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Multimodality-based Wind Speed Forecasting Method for the Wind Resistance Control of Large Radio Telescope

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天文和天体物理学研究:英文版 2023年第9期23卷 20-28页

作者： Wen-Juan Wang Bao-Qing Han Long-Yang Wang Tian Luan Yue-Fei Yan Wu-Lin Zhao De-Qing Kong Yang Wu Cong-Si Wang Key Laboratory of Electronic Equipment Structure Design Ministry of EducationXidian UniversityXi’an 710071China The 39th Research Institute of China Electronics Technology Group Corporation Xi’an 710065China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China The 54th Research Institute of China Electronics Technology Group Corporation Shijiazhuang 050081China Guangzhou Institute of Technology Xidian UniversityGuangzhou 510555China

A large,fully steerable radio telescope is susceptible to the wind load,leading to structure deformation andpointing deviation of the *** effectively suppress the influence of dynamic wind load,the wind resistancecontrol of the telescope is carried out based on wind speed *** study developed a wind speedforecasting model to efficiently forecast the wind speed at the telescope *** proposed model successfullyeliminates the random noise of the original wind speed,effectively extracts the wind speed features and solves theautomatic optimization of the hyperparameters of the forecasting *** model significantly improves theaccuracy and reliability of wind speed *** verify the forecasting performance of the proposed model,the wind data from the Qitai Radio Telescope site is examined as a case *** wind speed forecasting model’sMAE,RMSE and MAPE are 0.0361,0.0703 and 3.87%,*** performance of the proposed modelmeets the requirements of wind resistance control and can provide data support for the radio telescope.

关键词： telescopes-methods numerical-methods data analysis

Rapid Deformation Calculation for Large Reflector Antennas:A Surrogate Model Method

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Research in Astronomy and Astrophysics 2023年第1期23卷 4-17页

作者： Zi-Han Zhang Qian Ye Li Fu Jin-Qing Wang Meng Guo-Xiang Zhi-Qiang Shen School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China

The surface accuracy of the large-aperture reflector antenna has a significant influence on the observation *** researchers have focused on using the finite element(FE)simulation to study the effect of gravity and heat on the deformation distribution of the main ***,the temperature distribution of the antenna is challenging to obtain,and it takes a long time for the FE simulation to carry out FE modeling and *** address these limitations,this study presents a surrogate model based on Extreme Gradient Boosting(XGBoost)and deep Convolutional Neural Network(CNN)to get the deformation distribution of the main reflector *** the design of the surrogate model,using the XGBoost algorithm and sparse sampling to solve the difficulty of obtaining the entire temperature distribution is first proposed,and then a deep CNN is developed for estimating *** on the effect of dynamic loads on the antenna structure,a diverse data set is generated to train and test the surrogate *** results show that the surrogate model reduces the calculating time dramatically and can obtain the indistinguishable deformation compared to the FE *** technique provides a valuable tool for temperature and deformation calculation of large-aperture antennas.

关键词： telescopes-methods analytical-methods numerical-methods data analysis

Performance Analysis and Optimization of a Modified Stewart Platform for the Qitai Radio Telescope

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天文和天体物理学研究:英文版 2023年第9期23卷 241-250页

作者： Guljaina Kazezkhan Qian Xu Na Wang Fei Xue Hui Wang Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Key Laboratory of Radio Astronomy Chinese Academy of SciencesUrumqi 830011China Xinjiang Key Laboratory of Radio Astrophysics Urumqi 830011China

This paper presents a modified Stewart platform that enables precise adjustment of the sub-reflector for the Qitai Radio Telescope(QTT).QTT demands a parallel platform capable of carrying a heavy load(≥4000 kg),and moving in elevation from 5°to 88°together with the primary reflector while precisely adjusting the sub-reflector’s position in five degrees of *** meet these requirements,a modified Stewart platform with two separated actuators is proposed,and the comprehensive performance is analyzed and optimized for practical *** performance of the modified platform is compared to that of the traditional Stewart platform,and the results demonstrate that the modified platform has superior load-bearing capacity and stiffness over the entire elevation angle with more uniform actuator load and stiffness *** results indicate that the modified Stewart platform is well-suited for practical application in QTT.

关键词： telescopes-methods analytical-methods numerical

Influence and Correction of Wavefront Primary Aberrations for Radio telescopes using Aberration Theory

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Research in Astronomy and Astrophysics 2023年第2期23卷 187-196页

作者： Bin-bin Xiang Wei Wang You Ban Shang-min Lin Zhi-gang Wen Da-lin He Ming-hui Cai School of Mechanical Engineering Xinjiang UniversityUrumqi 830017China School of Mechano-Electronic Engineering Xidian UniversityXi'an 710071China Xi’an Institute of Optics and Precision Mechanics Chinese Academy of SciencesXi'an 710119China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China

Dual-reflector antennas are widely used in astronomical observations and satellite *** deformations of the reflectors for radio telescopes are inevitable in outside working conditions due to exterior environment loads,which will cause distortion in the surface of the primary reflector and displacement of the subreflector,then lead to gain degradation and *** this paper,the influence and correction of misalignment in a dual-reflector antenna have been *** the perspective of wavefront aberration,a method is proposed to correct the wavefront primary aberration by adjusting the subreflector *** characteristics of wavefront errors caused by structural deformation of the reflector have been analyzed,and relationships between the position motions of the subreflector and the Seidel wavefront aberrations are *** adjustment quantities of the subreflector are also *** results show the appropriate positional change of the subreflector in the lateral and axial directions can effectively correct the effects of the tilt and defocus in the primary aberrations caused by antenna structural deformations.

关键词： telescopes-methods analytical-instrumentation miscellaneous

An approximately analytical solution method for the cable-driven parallel robot in FAST

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Research in Astronomy and Astrophysics 2021年第2期21卷 169-179页

作者： Jia-Ning Yin Peng Jiang Rui Yao National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China

The Five-hundred-meter Aperture Spherical radio Telescope(FAST)is the largest single-dish aperture telescope with a cable-driven parallel robot introduced to achieve the highest sensitivity in the ***,to realize the high-precision,mechanical equations of such a robot are always complicated,so that it is difficult to achieve real-time control by the traditional iterative *** this regard,this paper proposes an approximately analytical solution method,which uses the approximately linear relationship between the main parameters of FAST to bypass some *** the coefficients of the relationship extracted,static or quasi-static mechanical equations can be analytically *** this paper’s example,this method saves at least 90%of the calculating time and the calculated values are consistent with the experimental *** such huge efficiency improvements,real-time and high-precision control of the FAST will no longer be difficult ***,all the work in this paper is expected to be used in the FAST.

关键词： telescopes-methods analytical-instrumentation miscellaneous