2021
2021
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Record 325 of
Title:Non-invasive Highly Sensitive under Mattress Vital Signs Monitoring Based on Fiber Sagnac Loop
Author(s):Zeng, Huaili(1); Xu, Wei(2,3); Dong, Bo(4); Yu, Changyuan(6,7); Zhao, Wei(2,3,5); Wang, Yishan(2,3,5); Sun, Wenye(8)Source: 2021 Opto-Electronics and Communications Conference, OECC 2021 Volume: Issue: DOI: null Published: 2021Abstract:A non-invasive highly sensitive under mattress vital signs monitoring system is proposed for real-time and long-term respiration and heartbeat monitoring, which is based on Sagnac loop and polarization-maintaining fiber. ? 2021 OSA.Accession Number: 20224012832605 -
Record 326 of
Title:An Improved Method of Friction Compensation and Stability Control for Optoelectronic Stabilized Platform
Author(s):Gao, Peng(1,2,3); Lu, Weiguo(1); Zhang, Wenbo(1,2,3)Source: 2021 IEEE Conference on Telecommunications, Optics and Computer Science, TOCS 2021 Volume: Issue: DOI: 10.1109/TOCS53301.2021.9688889 Published: 2021Abstract:In order to improve the anti-disturbance ability of the optoelectronic stabilized platform, an improved active disturbance rejection control algorithm is proposed, which combines LuGre friction model and linear reduced extended state observer. Firstly, LuGre friction model is established to compensate the friction torque of bearing. Then, the friction compensation error and other disturbances are regarded as an extended state, which is estimated by a linear reduced-order extended state observer. The estimated value is fed back to the controller to further compensate the disturbance. The improved ADRC algorithm has superior disturbance rejection ability taking advantage of the accurate compensation of LuGre model and the adaptation of extended state observation. Experimental results show that the improved algorithm can well suppress external interferences and significantly improve the ability of anti-interference and tracking response of the system. ? 2021 IEEE.Accession Number: 20220911706704 -
Record 327 of
Title:Design of Φ450 mm light-weighted SiC mirror subsystem in space-based astronomy telescope
Author(s):Feng, Liangjie(1); Cheng, Pengfei(1); Wang, Wei(1)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 50 Issue: 2 DOI: 10.3788/IRLA20200175 Published: February 25, 2021Abstract:A Φ450 mm primary mirror subsystem of a space-based astronomy telescope was designed with mass, optical surface distortion and reflectivity requirement. The open-back primary mirror was made of pressure-less sintering silicon carbide, light-weighted at a ratio of approximately 70%. Three side supporting invar flexure bipods were designed to minimize the assembling stress and the thermal stress. The high reflection was obtained from the optical surface cementite. The mirror weighted 7 kg and the reflectivity was 98% after optical polishing. The mirror subsystem was precisely assembled under the strict technical condition. The optical test with interferometer show that the optical surface distortion is less than 0.02λ RMS, which meet the critical optical requirements for the primary mirror of the space-based astronomy telescope. Copyright ?2021 Infrared and Laser Engineering. All rights reserved.Accession Number: 20211210117108 -
Record 328 of
Title:Improved Active Disturbance Rejection Control of optoelectronic stabilized platform Based on Reduced-order Extended State Observer
Author(s):Gao, Peng(1,2,3); Su, Xiuqin(1); Wang, Weifeng(1); Zhang, Wenbo(1,2,3)Source: IEEE Information Technology, Networking, Electronic and Automation Control Conference, ITNEC 2021 Volume: Issue: DOI: 10.1109/ITNEC52019.2021.9587065 Published: October 15, 2021Abstract:In order to improve the anti-disturbance ability and dynamic response characteristics of the optoelectronic stabilized platform, an improved linear active disturbance rejection control (ADRC) algorithm is proposed. The algorithm adopts reduced-order extended state observer (RESO) to realize fast tracking and estimating disturbances, which improves the restraining rapidity of disturbances. The Variable Speed Integral Proportional Integral (VSIPI) algorithm is introduced to solve the contradiction between transition speed and response overshoot, so as to obtain faster response speed and lower overshoot. The simulation results show that the algorithm has stronger anti-interference ability and robustness than the traditional PI. ? 2021 IEEE.Accession Number: 20214711192834 -
Record 329 of
Title:Cross-Domain Scene Classification by Integrating Multiple Incomplete Sources
Author(s):Gong, Tengfei(1); Zheng, Xiangtao(1); Lu, Xiaoqiang(1)Source: IEEE Transactions on Geoscience and Remote Sensing Volume: 59 Issue: 12 DOI: 10.1109/TGRS.2020.3034344 Published: December 1, 2021Abstract:Cross-domain scene classification identifies scene categories by learning knowledge from a labeled data set (source domain) to an unlabeled data set (target domain), where the source data and the target data are sampled from different distributions. A lot of domain adaptation methods are used to reduce the distribution shift across domains, and most existing methods assume that the source domain shares the same categories with the target domain. It is usually hard to find a source domain that covers all categories in the target domain. Some works exploit multiple incomplete source domains to cover the target domain. However, in such setting, the categories of each