Passive Method and System to Detect and Measure Internal Flaws within Metal Rails

Abstract

This invention utilizes sensing technologies in combination with or in isolation of an automated inspection vehicle to conduct inspections of internal rail flaws in steel railroad track. A vehicle equipped with X-radiation sensing is used as a secondary method to assess the deviations in magnetic fields that are sensed by a primary sensor consisting of a single or multiple magnetometers. The magnetometers sense changes in magnetic field that are correlated to the flaws inside the steel rail. The technologies improve the probability to detect railroad flaws and offer the ability to accurately track and monitor flaws.

What is claimed is: 
     
         1 . A track inspection device comprising:
 a rail vehicle;   one or more passive magnetometers in an array mounted to the rail vehicle, wherein the system of passive magnetometry detects changes in the magnetic field of a rail without exciting the rail by magnetic induction nor by transmitting an electronic current into the rail;   a guide shoe housing the one or more passive magnetometers, the guide shoe positioning the one or more passive magnetometers to measure a magnetic field within a rail while the rail vehicle operates at speeds greater than twenty miles an hour; and   a computer system on the rail vehicle, the computer system receiving data from the one or more passive magnetometers;   wherein the guide shoe:
 fits around the rail to position magnetometer measurement of a head of the rail, a web of the rail, and a base of the rail, or 
 includes guide wheels controlling a set off distance between the rail and the one or more passive magnetometers. 
   
     
     
         2 . The track inspection device of  claim 1 , wherein the guide shoe fits around the rail to position magnetometer measurement of a head of the rail, a web of the rail, and a base of the rail and is positionable for magnetometer measurement of track fixtures in addition to the rail, including at least one of a frog, a switch, and a crossover. 
     
     
         3 . The track inspection device of  claim 2 , wherein the rail vehicle is a self-propelled autonomous vehicle. 
     
     
         4 . The track inspection device of  claim 1 , wherein the guide shoe includes guide wheels controlling a set off distance between the rail and the one or more passive magnetometers and wherein the guide shoe includes linear slides and bearings to traverse rail joints or gaps in the rail while maintaining magnetometer set off distance. 
     
     
         5 . The track inspection device of  claim 4 , wherein the rail vehicle is a self-propelled autonomous vehicle.