【作者】 杨杰；

【导师】 朱志伟；

【作者基本信息】 南京理工大学 ， 机械电子工程， 2024， 硕士

【摘要】 超精密主轴作为超精密机床的核心功能部件,能够准确测量出其平面内径向运动误差和平面外偏摆运动误差与轴向运动误差共五个自由度的运动误差对于最终加工精度的提高十分重要。对此,本文提出了一种基于白光干涉增强显微视觉测量方法,研制了一套结构简单紧凑的测量装置,实现了通过工业相机采集的单张灰度图像就可以得到该时刻主轴五自由度运动信息,再分析计算测试工件安装误差和加工误差对运动测量数据的影响,准确分离出超精密主轴五自由度运动误差,并且采用数值模拟方法验证了测量方法的可行性,最终完成测量实验并评定了不确定度。本文的主要的工作和贡献在于:(1)针对常规白光干涉测量相对高度方法中每次测量都需要进行高精度扫描运动的问题,提出了直接标定干涉光强与相对高度的映射关系,在不改变干涉光路中各元件参数情况下,只需要完成一次扫描就可以用于后续所有测量,限定测量范围为干涉零级亮条纹至第一级暗条纹之间,实现了高度测量时的高精度与高敏感度,并以该方法作为后续主轴平面外运动测量的基础。(2)针对超精密主轴五自由度运动误差测量装置结构复杂传感器昂贵受限的问题,研制了白光干涉增强的显微视觉测量装置,采用普通工业相机和常规光学元件,在同一光路中同时实现白光干涉和显微成像,通过采集的灰度图像就可以实现五自由度运动误差的测量。(3)提出了白光干涉增强五自由度运动误差测量方法,通过测试工件圆形轮廓圆心位置变化表征主轴平面内径向运动,通过测试工件表面中心高度变化表征平面外轴向运动,通过测试工件表面法向量变化表征平面外偏摆运动,实现了超精密主轴五自由度运动的测量。并且建立了测量方法的数学模型进行数值模拟计算,仿真结果验证了算法的可行性。(4)针对传统误差分离方法中需要依靠多传感器在多位置多步完成误差分离的问题,提出了在本文白光干涉增强显微视觉测量中的误差分离方法,借助最小二乘圆拟合和平面拟合将测试工件安装误差和加工误差对测量数据的影响转换为可以直接简单滤除的一次谐波分量,大大简化了误差分离方法的操作与计算步骤。(5)开展了分辨率测量实验证明测量方法的准确性,对超精密主轴运动误差进行了测量,得到了主轴运动误差与转速的关系,建立实验时的测量模型并采用了蒙特卡洛方法评定了测量结果具有较低的不确定度。更多还原

【Abstract】 Measurement of five-degree-of-freedom(5-DOF)error motions involving radial,axial,and tilt motions are crucial for ultra-precision spindles,which are the key components for ultra-precision machine tools.this paper proposes a method based on white light interference-enhanced micro-vision measurement,developed a set of simple and compact structure of the measurement device,which can derive the 5-DOF motions from a single-shot two-dimensional image captured by a standard industrial camera,and then analyze the calculation of the workpiece mounting error and machining error on the motion measurement data,accurately separated the 5-DOF error motions of the ultra-precision spindle,and numerical simulation methods to verify the feasibility of the measurement method,and finally complete the measurement experiment and assess the uncertainty.The main work and contributions of this paper are:1.Aiming at the problem that each measurement in the conventional white light interferometric relative height measurement method requires a high-precision scanning movement,we propose to directly calibrate the mapping relationship between the interferometric light intensity and the height,and limit the measurement range between the interferometric zero-level bright fringes and the first level of dark fringes,so that without changing the parameters of the components in the interferometric optical path,only one scanning needs to be completed and it can be used for all the subsequent measurements,thus high precision and high sensitivity are achieved,and the method is used as the basis for subsequent spindle out-of-plane motion measurements.2.for the problem of complicated structure and expensive sensor limitation of 5-DOF error motions measurement device of ultra-precision spindle,a white light interference-enhanced micro-vision measurement device is developed,which adopts ordinary industrial camera and conventional optical elements to achieve white light interference and micro-imaging in the same optical path at the same time,so that the measurement of 5-DOF error motions can be achieved by the collected grey scale image.3.A white light interference-enhanced micro-vision measurement method is proposed to achieve the measurement of 5-DOF error motions of the ultra-precision spindle.by testing the change of the position of the center of the circular contour of the workpiece to characterize the in-plane radial motion of the spindle,the change of the height of the center of the surface of the workpiece to characterize the out-of-plane axial motion,and the change of normal vectors on the surface of the workpiece to characterize the out-of-plane tilt motion.The mathematical model of the measurement method is established for numerical simulation calculation,and the simulation results verify the feasibility of the algorithm.4.Aiming at the problem that traditional error separation methods need to rely on multiple sensors in multiple locations and multiple steps to complete the error separation.An error separation method for the white light interference-enhanced micro-vision measurement is proposed,which converts the influence of the installation error of the test workpiece and the machining error on the measurement data into the first harmonic component that can be filtered out directly by the help of the least-squares circle fitting and plane fitting,which greatly simplifies the operation and computation steps of the error separation method.The operation and calculation steps of the error separation method are greatly simplified.5.The resolution measurement experiment was carried out to prove the accuracy of the measurement method.The ultra-precision spindle motion error was measured,the relationship between the spindle motion error and the rotational speed was obtained.The measurement model during the experiment was established,and the Monte Carlo method was used to assess the measurement results with a low degree of uncertainty.更多还原