Novel Vision Monitoring Method Based on Multi Light Points for Space-Time Analysis of Overhead Contact Line Displacements

Abstract

The article presents an innovative vision monitoring method of overhead contact line (OCL) displacement, which utilizes a set of LED light points installed along it. A light point is an, LED fed from a battery. Displacements of the LED points, recorded by a camera, are interpreted as a change of OCL shape in time and space. The vision system comprises a camera, properly situated with respect to the OCL, which is capable of capturing a dozen light points in its field of view. The monitoring system can be scaled by increasing the number of LED points and video cameras; thus, this method can be used for monitoring the motion of other large-size objects (e.g., several hundred meters). The applied method has made it possible to obtain the following novel results: vibration damping in a contact wire is nonlinear by nature and its intensity depends on the wire vibration amplitude; the natural frequency of contact wire vibration varies, and it is a function of vibration amplitude; the natural frequency of contact wire vibration also depends on the wire temperature. The proposed method can be used to monitor the uplift of contact and messenger wires in laboratory conditions, or for experimental OCL testing, as well as for verifying simulation models of OCL.

Micro-Image Strain Sensing Method for Displacement and Strain Measurement in One United Sensor

“…Displacement is defined as the change of the deformation of an object from the initial position to the final position and is a scalar quantity. Various techniques for measuring surface displacement have been developed to estimate the structural behavior, such as displacement sensors, laser technology and vision-based technology [ 11 , 12 , 13 , 14 , 15 ]. There are different types of displacement sensors, which are applicable on a large scale for defect detection and deformation measurement in civil engineering [ 16 ].…”