2024
2024
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Record 241 of
Title:Random laser emission at 1064 and 1550 nm in a Er/Yb co-doped fiber-based dual-wavelength random fiber laser
Author Full Names:Li, Zhe(1,2); She, Shengfei(1,2); Li, Gang(1,2); Gao, Qi(1,2); Ju, Pei(1,2); Gao, Wei(1,2); Sun, Chuandong(1); Wang, Yishan(1)Source Title:Optics ExpressLanguage:EnglishDocument Type:Journal article (JA)Abstract:Dual-wavelength fiber lasers operating with a wide spectral separation are of considerable importance for many applications. In this study, we propose and experimentally explore an all-fiberized dual-wavelength random fiber laser with bi-directional laser output operating at 1064 and 1550 nm, respectively. A specially designed Er/Yb co-doped fiber, by optimizing the concentrations of the co-doped Er, Yb, Al and P, was developed for simultaneously providing Er ions gain and Yb ions gain for RFL. Two spans of single mode passive fibers are employed to providing random feedback for 1064 and 1550 nm random lasing, respectively. The RFL generates 5.35 W at 1064 nm and 6.61 W at 1550 nm random lasers. Two power amplifiers (PA) enhance the seed laser to 50 W at 1064 nm with a 3 dB bandwidth of 0.31 nm and 20 W at 1550 nm with a 3 dB bandwidth of 1.18 nm. Both the short- and long-term time domain stabilities are crucial for practical applications. The output lasers of 1064 and 1550 nm PAs are in the single transverse mode operating with a nearly Gaussian profile. To the best of our knowledge, this is the first demonstration of a dual-wavelength RFL, with a spectral separation as far as about 500 nm in an all-fiber configuration. ? 2024 Optica Publishing Group.Affiliations:(1) State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, China; (2) University of Chinese Academy of Sciences, Beijing; 100049, ChinaPublication Year:2024Volume:32Issue:4Start Page:5737-5747DOI Link:10.1364/OE.508025數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20240815569595 -
Record 242 of
Title:Adaptive Coding Fringe Projection Profilometry on Color Reflective Surfaces
Author Full Names:Wang, Ying(1); Ni, Yubo(1); Meng, Zhaozong(1); Gao, Nan(1); Guo, Tong(2); Yang, Zeqing(1); Zhang, Guofeng(3); Yin, Wei(4); Zhao, Hongwei(3,4); Zhang, Zonghua(1)Source Title:Guangxue Xuebao/Acta Optica SinicaLanguage:ChineseDocument Type:Journal article (JA)Abstract:Objective Fringe projection profilometry is widely employed to reconstruct the three-dimensional (3D) shape of an object surface. However, when this method is utilized to measure objects with color reflective surfaces, the image captured by the camera is oversaturated with pixels due to ambient lighting and reflections from the projected fringes, which results in the inability to measure the surface of the reflective area. This problem is mainly due to the unevenly varying reflective of surfaces, which is affected by both the roughness and the surface color. To solve the problem of eliminating the interference of the object surface color and complete the 3D shape measurement method based on the reflectivity change of colored highly reflective surfaces, we propose an adaptive generation of complementary color sinusoidal fringes method. By different absorption of colors by the object surface color to be measured, a complementary color of lighting is projected onto the highly reflective area to reduce the surface reflectivity of the region and suppress the exposure phenomenon. Methods We put forward a method to measure the 3D shape of colored objects with high reflectivity, which is based on adaptively encoded complementary color fringes. Firstly, the highly reflective region of the object to be measured should be located. The image of the object surface is captured by the camera when the projector projects the strongest white light, and the coordinates of the oversaturated pixel points are extracted by an inverse projection technique. The location of the highly reflective region in the coordinate system of the projected image is obtained via the matching relationship between the projector and the camera. Then, the optimal color adopted for projecting the highly reflective region of the object is calculated by the color image of the object surface and then captured by the camera. The projecting color obtained in the previous step is employed to generate an image that is projected to the highly reflective region on the measured surface. The saturation value of the adopted projecting color is adjusted according to the magnitude of the adjacent light