Research of a fiber grating demodulation system based on monitoring the auto-tyre health status

A polarization maintaining fiber grating multiplexed sensors based on characteristics of some parameters such as transverse strain, longitudinal strain, temperature and rotating speed of tyre and so on is introduced in the article, and all of those are important for safe operation of cars. In addition, a novel fiber grating wavelength demodulation scheme based on the phase-shifted fiber grating is proposed. One or several spectral windows with slight line-width are unfolded in reflecting spectrum of phase-shifted fiber grating. And the location of window changes at linearly with phase-shifted change. The phase-shifted change of phase-shifted fiber grating can match with phase-shift change of multiplexed sensors through using special phase-shifted fiber grating in the demodulation systems. So we can gain some spectral windows with slight line-width in the end, which is looked upon an impulse signal, and these signals can provide convenience for searching wave peak later.