【作者】 于兴滨；

【导师】 张飞虎；

【作者基本信息】 哈尔滨工业大学 ， 机械制造及其自动化， 2014， 博士

【摘要】 在观测系统、激光系统、光刻投影系统等高科技光学系统设计和制造中，为了获得更优越的系统性能，人们越来越多地使用精密、超精密曲面光学元件。对高质量光学曲面的需求使多种光学加工方法获得发展，并与计算机数字控制(CNC)技术相结合，形成了计算机控制抛光(CCP)技术。但是现有的光学加工方法大多受到加工条件的限制而不能应用于小曲率半径凹曲面的加工。超声磁流变复合抛光技术是针对小曲率半径凹曲面进行超精密抛光加工的新方法，在光学制造领域有着广阔的应用前景。本课题对超声磁流变复合抛光面形误差修正技术中的关键问题进行研究，将这种抛光方法与计算机控制抛光技术相结合，实现了平面、小曲率半径凹球面的面形误差修正。本课题的研究为推广应用超声磁流变复合抛光方法进行光学表面的面形误差修正做了技术准备，研究中开发的驻留时间算法和抛光路径规划算法等成果可用于多种类型光学加工方法的计算机控制抛光，对推动我国光学曲面面形误差修正技术的发展具有重要意义。论文主要研究内容包括：基于超声磁流变复合抛光的原理，研制了一套抛光实验装置，为面形误差修正技术的研究奠定了基础。对超声磁流变复合抛光的去除函数的建模方法进行了研究，根据超声磁流变复合抛光原理，通过分析加工区工件表面所受的超声压力、磁场压力和流体动压力，建立材料去除理论模型。通过实验验证了理论模型的正确性。驻留时间求解问题是面形误差修正技术中的关键问题之一，开发了两种驻留时间算法，并对确定驻留时间初值和克服边缘效应的方法进行了研究。通过驻留时间算法仿真分析了不同特性去除函数对加工后表面面形精度以及驻留时间的影响规律。研究了轴对称面形误差的修正方法及其专用驻留时间算法。为了克服驻留时间求解问题的病态性，并满足约束条件，将驻留时间的求解问题转化为一个约束优化问题，并用Thikhonov正则化方法求解，使驻留时间向量的解在满足约束条件时，尽量减小的预期残余误差。提出等驻留单元面积法，解决了确定非平行线抛光路径上驻留点的问题。这种方法使相邻驻留点的驻留单元面积相等，可以在抛光路径上获得均匀分布在工件表面的驻留点。为了解决采用非平行线抛光路径时驻留时间的计算问题，提出了非平行线路径驻留时间误差比例算法，该算法能够直接获得抛光路径上驻留点的驻留时间。为了降低小抛光工具头加工后在工件表面留下的中高频误差，开发了伪随机抛光路径规划算法。开发了边界优化算法对伪随机抛光路径进行优化，使其可高效地应用于各种边界表面的抛光。通过对比伪随机路径抛光前后工件表面的功率谱密度(PSD)值，证明了采用伪随机抛光路径规划算法能降低工件表面的中高频误差。在UG平台上，实现了超声磁流变复合抛光中，工件与实验装置的建模、前置处理、后置处理，并开发了集成仿真与校验(IS&V)系统，实现了面形误差修正加工的数控代码生成和加工过程仿真校验。对于超声磁流变复合抛光面形误差修正过程中的误差源，以驻留时间算法为工具进行仿真分析，研究了定位误差和去除函数误差对材料去除量和预期残余误差的影响规律。用超声磁流变复合抛光面形误差修正技术，在平面和凹球面工件上进行面形误差修正实验，对本文提出的驻留时间算法和抛光路径规划方法进行验证，证明了该技术在制造高质量光学元件方面的可行性。更多还原

【Abstract】 For more superior performance, people apply more and more precision andultra-precision curved optical components in design and fabrication of opticalobservation system, laser system，lithography system and other high-tech opticalsystems. Many novel processing methods have been developed by the requirementfor high quality optical curved surface, and computer controlled polishing(CCP) isengendered by combination of these processing methods and computer numericallycontrolled(CNC)) technology. However，concave surface with small curvature radiusis difficult to fabricate by most of existing technologies for the restriction of theirmachining conditions. Ultrasonic-magnetorheological compound finishing (UMCF)is a new kind of polishing technology for ultraprecision machining of concavesurfaces with small curvature radius and has broad application prospects.The theoretical and technical problems in UMCF figure correction technologyhave been studied in the dissertation. The figure correction of the plane and spherewith small curvature radius is realized by the combination of UMCFmethod and computer controlled technology. The study in the dissertation carrythrough technical preparations for the practical application for figure correction ofoptical curved surface by UMFC, and the dwell time algorithms and polishing pathplanning algorithms developed in the study can be applied in computer controlledpolishing by manifold other polishing technologies. The study has importantsignificance for promotion of figure correction technology for optical curvedsurface.The main aspects of the study are including:An experimental set-up of UMCF has been developed based on the principle ofUMCF, and it is the basis for figure correction study. The study on UMCF removalfunction has been conducted, and the material removal mathematical model isestablished based on the study of the principle of UMCF. The theoretical models areachieved by the analysis of the ultrasonic stress, the magnetic stress and thehydrokinetic stress on the workpiece surface in the polishing zone. The validity of thetheoretical models is examined by the experimental results.The dwell time solution problem is a key issue in the figure correction and,consequently, two dwell time algorithms have been developed. Themethod to determine dwell time initial value and to overcome the edge effect hasbeen studied. The effect of removal functions with different characteristics on surfaceaccuracy after polishing and processing time has been studied by dwell timealgorithm simulation analysis. The figure correction method for axisymmetric figure error and its dwell time algorithm have been studied. The figure correction problemwas solved as a constrained optimization problem, and Thikhonov regularization hasbeen used to achieve small expected residual error and overcome ill-conditioning.The equal dwell unit area method has been developed to solve the problem, howto determine the dwell points on non-parallel polishing path. This method makes thedwell unit areas of the adjacent points equal; thereby dwell points of thepolishing path homogeneous distribution on the workpiece surface can be obtained.In order to solve the problem of the calculation of the dwell time on the non-parallellines polishing path, the dwell time error proportional algorithm fornon-parallel paths has been developed, and the dwell time of the dwell points on thepolishing path can be solved by the algorithm directly. The pseudo-random polishingpath has been developed to remove the mid and high-frequency errors after small toolpolishing. The boundary optimization algorithm has been developed to optimizepseudo-random path, thereby it can be used in polishing workpiece surface of anyboundary shape efficiently. The power spectral density (PSD) of surface before andafter polishing with pseudo-random path has been analyzed and the result indicatedthat the high frequency error can be reduced by the application of pseudo-randompath. Workpiece and the experimental device modeling, preprocessing andpost-processing have been achieved, and the integrated simulation, and verification(IS&V) has been developed. The generation of NC code for UMCF figure correctionand process simulation verification have been achieved.The analysis of error source in the UMCF figure correction process has beenconducted. A dwell time algorithm was used as a tool for simulation study, and theeffect of the positioning error and removal function error on material removal andresidual error has been studied.Figure correction experiments on planar and spherical surfaces have beenconducted by UMCF figure correction technology, and it validate the effectiveness ofthe dwell time algorithms and polishing path planning algorithms. The security ofUMCF in fabrication of high quality optical components is proved by figurecorrection experimental results.更多还原