大射电望远镜精调平台运动对柔索牵引系统的动力耦合影响分析

发布时间：2018-01-09 19:37

本文关键词：大射电望远镜精调平台运动对柔索牵引系统的动力耦合影响分析　出处：《西安电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：近年来，国家天文台一直在全力推进位于贵州喀斯特洼地的500m口径球面射电望远镜FAST(Five-hundred-meter Aperture Spherical Telscope)的建设工作。目前FAST望远镜的设计方案中柔性馈源支撑系统由两级调整子系统即一次柔索牵引系统和二次精调机构组成，其中二次精调机构包括AB转轴和Stewart平台。由于两级子系统间存在的动力学耦合作用会影响馈源的动态定位精度，，因此本文利用多体系统动力学分析软件ADAMS对柔索牵引系统和精调Stewart平台进行动力学建模和仿真分析，其中重点探讨在Stewart平台运动过程中馈源舱与动平台的质量比对两级子系统间动力学耦合的影响。首先，分析了多体系统动力学基本理论及多体动力学分析软件ADAMS的相关技术。着重研究了多体系统动力学方程的建立与求解方法，以及基于ADAMS软件对多体系统进行建模与运动学及动力学仿真分析的关键技术。其次，在多体系统动力学理论的基础上，建立了Stewart平台的逆运动学和逆动力学模型，并利用ADAMS软件对一种Stewart平台进行运动学与动力学仿真分析。通过将仿真结果与理论计算结果进行对比，验证了本文利用ADAMS软件建模与仿真分析的准确性。随后，研究了ADAMS软件中柔索的轴套力连接建模方法及其参数化，通过对两根柔索受拉力模型进行建模和仿真分析，验证了轴套力建模方法的准确性。探讨了平面索杆混合结构的动力耦合影响，为LT500m模型的仿真研究提供指导。最后，完成了基于ADAMS的舱索系统和Stewart平台的动力学建模与仿真分析，重点研究了Stewart平台做不同的调整运动时馈源舱与动平台的质量比对馈源舱的位移响应的影响，并最终获得了在不同运动条件下使馈源舱的位移满足精度要求的临界质量比，为提高馈源的动态定位精度、降低两级子系统间的动力学耦合影响提供了参考依据。
[Abstract]:In recent years. The national observatory has been pushing forward the 500m spherical radio telescope FAST in Guizhou karst depression. Five-hundred-meter Aperture Spherical Telscope). At present, the flexible feed support system in the design of FAST telescope is composed of two stage adjusting subsystem, namely, the primary flexible cable traction system and the secondary fine adjusting mechanism. The secondary fine tuning mechanism includes AB axis and Stewart platform. The dynamic coupling between the two subsystems will affect the dynamic positioning accuracy of the feed. Therefore, the dynamic modeling and simulation analysis of flexible cable traction system and fine-tuned Stewart platform are carried out by using multi-body system dynamics analysis software ADAMS. The effect of the mass ratio of the feed cabin to the moving platform on the dynamic coupling between the two subsystems is discussed in detail. Firstly, the basic theory of multi-body system dynamics and the related technology of multi-body dynamics analysis software ADAMS are analyzed. And the key technology of modeling and kinematics and dynamics simulation of multi-body system based on ADAMS software is presented. Secondly, based on the theory of multi-body system dynamics, the inverse kinematics and inverse dynamics models of Stewart platform are established. The kinematics and dynamics of a Stewart platform are analyzed by using ADAMS software, and the simulation results are compared with the theoretical results. The accuracy of modeling and simulation analysis using ADAMS software is verified. Then, the modeling method and parameterization of the axle sleeve force connection of the flexible cable in ADAMS software are studied, and the modeling and simulation analysis of the tension model of two flexible cables are carried out. The accuracy of the method is verified, and the influence of dynamic coupling of plane cable-bar hybrid structure is discussed, which provides guidance for the simulation of LT500m model. Finally, the dynamic modeling and simulation analysis of cable-cable system and Stewart platform based on ADAMS are completed. The effect of the mass ratio of the feed cabin to the moving platform on the displacement response of the feed cabin is studied. Finally, the critical mass ratio is obtained to make the displacement of the feed cabin meet the requirement of accuracy under different moving conditions, in order to improve the dynamic positioning accuracy of the feed. The reference is provided to reduce the effect of dynamic coupling between two stage subsystems.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TH751

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