source domain are a subset of the target-domain categories, and the target domain contains 'unknown' categories for each source domain. The existence of unknown categories results in the conventional domain adaptation unsuitable. Known and unknown categories should be treated separately. Therefore, a separation mechanism is proposed to separate the known and unknown categories in this article. First, multiple-source classifiers trained on the multiple source domains are used to coarsely separate the known/unknown categories in the target domain. The target images with high similarities to source images are selected as known categories, and the target images with low similarities are selected as unknown categories. Then, a binary classifier trained using the selected images is used to finely separate all target-domain images. Finally, only the known categories are implemented in the cross-domain alignment and classification. The target images get labels by integrating the hypotheses of multiple-source classifiers on the known categories. Experiments are conducted on three cross-domain data sets to demonstrate the effectiveness of the proposed method. ? 1980-2012 IEEE.Accession Number: 20214911290233 -
Record 330 of
Title:Audio description from image by modal translation network
Author(s):Ning, Hailong(1,2); Zheng, Xiangtao(1); Yuan, Yuan(3); Lu, Xiaoqiang(1)Source: arXiv Volume: Issue: DOI: null Published: March 18, 2021Abstract:Audio is the main form for the visually impaired to obtain information. In reality, all kinds of visual data always exist, but audio data does not exist in many cases. In order to help the visually impaired people to better perceive the information around them, an image-to-audio-description (I2AD) task is proposed to generate audio descriptions from images in this paper. To complete this totally new task, a modal translation network (MT-Net) from visual to auditory sense is proposed. The proposed MT-Net includes three progressive sub-networks: 1) feature learning, 2) cross-modal mapping, and 3) audio generation. First, the feature learning sub-network aims to learn semantic features from image and audio, including image feature learning and audio feature learning. Second, the cross-modal mapping sub-network transforms the image feature into a cross-modal representation with the same semantic concept as the audio feature. In this way, the correlation of inter-modal data is effectively mined for easing the heterogeneous gap between image and audio. Finally, the audio generation sub-network is designed to generate the audio waveform from the cross-modal representation. The generated audio waveform is interpolated to obtain the corresponding audio file according to the sample frequency. Being the first attempt to explore the I2AD task, three large-scale datasets with plenty of manual audio descriptions are built. Experiments on the datasets verify the feasibility of generating intelligible audio from an image directly and the effectiveness of proposed method. ? 2021, CC BY.Accession Number: 20210084416 -
Record 331 of
Title:Non-invasive highly sensitive under mattress vital signs monitoring based on fiber sagnac loop
Author(s):Zeng, Huaili(1); Xu, Wei(2,3); Dong, Bo(4); Yu, Changyuan(6,7); Zhao, Wei(2,3,5); Wang, Yishan(2,3,5); Sun, Wenye(8)Source: Optics InfoBase Conference Papers Volume: Issue: DOI: null Published: 2021Abstract:A non-invasive highly sensitive under mattress vital signs monitoring system is proposed for real-time and long-term respiration and heartbeat monitoring, which is based on Sagnac loop and polarization-maintaining fiber. ? OSA 2021, ? 2021 The Author(s)Accession Number: 20214811222113 -
Record 332 of
Title:Research of robotic spherical polishing end effector based on finite element simulation
Author(s):Mu, Ruixin(1,2); Zhang, Jian(2,3)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 11761 Issue: DOI: 10.1117/12.2584956 Published: 2021Abstract:In this paper, using Preston hypothesis and CCOS removal model, analyzing removal function of the spherical polishing end is analyzed as Gaussian distribution, four schemes are proposed to design the robot optical spherical polishing end effector. Through the analysis and comparison of advantages and disadvantages, an optimal solution is obtained and a standardized design is carried out to realize the synthesis of revolution and rotation of the spherical polishing wheel. The design of the spherical polishing tool adopts bevel gear transmission, belt transmission and planetary gear structure. When the motor input is 200r/min, by adjusting the specifications of the pulley, the spherical polishing wheel can achieve a revolution speed of 60r/min and a rotation speed of 100～400r/min. After the design is completed, finite element analysis is performed on the important parts of the structure, and the designed structure meets the strength requirements. ? COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.Accession Number: 20210509874581 -
Record 333 of
Title:Testing of annular hyperboloid mirror for Cassegrain system
