基于线驱动并联机构的FAST馈源平台位姿测量方法

发布时间：2018-01-19 06:04

本文关键词： FAST 馈源跟踪位姿测量并联机构运动学正解误差分析　出处：《机械工程学报》2017年17期 　论文类型：期刊论文

【摘要】："中国天眼"——500 m口径球面射电望远镜(Five hundred meter aperture spherical radio telescope,FAST)日前已投入使用,其独创的光机电一体化馈源支撑方案使得结构重量降低2个数量级。在6根柔索对馈源舱进行初步定位的基础上,舱内的AB轴机构和精调Stewart平台支撑起馈源平台,并进行实时位姿补偿以实现馈源对天文目标的高精度跟踪。为避免通过各级驱动关节反馈值计算馈源平台位姿时,不能反映杆件弹性变形、铰链间隙引入的馈源平台误差,提出一种基于线驱动并联机构的馈源平台6自由度位姿直接测量方法,研究了测量系统的数学模型,利用机构构型的特点简化了线驱动并联机构的位姿正解算法。通过将简化后的位姿正解算法与传统6自由度机构位姿正解算法进行对比,验证了该方法的有效性和实时性;进一步分析了基于该方法的测量系统误差来源,得出了机构参数的误差映射关系。数值仿真结果表明:基于线驱动并联机构6自由度位姿测量系统具有误差平均效应,通过拉线连接点优化布局能够达到0.5 mm和0.025°的测量精度。
[Abstract]:"Chinese Sky Eye" -500 m spherical Radio Telescope (. Five hundred meter aperture spherical radio telescope. FAST was put into use a few days ago, and its original optical-electromechanical integrated feed support scheme reduces the weight of the structure by two orders of magnitude. On the basis of the initial positioning of the feed cabin by six flexible cables. The AB shaft mechanism in the cabin and the fine-tuned Stewart platform support the feed platform. In order to avoid calculating the position and attitude of the feed platform through the feedback value of the drive joint at all levels, the elastic deformation of the rod can not be reflected by the compensation of the position and attitude of the feed platform in order to realize the high-precision tracking of the astronomical target by the feed source. Based on the error of feed platform introduced by hinge clearance, a 6-DOF direct measurement method of feed platform position and attitude based on linear drive parallel mechanism is proposed, and the mathematical model of the measurement system is studied. By using the characteristics of mechanism configuration, this paper simplifies the position-attitude forward solution algorithm of line-driven parallel mechanism, and compares the simplified position-attitude forward solution algorithm with the traditional 6-DOF mechanism pose forward solution algorithm. The effectiveness and real-time performance of the proposed method are verified. The error source of measurement system based on this method is further analyzed. The error mapping relation of the mechanism parameters is obtained. The numerical simulation results show that the 6-DOF position and attitude measurement system based on the linear drive parallel mechanism has the error average effect. The measuring accuracy of 0.5 mm and 0.025 掳can be achieved by optimizing the layout of the connecting points.
【作者单位】：西安电子科技大学电子装备结构设计教育部重点实验室;
【基金】：国家自然科学基金资助项目(51405362,51679398)
【分类号】：TH751
【正文快照】： 0前言*“中国天眼”——500 m口径球面射电望远镜(Five hundred meter aperture spherical radio telescope, FAST)日前已落成并投入使用,借助这只巨大的“天眼”,科学家们将着力研究宇宙大尺度物理学,以探索宇宙起源和演化;还可持续观测脉冲星,研究极端状态下的物质结构与物

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