The Design Of Fire Control System Based On Power Line Carrier Technology

With the rapid development of social economy, the population growth is more and morequickly, the floor is becoming higher. The number of all kinds of electrical equipment isincreasing so quickly that there are more security risks around us. According to statistics, in thenumerous disasters, the direct economic losses caused by the fire is about five times,after thefrequency of occurrence to earthquake, drought and flood. Consequently, the fire alarm systemfor the good development opportunity. At present, the market of the fire alarm system is varied,but most of the main control system based on sensor. These sensors are mainly collected thetemperature, smoke, CO and other data signal. However, in real life, often excessive current onthe wire cause fire.And the fire alarm system has ignored the current signal on the wirecollection. In addition, most of them using two-wire or wireless transmission module, detectorsignal is transmitted through the bus to controller.Not only the signal transmission is not stable,easy to open, resulting in unnecessary losses, but also the cost is high.In order to improve the reliability and reduce the cost, this paper designs a kind of firemonitoring system based on power line carrier technology, the signal transmission by power line,the power line of low cost, reliable performance. Power line carrier communication (Power LineCarrier PLC) is a special kind of communication as an information transmission medium forvoice or data based on power transmission line. Power line carrier communication,by the carrier,the modulated signal with the original load to the power line, the data transmission by power line,and then through the special PLC modem separates from the power line frequency signal, thesignal is transmitted to the terminal equipment. The biggest characteristic of the power linecarrier communication is no need to set up lines of communication, as long as there is a wire.Wecan carry out data transfer, and the power line as the communication medium, solid structure,high reliability. Therefore, the power line carrier communication is a very wise choice. Secondly, this design chose the Holzer effect sensor to monitor the current on the wire taking into account alot of fire in the selection of sensors,because the current is too large compared with other firealarm system advantage.This paper first introduces power line carrier technology, communication channel and thesignal modulation technology. The power line as the channel of power line carriercommunication, its complexity and the interference noise is very large, so the need to seriouslyconsider the modulation channel, through comparative analysis, the paper finally selects thedirect sequence spread spectrum modulation techniques.The hardware part of system design, module design, including fire alarm fire alarm module,Holzer current sensor, temperature sensor, smoke sensor module to monitor various parameters,the design of power circuit module, serial communication module, the carrier communicationmodule and so on, among them, the fire alarm module and communication module is the key.The part of software design involves the fuzzy judgment part of neural network, using thethreshold method for the analysis of the sensor to collect the feedback information and whetherthe alarm.Finally, the work in this thesis is summarized and the prospect of the future development ofpower line carrier technology.