Tire Pressure Monitoring System Based On Organic Piezoelectric Materials

The car has become an indispensable means of transport in the daily lives ofpeople，Along with the increasing development of the automobile industry, caraccidents also become a topic of growing interest,Not only to improve their awarenessof prevention also requires the car to have a higher level of safety performanceindicators，Traditional automotive safety measures are limited to seat belts andairbags.These measures can be taken only at the time of the accident approach,Thevehicle was the situation in advance of alarm security system has become the subjectof car designers.The invention belongs to the field of automotive electronicsmeasurement,Specifically related to the automobile tire monitoring devices based onorganic piezoelectric material.The tires are an important component of the car, itsperformance directly affects the vehicle’s driver, comfort, stability and security.Sincethe beginning of the21st century, due to tire quality problems, has caused manytraffic accidents and casualties.Cars in the process of moving, especially at highspeeds, it is prone to tire failure, all drivers are worried about one of the importantissues.According to the latest survey report of the American Institute of Engineers, theUnited States each year over200,000accidents are caused by low tire pressure.Threeyears, the annual domestic average traffic accident death toll has exceeded20,000,how to prevent a flat tire and the tire has become in recent years, need expert group toaddress the important problem.Real-time detection and alarm system of the tirepressure is also known as a tire pressure monitoring system (abbreviationTirePressure Monitoring System TPMS), a major role in the vehicle was real-time automatic monitoring of tire pressure alarm tire abnormal conditions to ensuretrafficsafety.Piezoelectricity by the Curie brothers in1880, and now has over100years ofhistory.So-called piezoelectric effect is some of the dielectric in the role of externalforces and deformation along a certain direction by its internal polarizationphenomenon.In its two relative surface positive and negative charge to the contrary.When the external force is removed, it will revert to the uncharged state.The present invention utilizes a new organic functional materials, PVDF(polyvinylidene fluoride) thin film of piezoelectric effect, car tires during operation ofthe tire pressure after a probe into the role of stress and deformation in the PVDFmembrane,resulting in the polarization charge of the piezoelectric effect, and then thepiezoelectric signal to reflect the characterization of the state of the tire.Limited to the work environment, tire remote monitoring module as small size,low power consumption. If too large car tires will not only affect the balance ofnormal driving, and not easy to install. System framework is shown belowLaunch systems, including part of the sensor, signal processing circuit, the signaltransmission unit of the present invention microcontroller is STC89C51.Itsoutstanding feature is the low-power, high performance, rich on-chip resources, richinterrupt resources, with a watchdog circuit, and online debugging features, verysuitable for the development of this system.A/D analog to digital conversion moduleusing the PCF8591, the wireless transceiver module using nRF24L01. NRF24L01Nordic has developed a single-chip UHF radio transceiver chip, software-definedtransceiver mode, when the transmit power in transmit mode for the-6dBm currentconsumption is9.0mA,Sensor temperature and pressure signal after amplificationprocessing is passed to the MCU, the MCU through the wireless transceiver module, calculated through the analysis of data sent to the receiver module.The receiver section includes a wireless transceiver module, signal processingcircuit, the sound and light alarm circuit.The transceiver module using NRF24L01defined as the receiving part, the MCU using STC89C51wireless receiving devicereceives the signal of the launch system and the signal is sent to the MCU,digitaldisplay pressure. Under normal circumstances, if the tire is abnormal, an alarm systemto alert drivers to take appropriate measures to avoid danger. Display equipment, LEDdigital tube can visually display the tire pressure.TPMS system based on PVDF piezoelectric films of organic materials for the tiresituation in the vehicle was a version of dynamic monitoring, if the tire is deflated airleakage and so on can be the first time to remind the driver, to prevent accidents, theincidence of this paper developed. System power consumption is very small to be ableto adapt to a variety of road surface state of the environment, with a high practicalvalue.