Research On Intelligent Precaution System For Electrical Fire Based On Non-Contact Measurement

As the increase of demand for electricity, electricity is benefiting human in the time, also causes great damage and loss of life.The predominating mechanism of electrical fire is high temperature caused by overloads, ill touch or short circuit, which may cause fire of the combustible substance or spontaneous combustion of wires. Problems of traditional contact method are low security, poor maintainability and hard installation. Non-contact method with infrared imaging system are complicated construction, expensive and low degree of automation. In this paper, non-contact method with infrared thermal sensor is provided which overcome the shortcoming of the traditional methods, has some properties such as contactless, simple construction and low cost. It's able to precaution in finite time to prevent the electrical fire. The paper presents the detail about the procedure of the design for the intelligent precaution system from both hardware and software aspects.The hardware design part introduces the selection of infrared thermal sensor and the design scheme of signal conditioning, single chip and RS-485 network circuit. The main contention is as follows: the hardware design of the MSP430F149 and peripheral circuit; the standard of RS-485 and the design of master-slave network with RS-485 communication protocols; the major EMI(Electromagnetic Interference) source is analysized, and the methods of enhance the dependability and reduce EMI are improved.The software design part introduces the design of lower machine, RS-485 network and upper machine. The main contention is as follows: the achievement process of the main program and sub-program of the lower machine; the principle and application of RS-485 serial communication; the construction of soft of host with Delphi and the achievement process of serial communication, data real-time display and databases. In the last, the different kinds of interfere effectors affected the measurement result of infrared sensor and the temperature correction method to enhance the precision of temperature measurement are introduced. And prospect for study in infrared sensing in future is present.