大型射电天线轮轨接触分析与实验

发布时间：2018-08-28 15:30

【摘要】：射电天文学及深空探测技术的发展，对大型射电天线的口径、灵敏度以及指向跟踪精度等提出了更高的要求。当大型射电天线方位转动部分采用轮轨式结构时，探讨轮轨精度对指向误差的影响、轮轨的磨损问题成了亟待解决的课题。本文以国家天文台50m天线轮轨系统为主要研究对象，引入三维弹性体非Hertz滚动接触理论，构建天线轮轨滚动接触系统模型，从数值计算层面分析天线轮轨在滚动接触中的几何形变及滚动接触滑移。通过天线轮轨三维弹性体非Hertz滚动接触的分析，为仿真模型和实验测试提供理论支持。其次，根据理论分析模型建立50m天线轮轨三维接触模型，仿真分析了轮轨接触区部分的接触应力及变形，，分析天线轨道结构特别是轨道接头处几何型面突变对轨道的影响，讨论轨道接缝角度、温度等外部因素对轨道力学性能的影响。最后，实地勘测50m射电天线轮轨滚动接触疲劳磨损情况，获得轮轨磨损数据。对50m射电天线轨道进行全轨水平度及加载变形测量，检验理论及仿真模型的计算结果。根据实测数据，分析轨道与轨道面产生大裂缝的原因，提出天线轨道的维修方案，对50m天线进行维修与调整，并对轨道全轨不平度等参数进行重新实测，评估天线轨道维修效果。考虑轨道因素导致的指向精度误差，建立射电天线的指向修正模型，利用50m射电天线进行全天域指向校准实验，验证修正后的指向精度。本文所建立的三维轮轨滚动接触模型与轨道测量方案，有利于大型轮轨式射电天线轨道问题的研究，为解决因轨道问题引起的天线指向跟踪精度降低和大型轮轨式射电天线轨道结构设计与运行维护提供一定的参考与指导。
[Abstract]:With the development of radio astronomy and deep space exploration technology, the aperture, sensitivity and tracking accuracy of large radio antenna are required. When the azimuth rotation part of large radio antenna adopts wheel-rail structure, the influence of wheel-rail precision on pointing error is discussed, and the wear problem of wheel-rail becomes an urgent problem to be solved. In this paper, taking the 50m antenna wheel-rail system of the National Observatory as the main research object, the model of the antenna wheel-rail rolling contact system is constructed by introducing the three-dimensional elastomer non-Hertz rolling contact theory. The geometric deformation and rolling contact slip of antenna wheel-rail in rolling contact are analyzed from the aspect of numerical calculation. Through the analysis of the non-Hertz rolling contact of the antenna wheel-rail elastomer, the theoretical support is provided for the simulation model and the experimental test. Secondly, according to the theoretical analysis model, the three-dimension contact model of 50 m antenna wheel-rail is established, and the contact stress and deformation of the wheel-rail contact area are simulated and analyzed. The influence of external factors such as rail joint angle and temperature on track mechanical properties is discussed. Finally, the rolling contact fatigue wear of 50 m radio antenna wheel / rail is investigated in the field, and the wheel / rail wear data are obtained. The full rail flatness and load deformation of the 50m radio antenna track are measured, and the theoretical and simulation results are tested. Based on the measured data, the causes of large cracks in track and track surface are analyzed, and the maintenance scheme of antenna track is put forward. The maintenance and adjustment of 50m antenna are carried out, and the parameters such as track irregularity are remeasured. Evaluate the effectiveness of antenna track maintenance. Taking into account the error of pointing accuracy caused by orbit factor, the pointing correction model of radio antenna is established, and the calibration experiment of all space pointing is carried out by using 50 m radio antenna to verify the corrected pointing accuracy. The 3D wheel-rail rolling contact model and track measurement scheme established in this paper are beneficial to the research of the orbit problem of large wheel-rail radio antenna. This paper provides some reference and guidance for solving the problem of antenna pointing and tracking accuracy reduction and track structure design and operation maintenance of large wheel-rail radio antenna.
【学位授予单位】：杭州电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TH75

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