【作者】 徐勇；

【导师】 殷跃红；

【作者基本信息】 上海交通大学 ， 机械电子工程， 2016， 博士

【摘要】 空间光学镜面采用SiC、微晶玻璃等难加工硬脆材料,其加工效率并不高,随着镜面尺寸的增大,镜面的加工效率成为制约光学系统发展的关键问题之一。作为光学镜面加工工序中重要的一环,光学镜面研磨普遍采用时不变去除函数的加工方式,存在效率不高并且边缘效应明显的问题,对后续工艺的效率产生了极大的影响。此外,随着镜面尺寸的增加,机床刚度对跨度的限制使得传统的研抛机床并不完全适应大口径光学镜面的加工需求。因此,大口径光学镜面的高效研磨方法是光学镜面加工工艺的关键问题之一。传统研磨中的常压加工方式限制了加工效率的进一步提高,而变压强研磨能克服这种极限,显著提高光学镜面研磨工序的加工效率。本文以变压强研磨为研究对象,对变压强研磨加工过程中工件材料的去除效率及影响因素进行研究,根据误差曲面特性进行轨迹、压强和驻留时间规划,并对边缘效应进行处理。本文的主要工作及成果归纳如下:一、针对大口径镜面研磨加工效率低,根据磨粒分布与磨粒运行形式,建立变压强条件下压强与研磨盘、工件距离的映射关系,推导变压强下滑动、滚动有效磨粒分布,结合研磨去除机理推导其去除函数,建立变压强下去除函数与压强的非线性映射,提出变压强研磨数学与力学原理,并通过实验验证了变压强下研磨去除函数模型的准确性。模仿手动研磨经验,根据误差曲面特性规划压强区域,采用蚁群算法对驻留时间算法中的压强区域进行排序,从而实现驻留时间、压强与轨迹规划,在连续轨迹加工中实现对高误差区域的快速加工以及低误差曲面的微量加工,极大缩短了光学镜面研磨工序时间。建立大型光学镜面机器人研磨平台,通过音圈电机研磨工具实现压强的快速响应,实验结果证明变压强研磨相比传统恒压研磨,镜面加工时间减少30%,在保证收敛率的同时能显著提高加工效率。二、根据Preston方程的弧长微分形式,推导出基于机器人实现的任意轨迹去除函数形式,结合边缘效应特征,提出了一种不露边的研磨盘运动形式,得到窄边光滑的去除函数,提高了对边缘效应的抑制能力。三、加工状况实时反馈理解的柔顺加工方式是光学镜面研磨加工的发展方向。通过力感知实现接触力对未知环境的理解初步探讨了柔顺加工的理论基础。力位混合标架是力感知的基础,通过力感知实现对未知表面的快速跟踪。更多还原

【Abstract】 SiC and Zerodur is material often used in spacing optics.This material is hard and brittle,difficult to manufacture.With the increasing size of optics,the effectiveness of optics manufacture has become a key problem in optics system.As an important part in optics manufacturing process,lapping in computer controlled optics surfacing(CCOS)use time-invariant tool influence function(TIF)and features with low removal rate and edge effect,this had a bad impact on the subsequent process.The structure of lathe is no longer suit for optics lapping as the size become larger.High effective lapping method for large optics is an extreme important problem in optics manufacturing.1.Lapping with varied pressure is proposed to increase the efficiency.With varied lapping pressure,the transforming distance between the pad and workpiece changes the abrasive number participating in lapping,as well as the pressure on each abrasive.It results in varied proportion of movement pattern of abrasive and corresponding removal pattern.Removal mechanism and nonlinear removal rate with varied lapping pressure distinct from Preston’s equation is deduced through the collective removal behavior of abrasive.Bio-inspired from handwork lapping,surface characteristics of error profile and pressure distribution along the trajectory is obtained.The results point out that pressure-variant lapping contributes to further decrease the process time,and thus to make a computer controlled lapping process more efficient.The platform for large optics robot lapping is established.Varied pressure is realized through voice coil motor.The reduction of the process time was observed to approximately 30% using a combination of the dwell time method with pressure-variant tool influence function compared to stable pressure lapping.2.Arc length edition of Preston’s equation is proposed to obtain tool influence function with arbitrary trajectory.Trajectory with no edge across is deduced to solve the problem of edge effect.3.Compliant lapping would be a develop direction for optics lapping.Work status is derived from force sensing to understand the lapping situation and better arrange the process parameter.Force and position frame from contact force serves as theoretical foundation for compliant lapping,and tracking of unknown surface with high speed demonstrates the effectiveness of this idea.更多还原