intensity values at either end of the boundary encoded color until the adjacent light intensity values are less than 20. Finally, after sinusoidal fringes on the V component of the HSV color space are encoded, and meanwhile adaptive complementary color sinusoidal fringe patterns are generated and projected onto the object surface to be measured. The complete 3D shape of the object surface to be measured is recovered by solving the unwrapped phase. Results and Discussions The proposed method employs adaptively encoded complementary color fringes. It reduces the reflectivity of the highly reflective region on the surface, solves the unwrapped phase loss after utilizing traditional fringe projection profilometry, and finally obtains the complete 3D shape of the yellow ceramic cup (Fig. 5). Additionally, the phase resolution results of the yellow ceramic cup are compared and analyzed by traditional gray fringes and the proposed complementary color-coded fringes under different exposure time. The results show that when the exposure time is greater than 40 ms, the phase recovery completeness of the region D is maintained at 100% (Fig. 6) by applying the proposed method. The purpose of measuring the complete 3D shape of the surface of a color highly reflective object by projecting only a set of adaptively encoded complementary color sinusoidal fringe patterns is achieved. Meanwhile, the mean error of the proposed method is 0.5281 mm, smaller than that of the traditional multiple exposure method. In conclusion, this method is not only more efficient than the traditional multiple exposure method in the measurement process but also improves the measurement accuracy. Conclusions To address the challenges in measuring the 3D shape of colored highly reflective objects, we propose a novel fringe projection profilometry method based on adaptive color encoding. The proposed method encodes and projects fringe structured light complementary to the measured surface color into the highly reflective region in the HSV color space based on the theory of photometric complementarity. As a result, it reduces the surface reflectivity of the highly reflective region and achieves 3D shape measurement of colored highly reflective objects. The experimental results show that this method reduces the number of projected images during the measurement compared with the traditional multiple exposure methods. Only a set of adaptively encoded complementary color sinusoidal fringe maps should be projected to obtain a complete 3D shape of the surface of a colored highly reflective object. The proposed method shows certain advantages in measurement efficiency and accuracy. ? 2024 Chinese Optical Society. All rights reserved.Affiliations:(1) School of Mechanical Engineering, Hebei University of Technology, Tianjin; 300401, China; (2) School of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin; 300072, China; (3) School of Mechanical Engineering, Xi'an Jiaotong University, Shaanxi, Xi'an; 710049, China; (4) National Key Laboratory of Strength and Structural Integrity, Aircraft Strength Research Institute of China, Shaanxi, Xi'an; 710065, ChinaPublication Year:2024Volume:44Issue:7Article Number:0712001DOI Link:10.3788/AOS231894數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20241815997939 -
Record 243 of
Title:Tracking control of a flexible-link manipulator based on an improved barrier function adaptive sliding mode
Author Full Names:Jing, Feng(1,2,3); Ma, Caiwen(1,2,3); Wang, Fan(1); Xie, Meilin(1,3); Feng, Xubin(1,3); Fan, Xiao(1,3); Wang, Xuan(1,3); Liu, Peng(1,3)Source Title:Asian Journal of ControlLanguage:EnglishDocument Type:Journal article (JA)Abstract:In this paper, a novel controller designed for robust tracking control of a flexible-link manipulator operating in the presence of parameter uncertainties and external disturbances within the joint space is introduced. The proposed controller employs an adaptive sliding mode control approach, incorporating an improved barrier function, to ensure that trajectory errors remain within predefined performance bounds. This design enhances the tracking performance without overestimating control-switching gains. Additionally, a fixed-time adaptive sliding mode control, featuring a rapid nonsingular terminal sliding mode variable, is introduced to expedite the convergence rate of the system state during the initial stages. The efficacy of the proposed control scheme is established through the Lyapunov method, demonstrating finite-time convergence of the trajectory error