Design Of Tire Pressure Monitor System

With the development of social civilization and technology, Automobile has been playing an important role in national transportation. But with the rapid development of automobile industry, traffic accidents are increased steadily. Tire blowout is the main reason that causes the accidents. Thus, Real-time monitoring tire pressure and finding out abnormal situation in time is the key point to avoid this type of accident. Tire Pressure Monitor System(TPMS) can collect the pressure and temperature signals of each tire, and display them on LCD screen. Beacuse it can alert the driver when the data exceeds standard ones, it makes the driver more safe. It is also a part of Automobile Chassis Control System, and can provide data for automobile active control system, too.The basic theory, key technologies, hardware design and software design of TPMS are studied in this paper. First of all, this paper introduces the development and tendency of TMPS, and the key knowledge which TPMS is needed. Secondly, the system framework of the TPMS is presented in detail. Thirdly, the system hardware design is given in system framework of TPMS. This system can divide into two parts: Host MCU and Client MCU. The Host MCU is set in cab, and the Client MCU is mounted on wheel hub. The two parts communicate with each other by Radio Frequency. The Client MCU is responsible to gather pressure signal, temperature signal and acceleration signal, and send them to Host MCU by RF. The Host MCU deals with these data after receiving it from Client MCU. It can also communicate with other system for further active control of chassis. The Client MCU is composed of sensor SP12, MCU PIC16F876 and RF transmitter T5754; and the Host MCU is made up of RF receiver T5743, MCU PIC16F877, CAN controller SJA1000 and LCD screen 1602. The circuit of every module is expatiated respectively. Then, the source code using C Language and Assemble Languageis programed to realize the function of TPMS. In order to reduce the power consuming, the rational strategy is needed in the system. At the same time, the format of data frame transferred between Host MCU and Client MCU is defined. The Host MCU must deal with the interrupt from the CAN controller besides analyzing the data received from Client MCU and alerting the driver. Through system test, the results show the application of the developed TPMS and the basic function of TPMS are realized. Finally, the paper summarizes the system design and provides the development tendency of TPMS in future.