The Optimal Design And Experimental Research On Piezoelectric Power Generator For TPMS

TPMS (Tire Pressure Monitoring System) is used for monitoring the pressure and temperature of the tire when the car is moving. TPMS, as a active safety warning system, will alarm the driver in order to ensure the traffic safety when the pressure is not enough or leak, the temperature is too high or low, because it can monitor the condition of the tire in real-time. The conventional way to power TPMS is battery-powered, but it needs replace battery regularly because of its limited life. To solve this problem, we expanded the research on through the piezoelectric to power the detection and transmitter module in the paper, and we made the prototype of the piezoelectric power generator by means of theoretical analysis and experimental research. Finally it proves that it is a viable technical solution using the piezoelectric power generator to charge the TPMS.Piezoelectric bimorph is the important part of the piezoelectric power generator, which directly affects the performance of the piezoelectric power generator. So we need to research its performance parameters. We selected the most suitable support form by means of the simulation analysis and experimental testing.we established the power generation model of Single or double cantilever chip piezoelectric bimorph and after the derivation and experimental analysis, we acquired the relationship between the external excitation amplitude, frequency, the thickness ratio of the piezoelectric vibrator, Young's modulus ratio and the amount of energy output. So we get to know how to improve the ability of piezoelectric power generator.The study found that we can get a higher power generation capacity and energy conversion efficiency when the external excitation frequency is close to its natural frequency in the process of using piezoelectric material to harvest energy. But in practical application, this effective frequency range is narrow, may be only a few hertz or so, so its power generation capacity will be greatly weakened and cannot fully play its generation effect if the vibration frequency of the external environment is fluctuant. Therefore, it is important to research on improving the piezoelectric power generator's power generation capacity in a wide frequency range for improving the overall power generation capacity. Basing on this case, we used multiple piezoelectric bimorph by changing the quality of the end mass to construct an interval moderated piezoelectric power generator with certain frequency width. In this way, it can effectively improve the output voltage amplitude and enhance effective frequency bandwidth.Through theoretical analysis and experimental test, we got the most suitable capacitance of energy storage devices for piezoelectric power generator. We designed the storage control circuit based on the characteristics of piezoelectric power harvesting:high-voltage, low current, which can solve the problem that piezoelectric power generation cannot directly power for the TPMS.We made the prototype of the piezoelectric power generator, and did a lot of test. The results showed that the main factors which affect the ability of piezoelectric power generator are the speed and road conditions. With a speed of more than 25km/h even under all road conditions, the piezoelectric power generator is able to meet the operational requirements of TPMS, the time, from the start of the car to the TPMS working, is less than 5min.and its performance is stable, which demonstrated that using the piezoelectric power generator as a power supply to replace battery for powering TPMS is a feasible technology solutions.