Design On Tire Pressure Monitoring System

With the expansion of the development of automobile industry andtransportation network, people travel safety problem is becoming more and moreserious, hence, The occurrence of traffic accidents are increasing; To the tirepressure condition of the car itself, the people’s attention to it increased in thegradually, because there is a lot of traffic accidents which are caused by thepressure problem of the tire, according to this reason, the TPMS(Tire PressureMonitoring System)to monitor tire emerge as the times require, it can effectivelyreduce and prevent problems caused by tire pressure of traffic accidents.The paper analyzes the present research situation of TPMS at home andabroad, compares the advantages and disadvantages of TPMS of the differenttypes, Accordingly, The active TPMS is as the target of this research.Making a thorough study to the design goals and requirements analysis ofsystem, the paper describes the working principle of the active TPMS, the systemadopts embedded installation mode(installed in the tire)and the paper putsforward the general design scheme of software and hardware.According to the overall design scheme of hardware, from the comparativeanalysis of various aspects of cost﹑power consumption﹑safety and reliability,the hardware composition is determined: sampling end is composed of SP12Tsensor﹑microprocessor PIC16F628A﹑wireless transmission chip T5754, thereceiving end uses the PIC18F4580microcontroller as the core, and the externalwireless receiving chip T5743; To send and receive antenna, the paper makes thetheoretical analysis, matching circuit of the antenna is given; According to powermanagement mechanism and the application environment, the transmitter powersupplies to lithium batteries; Finally, the paper design the circuit diagram of thesampling end and receiving end. According to designed circuit diagram, the paper analyses working processof the system, uses C language to compile the software system, draws the systemflow chart; the paper research anchester coding method, uses FSK as the signalmodulation, eliminates the errors of data acquisition which bases on the methodof filtering software.According to manufactured circuit board and designed software, the papermakes pressure and temperature measurement, measures signal strength receivedby the antenna, and it has the broad application prospect.