Monitoring system for cable transportation

摘要

This work focuses on a new kind of monitoring tool, using microelectromechanical systems (MEMS) applied to cable transportation. During their lifetime, cables used in transportation fields suffer from elasticity changes leading to lengthening, for instance. In this way, monitoring theirshape over time and observing suitable indicators (such as length, sag, etc) can alert personnel to the first signs of failure. Our laboratory at CEA-Leti has worked for over ten years on capturing shape via inertial sensors. When placed onto a shape, sensors provide local surface orientations.We thus developed a methodology involving signal processing and geometrical models to provide virtual surfaces of instrumented shapes. Our new device uses a single mobile node of inertial sensors and an odometer. Installed, for instance, near the hangs of a cable car, this system can automaticallyscan the trajectory of the cable car and thereby the cable shape during all periods of travel and provide data regarding its length and sag. A demonstration cable car was developed on a reduced scale, which integrated a MEMS accelerometer and an odometer, communicating using Bluetooth. Thetrajectory is computed and displayed in real time while the cable car is moving along the cable. When the cable tension changes, the evolution of the shape can be clearly tracked, validating the principle of this cable shape monitoring approach.