Study Of Tire Pressure Monitoring Base On Surface Acoustic Wave

Tire pressure monitoring is an importance factor of guaranteeing automobile safety. The performance of tire plays a directly role of automobile's performance. Keeping right tire pressure makes automobile to be more comfortable, more safely, more smoothly. It has been proved that tire takes the well-balanced air pressure and the right temperature is very important to the tire life and to cut the using cost. But it isn't easy to measure the tire pressure because it works at a rolling place. We also should ensure the accuracy and timing tire and to guess the trend for the next forecast control. So the tire pressure measure must be high accuracy and speediness.The paper improve a new passive and wireless tire pressure monitoring system base on the analyses of the existent tire pressure monitor system, which can settle the problem in structure, accuracy, power-life and cost in existent monitoring system.The surface acoustic wave (SAW) sensors can be used to measure parameters of fast moving or rotating objects which are difficult to contact, because of the predominance of wireless passive sensing. The paper studies in passive and wireless tire pressure monitoring system base on surface acoustic wave which can realize small passive and high accuracy in simple structure.The paper introduce the theory of surface acoustic wave sensor, the digital signal treatment, the method of soft design in the passive and wireless tire pressure monitoring system in detail. It also depicts the function of different model in this system. The paper discusses the method of building on the tire pressure alarm model to get a more practical pressure model, and give a new design project about system hardware and to stimuli on the building laboratory platform. Following is the main content of the paper:(1) Structure of the passive and wireless surface acoustic wave sensor system. The paper introduces the structure and the principle of the delay and resonator surface acoustic wave sensor, and analyzes the structure of the surface acoustic wave resonator system and the project measurement.(2)The study on system ignite signal. Through the analysis of the response of resonator base on different pumping signals, sine burst is used for pumping signal of the system to improve the efficiency and detecting-distance.(3)Make up the alarm model of tire pressure. Through the analyses of the tire explosion theory we can know the infection on tire by the temperature and load. So we can build a more practical tire pressure model, and to alarm accurately.(4)Design of the host system part, the sine burst signal and the system Electromagnetic Compatibility. The micro controller is a chip of the 16bits MSP430F series controller. It samples the signal, sends the sine burst, receives the response of resonator, and shows the data in real time, alarms and memories the abnormal data.(5)Design the showing data part. Tire data is showed to the driver by using liquid crystal display (LCD), time is also showed in the LCD. It can change the system setting by a small keyboard.(6) Make a simulation using the building surface acoustic wave sensor model.