抄録
The use of physical security technology is becoming important to prevent intruders from stealing or vandalizing property, and leaking personal information, as well as to secure personal safety. At many important facilities, fences are installed along the boundary of the premises to prevent any intrusion. However, intrusion-detection sensors must still be additionally installed since such fences can be climbed over or cut, given their physical limitations in terms of height and strength. Vibration sensors need to be easily fixed to the fences even around intricately shaped premises for monitoring a wide range of areas. We have proposed and implemented a vibration sensor integrated with optical fiber and an optical interference system. This sensor features a structure of Sagnac interferometer based on the fiber-optic gyroscope and has exhibited high performance and reliability. In order to prevent any false or missing alarms, we have also investigated a signal processing system that can be used to judge whether an alarm is triggered by a natural phenomenon, small animals, or human intrusion. The sensor was installed on the perimeter fence of an electric power plant, and the performance of vibration sensor and the validity of signal processing to judge human intrusion was verified.
