光学系统中,为防止像差的引入造成成像质量下降,光学元件的准直与间距必须严格保证。所以,在光学仪器接口设计过程中,提高接口的重复性定位能力和降低接口的接触应力水平是非常重要的。在30 m望远镜(TMT)三镜系统设计过程中,三镜作为Ritchey-Chirtien(R-C)式光学系统中重要的光学元件,需严格保证其位置和姿态。三镜系统寿命周期中,由于清洗、镀膜的要求,需要多次拆装,为保证装配精度,需设计了一套定位用运动学接口。从运动学定位原理出发,使用赫兹接触理论以及IBM磨损理论对运动学接口进行了相应校核,并分析了影响运动学接口重复性定位精度的相应误差源,使用蒙特卡罗方法进行了相应仿真。另外,以三镜面形作为评指标,使用Ansys软件模拟了运动学接口,研究了接口参数对于三镜面形的影响。分析结果显示,在现有的设计及精度下,接口的接触应力水平满足使用要求,三个方向的重复性定位精度以及支撑效果能够达到设计指标。 Optical systems, in order to prevent the introduction of aberration caused by the decline in image quality, optical components of the alignment and spacing must be strictly guaranteed. Therefore, it is very important to improve the repetitive positioning ability of the interface and reduce the contact stress level of the interface during the design of optical instrument interface. Three mirrors are important optical elements in a Ritchey-Chirtien (R-C) optical system during the TMT three-mirror system design. Their position and orientation are strictly guaranteed. Three mirror system life cycle, due to cleaning, coating requirements, the need for multiple disassembly, in order to ensure assembly accuracy, the need to design a positioning kinematic interface. Based on the principle of kinematic positioning, the kinematic interface was checked using Hertzian contact theory and IBM wear theory, and the corresponding error sources that affected the repeatability of the kinematic interface were analyzed. The Monte Carlo method was used to simulate the kinematic interface. . In addition, using the three-mirror shape as the evaluation standard, Ansys software was used to simulate the kinematic interface and the influence of interface parameters on the three-mirror shape was studied. The analysis results show that under the existing design and accuracy, the contact stress level of the interface meets the requirements of use. The repeatability positioning accuracy and the support effect in three directions can reach the design indexes.