Author(s):Hao, Sanfeng(1,2); Zhang, Jian(2,3); An, Fei(2); Yang, Jianfeng(2)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 11761 Issue: DOI: 10.1117/12.2585089 Published: 2021Abstract:This paper introduces the testing of annular hyperboloid mirror with 460mm diameter in the Cassegrain system. To improve the testing efficiency and meet the requirements of utilization, the study is carried out from three stages: precision grinding, precision polishing, and optical coating. In the precision grinding stage, the annular Zernike polynomial is used to fit the measured surface combining with the data measured from the coordinate measuring machine, so that it can facilitate the testing of the distribution of the surface shape deviation over the entire surface. During the precision polishing stage, a feasible Offner compensator is designed to achieve the goal of high-precision testing of the hyperboloid surface, with a measurement accuracy of RMS≤0.02λ. Also, 0.5-0.7μm and 3-5μm dual-band high reflectivity and high uniformity reflective coating is designed for the Cassegrain system requirements, the actual test reflectivity is 96.2%, which can meet the design requirements. ? COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.Accession Number: 20210509874589 -
Record 334 of
Title:Development and prospects of deployable space optical telescope technology
Author(s):Hu, Bin(1,2); Li, Chuang(1); Xiang, Meng(2); Li, Liangliang(2); Dai, Haobin(2); Yao, Pei(2); Li, Xuyang(1)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 50 Issue: 11 DOI: 10.3788/IRLA20210199 Published: November 25, 2021Abstract:In order to obtain higher angular resolution, the aperture of the space optical telescope is getting larger and larger, and the space telescope with aperture of more than four meters will be difficult to break through the limitation of the effective envelope of the fairing of the existing launch vehicle. On the other hand, the micro-nano optical remote sensing satellite, which has great advantages in terms of development cycle and cost, also has extensive requirements for improving spatial resolution and light gathering area, requiring a smaller launch volume to accommodate a large opto-mechanical system to reduce the launch cost. Deployable space telescopes will be a feasible solution to overcome the limitations of launch size. The research status of deployable space telescopes was reviewed from the aspects of large aperture space astronomical telescopes, segmented mirror deployable telescopes for earth observation and micro-nano satellite optical telescopes deploying along optical axis. Some key technologies and development trends involved in deployable space telescopes were described and summarized. ? 2021, Editorial Board of Journal of Infrared and Laser Engineering. All right reserved.Accession Number: 20214911288601 -
Record 335 of
Title:Design of underwater large field of view zoom optical system
Author(s):Qu, Rui(1,2); Yang, Jianfeng(1); Cao, Jianzhong(1); Liu, Bo(1)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 50 Issue: 7 DOI: 10.3788/IRLA20200468 Published: July 25, 2021Abstract:Under the requirements of an underwater large field of view zoom optical system, the selection of optical window and its influence on objective lens were discussed, by which the relative distortion and lateral color induced by the plane window were analyzed and corresponding design methods were given. Regarding the special envelope and working distance requirements of the underwater optical system, a three-part zoom system design model and the design method of the corresponding focusing components were provided by introducing aberration stabilizers in the PNNP structure, dynamic aberration correction capability of the optical structure was improved, also, the problems of the cam curve breakpoints were avoided; by setting the focus lens group in the objective parts, close-range imaging through the entire zoom range was guaranteed. A 4 K underwater large field of view zoom optical system was completed using 3840×2160 high-sensitivity CMOS detector, with 0.5 m-inf working distance, 0.48?0.64 μm work waveband, constant F number of up to 2.8 and 5.9°?62° full field of view. The image quality and tolerance characters are validated by an assembled lens and its underwater imaging experiments. Copyright ?2021 Infrared and Laser Engineering. All rights reserved.Accession Number: 20213110716910 -
Record 336 of
Title:Design of visible-near infrared athermal continuous zoom optical system
Author(s):Qu, Rui(1,2); Guo, Huinan(1); Cao, Jianzhong(1); Yang, Jianfeng(1)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 50 Issue: 9 DOI: 10.3788/IRLA20210090 Published: September 25, 2021Abstract:The primary aberration of each lens group will be changed with their movement, and the change of environment temperature will also lead to defocus, both of which will cause a lot of difficulties in the zoom lens design process. To solve this problem, aberration functions do depend and not depend on group movement were introduced based on optical aberration theory, and lens power distribution and material selection method were discussed with the achromatic and athermal design model futher. A visible-near infrared (Vis-Nir) optical system under the requirements of F/5, focal length of 8-120 mm, focal plane diameter of 6.2 mm, work waveband of 0.48-0.68 μm and 0.7-0.9 μm was designed with mechanically compensated method and optical passive athermal technology. The proposed zoom lens system, which used 7 kinds of common optical glass, consists of 12 groups 16 lenses, total length of only 90 mm, has good image quality and tolerance character among the zoom range within ?40~60 ℃. ? 2021, Editorial Board of Journal of Infrared and Laser Engineering. All right reserved.Accession Number: 20214111012762