to a specified neighborhood of zero. Experimental validation on a flexible-link system supports the effectiveness and advantages of the proposed control strategy, as evidenced via comparisons with two existing adaptive control schemes. ?2024 Chinese Automatic Control Society and John Wiley & Sons Australia, Ltd.Affiliations:(1) Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an, China; (2) University of Chinese Academy of Sciences, Beijing, China; (3) Key Laboratory of Space Precision Measurement Technology, Chinese Academy of Sciences, Xi'an, ChinaPublication Year:2024Volume:26Issue:6Start Page:2916-2932DOI Link:10.1002/asjc.3383數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20241715988203 -
Record 244 of
Title:Optical design of a visible/short-wave infrared common-aperture optical system with a long focal length and a wide field-of-view
Author Full Names:Yan, Aqi(1,2); Chen, Weining(1,2); Li, Qianxi(1,3); Guo, Min(1); Wang, Hao(1,2)Source Title:Applied OpticsLanguage:EnglishDocument Type:Journal article (JA)Abstract:Addressing the urgent need for long-distance dim target detection with a wide field-of-view and high sensitivity, this paper proposes a visible and short-infrared dual-band common-aperture optical system characterized by a broad field and extended focal length. To achieve system miniaturization and high-sensitivity target detection, the visible and infrared optical systems share a Ritchey-Chretien primary and secondary mirror. The primary optical path is segmented into visible light (0.45–0.75 μm) and short-wave infrared (SWIR) (2–3 μm) bands by a dichroic spectral splitter prism. The SWIR optical system utilizes four short-wave cooled infrared detectors, and wide-field stitching is achieved using a field-of-view divider. While ensuring the high cold-shield efficiency of cooled infrared detectors, this common-aperture optical system delivers visible and SWIR dual-band images with expansive fields, elongated focal lengths, and sizable apertures. The visible-light optical system has a focal length of 277 mm, a field-of-view of 2.3? × 2.3?, and an entrance pupil diameter of 130 mm. Meanwhile, the SWIR optical system features a focal length of 480 mm, a field-of-view of 2.26? × 1.8? and an entrance pupil diameter of 160 mm. The design outcomes suggest that the imaging quality of the optical system approaches the diffraction limit. This visible/SWIR common-aperture optical system exhibits high sensitivity, a large field-of-view, compact structure, and excellent imaging quality, thereby meeting the requirements for long-distance dim target detection and imaging. ? 2024 Optica Publishing Group.Affiliations:(1) Xi’an Institute Optics and Precision Mechanics, Chinese Academy of Sciences, Shaanxi, Xi’an; 710119, China; (2) Xi’an Key Laboratory of Aircraft Optical Imaging and Measurement Technology, Shaanxi, Xi’an; 710119, China; (3) University of Chinese Academy of Sciences, Beijing; 100049, ChinaPublication Year:2024Volume:63Issue:9Start Page:2382-2391DOI Link:10.1364/AO.517643數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20241315795896 -
Record 245 of
Title:Prediction of optical chaos using a multi-stage extreme learning machine with data uncertainty
Author Full Names:Gao, Dawei(1); Ma, Chen(1,2); Fan, Yuanlong(1,2); Wang, Yangyundou(1,2); Shao, Xiaopeng(3)Source Title:Optics ExpressLanguage:EnglishDocument Type:Journal article (JA)Abstract:In this paper, we study the problem of predicting optical chaos for semiconductor lasers, where data uncertainty can severely degrade the performance of chaos prediction. We hereby propose a multi-stage extreme learning machine (MSELM) based approach for the continuous prediction of optical chaos, which handles data uncertainty effectively. Rather than relying on pilot signals for conventional reservoir learning, the proposed approach enables the use of predicted optical intensity as virtual training samples for the MSELM model learning, which leads to enhanced prediction performance and low overhead. To address the data uncertainty in virtual training, total least square (TLS) is employed for the update of the proposed MSELM’s parameters with simple updating rule and low complexity. Simulation results demonstrate that the proposed MSELM can execute the continuous optical chaos predictions effectively. The chaotic time series can be continuously predicted for a time period in excess of 4 ns with a normalized mean squared error (NMSE) lower than 0.012. It also demands much fewer training samples than state-of-the-art learning-based methods. In addition, the simulation results show that with the help of TLS, the length of prediction is improved significantly as the uncertainty is handled properly. Finally, we verify the prediction ability of the multi-stage ELM under various laser parameters, and make the median boxplot of the predicted results, which shows that the proposed MSELM continues to produce accurate and continuous predictions on time-varying optical chaos. ? 