The Research Of Vibration Signal Based On Optical Fiber Sensor Detective System

Optical fiber sensing technology is a new technology, which has been expanding rapidly along with the emergence of optical fiber and the development of optical fiber communication technology. The core of optical fiber sensing technology is the optical fiber sensor, which uses the optical fiber as the transmission medium and uses optical signal as a carrier.The optical fiber sensor detects ambient light signal by measuring the changes of optical parameters, such as phase, frequency, wavelength, light intensity and so on. Because of the advantages such as anti-electromagnetic interference, high sensitivity, high reliability, corrosion resistance, small size and so on, it has become a hot spot in the research of security system. In this article, firstly, the principle, classification and the development of the optical fiber sensor are introduced; then the fiber transmission principle, interference principle and Maher-Zehnder Interferometer structure and working principle are introduced in detail, at the same time a system based on Maher -Zehnder interferometer is built. Through the LAB VIEW software, this system collected the real-time vibration signal from Maher Zehnder interferometer system. Besides, this paper analyzed the characteristic parameters change rules of common vibration signal in time domain and frequency domain, and then extracting the effective characteristic parameters, for example, RMS value, wave coefficient, duration, high frequency energy coefficient and cutoff the frequency. Next, the thresholds of features are determined to identify the type of the vibration signal. The intrusion signal is determined by multi threshold method, and the alarm is carried out. At the same time, the intrusion signal is sent into the positioning system. Finally, determine the specific location of the intrusion behavior by the effective array and the generalized cross correlation algorithm in positioning system. In this paper, through a large number of experiments showing that, it is can be effectively divided into environmental disturbance and human intrusion interference through on setting a threshold to characteristic parameters extracted, which reduces the false positive rate and false negative rate of the system. At the same time, it is effective to improve the positioning accuracy of the system through generalized cross correlation algorithm to calculate the array of effective extraction, along with the method of obtaining the delay difference.