中文摘要：

为了提高光纤周界安防系统中扰动信号端点检测的性能,提出一种新型端点检测方法。首先通过计算信号的短时能量和过零率分布分别找出信号中短时能量比和过零率满足一定门限的信号点,通过对这两信号点进行一定的加权确定扰动信号的端点位置。与离散小波提取起始点信号相比,本文方法由于综合了短时能量和过零率法的优势,能够适应更多的扰动事件类型,通过加权极大提高了端点检测的精度,并且运算时间大幅降低,提高了系统的实时性。实验结果表明,本文算法在10 MHz的采样速度和采集0.3s数据情况下,93.47%的数据定位误差低于10m,计算时间少于0.3s。

英文摘要：

Fiber perimeter security system based on dual Mach-Zehnder interferometer （DMZI） is a kind of sensor system that uses fiber as the sensing media. The endpoint detection in the fiber perimeter secu- rity system can confirm the start of the disturbance signal, which is the basis of disturbance position eal eulation and action mode judging. In order to improve the performance of the disturbance signal endpoint detection and the accuracy of position, this paper presents a novel endpoint detection method. First, through calculating the short-term energy and zero-crossing rate of the signal, the signal points which can meet some thresholds are found respectively. And then by weighing the two signal points, the end- point of the disturbance signal can be obtained. Compared with the discrete wavelet method, this method analyzes shorvterm energy and zero-crossing rate synthetically,and is able to accommodate more types of disturbance events,improving the precision of endpoint detection greatly and reducing the computation time significantly. Experimental results show that the method achieves that 93.47 % of the position error is less than 10 m with calculation time less than 0.3 s,in the case of 10 MHz sampling rate and 0. 3 s signals.