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.Affiliations:(1) Hangzhou Institute of Technology, Xidian University, Hangzhou; 311231, China; (2) School of Optoelectronic Engineering, Xidian University, Xi’an; 710071, China; (3) Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, ChinaPublication Year:2024Volume:32Issue:23Start Page:40820-40829DOI Link:10.1364/OE.534975數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20244617373847 -
Record 246 of
Title:Simultaneous Transmission of Multi-Format Signals in the Mid-Infrared Over Free Space
Author Full Names:Su, Yulong(1); Xue, Jiayi(1); Wang, Wei(2); Tian, Wenlong(1); Zheng, Yunqiang(1,2); Zhu, Jiangfeng(1)Source Title:SSRNLanguage:EnglishDocument Type:Preprint (PP)Abstract:Mid-infrared (MIR) light within the 3~5 μm spectrum offers distinct advantages over the 1.5 μm band, particularly in adverse atmospheric conditions, rendering it a favorable option for free-space optical (FSO) communication. The transmission capacity within the 3~5 μm band is relatively low due to the immature state of its devices. In this study, we demonstrate multi-format signals FSO transmission with a total of 40 Gbps in the 3 μm band, utilizing our developed MIR transmitter and receiver modules. These modules facilitate wavelength conversion between the 1.5 μm and 3 μm bands through the utilization of difference-frequency generation (DFG) effect. The MIR transmitter effectively produces three MIR signals: On-Off Keying (OOK), Binary Phase Shift Keying (BPSK), and Quadrature Phase Shift Keying (QPSK) optical signals. The generated MIR power is 7.8 dBm, covering a wavelength range from 3.5864 to 3.5885 μm. The MIR receiver regenerates the three format signals with a power of -29.6 dBm. Relevant results of regenerated signal demodulation have been collected in detail, including bit error ratio (BER), constellation diagram, and eye diagram. The required powers for the 10 Gbps OOK, BPSK, and QPSK are ?37.82, ?40.24, and -39.4 dBm at BER of 1 × 10?6. It is expected to further push the data capacity to the terabit-per-second level by adding more 1.5 μm band laser sources and using wider-bandwidth chirped nonlinear crystals. ? 2024, The Authors. All rights reserved.Affiliations:(1) School of Optoelectronic Engineering, Xidian University, Xi’an; 710071, China; (2) State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics (XIOPM), Chinese Academy of Sciences (CAS), Xi’an; 710119, ChinaPublication Year:2024DOI Link:10.2139/ssrn.4893992數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20240293827 -
Record 247 of
Title:Research on Plasma Electrodeless High-Precision Spectral Calibration Light Source with Wide Spectrum Range
Author Full Names:Pang, Ziliang(1); Zhen, Jingkun(2); Zhang, Yifan(3); Duan, Jingyao(1); Bai, Yong Lin(2); Song, Yuchao(4)Source Title:2024 25th International Conference on Electronic Packaging Technology, ICEPT 2024Language:EnglishDocument Type:Conference article (CA)Conference Title:25th International Conference on Electronic Packaging Technology, ICEPT 2024Conference Date:August 7, 2024 - August 9, 2024Conference Location:Tianjin, ChinaAbstract:Spectral calibration sources are essential for the calibration and characterization of spectroscopic detection equip-ment. This paper presents the design of an inductively coupled light source as a spectral calibration source. We employed a longitudinal magnetic field inductive discharge design, conducted a simulation analysis of the magnetic field distribution within this design, and solved the drift-diffusion equations to obtain the electron temperature and energy distribution of the generated plasma. The designed RF circuit has a stable resonant frequency at 13 MHz, and the operating power can be adjusted between o and 20 W. This device demonstrates excellent performance and stability, offering a longer lifespan compared to traditional calibration sources. ? 2024 IEEE.Affiliations:(1) Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, The University of Chinese Academy of Sciences, Beijing, China; (2) Key Laboratory of Ultra-fast Photoelectric Diagnostics Technology of Chinese Academy of Sciences, The Laboratory of Space Science Weak-signal Detection Technology, Xi'an, China; (3) Northwest University, Xi'an, China; (4) School of Electronic Engineering, Xi'an University of Post & Telecommunications, Xi'an, ChinaPublication Year:2024DOI Link:10.1109/ICEPT63120.2024.10668744數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20244217191917 -
