Application of WPT and FBG techniques for prognostic of escalator abnormality: A case study of degraded step wheel

This study explores the adoption of fibre Bragg grating (FBG) strain sensor for in situ condition monitoring of the interaction between the step wheels and rail of escalator system. Time and frequency domain signal-processing techniques are proposed to extract the useful signatures from the measurements collected by the FBG sensors. It is shown that these signatures can be used accurately to provide crucial information of the escalator condition such as passenger loading of steps as well as abnormal vibration induced by component defects of the escalator system. These information are important as they give real-time information of the dynamic behaviour of an operating escalator and hence the monitoring system can also be used as a tool to enhance the safety and maintainability of escalators. Discussions on the results as well as technical issues to be addressed for the scheme in practice are given.