Research And Engineering Realization On Tire Pressure Monitoring System

With the development of the society, the rapid rise in automobile retention around worldwide and the frequent occurrence in traffic accidents, the attention of the automobile safety has been increasing among the consumers and relevant government departments. About 60% of the traffic accidents are aroused by the tyre, therefore, keeping the pressure of the tyre in standard status is the key factor in tyre-burst prevention. If the pressure is too high, leading to the tyre elasticity decreased, the moving load during the driving will increase subsequently. Once the tyre is struck, it will split internally or burst. However, if the pressure is to low, the tyre metamorphosis happens and ascends. The temperature of the tyre will climb rapidly because of friction, bringing about the tyre softened and the intensity dropped, which do harm to tyres. Meanwhile, the high temperature of the tyre will accelerate its ageing and shorten its lifespan.Tyre Pressure Monitor System (TPMS) combined with automobile safety airbag and anti-lock system (ABS), as the three main automobile safety systems, its introduce to running safety is quite vital and urgent. TPMS has two categories mainly: Wheel-Speed Based TPMS and Pressure-Sensor Based TPMS. Wheel-Speed Based TPMS analyses the rotating speed differences among the tyres through the wheel speed sensor of ABS to monitor the tyre pressure. Pressure-Sensor Based TPMS measures the tyre pressure directly through the pressure sensor installed on the tyre, than it transmits the signals using high frequency radio wave after modulation. The thesis adopts the Pressure-Sensor Based TPMS to study the software design of the system in engineering.Pressure-Sensor Based TPMS uses wireless radio frequency communication technology to real time monitor tyre pressure and gives alarms according to the abnormal situations to make sure the safety of the running automobile, such as steam leakage, high pressure, low pressure, high temperature and so on. The thesis 1) precisely presents the principle and technical scheme of TPMS; 2) analyses and designs the hardware circuit and software flowchart of the TPMS, aiming at the deficiency in current technology and the market existing products; 3) provides the solutions to the information coding, tyre location, system extension and other matters in engineering. Those solutions are as follows:1) the thesis proposes an error control information coding method to solve the error rate problem in TPMS signal transmission and reduce the energy consumption as well; 2) the new tyre location method is concise and effective, making the application and later maintenance easier; 3) the thesis also proposes an new technology based on finite state machine menu function realization, to make the menu logical control concise and easy to extend. If it needs a new function, just add a status to the state machine; 4) wedesigned a simple and beautiful UI interface. At the same time, the TTS voice broadcast function of IFLYTEK has been introduced to Android client, releasing the hands of the users and enhancing the users experience.In the TPMS development life cycle, its performance and function have been tested and analyzed, and the result shows that the TPMS system can meet the demand of the practical application entirely.