Research on Position-orientation Error Analysis and Test for a New-style Adjustment Mechanism of Secondary Mirror
Abstract
In order to satisfy the structure positioningaccuracy requirement of the telescope secondary mirror, an axial translational motion model for the fixed length rod end of hexapod is proposed. According to the structure and motion mode of the hexapod, the error sources of the end position-orientation are analyzed, and the influence of sliding block motion error on the operation accuracy of the hexapod is particularly discussed. Finally, the hexapod is tested by building a multi-degree-of-freedom detection platform. The test results show that: in the range of the whole moving distance, for the secondary mirror hexapod, the testing accuracy of the translational axis is better than 0.25 μm, accuracy of the rotation axis is better than 0.2''; the maximal repositioning accuracy of the two-dimensional rotation axis is better than 1.4'', and the maximal three-dimensional translational axis variation is less than 4 μm; the maximal repositioning accuracy of the three-dimensional translational axis is better than 4.5 μm, and the maximal two-dimensional axis variation is less than 3.4''. The design analysis and experiment results have showed that the movement error of sliding block caused by the straightness of the rail is the main factor affecting the accuracies. The hexapod can satisfy the needs of actual telescope observations, and it also can provide reliable technical support to build large diameter optical infrared telescope for our country.
- Publication:
-
Acta Astronomica Sinica
- Pub Date:
- March 2018
- Bibcode:
- 2018AcASn..59...18Y
- Keywords:
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- precision instrument;
- telescope;
- secondary mirror;
- methods: data analysis