A system and a method for the diagnosis of abnormal bending in railway rails, in particular at connections between railway rails

Abstract

A system is described for the diagnosis of the operating conditions of joints between rails, including: a frame configured for installation on a railway vehicle at a wheel of the railway vehicle, a first distance sensor and a second distance sensor installed on said frame and arranged in such a way as to be on opposite sides of a wheel of the railway vehicle, each of said first distance sensor and second distance sensor being configured to detect, respectively, a first distance and a second distance between said frame and a top of a rail, and a third distance sensor installed on said frame and configured to detect a third distance of said frame with respect to a journal box associated to the wheel of the railway vehicle.

1 . A system for diagnosis of bending of railway rails, comprising:
 a frame configured for installation on a railway vehicle at a wheel of the railway vehicle,   a first distance sensor and a second distance sensor installed on said frame and arranged so as to be on opposite sides of the wheel of the railway vehicle, each of said first distance sensor and second distance sensor being configured to detect, respectively, a first distance and a second distance between said frame and a top of a rail, and   a third distance sensor installed on said frame and configured to detect a third distance of said frame with respect to a journal box associated to the wheel of the railway vehicle.   
     
     
         2 . The system according to  claim 1 , comprising at least one further sensor configured to determine, on a basis of said first distance, second distance and third distance, a spatial trajectory of said frame relative to the top of said rail. 
     
     
         3 . The system according to  claim 2 , wherein said at least one further sensor comprises at least one inertial sensor installed on said frame. 
     
     
         4 . The system according to  claim 3 , wherein said at least one inertial sensor comprises a first accelerometer installed on said frame and a second accelerometer, each of said first accelerometer and second accelerometer being accelerometers configured to detect a vertical acceleration. 
     
     
         5 . The system according to  claim 4 , wherein said first accelerometer is installed on said frame in correspondence of said first distance sensor, and wherein said second accelerometer is installed on said frame in correspondence of said second distance sensor. 
     
     
         6 . The system according to  claim 3 , wherein said at least one inertial sensor comprises an inertial platform installed on said frame. 
     
     
         7 . The system according to  claim 3 , further comprising a locating unit configured for spatial referencing of the distance detected by at least one of said first, second and third distance sensors. 
     
     
         8 . A method for diagnosing bending of railway rails by means of a system according to  claim 3  on board a railway vehicle, the method comprising:
 running the railway vehicle along said track in order to go through an inspection area, 
 detecting, during the running of the railway vehicle, said first distance at a first point, said second distance at a second point, and said third distance at a third point, said first, second and third points being located on the top of the rail, 
 determining a figure having vertices at said first, second and third points, 
 determine values of a first angle defined between a side of said figure joining the first point and the second point and a side of the figure joining the first point and the third point, and of a second angle defined between the side of said figure joining the first point and the second point and a side of the figure joining the second point and the third point, 
 determining a fourth distance value between said third point and the side of said figure joining the first point and the second point, and 
 comparing the values of said first angle, second angle and fourth distance value with respective threshold values. 
 
     
     
         9 . The method of  claim 8 , further comprising correcting the values of said first distance, said second distance and said third distance on a basis of displacements of the frame with respect to the rail determined by means of said inertial sensor, and determining:
 a first difference between a corrected value of the first distance and a corrected value of the second distance,   a second difference between a corrected value of the first distance and a corrected value of the third distance, and   a third difference between a corrected value of the second distance and a corrected value of the third distance.   
     
     
         10 . The method of  claim 8 , further comprising comparing said first difference, second difference and third difference with respective threshold values.