Research On Array Energy Harvesting System In Intelligent Tire

The sensor in the intelligent tire system can monitor the pressure, temperature and other state of the tires. It can avoid the traffic accident, which enhances safety of the automobile. But in this system, the traditional battery supply system has the drawbacks of short lifetime, replacement difficulty, pollution and so on, which restrict its development. A research on array energy harvesting system in intelligent tire is proposed in this paper, which is based on the actual tire inner wall acceleration signal. Output performance of energy harvesters and matching design of the energy management system is given. The main research contents include the following aspects:First, according to the physical model of the energy harvester, the influence factors of vibration displacement and the output power of the system under sine acceleration excitation signal is theoretically analyzed. The load resistance was studied for the largest output power. By analyzing the waveform characteristics and harmonic distribution of the acceleration signal caused by the deformation of the tire, an approximation analysis method is presented. The expression of the oscillator motion state is given.Secondly, based on the expression of the average output power, the electromagnetic parameters such as flux gradient, electrical damping, which affects the output power, are studied. For the stator ironless structure, the magnetic field distribution is calculated theoretically. Flux waveform is compared under different coil arrangement. For the structure with stator iron, the magnetic field is calculated by using the scalar magnetic potential method. According to the different magnetization of the oscillator, the influence of variation of the size parameters is researched. Further comparative analysis of the effect of oscillator magnetizing method of electromagnetic parameters is presented.Thirdly, considering the specific situation of the energy harvester, an accurate simulation model is established, and the output performance of the energy harvester under different conditions is analyzed. The influence of mechanical parameters on the average output power is studied. For the structure with stator iron, the influence of the cogging force on the motion of the oscillator and the average output power is analyzed.Finally, considering plenty of energy harvesters along the circumferential direction of the tire arranged in an array type, based on the idea that energy harvesters are used in groups, the energy management system with multi input is proposed. The super capacitor is used as an energy storage element. The specific design method of each module in the circuit is given, which can meet the energy requirement when the wireless sensor transmits data.