A New-type Passive TPMS System Design

In a car’s high-speed process, tyre fault is the most worried and the most difficultto prevent problem to all drivers, tyre is also the important reasons for the suddentraffic accident. According to statistics,70%of the traffic accident was caused by tirein China highway, and the ratio in U.S. is as high as80%. How to prevent tire bursthas become an important issue of safe driving. According to the expert of nationalquality supervise center of rubber tyre, keep the standard tyre pressure during drivingand in time to prevent leakage is key to prevent tire burst. And TPMS-car tire pressuremonitoring system will no doubt to be the ideal tool.Based on the basic principle of TPMS, this paper analyzes the present mainsolutions of TPMS, put forward a solution of passive TPMS use the surface acousticwave technology. First, according to surface acoustic wav e theory, the theoreticalmodel of SAW pressure sensor and mechanical models have been established, then theSAW pressure sensor signal detection and the realization of the temperaturecompensation function have discussed as key consideration,the sensor m odules ofSAW pressure sensor was designed. And then in the basis of SAW, the passivetemperature sensor is realized, the purpose of the tire pressure and the temperaturesignal detection have achieved.Second, according to the requirements of the network sensors, using ZigBeecommunication technology to realize the sensor communication. After analysis of theorigin and the characteristics of ZigBee technology,put forward a solution of networkvehicle sensor by using ZigBee, according to the network struct ure of ZigBee,combine with TI company’s CC2530chip,designed the graphical development systemof TPMS passive receiver, and processed a data transceiver experiment and thetemperature sensor network experiment.Then, throughout the wireless transceiver circuit of the SAW sensor,specificcircuit design,simulation, and part of the circuit experiments have been done. Theanalysis and calculation of the transceiver’s signal detection system framework wastake into important consideration,and mainly focusing on the transmission distance ofthe architecture, the input and output power, and gain budget. After these process,wecan get the wireless transceiver system specifications and parameters, and providesthe basis for the selection and design of the circuit. Then focus is given on the transmitter circuit and receiver circuit design, such as DA, LNA, AGC and otheremphasis circuit have been simulation through experiments. Simulation results showthat the circuit design in line with the gain budget request, su ccessfully achievedbetter sensitivity under the prescribed distance and transmit power.Finally, designed key circuit of the TPMS system, the core circuit of the controlsystem and the man-machine interface of touch screen were designed and debugged.At last, discussed the system control flow and TPMS experimental methods.