【作者】 赵素文；

【导师】 汶德胜；

【作者基本信息】 中国科学院研究生院（西安光学精密机械研究所） ， 信号与信息处理， 2012， 博士

【摘要】 大量程、高精度的单频激光干涉精密距离测量关键技术的研究课题具有重要的现实意义。该技术是非接触测量中的关键和前沿技术之一，在纳米测量、生物工程、材料科学、微电子以及超精加工等领域有广泛的应用前景，对我国国防工业和国民经济的发展具有重要意义。本文的主要工作和创新性包括以下几个方面：1，基于干涉仪理论，对干涉仪系统的误差源及其补偿方法进行分析和研究。利用单频干涉仪信号特点，提出了一种利用共轭抑制进行光路设计的方法，可对干扰噪声进行有效抑制，从而提高信号测量的精度。基于琼斯矩阵原理，建立单频干涉仪的光路数学模型，对光路进行分析计算，并分析了波片、偏振分光棱镜、激光源等多个参数对测量结果的影响，对干涉仪光学系统的优化设计具有指导意义。2，根据跟踪仪目标移动的速度要求，设计出一种低噪声响应带宽高的电路。实验表明，在目标以4m/s的较高速度移动时，系统对其检测精度可达微米量级，与低速运动时相同，达到跟踪仪系统的指标要求。3，根据跟踪仪的跟踪特性，提出了一种实时性较高的跟踪状态测量方法。对测量过程中存在的断光、偏光以及目标静止做出有效的区分和鉴别，并实时传递给上位机，从而保证上位机跟踪系统的实时处理和跟踪功能。4，提出了一种干涉信号的细分方法，可以实现对非正交信号的准确细分。通过跟踪两路干涉信号的交点，对信号周期进行浮动式分段，来准确跟踪两路信号间的相位差，实现精确细分。此法可使计数不受信号直流电平漂移和高频扰动的影响。分析了细分倍数和ADC位数与该方法可以处理的干涉信号相位差极限的关系。采用该技术细分法，可以使单频干涉精密距离测量系统具有更强的环境适应性和抗干扰能力，更适用于工程现场应用。5，提出并验证了一种能在线实时修正干涉信号“三差”的修正方法。传统的误差修正方法因计算量大，存在着只能对信号进行离线修正的问题。该方法能大幅度减小计算量，从而使得干涉信号的三差得到实时修正。经验证，采用该修正方法，可以使单频干涉精密距离测量在自然环境中得到纳米量级的测量精度。更多还原

【Abstract】 The research topic of large range, high-precision distance measurement byhomodyne interferometry has important practical significance. The technology hasbroad application prospects in the field of superfinishing, microelectronics, MEMS,nano-measurement, etc. It has great significance for the development of our nationaleconomy and defense industry. The dissertation conducted thorough researchesmainly focus on the measuring theory, optical design, high-frequency signalprocessing and segmentation method of precision distance measurement of the laserinterferometer. The main research contents and concrete work of this dissertation areshown below:1. Based on the theory of the interferometry, the error sources of theinterferometry system and the compensation methods were analyzed. According to thecharacteristics of homodyne interference signal, the conjugate suppression methodswas proposed and used for design the optical path. The noise signal caused by outsideinterference could be suppressed effectively; thereby the measurement accuracy wasimproved greatly. The mathematical model of the homodyne interferometer’s opticalpath was established based on the Jones matrix theory. The analytical calculation ofthe light path was advanced. The variation that the interference signals along with thewaveplates, the polarizing beam splitters or the laser source is numerically analyzed.It has the guiding significance for the optical optimization design.2. According to the required speed of the tracker’s moving target, a low-noiseand wide bandwidth circuit was designed. The result of experiment show that thesystem can achieve the micrometer accuracy when the target moving at a speed of4m/s, which was the same as the measurement accuracy achieved when the targetmoving at a lower speed, that the design met the qualification of the tracker system.3. According to the tracking features of the tracker, a measuring method of thetracking state was proposed. It can distinguish the diffirent state between the light’sbeing interrupted and the light’s departure from the center of the target and the targetis stationary, and transmit the state to the upper computer in real time, thus ensuringthe upper computer’s real-time processing and tracking functions.4. A new method was brought out for subdividing the non-orthogonalinterference signals exactly. By tracking the intersections of the two-channel signals dynamically, the interference signal’s one period was subdivided floatingly, the phasedifference between two signals was tracked accurately, thus ensuring the accuracy ofthe non-orthogonal signals’ counting and subdividing. The influences of the DC levelshift and the high-frequency disturbances can be avoided. The relationgship betweenthe phase difference deviates from orthogonal state and the multiples of thesubdividing or the bit of the ADC was analysed. Using this subdividing technology,the homodyne interferometry distance measuring system could resist strongdisturbance and show sound reliability, and more suitable for using on outdoorengineering site.5. A new correction method, which could remove the cyclic error of thehomodyne interferometer in real-time was introduced. Traditional error correctionmethods require reliable abundant data and time for processing so they corrected thecyclic error off-line. The new method can significantly reduce the calculation amount,so the cyclic error of the interference signal could be removed real-time. Results showthat using the new correction method can make the homodyne interferometry distancemeasurement achieve nanometer accuracy in the natural environment.更多还原