Record 248 of
Title:EC-RFERNet: an edge computing-oriented real-time facial expression recognition network
Author Full Names:Sun, Qiang(1,2); Chen, Yuan(1); Yang, Dongxu(1); Wen, Jing(1); Yang, Jiaojiao(1); Li, Yonglu(3)Source Title:Signal, Image and Video ProcessingLanguage:EnglishDocument Type:Journal article (JA)Abstract:Edge computing has shown significant successes in addressing the security and privacy issues related to facial expression recognition (FER) tasks. Although several lightweight networks have been proposed for edge computing, the computing demands and memory access cost (MAC) imposed by these networks hinder their deployment on edge devices. Thus, we propose an edge computing-oriented real-time facial expression recognition network, called EC-RFERNet. Specifically, to improve the inference speed, we devise a mini-and-fast (MF) block based on the partial convolution operation. The MF block effectively reduces the MAC and parameters by processing only a part of the input feature maps and eliminating unnecessary channel expansion operations. To improve the accuracy, the squeeze-and-excitation (SE) operation is introduced into certain MF blocks, and the MF blocks at different levels are selectively connected by the harmonic dense connection. SE operation is used to complete the adaptive channel weighting, and the harmonic dense connection is used to exchange information between different MF blocks to enhance the feature learning ability. The MF block and the harmonic dense connection together constitute the harmonic-MF module, which is the core component of EC-RFERNet. This module achieves a balance between accuracy and inference speed. Five public datasets are used to test the validity of EC-RFERNet and to demonstrate its competitive performance, with only 2.25?MB and 0.55?million parameters. Furthermore, one human–robot interaction system is constructed with a humanoid robot equipped with the Raspberry Pi. The experimental results demonstrate that EC-RFERNet can provide an effective solution for practical FER applications. ? The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature 2023.Affiliations:(1) Department of Communication Engineering, School of Automation and Information Engineering, Xi’an University of Technology, Xi’an; 710048, China; (2) Xi’an Key Laboratory of Wireless Optical Communication and Network Research, Xi’an; 710048, China; (3) Xi’an Founder Robot Co., LTD, Xi’an; 710068, ChinaPublication Year:2024Volume:18Issue:3Start Page:2019-2035DOI Link:10.1007/s11760-023-02832-4數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20235115261198 -
Record 249 of
Title:An Intersection Measurement Method With Two Optoelectronic Pods for Drop Point Measurement in Far Seas
Author Full Names:Xuezheng, Lian(1,2,3); Meilin, Xie(1,2,3); Wei, Huang(1,2,3); Kai, Liu(1,2,3); Heng, Shi(1,2,3)Source Title:Proceedings of SPIE - The International Society for Optical EngineeringLanguage:EnglishDocument Type:Conference article (CA)Conference Title:6th Conference on Frontiers in Optical Imaging and Technology: Applications of Imaging TechnologiesConference Date:October 22, 2023 - October 24, 2023Conference Location:Nanjing, ChinaConference Sponsor:The Chinese Society for Optical EngineeringAbstract:Drop point measurement precision is one of the core indexes to evaluate the combat effectiveness of weapons. With the development of experimental equipment, the experimental training venue has been expanded to the far sea. Due to the little known data in the far sea area and the measuring area, the measurement methods are limited. In response to the characteristics of the high seas, this paper proposes a method of mounts an optoelectronic pod on a drone and utilizes two drones for collaborative intersection measurement, achieving high-precision landing point measurement and high reliable data acquisition rate. This paper provides a detailed comparison between the traditional H-E-A single station angle measurement and distance measurement methods, the collinear equation based non ranging information positioning method, and the dual aircraft intersection positioning measurement