大口径天线3-RPS驱动机构结构优化设计与分析

Structure optimization design and analysis of the 3-RPS driving mechanism for large antennas

采用并联机构替换现有的方位-俯仰式串联机构作为反射面天线的驱动机构可以满足其位姿调整的功能,并有效改善反射面天线整体结构的轻量化效果。目前少有将并联机构应用于大口径天线的分析与实际工程应用案例,故需要对承受较大载荷的并联机构展开力学分析并对其结构进行优化,从而使其满足承载与运动精度的要求。针对3-RPS并联机构承受较大载荷时支链的结构方案展开优化设计并进行有限元仿真分析。首先,对3-RPS并联机构展开静力学分析,得到在动平台承受一定载荷的情况下机构各个支链的受力特性;其次,在给定机构基本尺寸参数及活动范围要求下,对3-RPS并联机构支链的结构方案进行设计,针对并联机构支链弯曲变形较为严重的情况提出了并联液压缸的结构方案;最后,对并联液压缸结构方案进行了优化以及稳定性分析。结果表明,优化后的并联液压缸方案各项性能指标均优于原有方案,且满足稳定性安全性要求,为实际的工程应用提供参考。

Replacing the azimuth-pitch serial mechanism with a parallel mechanism as the driving mechanism for the reflector antenna can satisfy its pose adjustment requirements and achieve lightweight design of the overall structure.At present,there are few research and engineering practice of applying parallel mechanism to large antennas.Therefore,it is necessary to conduct mechanical analysis and structure optimization of the parallel mechanism that bears large loads to satisfy the requirements of load-bearing and motion accuracy.Optimization design and finite element analysis are carried out for the structural scheme of the branch chain of the 3-RPS parallel mechanism under large loads.Firstly,static analysis is conducted on the 3-RPS parallel mechanism to obtain the force characteristics of each branch chain of the mechanism under a certain load on the moving platform.Secondly,given the basic size parameters and activity range requirements of the mechanism,the structural scheme of the 3-RPS parallel mechanism branch chain is designed.A parallel hydrocylinder scheme is proposed to address the severe bending of the branch chain of the parallel mechanism.Finally,the structural scheme of the parallel hydrocylinder is optimized,and its stability is analyzed.The results show that the optimized parallel hydrocylinder scheme has better performance than the original scheme and satisfies the stability and safety requirements.This study has provided reference for practical engineering application.