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所属单位：自动化学院
发表刊物：RESEARCH IN ASTRONOMY AND ASTROPHYSICS
关键字：telescopes methods: analytical methods: miscellaneous techniques: miscellaneous
摘要：This paper presents a novel hexapod as the adjustment mechanism for a telescope to actively align its secondary mirror. The special hexapod provides six degrees of freedom (6-DOFs) with decoupled translation and rotation. The decoupled kinematic motions are analyzed and commented on as the alignment mechanism of a secondary mirror from an optical alignment point of view. In terms of performance of the adjustment generally required by the secondary mirror in a telescope, we developed a prototype that uses a novel hexapod design with linear micro-displacement actuators. Especially, in order to achieve high precision, flexures were used to build joints for the hexapod to minimize frictions and eliminate backlashes. Based on the specific configuration and dimension of the prototype hexapod, an analytical model of the reachable workspace was built with the constraints defined by limited rotation angles of the flexure-based joints. We used a laser tracker to verify that the hexapod can reach a spherical translation workspace of phi 6 mm and a rotation workspace of +/- 1 degrees. The translational repeatability was tested to be around half a mu m by laser displacement sensors. In addition, we also measured the axial and lateral stiffnesses of the hexapod to be around 5500 N mm(-1) and 1750 N mm(-1), respectively. The kinematic analyses and convincing test results jointly encourage implementing the novel hexapod design with decoupled translation and rotation as a favorable alignment mechanism for secondary mirrors in astronomical telescopes.
ISSN号：1674-4527
是否译文：否
发表时间：2018-08-01
合写作者：娄成英,F70206529,周菲菲,Jin, Zhen-Yu
通讯作者：杨德华