共形曲面光学窗口高精度低损伤制造关键技术研究

The conformal optical windows is one type of special windows, it requires not only high-precision (sub-micron) but also low-damage (micron) due to its high-speed or high-temperature application. The conformal surface is non-rotationally-symmetric, its inner and outer surface are both freeform surfaces. In addition, the conformal surface is non-monotonic, and the rate of curvature change, the surface slope as well as the normal vector all change fast. These manufacturing properties make it much more difficult to manufacture high-precision and low-damage conformal surface. As there is no corresponding theory and process, the fabrication of conformal surface exhibits low machining precision, passive damage control, and lack of optimization of precision and damage. This proposal adopts few-axis grinding and ultrasonic-assisted local error figuring method to correct the surface form error and realizes the synergism control of geometric error based on the interactive and couple principle. The high-precision positioning is realized by machining position and attitude identifying technique, the match model of precision and damage is established based on the model, principle, as well as evolution of damage. The ratio of damage and precision is also regarded as the evaluation criterion of damage and precision, and the optimization of precision and damage is researched to establish high-precision, high-efficiency, and low-damage process route. These key techniques tend to solve the difficult problems in the manufacturing process, and supplies technical support for the widespread application of conformal optical windows.

共形曲面光学窗口是一类特殊的光学观察窗口，其高速、高温的使用环境决定其同时具有高精度（亚微米量级）和低损伤（微米量级）的制造要求。共形曲面具有非回转对称形状，内外面均为自由曲面，且曲面具有非单调性、大曲率变化率、面形斜率及法向量变化剧烈等制造特性，使得共形曲面高精度低损伤的制造难度大大增加。由于缺乏相应的理论和工艺，共形曲面制造目前面临加工精度不足，损伤控制被动，精度损伤控制没有优化等突出问题。本项目采用少轴磨削和超声辅助局部误差修研的方式实现共形曲面误差修正，基于形位误差的交互耦合规律实现形位误差的协同控制，采用加工位姿辨识技术实现共形曲面的高精度定位，基于曲面的低损伤模型、规律和演变特性，提出以损伤精度比为评价指标的精度损伤匹配关系模型，最终建立精度和损伤的综合优化控制方法，形成高精高效低损伤的加工工艺路线，解决共形曲面的制造难题，为共形曲面光学窗口的广泛应用提供技术支撑。

共形曲面光学窗口在航空航天、军事观测等领域应用广泛，一般具有高精度和低损伤的制造需求。由于需要满足光学系统的特殊形状或者气动力学要求，其表现出表面非单调性、大曲率变化率、面形斜率变化及法向量变化剧烈等典型特征，加工精度和损伤控制都成为限制共形曲面应用的瓶颈问题。本项目通过研究磨削形位精度的内在控制机理，采用少轴磨削和辨识补偿的方法实现共形曲面的精度提升；通过揭示共形曲面磨削的损伤产生机理，掌握损伤的分布及扩展规律，提出共形曲面的损伤控制工艺方法；通过研究精度和损伤的协同匹配问题，建立共形曲面的综合加工工艺路线，在复杂曲面观测窗口和楔形透镜样件上得到了验证，取得了较好效果，为共形曲面的进一步应用提供了技术支撑。