基于平面正交离散栅面阵列传感的二维纳米位移测量方法及传感器研究

Nowadays, modern ultra-precision manufacturing equipments are becoming more and more urgent for the functional requirements of planar two-dimensional nanometer displacement measurements over a large range. However, only two-dimensional nanometer optical planar encoders are presently available for meeting this challenge. Aiming at the technical situation that the manufacturing capacity of two-dimensional nanometer optical planar encoders can't make a breakthrough in the near future in China, a new method and a new sensor of planar two-dimensional nanometer displacement measurement using the principle of space-time transformation, which is based on the research of the nanometer time-grating with Single-degree-of-freedom, is proposed in this project. The alternating electric field with plane motion excited by the discrete grating-plane array is used to be a carrier to establish the relationship between the space plane displacement and the time standard; thus, the problem of precision manufacturing of grid with large size is avoided. With taking the transient modeling of the alternating electric field in three-dimensional space as the basis and the quality control of signal formation as the core, the key problems including the measurement signal decoupling method, the space harmonic suppression method, and the multi-factor dynamic error real-time correction technology, are studied systematically. A design criterion for sensing characteristic parameters and sensing structure is established, and the displacement measurement theory of planar two-dimensional nanometer time-grating is formed. A prototype sensor with independent intellectual property rights is developed, which aims to achieves ±500nm accuracy and 10nm resolution over a 200mm×200mm measurement range.

现代超精密加工制造设备对大量程平面二维纳米位移测量的功能需求日趋迫切，而目前唯有平面二维纳米光栅能够胜任。针对我国平面二维纳米光栅制造水平短期内无法取得突破的技术现状，在前期单自由度纳米时栅研究基础上，本项目提出研究一种基于时空转换原理的平面二维纳米位移测量新方法和新传感器。采用平面正交离散栅面阵列上激发运动的交变电场作为载体，建立空间平面位移和时间基准之间的联系，从根本上回避大尺寸精密栅格刻划的光栅制造问题。以交变电场三维空间瞬态建模为基础，以信号形成质量控制为核心，系统研究多电场耦合作用下的测量信号解耦、空间谐波抑制以及动态误差实时修正等关键科学问题，建立传感特征参数和传感结构形式的设计准则，形成平面二维纳米时栅位移测量理论。研制出具有自主知识产权的平面二维纳米时栅传感器样机，预期指标为：在200mm×200mm的量程范围内测量精度达到±500nm，分辨率达10nm。

随着高端制造业的不断发展，以光刻机为代表的现代超精密加工制造设备对大量程平面二维纳米位移测量的功能需求日趋迫切，目前唯有平面二维纳米光栅能够胜任。平面二维纳米光栅采用栅尺上均匀刻划的精密“栅格”作为测量基准，受到光学衍射极限的制约，栅格制造的精密程度已趋于极限，直接制约着其测量精度的进一步提升。针对当前平面二维纳米光栅存在的技术瓶颈，本项目开展基于时空转换原理的平面二维纳米位移测量新方法和新传感器研究，不是通过提高栅尺制造要求来实现更高精度的测量，而是从传感原理上创新，通过采用平面交变电场在空间形成的双运动参考系来建立空间位移和时间基准之间的联系，利用感应电极阵列之间的空间位置与感应信号的传递关系，将空间二维的位移测量误差都溯源到时间基准上，通过“以时间测量空间”来提高测量精度。本项目围绕上述研究内容开展工作，提出了基于双运动参考系进行时空转换的二维位移测量学术思想，建立了一套比较系统的平面二维纳米时栅测量理论体系，发明了一种离散式栅面空间排布集合的编码以及栅面阵列冗余信息组合运算的信号解耦新方法，形成了一套消除周期谐波误差的栅面阵列传感结构和参数设计准则。解决了误差在线修正、传感结构与参数优化、器件制造和信号处理集成化等关键技术问题，实现了核心性能指标的重大突破。研制出量程为300mm×300mm的平面二维纳米时栅样机，分辨率10nm，重复性100nm。重庆市计量质量检测研究院检定，经校准后X轴精度为±250nm，Y轴精度为±150nm，性能指标总体上达到了国际先进水平。相关专利技术作价约1350万元进行了转化。研究表明，平面二维纳米时栅从原理层面摆脱了空间基准的制造问题对位移测量精度的制约，采用低制造要求的栅尺加工工艺实现了高精度的平面二维位移测量。从当前研究进展来看，平面二维纳米时栅有望将国际上极具挑战性的平面二维纳米位移测量技术变为一项常规技术。