基于方波的相位式激光测距系统的研究

【作者】 刘国光；

【导师】 倪旭翔；

【作者基本信息】 浙江大学 ， 光学工程， 2004， 硕士

【摘要】 激光测距是随着激光技术的出现发展而发展起来的一种精密测量技术，因其良好的精确度特性而广泛的应用在军事和民用领域。 本文介绍了一种基于方波的相位法多频同步测距技术，依据方波的性质，以数学傅立叶变换为基础，通过频谱分析，可以实现对基波和谐波的同步检相，进而计算出待测距离。与传统的相位法测距相比，本方法使用单调制频率实现了多频测距，有效地解决了相位法测距中测程与测量精度之间的矛盾，具有高精度、大量程、大噪声容限的特点，而且简化了硬件设计，降低了成本；其次在数据处理中采用数据加窗函数的方法，提高了方波信号的频谱分辨率，进而提高了测量的精度。 论文阐述了相位式激光测距的原理，分析了各种测相的方法，着重介绍了系统的硬件和软件的组成。硬件部分包括激光发射电路、回波接收电路，高速数据采集电路等。软件方面介绍了基于快速傅立叶变换原理的测相方法，并结合窗函数来提高频谱的分辨率，从而提高了测量的精度。最后介绍了基于Matlab平台的实验数据处理结果，并分析了产生误差的各种原因。 本论文也对系统以后的改进作了一些探讨，以及对研究工作的总结和展望。更多还原

【Abstract】 The laser ranging is a technology for precision measurement, it is developing along with the development of the laser technology, which is extensively used in the military field and the civil field because of the good accuracy.This paper introduced a laser ranging system which was based on the square wave. By using FFT and analyzing the spectrum, we implement the phase-detecting synchronously for the first-harmonic and the harmonics, then proceed to calculate the distance. Comparing with the traditional phase-shifted laser range finder, the method could implement the ranging with multifrequency by using single modulated frequency. It could not only solve the contradiction of the range and the precision, but has high degree of accuracy and wide range, simplify the hardware design, and reduce the cost.This paper introduced the theory of phase distance measurement, analyzed various testing methods and expatiated the hardware and the software for the proposal system. The hardware mainly included the emitting circuit of the laser light, receiving circuit and high speed data acquisition circuit. In the software design, we used the window function to improve the resolution of the spectrum, then improve the precision for measurement. In the end, the paper gave the outline of the processing result of the experiment based on Matlab, and analyzed the factors which caused experiment errors.At last, the improvement for the system was brought forward, and research was summarized and expected in this paper.更多还原