基于光谱共焦原理的五轴数控机床工件在位测量系统  

A workpiece in-place measurement system for 5-axis CNC machinetools based on spectral confocal principle

作　　者：贺帅宇 周涛 金玲兴 荣佑民 刘秀峰 He Shuaiyu;Zhou Tao;Jin Lingxing;Rong Youmin;Liu Xiufeng(School of Mechanical Science&Engineering of HUST,Wuhan 430074,China;Sichuan Precision and Ultra-Precision Machining Engineering Technology Center,Chengdu 610200,China;Taizhou Eastern CNC Equipment Co,Taizhou 318000,China;School of Physics and Mechatronic Engineering,Hubei University of Education,Wuhan 430074,China)

机构地区：[1]华中科技大学机械科学与工程学院,武汉430074 [2]四川省精密超精密加工工程技术研究中心,成都610200 [3]台州市东部数控设备有限公司,台州318000 [4]湖北第二师范学院物理与机电工程学院,武汉430074

出　　处：《仪器仪表学报》2025年第1期75-82,共8页Chinese Journal of Scientific Instrument

基　　金：工信部高质量发展专项(J0017-2326-QT);湖北省教育厅科学研究计划项目(Q20233006)资助。

摘　　要：精密光学元件目前广泛应用于天文观测、空间对地观察、投影光刻物镜等诸多重要的领域,其具有高表面质量、高面形精度、低表面损伤等特点。光学元件精加工的最后一道工序一般为抛光,光学元件进行抛光加工时,需要经历“测量-加工”的反复迭代过程以实现纳米级面型精度和亚纳米级表面粗糙度。因此,数控抛光加工时在对工件待加工表面面型离线测量后,需要在机床上对工件进行二次安装及找正,对工件位姿进行精确定位以保证后续的加工精度,而传统的接触式找正或定位方法存在效率低下、易划伤工件表面等问题。为此,基于光谱共焦传感器构建了立式五轴机床非接触式在位测量系统,建立了该测量系统获取工件表面坐标数据的数学模型及光谱共焦传感器在机床上标定的数学模型,利用球面约束方程提出了基于标准球的补偿标定的方法,并在磁流变抛光机床上开展了实际的标定实验,验证了标定方案的可行性和精确性。最后进行工件位姿测量实验,通过雷尼绍三坐标接触式在位测量系统对光谱共焦非接触式在位测量系统的工件位姿测量精度进行了验证。实验结果表明本文所提出的光谱共焦非接触式在位测量系统测量标准球的直径误差<6μm,工件定位误差<10μm,能够满足磁流变抛光实际的定位要求。Precision optical components are widely used in many important fields such as astronomical observation,space observation,projection lithography objective,etc.They have the characteristics of high surface quality,high profile accuracy and low surface damage.The last process of optical element finishing is polishing.When optical element is polishing,it needs to go through the iterative process of“measurement-processing”to achieve nano level surface accuracy and sub-nano level surface roughness.Therefore,after the off-line measurement of the surface shape of the workpiece to be machined,the workpiece needs to be installed and aligned on the machine tool twice,and the workpiece position and posture are precisely positioned to ensure the subsequent processing accuracy,while the traditional contact alignment or positioning method has problems such as low efficiency and easy to scratch the surface of the workpiece.Therefore,based on the spectral confocal sensor,this paper constructed a non-contact in-place measurement system for vertical five-axis machine tool,established the mathematical model for the measurement system to obtain the workpiece surface coordinate data and the mathematical model for the calibration of the spectral confocal sensor on the machine tool,and proposed a compensation calibration method based on the standard ball by using the spherical constraint equation.The feasibility and accuracy of the calibration scheme are verified by practical calibration experiments on magnetorheological polishing machine tools.Finally,the position and pose measurement experiment of the workpiece is carried out,and the accuracy of the position and pose measurement of the spectral confocal non-contact in-place measurement system is verified by Renishaw three-coordinate in-place measurement system.The experimental results show that the diameter error of the standard ball is less than 6μm and the workpiece positioning error is less than 10μm,which can meet the actual positioning requirements of Mr Polishing.Precision

关 键 词：光谱共焦传感器 标定 在位测量 工件定位 

分 类 号：TH-39[机械工程] TH705