Distributed Vibration Sensing And Positioning Technology For Video Monitoring

With the rapid development of video monitoring technology, many excellent features such as networking, cooperative-fused have emerged in modern video monitoring system. Integrated with more sensing elements and more monitoring perspectives, the video monitoring system became more functional in security monitoring and thus more convenient, real-time and direct in alarm information processing, which has attracted much attention and wide concern.Piezoelectric ceramic material Pb(Zr1-xTix)O3(PZT), with its low cost, good frequency response feature, can be used not only in power generation, but also in vibrating signal detection. Applied with PZT material, the positioning video monitoring system based on distributed wireless vibration sensor network, can well solve the problem of power supply for sensor nodes and target intrusion vibration detecting with distributed PZT sensors mounted in certain environment, so as to solve the problem of positioning and monitoring alarm in the traditional video monitoring system.Therefore, based on distributed wireless PZT vibration sensor network, research has been carried out in this thesis on the positioning video monitoring technology. Main contents are as follows:(1) For the piezoelectric material—rectangular cantilever beam structure and the circular buzzer structure, the main vibrating influence factors for these two typical structure, such as the length of cantilever beam, the location of mass block(or location of metal gasket) and the circuit connection modes, have been analysed on detail by ANSYS finite element method after the building of reasonable model, thus effectively adjusting vibration frequency and studying the vibration situation under different modes. Then, the correctness of the theoretical calculation has been verified as correct through several experiments.(2) Piezoelectric power generating device and vibration detecting device have been designed. After the experiment research on output response of piezoelectric power generating, frenquency adjustment, impedance match and the analysis of the system’s power consumption, the schemes have been proposed and implemented that the vibration energy from environment can be captured and stored by piezoelectric power generating device for power supply of piezoelectric sensor nodes and that target vibration signal can be detected by piezoelectric vibration detecting device with certain environmental applicability.(3) A method of positioning video monitoring has been put forward in this paper, which is that intrusion vibration signal is detected and numbered by piezoelectric sensor nodes, alarm signal is decoded by PC monitoring terminal, rotating angle is positioned by motor controlling camera. The distributed vibration sensor positioning video monitoring system has been designed in general, which mainly contists of PC monitoring terminal, lower machine(piezoelectric sensor node) and execution device(video monitoring module). Inside, the piezoelectric sensor node takes a single chip microcomputer(SCM) MSP430F5738 as the processing center, including the piezoelectric vibration detecting module, the SCM processing module, the wireless RF module and the power module; the wireless RF communication method has been adopted between every sensor node and PC; MATLAB serial port programming has been used to implement PC monitoring terminal; the video monitoring module comprises a stepper motor, the motor driver control module, a camera and the power supply. Through the experimental test, the system can work well and effectively detect intrusive vibration, solving the problem of real-time positioning and monitoring alarm in the traditional video monitoring system.