Optimal design of a 2.7 m standard spherical inspection mirror support

Aiming at the problem that the decrease of inspection accuracy caused by an increase in the diameter of a spherical inspection mirror, the weight support parameters of the 2.7-meter standard spherical mirror are optimized and the structural design of its adjustment frame and support system is implemented. Firstly, the 54-point equal-force support ring is optimized for the mirror body using a finite element and genetic algorithm. In order to increase the rigidity of the mirror body when increasing the nesting hole, the bottom support force and the side support force of each ring are optimized separately and the influence of support radius and support force error on the support deformation is statistically analyzed. Finally, based on the analysis results, a structural frame of the standard inspection mirror and a support system are designed. The analysis results show that after optimization of the 54-point support position of the standard spherical mirror, the bottom support force and the side support force of each ring and under the condition that the spherical mirror support deformation is less than 1/115 lambda(lambda=632.8 nm), the bottom support position is disturbed by +/- 2 mm, the side support position is disturbed by +/- 0.6 mm, and the support force disturbance is +/- 3 N, the support deformation is less than 1/70 lambda, which shows little deterioration. This meets the requirements of standard spherical mirror support.