【作者】 郭亮；

【导师】 翟超；

【作者基本信息】 中国科学技术大学 ， 仪器科学与技术， 2017， 硕士

【摘要】 LAMOST(The Large Sky Area Multi-Object Fiber Spectroscopic Telescope)是一个反射式施密特天文望远镜,它的最重要组成部分就是一个直径为1.75m的焦面板,并且在焦面板上安装有4000根光纤。为了 4000根光纤的准确定位,在焦面板上还安装有4000个光纤定位单元,每一个光纤定位单元精确的控制着一根光纤的位置。作为中国科技大学工程科学学院自主创新和设计的国家大科学工程项目,截止到2017年,LAMOST的光纤定位系统已经稳定的工作了 9个年头。但随着LAMOST天文望远镜的不断优化和改进,现在对其提出了更高的观测要求。为了达到这个要求,就需要将光纤定位单元小型化设计。每一个光纤定位单元包含3部分:无线驱动板系统、双回转机械机构、2个步进电机。为了将光纤定位单元小型化设计,将步进电机的直径从10mm缩小到了 6mm,但双回转机械结构的尺寸还要由无线驱动板来决定,所以小型化无线驱动板成了本毕业设计的重点和难点。上一代无线驱动板的长度和宽度分别为104mm和15mm,其主要有基于Zigbee无线通信的片上系统和步进电机驱动模块两部分组成。为了将其小型化设计,本课题采取了两个步骤。第一步,用TI公司开发的基于IEEE 802.15.4和Zigbee的无线单片机CC2530代替飞思卡尔公司开发的MC13213无线单片机。MC13213的尺寸为9mm×9mm,而CC2530的尺寸为6mm×6mm,不仅比MC13213尺寸小很多,而且在性能上优于MC13213。第二步,重新设计整个无线驱动板,其中包含更换更小尺寸的元器件和重新布局元器件的位置,以达到最好的通信性能。最终,在满足各种功能的前提下,无线驱动板的整体尺寸相对于上一代缩小了 40%,这样使得每个光纤定位单元的尺寸可以设计的更小,最终达到了光纤定位系统的小型化设计。更多还原

【Abstract】 The fiber positioning system is one of the most important parts of LAMOST(The Large Sky Area Multi-Object Fiber Spectroscopic Telescope),which consists of 4,000 fiber positioning nodes and each of them can position a fiber.In addition,all of the fiber positioning nodes are distributed on the focal plate of 1.75m in diameter.As the self-innovation and key technology of LAMOST,the fiber positioning system has been working steadily for more than 8 years.At present,a higher demand to install at least 4,000 fiber positioning nodes on focal plate of 1.75m in diameter is put forward and the most effective solution is to miniaturize the fiber positioning nodes.Every fiber positioning node consists of three parts:the wireless driving system,the mechanical device and the two stepper motors.The size of stepper motor has reduced from 10mm to 6mm in diameter,but the size of mechanical device depends on the wireless drive system.Therefore,to miniaturize the wireless driving system is of great importance and difficulties as well.The previous is 100 mm long and 15 mm wide and consists of the minimum system of wireless SOC based on technology of ZigBee wireless communication and the stepper motor driver module.In order to miniaturize the wireless driving system,two steps a wireless driving system board re proposed in the paper.The first step is to adopt a smaller-size wireless SOC to replace the original one.The CC2530 used on new board is 6mm long and 6mm wide as a true system-on-chip solution for IEEE 802.15.4 and ZigBee applications launched by TI.The previous MC13213,with the size of 9mm x 9mm,possesses less performance of MCU and peripherals.The second step is to redesign the wireless driving system board including smaller-size components and layout in order to achieve the best communication performance.As a result,the size of the new wireless driving system reduces by above 40%.Meanwhile,the entire structure of every fiber positioning node can be designed smaller.更多还原