized the optoelectronic reconnaissance platform's locking and tracking capabilities to perform multiple measurements of the cooperative target point. Furthermore， it analyzed the differentiated representations of the multi-dimensional attitude systematic error offset from the positioning results. Based on the principles of deep neural networks， the proposed model aimed to perform adaptive estimation and reverse compensation of systematic errors in a multi-task temporal feature extraction framework. Results of experiments indicate that when UAV operates at an altitude of 4 000 m， the system is able to mitigate 77% of systematic errors. It successfully reduces the target positioning error from 103 m to 19 m， resulting in an 81% increase in overall positioning accuracy. Consequently， this system enables high-precision positioning of UAV targets..
Optics and Precision Engineering
- Publication Date: Jul. 25, 2024
- Vol. 32, Issue 14, 2272 (2024)
Solar cell defect detection network combining multiscale feature and attention
Ying ZHOU, Shibo XU, Haiyong CHEN, and Kun LIU
In order to improve the detection accuracy of various types of defects in the electroluminescence imaging of solar cells， a solar cell surface defect detection algorithm CMFAnet was proposed by fusing multiscale features and attention mechanism. Firstly， for the characteristics of solar cell surface defects with large In order to improve the detection accuracy of various types of defects in the electroluminescence imaging of solar cells， a solar cell surface defect detection algorithm CMFAnet was proposed by fusing multiscale features and attention mechanism. Firstly， for the characteristics of solar cell surface defects with large scale span， an enhanced multi-scale feature fusion method was designed， whose basic unit consists of a feature alignment module and a feature fusion module connected in series， and for the feature information with different semantic levels， the feature alignment module adjusts their scales， so that these features can be fused together more easily； secondly， for the characteristics of solar cell surface defects with high level and variable geometry， a deformable ghost convolution module is designed. Secondly， for the characteristics of high degree of similarity between defective features and background features on the solar cell surface and variable geometry， a deformable ghost convolution module was designed， whose basic unit consists of feasible variant convolution， multiplexed coordinate attention mechanism， and ghost convolution； the multiplexed coordinate attention mechanism optimizes the generation of offset in the feasible variant convolution， and the introduction of ghost convolution mechanism effectively reduces the FLOPs of the network model. The experimental results show that the mAP of this paper's method reaches 91.4% on the photovoltaic cell defect anomaly detection dataset PVEL-AD， which is improved to different degrees compared to other mainstream target detection networks..
Optics and Precision Engineering
- Publication Date: Jul. 25, 2024
- Vol. 32, Issue 14, 2286 (2024)
Multilevel noise suppression network of wrapped phase in interferometry
Yun LIU, Xiaoqiang WU, Qi KANG, Jinfeng XUE, Menglu CHEN, Bixuan ZHANG, Mingxing JIAO, and Junhong XING
The wrapped phase is a precondition for obtaining phase information in laser interferometry. In order to reduce the interference of noise in the wrapped phase fringe during measurement and improve the quality of reconstructed image， an asymmetric fusion non-local and verge extraction neural network （AFNVENet） was propoThe wrapped phase is a precondition for obtaining phase information in laser interferometry. In order to reduce the interference of noise in the wrapped phase fringe during measurement and improve the quality of reconstructed image， an asymmetric fusion non-local and verge extraction neural network （AFNVENet） was proposed. The network was designed to add an asymmetric fusion non-local block and a verge extraction module based on FFDNet. By incorporating the noise features with different levels and reverse-guiding the denoising process， it could effectively suppress the noise with different levels while retaining more image details. The wrapped phase dataset with multiplicative speckle and additive random noise was selected to train. The results of ablation and comparative experiments show that AFNVENet algorithm has better noise filtering effect for different level noises. When the noise standard deviation changes in the range of ［0， 2.0］， the means of PSNR， SSIM and SSI are 24.88 dB， 0.97 and 0.95 after noise suppression， respectively. In addition， the unwrapped phase results further show that the RMSE mean of unwrapped phase denoised by AFNVENet is reduced by 87%， 73%， 79% and 36%， respectively， compared to SCAF， NLM， KSVD and DnCNN. The feasibility of method is verified. The AFNVENet method has better robustness in suppressing noises. It is suitable for recovering the wrapped phase information with multilevel noises in different interferometric environments..
Optics and Precision Engineering
- Publication Date: Jul. 25, 2024
- Vol. 32, Issue 14, 2299 (2024)
Iterative reconstruction of compressive sensing combining image hierarchical-feature
Yuhong LIU, and Heng YANG
The compressive sensing image reconstruction algorithms based on Convolutional Neural Networks could not capture long-range dependency of high-resolution images. Although Transformer can address this issue， it significantly increases the number of network parameters and the image reconstruction time. This paper proposeThe compressive sensing image reconstruction algorithms based on Convolutional Neural Networks could not capture long-range dependency of high-resolution images. Although Transformer can address this issue， it significantly increases the number of network parameters and the image reconstruction time. This paper proposed CHFNet， a combining image hierarchical-feature network for compressive sensing iterative-reconstruction to improve image reconstruction quality and reduce reconstruction time. CHFNet consisted of two sub-networks， sampling and reconstruction. The sampling sub-network utilized a learnable sampling matrix to provide more effective measurements for reconstruction phase. In the reconstruction sub-network， we introduced an iterative strategy using gradient descent and feature optimization operations， and proposed a lightweight CNN-Transformer hybrid architecture to model and optimize extremely fine-grained image hierarchical-feature， enhancing network’s sensing-capability and reducing computation complexity. Moreover， CHFNet achieved complete end-to-end training by jointly optimizing sampling-reconstruction process. The experimental results show that the proposed algorithm obtains satisfactory recovery performance on several public benchmark datasets. On the Urban100 dataset， the method of this paper improves the average PSNR and SSIM metrics by 0.63 dB and 0.007 6 respectively compared to the existing optimal algorithm CSformer. At 0.10 sampling rate， the average reconstruction time of CHFNet decreases 2.744 7 s， 3.551 0 s， and 4.775 0 s compared to CSformer on Set11， BSD68， and Urban100 datasets respectively..
Optics and Precision Engineering
- Publication Date: Jul. 25, 2024
- Vol. 32, Issue 14, 2311 (2024)
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