Enhancement of the Sensing Distance of an Embedded Surveillance System with Video Streaming Recording Triggered by an Infrared Sensor Circuit

摘要

In this paper we propose a design for a home surveillance system with an enhancement circuit for the pyroelectric infrared sensor (PIR sensor) which has been included to improve the sensing distance. We implement the surveillance system with an embedded board which has the advantages of low power consumption, small size, low cost and high mobility. In this system we design an external circuit consisting of a PIR sensor to be the external interrupt. If the PIR sensor senses an intruder in the area, the embedded board is triggered by the PIR circuit and instantly captures the current image of the moment by web camera. In addition, by using an analog adder for the signal from the PIR we enhance the sensing distance. We also compare the distribution of the sensing distance between the uni-PIR sensor module and the enhanced sensor circuit module under different temperatures to obtain the average and standard deviation values of the sensing distance. By means of an analysis of our experimental data we can judge the stability of the PIR sensor circuit. Our design further allows the user to use either a PDA, a smart device or a PC to connect the video streaming server constructed on the embedded board to the internet in order to browse a webpage.