principle combined with RLS filtering algorithm. At the same time, this paper analyzed various factors that affect the accuracy of positioning measurement. Through actual measurement verification of simulated targets, this method achieved a drop point measurement accuracy of 2m within a range of 3Km and a measurement accuracy of over 95%, which is significantly improved compared to traditional methods. The method provides data support for evaluating weapon effectiveness and obtaining field situation, and can also serve as auxiliary means for personnel search and rescue, debris search, etc., greatly improving the fusion ability of multidimensional data and enhancing the independent innovation and support ability of far sea measurement equipment. ? 2024 SPIE.Affiliations:(1) Xi’an Institute of Optics and Precision Mechanics of CAS, Shaanxi, Xi’an; 710119, China; (2) Key Laboratory of Space Precision Measurement Technology, CAS, Shaanxi, Xi’an; 710119, China; (3) Pilot National Laboratory for Marine Science and Technology, Shandong, Qingdao; 266237, ChinaPublication Year:2024Volume:13157Article Number:1315704DOI Link:10.1117/12.3013196數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20242016100384 -
Record 250 of
Title:Reconstruction of spectral light field image based on compressed spectral imaging
Author Full Names:Dai, Wanting(1); Ding, Xiaoming(1); Feng, Yazhou(1); Zhang, Chuanwang(1); Yuan, Hao(1); Yan, Qiangqiang(2)Source Title:Proceedings of SPIE - The International Society for Optical EngineeringLanguage:EnglishDocument Type:Conference article (CA)Conference Title:2024 Applied Optics and Photonics China: Computational Imaging Technology, AOPC 2024Conference Date:July 23, 2024 - July 26, 2024Conference Location:Beijing, ChinaConference Sponsor:Chinese Society for Optical Engineering (CSOE)Abstract:This paper introduces a snapshot spectral volumetric imaging approach based on light field image slicing and encoding. By slicing and encoding light field information, followed by spectral dispersion and array reimaging lens acquisition of aliased data, a four-dimensional data hypercube is reconstructed using deep learning-based algorithms. This hypercube contains three-dimensional spatial information and one-dimensional spectral information of the scene. The proposed approach utilizes Sanpshot Compressed Imaging Mapping Spectrometer(SCIMS)principle for initial light field spectral data acquisition. Reconstruction of this data employs traditional algorithms like Alternating Direction Method of Multipliers (ADMM) and Generalized Alternating Projection (GAP), as well as deep learning methods such as LRSDN and PnP-DIP. Simulation experiments reveal that classical compressive sensing-based spectral data reconstruction algorithms perform poorly, especially affecting digital refocusing of individual spectral bands in light field images. In contrast, deep learning algorithms exhibit significant improvements, effectively extracting and preserving spatial distribution characteristics of light field data, thus robustly recovering light field information. This validates the effectiveness of the proposed spectral volumetric imaging approach and deep learning-based reconstruction methods. In future research, we will refine the mathematical model, integrate spatial and spectral correlations of light field imaging, develop specialized deep neural network algorithms, and enhance reconstruction of light field spectral data. ? 2024 SPIE.Affiliations:(1) Tianjin Key Laboratory of Wireless Mobile Communications and Power Transmission, Tianjin Normal University, Tianjin; 300387, China; (2) CAS Key Laboratory of Spectral Imaging Technology, Xi’an institute of Optics and Precision Mechanics, Xi’an; 710119, ChinaPublication Year:2024Volume:13501Article Number:1350102DOI Link:10.1117/12.3045867數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20250117641020 -
Record 251 of
Title:Feasible spindle speed interval identification method for large aeronautical component robotic milling system
