高精度激光测距信号处理技术研究

发布时间：2019-03-13 15:15

【摘要】：激光测距由于其测量精度高、测量距离远等优点而被广泛应用在诸多涉及测量技术的领域。目前随着诸如民事、科研、军用等领域对测距要求越来越高,如何在保证测量距离的前提下获得更高的测量精度成为一项热门研究。目前对中长距离测量多采用脉冲法激光测距,其测量速度快、测量范围广但精度较低。短距离测量多采用相位法激光测距,其测量精度高但测量效率较低、范围较小。因此这里将对提升脉冲法激光测距精度和扩展相位激光测距测量范围两个角度展开具体研究和相关实验。首先针对高精度脉冲法激光测距的信号处理系统进行了具体的原理分析、理论计算、精度分析和实验研究。并从关键技术对比、系统构建、误差分析等角度进行了深入分析。总结了时刻鉴别和时间间隔测量的几种设计方式,完成了器件选用、电路搭建、精度分析等工作。本文进行了脉冲法测距方式下的信号处理模块的相关实验。通过信号发生器发送固定延时间隔的两组信号,完成了接收和时间间隔测量,并在电脑上位机中显示出测量结果。对比所测得实验数据进行了误差分析。可以发现延迟线内插法的时钟分辨率受到温度和电压影响,可以通过校准基准时钟的方式避免时钟产生偏差。这里对200ns的时间间隔数据进行了时间间隔测量,其时差测量的标准偏差值为180ps。即表示对30m的测量距离,其测量误差为2.7cm。对30m到1.5km的测量距离,平均的标准距离偏差值为3.1cm,实现了较高的测量精度。在获得精度较高的脉冲激光测距方式的基础上,本文还提出一种脉冲与相位相复合的测距方式。在发送端发送方波与正弦波调幅相乘的合成波同时携带飞行时间信息和相位信息。在信号处理阶段以脉冲法测距结果作为测距粗尺,相位法测距结果作为测距精尺,从而使得复合后的测距系统既具有相位法的测距精度高的优点又可实现远距离的测量。针对脉冲相位复合的测距方式,本文对其中的脉冲和相位部分进行了具体的原理论述、理论计算和精度分析。论证了脉冲法测距精度可以达到该测距系统粗尺的要求,并完成了测距系统的设计。
[Abstract]:Laser ranging is widely used in many fields involving measurement technology because of its high precision and long distance. At present, with the increasing demand for distance measurement in civil, scientific research, military and other fields, how to obtain higher measurement accuracy under the premise of ensuring the measurement distance has become a hot research. At present, pulse laser ranging is mostly used in middle-long distance measurement, which has the advantages of fast measuring speed, wide measuring range but low precision. Phase laser ranging is usually used in short distance measurement, which has high measurement precision, low measurement efficiency and small range. In this paper, the laser ranging accuracy and the extended phase laser ranging range are studied in detail and related experiments are carried out. Firstly, the principle, theoretical calculation, precision analysis and experimental research of the signal processing system of high precision pulse laser ranging are carried out. And from the key technology comparison, system construction, error analysis and other aspects of in-depth analysis. Several design methods of time discrimination and time interval measurement are summarized, and device selection, circuit construction, precision analysis and so on are completed. In this paper, the experiment of signal processing module based on pulse distance measurement is carried out. Two sets of signals with fixed delay interval are transmitted by the signal generator to complete the receiving and time interval measurement, and the measurement results are displayed in the computer upper computer. The error analysis is carried out by comparing the measured experimental data. It can be found that the clock resolution of the delay line interpolation method is affected by the temperature and voltage, and the clock deviation can be avoided by calibrating the reference clock. The time interval data of 200ns are measured here, and the standard deviation of the time difference measurement is 180 PS. That is to say, the measuring distance of 30m is expressed, and the measuring error is 2.7cm. For the measuring distance from 30 m to 1.5km, the average standard distance deviation is 3.1 cm, and the measurement accuracy is high. On the basis of obtaining the pulse laser ranging method with high precision, this paper also proposes a pulse and phase compound ranging method. The composite wave of transmitting square wave and sine wave multiplying amplitude modulation at the transmitter carries both time-of-flight information and phase information at the same time. In the signal processing stage, the pulse distance measurement result is used as the ranging scale, and the phase method distance measurement result is used as the ranging precision scale, so that the compound ranging system not only has the advantage of high precision of the phase method, but also can realize the long distance measurement. In this paper, the principle, theoretical calculation and accuracy analysis of pulse and phase are discussed. It is demonstrated that the precision of the pulse ranging system can meet the requirement of the measuring system, and the design of the ranging system is completed.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN249

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