基于新型柱面光栅的高精度测角传感理论与技术

Cylindrical grating angle sensor has its own characteristics in respect of optical characteristics, etching error, shafting error, installation error, signal-to-noise ratio and environmental interference compared to the ordinary transparent glass grating. Especially due to the reflecting arc surface of the cylindrical grating the effects of relative displacement of graduation line and gap variation will interact. Preliminary results by applicant showed that significant residual errors still exist even with high precision cylindrical grating and double reading heads located at two ends of diameter. Therefore further study on the error generation mechanism and error characteristics of cylindrical grating is necessary for the use and fabrication of such kind of sensor. This project will focus on the adaption of multiple reading heads device, analysis of angle measurement error by reading heads distribution and its number and verification the validation of compensation by multiple reading heads. The project is featured by the combination of both theory and experiment. The Study of error generation mechanism and error characteristics of cylindrical grating is exploratory, which will lay the theoretical foundation for the correct use and error compensation of the sensor, and also for independent manufacture of high-precision cylindrical grating sensor by our own in the future. Furthermore, online self-calibration techniques have vital significance to develop high-precision and miniaturized optical angle measurement sensor, which will meet the urgent requirement for our domestic manufacturing industry and national defense industry.

柱面光栅测角传感器在光学特性、刻划误差、安装误差、轴系跳动、信噪比及环境干扰等方面具有很大的独特性，特别是由于柱面光栅的反射面为圆弧面，刻线相对位移的影响和间隙变化的影响交织在一起。申请人的初步实验表明，即使采用高精度柱面光栅和双头对径读数的方法也仍然有显著的残余误差。对柱面光栅的误差生成机理和误差特征进行深入研究，才能正确使用和研制该传感器。建立多头读数装置，验证读数头分布和数量取舍对测角误差的影响和对最终补偿效果的作用是本申请理论联系实际的特色之处。研究柱面光栅传感器的误差生成机理和误差特性是一项具有探索性的课题，是正确使用和自主制造高精度柱面光栅传感器和研究误差补偿技术的理论基础，在此基础上研究在线自校准技术是实现高精度、小型化光学测角传感器的必要手段，满足国民经济与国防建设的迫切需求，在制造和应用层面上均有重要意义。

本项目的主要研究内容包括三大部分：柱面光栅测角系统误差传递机理和误差补偿算法研究，多头读数对测角误差的抑制机理，测角系统误差自校准方法，以及相关的实验验证。在误差分析方面，搭建了柱面光栅测角误差标定装置，对测角系统的安装误差，刻划误差以及读数头细分误差等周期性误差和轴系晃动等随机误差进行了分离和分析，建立了误差模型；研究并比较了多种误差补偿算法，包括线性补偿算法、三次样条补偿算法、多项式补偿算法和谐波误差补偿算法等。开展了误差检测和补偿实验，比较了补偿效果。在多头读数对测角误差抑制的机理研究方面，分析了多头读数对柱面光栅测角误差抑制的机理，推导了相关公式，在此基础上，提出了多头读数优化布局方式，并开展了多头读数误差抑制实验，验证了相关的公式和布局方式。在自校准方法，完成了自校准方法的理论研究，编写了自校准算法，并设计了简便的实验装置和方法验证了自校准算法。另外，本项目经费已按预算完成了经费执行，目前已无结余。.通过项目的实施，完成了所有上述工作内容，发表了7篇论文，申请了9个专利，培养了研究生，本项目的误差补偿算法和多头读数技术应用在了项目组负责的国家重大科学仪器设备开发专项新型飞秒激光跟踪仪研发项目中。并在此基础上提出了立体光栅测角传感器的概念，将在本领域进一步开展深入的研究。