Research On Array Energy Harvester For TPMS Application At Wide Car Speed Range

In recent years,with the development of microelectronics technology,microelectromechanical systems(MEMS)technology,computer technology and wireless communication technology.Ultralow power microsensors and systems with small size,light weight and low cost have been greatly promoted and widely used in the military and civilian fields.The tire pressure monitoring system is a micro-sensing system for monitoring the pressure and temperature in automobile tires.It plays an important role in reducing traffic accidents and improving fuel efficiency.Legislation has been adopted to force automakers to install tire pressure monitoring systems in automobile tires in countries of Europe and the United States.At present,the tire pressure monitoring system is mainly powered by the traditional chemical energy battery.However,the traditional chemical energy battery has disadvantages of short life and complicated replacement.Based on the environmental acquisition and conversion,the vibration energy harvesting technology has the advantages of long life and maintenance-free,which has become one of the effective technical solutions to replace the traditional battery.In the course of driving,tire contact with the ground will produce abundant vibration energy.The vibration energy is converted into electric energy by vibration energy harvesting technology to power the tire pressure monitoring system.It is one of the important research directions of vibration energy collection technology in recent years,which has attracted the attention of researchers at home and abroad.The vibration energy harvester in the tire pressure monitoring system generally has the shortcomings of low power output and narrow working speed range.In response to these shortcomings,the piezoelectric vibration energy harvester applied to the tire pressure monitoring system is studied in this thesis.It is hoped that the power output of the vibration energy harvester can be increased and the working speed range can be expanded.The research of this thesis is based on the vibration characteristics of the tires inner lining.The vibration model of tire inner lining is established.According to the vibration characteristics,a new structure of trapezoidal piezoelectric energy harvester is designed suitable for wide vehicle speed range.The simulation analysis model of the trapezoidal piezoelectric energy harvester is established by using Mathematica numerical analysis software and ANSYS finite element analysis software.Based on this model,the key factors affecting the performance of the vibration energy harvester are analyzed firstly.Then the relationship between the natural frequency and the power output of the energy harvester is studied by using reverse design idea.The allowable natural frequency range of the device is determined.Finally,the size of the energy harvester is optimized and the optimum structural parameters are obtained.Under the optimized structure parameters,the power output of 1620?W~9600?W are achieved with the vehicle speed range of 80 km/h~120 km/h.The simulation results show that the energy harvester proposed in this thesis has high power output in a wide speed range,which provides a new design idea and method for the wireless power supply of tire pressure monitoring system.