鉴于当前光学抛物面面形参数计算模型的复杂性, 为解决直接基于抛物面的有限元分析数据, 获取高精度抛物面面形参数的计算问题, 提出了一种新的光学抛物面形参数计算方法。首先, 提出了光学抛物面有限元离散误差的概念, 并对其消除技术进行了研究, 这也是高精度算法的关键数据处理环节; 其次, 采用刚体位移数据处理算法分离了抛物面面形的刚体位移与面形畸变位移; 最后, 采用最优化设计算法获取了抛物面面形均方根等参数计算所需的基础数据。在对抛物面面形参数计算方法研究的基础上, 讨论了其算法实现, 并对算法程序的正确性进行了校验。校验结果表明: 高精度抛物面面形参数计算方法计算精度高, 算法校验误差在6%左右, 该算法精度能够满足工程需求; 为外部热力载荷作用下, 光学面形参数的高精度计算提供了新的技术参考。

Due to the complexity of calculating model for the current optical parabolic surface and to acquire the high-precision surface based on the data of finite element analysis for parabolic surface, a new high-precision algorithm of surface parameter for optical parabolic surface was proposed. Firstly, the discrete error of the optical parabolic surface was proposed, and elimination technique of discrete error was researched, which was also the crucial step for the data preprocessing of the surface parameter calculation. Secondly, the rigid body displacement and surface distortion displacement were distinguished with the data processing algorithm based on rigid body displacement. Lastly, the basic data to obtain parameter, just as the root mean square, was got using the optimal design algorithm. The algorithm realization of the high-precision parabolic surface parameter was discussed and the validity check of the algorithm was performed as well. The result of validity check demonstrated: the high-precision algorithm of parabolic surface parameter is higher, and the check error is about 6%. The precision of new algorithm can satisfy the engineering requirement, and it also provides a new technical reference for the high precision calculation of optical surface parameter under the external thermal load.