【作者】 吴晓峰；

【导师】 张国雄；

【作者基本信息】 天津大学 ， 测试计量技术及仪器， 2007， 博士

【摘要】 三坐标测量机以其精度高、柔性强等特点在现代化的生产和先进制造、航空航天和国防等领域中起着越来越重要的作用。随着科学技术的进步和国家对国防事业的重视,特别是未来武器装备的发展,如新“机”、“弹”、“星”种的不断发展,其中的一些关键精密零部件的结构越来越复杂、精度越来越高,对三坐标测量机的测量精度的要求也越来越高。本论文正是针对提高三坐标测量机的测量精度开展研究工作。提高测量精度不仅包括减小三坐标测量机的机械结构误差、测头的探测误差,还包括减小由环境条件和使用条件带来的测量不确定度等。本论文提出了以三个坐标方向上分别使用激光干涉仪进行位移检测、并配用三维传感器式精密测头的三坐标测量系统。论文通过对激光三坐标测量系统、三维传感器式测头、实时位置控制系统、误差补偿技术和小环境控制技术的研究,提高三坐标测量机的检测精度。本课题的研究内容主要包括:(1)超精密三维测量系统机械结构技术研究;(2)超精密激光位置检测与测量控制技术研究;(3)高精度三维电感模拟量测头系统研究;(4)三维测量过程与结果的数据处理技术研究;(5)三维测量技术的误差分离与补偿技术研究;(6)小环境控制技术研究。本论文的创新性体现在:1、设计并研制一种符合运动学原理、阿贝原则、动力学装配要求、且刚性好的机械结构;本系统核心的精密气浮导轨采用小孔节流技术,实现了导轨运动精度优于0.05μm /500mm,刚性提高到250N/μm。2、采用He-Ne激光干涉仪作为在线位置检测替代了传统的光栅尺测量技术,并稳定地实现纳米级实时位置检测和闭环控制,其位置检测分辨率达到0.01μm,实时性优于2ms。3、研制了采用精密电感位移检测技术的高精度三维测头,实现保持沿法线方向触测的点位测量和连续扫描测量,并提出了几何元素修正(多次迭代)的方法实现对测头的误差补偿,使测头的空间测量不确定度减小到0.2μm。4、采用一种多CPU分布式实时位置控制算法以及减速折线近似、在线位置修正和平滑处理等技术,有效地提高了位置随动系统的实时性和空间跟踪性能,实现了高精度位置的动态控制和实时测量。更多还原

【Abstract】 Coordinate Measuring Machines (CMMs) are playing more and more important role in modern production, advanced manufacture technology, aviation, space flight, and national defense industries since they possess high measuring accuracy and flexibility. With the rapid development of science and technology, more attention paid by the government to the national defense, and the development of new airplanes, bombs and satellites, high measurement accuracy and capability of measuring parts with complicated forms are essential for CMMs. This thesis focuses on the enhancement of CMM measurement accuracy.The enhancement of measurement accuracy includes reduction of structure and probing errors of the CMM, reduction of the uncertainties caused by the environmental factors during measurement. In this thesis, a CMM with three interferometers used for X, Y, and Z direction displacement measurements and a 3-dimensional inductive analog probe is designed. Based on the study of laser interferometric system, 3-dimensional inductive analog probe, real-time position control system, error compensation technology and small-volume environmental control technology, high measurement accuracy has been achieved.The main contents of the thesis include: (1) study on the mechanical structure of the super-accurate CMM, (2) study on the position measurement and control technologies using ultra-accurate laser interferometers, (3) study on high accurate 3-dimensional inductive analog probe, (4) data processing technology in the measurement process and that of the measurement results. (5) study on the coordinate measurement error separation and compensation technologies, (6) study on the small volume environmental control technology.The main creative ideas and innovations of the thesis include the follows.1. A new mechanical structure is proposed and designed. This structure complies with the principle of kinematical design, Abbe , meets the dynamics requirements in assembly and possesses good rigidi ty. The core of the structure is the use of precision air-floating guides with small-hole throttle technology, which offers a motion straightness accuracy of 0.05μm /500mm, and a rigidity of 250N/μm。2. He-Ne laser interferometers are used in the displacement measurement to replace the traditional grating scales. By using this technique high stable and nanometer precision displacement measurement and closed-loop control have been achieved. The displacement measurement resolution reaches 0.01μm, and the response time is less than 5ms.3. A high precision 3-dimensional inductive analog probe is developed to realize the point to point position measurement in the normal direction and continuous scanning measurement. A method for compensating the probe error based on geometric element correction by using repeated iteration is designed. The volumetric measurement uncertainty of the probe has been reduced to 0.2μm.4. A multi-CPU distributed real time position control algorithm with deceleration broken-line approximation, and on-line correction and smoothing is developed to achieve dynamic position control and real time measurement with high accuracy, and to improve the space tracking property of the CMM.更多还原