Optimization design method for Whiffletree support point position of primary mirror and sub-mirror models of telescope

Abstract

The invention discloses an optimization design method for a Whiffletree support point position of primary mirror and sub-mirror models of a telescope. The method comprises the following steps that (1)a sub-mirror model is simplified; (2) the quantity of Whiffletree support points is determined, and parametric representation is carried out on each support point; (3) parametric models of the sub-mirror and support points are constructed, initialization is carried out, constraint and loading are applied to perform first statics analysis, and all nodal displacement on the upper surface of the sub-mirror is obtained; (4) root-mean-square values RMSs of all the nodal displacement are calculated; (5) a position parameter of each support point is taken as an optimization variable, the minimum RMSis taken as an optimization objective, so that the optimization is carried out, and the optimized Whiffletree support point position is obtained. According to the method, whole process steps and parameters used by each key step of the optimization method are improved, reasonable support point position parameters can be obtained, and the surface precision of the upper surface of the sub-mirror satisfying design requirements is obtained.

Description

technical field [0001] The invention belongs to the fields of astronomy and mechanical automation, and more particularly relates to an optimal design method for the position of a Whiffletree support point of a main mirror mirror model of a telescope. Background technique [0002] With the development of modern astronomical technology, the requirements for the imaging capability of the telescope are getting higher and higher, and its aperture is also getting bigger and bigger. From the perspective of the construction, grinding, transportation and cost of the telescope's primary mirror, when the diameter of the telescope exceeds 8m, it is very difficult in any of the above aspects. And when using splicing mirror technology, the main mirror is composed of many sub-mirrors. As long as the rigidity of the sub-mirrors is sufficient, the weight and thickness of the main mirror will be greatly reduced, and large-sized mirror grinding machines and coating machines are not needed. Th...

AI Technical Summary

Problems solved by technology

Due to the gravity of the mirror itself, the design of the position of the axial support point will directly affect the surface shape accuracy of the upper surface of the sub-mirror, so the arrangement of the axial support point will greatly affect the final imaging quality

The traditional design method is to roughly confirm the position of the support point according to the position of the center of mass, and then use the interpolation method to verify one by one until the ideal surface shape accuracy requirement is reached, but this method is time-consuming and laborious, and it is likely to obtain a local minimum instead of the optimal value

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