The Research On The Tire Pressure And Temperature Monitoring System Based On Wireless Communication

In the high-speed running process of the automobile, tire breakdown is thething which drivers worried about most and the most difficult to prevent, and it'sthe main cause of the burst traffic accidents. According to the statistics, 70% of thetraffic accidents which occurs on the Chinese highway are caused by tire blowout.And in America this proportion reaches as high as 80%.How to prevent the tireblowout has become an important topic in the safe driving area. According to theexperts' analysis in the country rubber tire quality surveillance center, themaintenance of standard tire pressure in running and the detection in time whenthe tire leaks air are the keys to prevent the tire blowout. And the TPMS—tirepressure monitoring system will be the ideal tool without questing.The tire temperature and the tire pressure are influenced each other. Thepressure is either high or low all can cause the appearance of unusual attrition ofthe tire, and can cause the increment of the tire temperature, and the tire will beaging;the increment of the temperature will cause the increment of the tire, and itwill affects the traffic safety and may cause the tire blowout. Therefore, in theprocess of driving, if we can make on-line examination to the tire pressure and thetire temperature, then we control them in a reasonable scope. So we could enhancethe service life of the tire greatly and reduce the occurrence of tire blowoutaccidents. And enhance the traffic safety. This paper "The research about the tirepressure and temperature monitoring system based on wireless communication" isadaptable to this need. Its main research content as follows shows:1. The design of the emitter module unitThe emitting module unit is mainly made up by the tire pressure andtemperature monitoring unit, the microprocessor unit and the wireless emittingunit. According to the need of the design, the emitting module must have thecharacters of simple circuit, small volume, strong anti-jamming ability and lowpower expend. Refer to correlative materials and after careful analysis andcomparison, we use the chip C8051F300 made by Shenyang XinhualongCorporation as our microcontroller, and the chip SP12 made by InfineonCorporation as the pressure and the temperature monitoring unit, and the chipnRF401 which Nordic Corporation develops as the emitter unit, and we usesspecial-purpose lithium battery which for TPMS as the power.2. The design of the receiver module unitThe receiver module unit is mainly made up by the wireless receiver unit, themicroprocessor unit, the displaying unit, the alarming unit and man-machineinterface unit. The wireless receiver unit receives the signal which transmits by theemitting module, then sent them to the microprocessor unit after the process ofdemodulation and filtering. The displaying unit demonstrates the current value ofthe pressure and temperature in the normal condition. If the tire appearsexceptionally, the alarming unit gives alarm to the driver to take correspondingmeasures to avoid the danger. The user operation surface is completed by fivepressed keys. It can complete the reset of the transmission module address and thestandard tire pressure and temperature values. The demonstration surface uses thelight diode, and each tire has the corresponding light diode. When demonstrate thetire pressure and temperature values, the corresponding indicating diode light, thedriver can know the situation of each tire conveniently and directly. The voice andlight alarming unit is realized by the buzzer and the diode in the system.3. The design of the reliability of the systemThis application environment of the system is quite bad, and the vehicles areall made by the steel frame, and electromagnetism disturbance is quite serious.The all system needs simply structure, small volume, stable performance, reliableworking. All these ask the system for high reliability. The reliability design ismainly performed from the hardware reliability design and the software reliabilitydesign. The hardware reliability is mainly performed from the choice of thedevices aspect, the anti-jamming of the power source and the printed wiring board,and so on. The software reliability design is mainly performed from the digitalfilter, the software redundancy, the software trap, the disturbance avoidance andthe "watch-dog", and so on.4. The structure of the laboratory benchIn the experimental analysis process, we designed and made a dynamic testplatform. We carry on the emitter and the receiver module performance test in thisdynamic platform. In this platform, when it in static state, we can inflate or deflateto the tire, and adjust the tire pressure to certain proportion. When it in dynamicstate, the electromotor drives the tires to go round and round. and the speed can beadjusted. The tire receives certain impact and the friction in the process of running,which causes the tire to vibrate and the internal pressure and temperature willchange in a certain extent. We use signal generator to generate main noise source,it can modulate each kind of noise signal. After the laboratory bench installmentand the examination system installment are all completed, we put the examinationsystem installment in this laboratory bench to carry on the emitting and thereceiving experiment. we improve the system precept according to the effectwhich tests improves in order to obtain the all right anti-jamming ability.The tire burst warning system can monitor the tire status real-timely while theautomobile is running. As long as the status of a tire or tires have been lower orhigher than standard tire inflation pressure, tire temperature too high, or airleakage has happened, the driver will be warned immediately. Working longevityof the system is longer than that of tire, and it can adapt to atrocious workingenvironment. Application of the system can prevent the emergence of tire burstpartially. Thus it can improve the high-speed automobile security. The systemdeveloped in this paper has very high application value.