8mm LFMCW近程探测系统信号检测与处理

发布时间：2018-07-12 16:30

本文选题：8mm波段 + 线性调频连续波　；参考：《南京理工大学》2017年硕士论文

【摘要】：本文以三角波调制的8mm波段LFMCW近程探测系统为应用背景,主要围绕实时测距算法和软硬件实现对探测系统的信号处理部分进行了研究。给出了 LFMCW近程探测系统的设计方案,论述了对称三角波调制下探测系统的测距原理,分析了系统相关参数的选择原则,讨论了关于测距性能的影响因素。根据探测系统的差频信号与目标距离之间的线性关系,变测距为测频。毫米波调频探测系统经常采用"差频—FFT"的方法进行测频,但采样率的限制和FFT固有的栅栏效应使得实际的测距精度较低。ZoomFFT算法通过对局部区域频谱进行细致分析从而更精确地估计差频信号的频率,—定程度上提高了测距精度。但是通过对ZoomFFT算法分析可知,在复调制环节的运算量很大,一定程度上影响了探测系统的实时性,而且栅栏效应的影响依然存在。为此,本文在ZoomFFT算法的基础上研究了一种改进的高精度实时测距算法。根据相关项目的要求,以TI公司生产的TMS320VC5509A芯片为核心,设计了信号处理系统的硬件电路。在CCS开发环境中通过C语言编程实现了 DSP对三大功能模块的控制和测距算法。最后对整个调频测距系统进行了软硬件联调,给出了每一模块的调试方案和结果。对实验数据进行详细分析,验证系统软硬件设计和相关算法研究的有效性和可行性。
[Abstract]:In this paper, the signal processing of the 8mm band LFMCW detection system based on triangular-wave modulation is studied around the real-time ranging algorithm and the realization of software and hardware. This paper presents the design scheme of LFMCW short-range detection system, discusses the ranging principle of the detection system under symmetrical triangular wave modulation, analyzes the selection principle of system related parameters, and discusses the influencing factors on ranging performance. According to the linear relationship between the differential frequency signal and the target distance of the detection system, ranging is changed into frequency measurement. Millimeter-wave frequency modulation detection system often uses the method of "difference frequency FFT" to measure frequency. However, because of the limitation of sampling rate and the inherent fence effect of FFT, the actual ranging accuracy of .Zoom FFT algorithm is low, and the precision of ranging can be improved by analyzing the local region frequency spectrum more accurately and estimating the frequency of the difference frequency signal more accurately. But through the analysis of Zoom FFT algorithm, we can see that the complexity of the complex modulation link is very large, to some extent affect the real-time detection system, and the impact of the fence effect still exists. Therefore, based on Zoom FFT algorithm, an improved real-time ranging algorithm with high accuracy is studied in this paper. According to the requirements of related projects, the hardware circuit of signal processing system is designed with TMS320VC5509A chip produced by TI Company as the core. In the CCS development environment, the DSP control and ranging algorithm of the three functional modules is realized by C language programming. Finally, the whole FM ranging system is combined with software and hardware, and the debugging scheme and results of each module are given. The experimental data are analyzed in detail to verify the validity and feasibility of the software and hardware design of the system and the research of related algorithms.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN015

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