基于数字式波长编码光栅的光学位移传感器研制

发布时间：2018-04-14 14:01

  本文选题：光传操纵系统 + 光学位移传感器　； 参考：《中国科学技术大学》2017年博士论文

【摘要】：本论文研究了一种新型数字式波长编码光栅光学位移传感器,作为关键硬件,用于飞行器光传操纵系统中,取得了以下研究成果。1、提出了一种数字式波长编码光学位移传感器的系统结构。该传感器的系统结构简单紧凑,由读码系统和解调系统两部分组成。读码系统的核心元件是一个由若干种等间距光栅单元编码组成的编码光栅,该编码光栅上携带着与位移信息一一对应的图形编码,通过编码光栅的结构设计,可以调整光学位移传感器的分辨率和量程。图形编码信息通过光栅的自准直衍射转化为波长信息,传输至后续的解调系统中并输出数字编码,从而完成位移的测量。并通过编码光栅的独特设计,从源头上提高了传感器的环境适应能力。2、开发了两种结构的组合编码光栅,并形成了成熟的编码解码算法。组合编码光栅采用单通道循环、多通道组合的方式,在不增加光栅种类的情况下,大幅度提高了编码光栅的总编码量;并通过错位结构的应用,不减小光栅单元格的尺寸,进一步提高分辨率。编制了三套编码算法程序,能快速有效的将组合编码光栅的概念结构具体化、数字化,并针对不同的参数要求,提供优化设计的关键依据。根据大量计算结果,针对飞行器用光学位移传感器的设计要求,本文优先选择拥有千级编码量的"五位三分"或"六位二分"组合编码光栅结构。通过组合编码光栅的结构优化,可以获得十万级的编码量,颠覆了传统光学编码盘主导的编码方式,为大量程应用领域的器件设计提供了新的有效思路。3、建立了成熟的组合编码光栅制作工艺。设计了一套制作精度高、可重复性好的组合编码光栅制作工艺,完成了量程100mm,分辨率100μm的"五位三分"错位组合编码光栅的设计和制作,并利用光栅的复制技术,实现了组合编码光栅的标准化小批量产出。4、对光学位移传感器整体搭建的系统性研究。通过对传感器系统所有部件的制作、选型和匹配原则的研究,形成了理论与实践结合的系统搭建思路。并从实际出发,重点阐述了信号强度参考线的标定方法和意义,提出了动态信号强度参考线的标定原则,为全面提高传感器的稳定性提供了技术支持。5、搭建了光学位移传感器的台架系统并完成其性能评估。搭建了传感器的台架系统,并进行信号响应测试,实验结果表明"五位三分"错位组合编码光栅的制作精度和系统各元件的选型与配合很好的满足了传感器光谱响应的要求。同时在-55℃～70℃的温度范围内,测试了解调系统的输出信号,结果显示光敏元件的信号幅值随着温度的升高而降低,呈近似线性变化,变化后的曲线依然在预先标定的参考线之上,数字信号可以准确输出,即该传感器系统展现了优良的耐高低温性能。
[Abstract]:In this paper, a new type of digital wavelength coded grating optical displacement sensor is studied, which is used as the key hardware in the optical control system of aircraft.A digital wavelength coded optical displacement sensor is proposed.The system structure of the sensor is simple and compact, which consists of read code system and demodulation system.The core component of the code reading system is a coded grating composed of several kinds of equal-distance grating units. The coding grating carries a graphic code corresponding to the displacement information, which is designed by the structure of the coded grating.The resolution and range of the optical displacement sensor can be adjusted.The image coding information is transformed into wavelength information by the self-collimation diffraction of the grating and transmitted to the subsequent demodulation system and the output digital code is output to complete the displacement measurement.Through the unique design of the coding grating, the environmental adaptability of the sensor is improved from the source. The combined coding grating with two structures is developed, and a mature coding and decoding algorithm is formed.The combined coding grating adopts the method of single channel cycle and multi-channel combination, without increasing the type of grating, the total coding amount of the coded grating is greatly increased, and the size of the grating cell is not reduced by the application of the dislocation structure.Further improve the resolution.Three sets of coding algorithm programs are developed, which can quickly and effectively concretize and digitize the conceptual structure of the composite coding grating, and provide the key basis for optimization design according to different parameter requirements.According to a large number of calculation results, according to the design requirements of optical displacement sensors for aircraft, this paper gives priority to the "five-bit three-point" or "six-bit dichotomous" combinatorial coding grating structure with thousands of coding quantities.By optimizing the structure of the combinatorial coding grating, we can obtain a number of codes of 100,000 levels, which overturn the traditional optical coding disk dominated coding method.It provides a new and effective method for device design in a large range of applications, and establishes a mature fabrication process of combinatorial coding grating.A set of high precision and repeatable composite coding grating fabrication technology is designed. The design and fabrication of the "five bits and three points" dislocation coded grating with a measuring range of 100 mm and a resolution of 100 渭 m are completed, and the replication technology of the grating is used.The standard small batch output. 4 of the combined coded grating is realized, and the systematic research on the whole building of the optical displacement sensor is carried out.Through the research on the principle of making, selecting and matching all the components of the sensor system, the idea of combining theory with practice is formed.The calibration method and significance of the signal intensity reference line are expounded, and the calibration principle of the dynamic signal intensity reference line is put forward.It provides technical support for improving the stability of the sensor. 5. The bench system of the optical displacement sensor is built and its performance evaluation is completed.The sensor bench system is built and the signal response is tested. The experimental results show that the fabrication accuracy of the "five-bit three-point" staggered combined coding grating and the selection and coordination of each component of the system can meet the requirements of the sensor spectral response.At the same time, in the temperature range of -55 鈩，

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