A multi-channel real-time detection method for tunnel boring machine cutter wear based on Chirped Fiber Bragg Gratings

We propose a multi-channel real-time detection method for tunnel cutter wear of boring machine (TBM) based on Chirped Fiber Bragg Gratings (CFBG). We designed and fabricated the real-time wear detection sensor and the multi-channel real-time demodulation device for TBM cutter wear. According to the characteristics of grating area and wide reflection spectrum of CFBG, the CFBG is arranged vertically on the wear detection working face. When the end face of the TBM cutter is wear, the CFBG is worn at the same time. The wear action on the grating shortens the grating area, narrows the reflection spectrum bandwidth. The cutter wear detection of TBM is realized. After many field experiments, the wear detection sensors and the multi-channel real-time demodulation device can meet the requirements of complex working conditions and multi-channel real-time cutter wear detection. The experimental data show that the sensors and the device can meet the technical requirements of measuring wear length greater than 12 mm and measuring accuracy less than 1 mm.