精密旋转轴六自由度误差同时测量方法研究

Precision rotary axis is a key component of ultra-precision machining equipment. Its motion precision largely determines the machining precision and capability of the equipment. The evaluation and guarantee of the motion accuracy of precision rotating axis depend on effective measurement of the rotating accuracy. In view of the fact that the existing precision rotary axis motion accuracy detection technology cannot take into account high accuracy, high efficiency, dynamic continuity, complete error measurement and convenient installation, this project proposes a method of simultaneous measurement of six-degree-of-freedom errors of precision rotary axis based on standard micro-nano structure feature measurement and analysis. First, this research have designed standard samples with micro-nano structure features that are capable of carrying six-degree-of-freedom errors of rotary axis. After that, the decoupling model of the six-degree-of-freedom errors of the precise rotary axis based on standard micro-nano structure feature is established. Next, dynamic and high-precision absolute measurement of standard micro-nano structure feature is carried out by using the characteristics of non-contact, full-field, high-precision, fast and absolute measurement of multi-wavelength phase-shifting interferometry technology. Finally, the high-precision extraction and matching algorithm of the space position and attitude parameters of standard micro-nano structure feature is studied and combined with the error decoupling model to analyze the six-degree-of-freedom errors of rotary axis. This project constructs a system that realizes simultaneous measurement of six-degree-of-freedom errors with dynamic continuity, fast speed, high accuracy and easy implementation.

精密旋转轴是超精密加工装备的关键部件，其运动精度在很大程度上决定装备加工精度水平和能力。精密旋转轴运动精度评价和保证有赖有效的旋转运动精度检测手段。针对现有精密旋转轴运动精度检测技术无法兼顾高精度、高效率、动态连续、误差完整测量和安装便捷等，本项目提出研究一种基于标准微纳结构特征测量与分析的精密旋转轴六自由度误差同时测量方法。主要内容包括：研究设计易于携带旋转轴六自由度误差的标准微纳结构特征样件；建立基于标准微纳结构特征的精密旋转轴六自由度误差解耦模型；利用多波长相移干涉非接触、全场、高精度、快速与绝对测量的特点，研究标准微纳结构特征动态高精度绝对测量方法；研究标准微纳结构特征空间位姿参数高精度提取与匹配算法，结合误差解耦模型，实现精密旋转轴六自由度误差解析。本项目所建构的精密旋转轴六自由度误差同时测量系统具有六自由度误差同时测量，动态连续，速度快、精度高、实施方便等优点。

精密旋转轴系是超精密加工设备中不可或缺的关键部件，运动误差补偿是进一步提高加工精度的有效途径，如何对精密旋转轴运动误差进行有效地高精度、高效率、动态连续及全面的测量对现有技术提出挑战。项目提出基于绝对位移测量的精密旋转轴六自由度误差同时测量方法。区别于传统方法从旋转轴的径向对旋转轴误差进行测量，本方法从旋转轴的轴向对旋转轴误差进行测量，可以实现对精密旋转轴六自由度运动误差同步、准确、快速、动态连续测量，能更好地表征旋转轴的运动精度。重点研究了一种用于绝对位移测量的基于单彩色相机与棱镜分光的多波长相移干涉显微镜测量系统，提出了一种多通道相移干涉图整体失配评价与迭代配准方法，解决了空间分光同步相移干涉系统的干涉图失配问题；提出了一种基于参数预标定的非理想同步相移干涉包裹相位计算方法，解决了空间分光同步相移干涉系统光强分配不均与干涉图相移不准问题；特别设计了易于携带精密旋转轴六自由度误差的微结构特征，获取被测旋转台运动的瞬时绝对空间位姿；建立了精密旋转轴六自由度误差解耦模型，对测量得到的系列微结构特征表面瞬态空间位姿数据进行分析，分离出六自由度误差；搭建了精密旋转轴六自由度误差同时测量系统，开展了系统标定与测试，实现随旋转轴运动的微纳结构特征样件瞬时绝对测量。通过精度测试，验证了所建立的多波长相移干涉显微镜的测量精度；通过对精密气浮回转台测试，验证了本方法的有效性和准确性。以上研究内容和研究成果，对于精密旋转轴的设计、制造、误差补偿及超精密加工技术的发展都具有重要意义。