Author Full Names:Wang, Zhanxi(1); Zhang, Banghai(1); Gao, Wei(2); Qin, Xiansheng(1); Zhang, Yicha(3); Zheng, Chen(1)Source Title:MechatronicsLanguage:EnglishDocument Type:Journal article (JA)Abstract:Robotic machining systems have been widely implemented in the assembly sites of large components of aircraft, such as wings, aircraft engine rooms, and wing boxes. Milling is the first step in aircraft assembly. It is considered one of the most significant processes because the quality of the subsequent drilling, broaching, and riveting steps depend strongly on the milling accuracy. However, the chatter phenomenon may occur during the milling process because of the low rigidity of the components of the robotic milling system (i.e., robots, shape-preserving holders, and rod parts). This may result in milling failure or even fracture of the robotic milling system. This paper presents a feasible spindle speed interval identification method for large aeronautical component milling systems to eliminate the chatter phenomenon. It is based on the chatter stability model and the analysis results of natural frequency and harmonic response. Firstly, the natural frequencies and harmonics of the main components of the robot milling system are analyzed, and the spindle speed that the milling system needs to avoid is obtained. Then, a flutter stability model considering the instantaneous cutting thickness is established, from which the critical cutting depth corresponding to the spindle speed can be obtained. Finally, the spindle speed interval of the robotic milling system could be optimized based on the results obtained from the chatter stability model and the analysis result of the natural frequency and harmonic response of the milling system. The effectiveness of the proposed spindle speed interval identification method is validated through time-domain simulation and experimental results of the large aeronautical component milling system. ? 2024 Elsevier LtdAffiliations:(1) School of Mechanical Engineering, Northwestern Polytechnical University, Xi'an; 710072, China; (2) Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an; 710119, China; (3) Mechanical Engineering and Design Department, Université de Bourgogne FrancheComté, Université de Technologie de Belfort Montbéliard, ICB UMR CNRS 6303, Belfort Cedex; 90010, FrancePublication Year:2024Volume:99Article Number:103143DOI Link:10.1016/j.mechatronics.2024.103143數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20240715537558 -
Record 252 of
Title:Design of multi-channel sequential front light imaging system for transient condition
Author Full Names:Zhang, Zhanfei(1); Huang, Jie(2); Song, Qiang(2); Feng, Fei(1); Ding, Jianwen(2)Source Title:Guangxue Jingmi Gongcheng/Optics and Precision EngineeringLanguage:ChineseDocument Type:Journal article (JA)Abstract:In order to obtain stable and high-quality sequential images under transient condition and different object distances, a four-channel sequential front light high-speed imaging system was designed. The system used image space parallel light splitting, taking the imaging principle as the starting point to analyze the key design elements of system. Based on the theoretical calculation parameters, the sub-lens groups (objective lens group, field mirror and collimating lens group, converging lens group) was designed and aberrations were independently corrected. Adding field mirror to reduce the size and weight of system and improve light energy utilization. The transmission effect of beam was improved by accurate connection of field of view and pupil. On this basis, the sub lens groups were integrated and optimized, and beam splitters were added to form the final four-channel sequential front light imaging system. The object distance adjustable optical path was designed, and the image quality of system at the object distance of 0.5 m~∞ was guaranteed by adjusting the handwheel of objective lens group in use, while keeping the position of primary image plane unchanged, enhancing the stability of system performance stability and reducing the difficulty of installation and adjustment. The receiving part of system can be replaced according to actual needs, and the system can be expanded to eight-channel system after adding splitters in the beam splitting region. The installed and adjusted sequential front-light imaging system is used for laboratory testing and field tests, and main optical performance is good. the resolution of each channel can reach 72 lp/mm, and imaging consistency is greater than 98%. Field test results show that the optical system can meet the requirements for shooting sequence images under transient condition. ? 2024 Chinese Academy of Sciences. All rights reserved.Affiliations:(1) Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an; 710119, China; (2) China Aerodynamic Research and Developmnet Center Super High Speed institute, Mianyang; 621000, ChinaPublication Year:2024Volume:32Issue:4Start Page:478-489DOI Link:10.37188/OPE.20243204.0478數(shù)據(jù)庫(kù)ID（收錄號(hào)）:20241115748899