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Analysis of effect of pressure on surface accuracy for inflatable antenna

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Journal of Harbin Institute of Technology(New Series) 2008年第6期15卷 786-789页

作者：付丽杜星文万志敏 Center for Composite Materials Harbin Institute of Technology Center for Test and Analysis Harbin Institute of Technology

Pressure is one of the important measures to control the surface accuracy of the reflector of inflatable antenna. Experiments and numerical analysis were carried out to highlight the effect of pressure on accuracy. The rapid, contactless and low-cost digital photogrammetry system （DIES） was employed to investigate the effect according to its lightweight and flexible characteristics. Measurement data show that the best pressure and the best area in this pressure can be obtained. Numerical analysis was conducted to check the measurement result. It is indicated that there is a little difference between them attributed to wrinkle. Results of analysis and experiments show that surface accuracy of the reflector can be adjusted by controlling pressure.

关键词： inflatable antenna surface accuracy seam end cap wrinkle

Study on Wheel and Workpiece Position Error Influence on surface Shape accuracy during Ceramic Ball Grinding

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Journal of Harbin Institute of Technology(New Series) 2013年第4期20卷 31-35页

作者： Feng-Ming Nie Zhan-Guo Li Qing-Tang Wu Huan Wu Shan Li Bo Guo Mechanical and Electrical Engineering College Changchun University of Science and Technology Lab of Ultra-precision Fabrication Changchun Institute of Equipment and Process The Principal's Office Changchun University

The reasons for bringing surface accuracy error in ultra-precision grinding ceramic ball joint were analyzed,and the influences wheel position error and shaft run-out error on the ball joint surface accuracy were *** establishing three-dimensional grinding model,the mathematical relationship between the position error and surface accuracy was derived,and the distance from any point on spherical surface to the ideal center was calculated when position error existed,and a precise surface shape was got,and theoretical support was provided to improve the surface accuracy during the grinding *** self-developed ultraprecision grinding machine to do the ceramic ball grinding experiment,the surface accuracy PV value of ceramic spherical joint is 4.8μm.

关键词： precision grinding error analysis surface accuracy ball joint

Hybrid-panel-based new design idea for large reflector antenna

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Science China(Technological Sciences) 2023年第1期66卷 115-126页

作者： LIAN PeiYuan YAN YueFei WANG CongSi QIN Long XUE Song WANG Na XU Qian ZHAO WuLin ZHENG YuanPeng School of Mechano-Electronic Engineering Xidian UniversityXi'an 710071China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 8300llChina China Electronics Technology Group Corporation No.39 Research Institute Xi'an 710065China China Electronics Technology Group Corporation No.54 Research Institute Shijiazhuang 050081China

Large reflector antennas are widely used as radio telescopes and active main reflectors are generally applied to improve the surface accuracy. Considering that the high cost has been one important problem in engineering, it is worth discussing whether it is necessary to install actuators on all the panels. Thus, in this paper, a hybrid-panel-based new design idea for large reflector antenna is proposed. Assuming that the actuators are installed only in the region of the reflector with large deformations and there are no actuators in other region to reduce the actuator number, the surface accuracies and the corresponding electromagnetic(EM) performances calculated by three different panel adjustment strategies are compared. The most effective method is that the deformed reflector should be first preadjusted to reduce the gravity deformation and then the panels equipped with actuators should be adjusted to the locations determined by the best fitting reflector(BFR) derived by the deformed reflector with no actuators. A 35 m reflector antenna is adopted as an example to calculate the surface accuracy and EM performance when parts of the panels are equipped with actuators. The simulation results show that there is no need to install actuators on all panels and the presented method can greatly reduce the number of actuators with guaranteed surface accuracy. Thus, during the antenna structural design phase, once the surface accuracy requirement is given, the number of actuators can be minimized to reduce the manufacturing and maintenance costs as much as possible. This paper can provide valuable guidance for the design of an active main reflector with hybrid panels.

关键词： reflector antenna hybrid panel actuator distribution adjustment strategy surface accuracy power pattern

同方期刊数据库

Force-finding analysis of cable-net deployable antenna considering shape constraints

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Journal of Southeast University(English Edition) 2018年第2期34卷 213-219页

作者： Wang Xinyu Cai Jianguo Feng Jian School of Civil Engineering Southeast UniversityNanjing 210096China

The force-finding process of the cable-net in the deployable mesh reflector antenna,AstroMesh,is investigated to optimize the pretension distribution and satisfy surface *** the geometry and topology of the mesh reflector antennas are given as a constraint with the boundary condition assumed to be fixed,the force-finding process can be performed on a constant equilibrium matrix to obtain a feasible set of ***,the equilibrium matrix can be rewritten in terms of force modes after the singular value *** object of force design is to minimize the deviation of member forces and,therefore,the surface accuracy can be guaranteed by transforming an optimization of the distribution of prestresses into an optimization with multiple prestress ***,numerical examples solved by the sequential quadratic programming(SQP)algorithm and the genetic algorithm are given to validate the efficiency of the proposed *** comparison results show that the genetic method can converge to the optimized point after approximately 50 iterations while the converging process of the sequential quadratic programming method depends largely on the initial points.

关键词： AstroMesh force-finding shape constraint optimization surface accuracy

The Tianma 65 m radio telescope at Shanghai

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Astronomical Techniques and Instruments 2024年第5期1卷 239-246页

作者： Qinghui Liu Zhiqiang Shen Xiaoyu Hong Qian Ye Bin Li Jinqing Wang Rongbing Zhao Li Fu Weiye Zhong Lingling Wang Juan Li Zhen Yan Wu Jiang Bo Xia Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China

The Shanghai Tianma 65 m radio telescope(TMRT)is a large,fully rotatable radio telescope with multiple scientific *** main body of the telescope and four low-frequency receiving systems,including L,C,and S/X bands,were completed between 2008 and *** 2013 to 2017,four high-frequency receiving systems,including Ku,K,Ka,and Q bands,were constructed and their performance was comprehensively *** are three main innovations.(1)A fully movable large radio telescope system with advanced performance and complete functions has been built.(2)An advanced,reliable main reflector adjustment system has been completed,overcoming gravity deformation and creating a large antenna with a main reflective surface accuracy of 0.28 mm(root mean square)for any elevation.(3)Five innovative technologies have been developed to achieve high-precision pointing in any direction within 3″.The TMRT has made a crucial contribution to the orbital measurement and positioning of China’s lunar and deep space *** enhancing China's ability to participate in international VLBI observations and radio astronomy,this has facilitated a series of achievements in observational radio astronomical research,in areas such as VLBI,spectral lines,and pulsars.

关键词： Radio telescope Tianma Large antenna Receiving system surface accuracy