A new approach of a piezoelectric vibration-based power generator to supply next generation tire sensor systems

This paper proposes a new design of a vibration-based piezoelectric generator, utilizing mechanical energy within a rolling tire. The power generator is adapted to the tire vibration spectra and the superimposed centripetal acceleration. Asymmetric motion stops and a metal-piezo bimorph structure allow higher deflections in compressive stress direction of the piezo than it would be possible in tensile stress direction. This significantly improves robustness and power output in small designs. In addition, the concept of a both-side supported beam with center deflection avoids complicated stiff clamping and therefore simplifies integration into plastic sensor housings. System behavior and power output are predicted by a full system model taking into account the nonlinear behavior of the spring-mass-system in contact to motion stops. First prototypes demonstrate power generation over a wide speed range and enable sensor systems to transmit tire information multiple times per minute.