Laboratory and field testing results of the LMT/GTM primary surface actuators
Laboratory and field testing results of the LMT/GTM primary surface actuators
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LMT/GTM 主表面执行器的实验室和现场测试结果
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
E. Anaclerio
中科院分区：
文献类型：
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作者：
David R. Smith;K. Souccar;Gabriela Montalvo;César Arteaga Magaña;José Luis Hernández Rebollar;Arak Olmos Tapia;D. Gallieni;P. Lazzarini;Pierluigi Fumi;E. Anaclerio
随着大型毫米望远镜/Gran Telescopio Milimétrico (LMT/GTM) 主表面两个最外环的最终安装，该项目还在升级主表面执行器。有一些商业执行器可以达到所需的操作精度和行程，但尺寸和负载要求的结合最终需要定制设计。新的执行器符合外环更紧密的内角所施加的体积限制，并且设计用于支持操作和生存负载条件，即使对于最大的表面部分也是如此。实验室测试证实执行器应满足精度、重复性、负载和寿命要求。然而，LMT/GTM 对于机电系统来说是一个特别困难的地方。高海拔通常会降低驱动器和电机的冷却效率，并且环境温度徘徊在冰点附近。由于一年中的某些时候降水量很大，因此经常出现冻融循环。冰的不断形成、升华或融化，以及相关的高湿度，对 LMT/GTM 的许多设备的环境保护构成了挑战。由于系统中共有720个主表面执行器，因此即使在现场条件下，执行器及其本地驱动控制箱及其电缆连接也能够满足其规格，这一点尤为重要。为了确认执行器的适用性，LMT/GTM 采购了一套初始的 16 个执行器用于现场测试。经过实验室测试后，执行器被安装到望远镜的外两个环中，并在 2015-16 科学观测季的初冬几个月内循环运行。由于这两个环内的安装活动仍在继续，它们不会被接收器照亮，因此可以在实际操作条件下进行现场测试，而不会影响正在进行的科学观测。本文介绍了执行器测试前后的特征性能，以及关于其环境鲁棒性的报告。
With the final installation of the two outermost rings of the primary surface of the Large Millimeter Telescope/ Gran Telescopio Milimétrico (LMT/GTM), the project is also upgrading the primary surface actuators. There are commercial actuators that can approach the required operational accuracy and stroke, but the combination of the size and load requirements ultimately required a customized design. The new actuators fit within the volume constraints imposed by the tighter interior angles in the outer rings and are designed to support the operational and survival loading conditions even for the largest surface segments. Laboratory testing confirmed that the actuators should meet the precision, repeatability, load, and lifetime requirements. However, the LMT/GTM is at a particularly difficult site for electromechanical systems. The high altitude has the usual effect of reducing cooling effectiveness for the drives and motors, and the ambient temperature hovers near freezing. Since there is a significant amount of precipitation during some times of the year, there are frequent freeze/thaw cycles. The constant formation and either sublimation or melting of ice, along with the associated high humidity, has been a challenge for the environmental protection of many devices at the LMT/GTM. Because there are a total of 720 primary surface actuators in the system, it is particularly important that the actuators, their local drive control boxes, and their cable connections be able to meet its specifications even under the site conditions. To confirm the suitability of the actuators, the LMT/GTM procured an initial set of sixteen actuators for testing at the site. After laboratory testing, the actuators were installed into the outer two rings of the telescope and cycled during the early winter months of the 2015–16 scientific observing season. Because of the continuing installation activities in these two rings, they are not illuminated by the receivers, so field testing under actual operational conditions could be conducted without affecting the ongoing scientific observations. This paper presents the characterized performance of the actuators before and after testing, as well as a report on their environmental robustness.