Device for detecting rail defects and associated detection method

Abstract

The present invention relates to a device for detecting defects in a rail, including at least one collection of sensors which are able to generate an electrical signal indicative of a distance (dn,i) separating the sensors and the rail, and at least one rail vehicle able to move along the rail; the collection of sensors being assembled to the rail vehicle; the rail vehicle being configured to rest on the rail in such a way that said sensors are positioned facing and some distance away from said rail. The device includes a friction pad comprising a lower surface able to slide along the rail, the friction pad further comprising at least one cavity formed in the lower surface, the at least one collection of sensors being housed in the cavity.

What is claimed is: 
     
         1 . A device for detecting rail defects, comprising:
 at least one collection of sensors, each of said sensors being able to generate an electrical signal indicative of a distance separating said sensor and the rail,   at least one rail vehicle able to move along the rail;   the collection of sensors being assembled to the rail vehicle; the rail vehicle being configured to rest on the rail in such a way that said sensors are positioned facing and some distance away from said rail;   wherein the device includes a friction pad comprising a substantially flat lower surface,   said friction pad being assembled to the rail vehicle in such a way that the movement of said vehicle along the rail causes a sliding on said rail by said lower surface, along a longitudinal direction of said friction pad;   the friction pad further comprising at least one cavity formed in the lower surface, the at least one collection of sensors being housed in said cavity.   
     
     
         2 . The detection device according to  claim 1 , wherein the at least one collection of sensors comprises at least one row of sensors aligned in a transverse direction, perpendicular to the longitudinal direction of the friction pad. 
     
     
         3 . The detection device according to  claim 1 , wherein the at least one collection of sensors comprises several rows, each row being formed by sensors aligned in a transverse direction, perpendicular to the longitudinal direction of the friction pad. 
     
     
         4 . The detection device according to  claim 3 , wherein the sensors of the at least one collection are arranged in a regular mesh, formed by lines extending in the transverse direction (Y) and lines extending in a direction inclined by an angle relative to said transverse direction, said angle preferably being between 45° and 90°. 
     
     
         5 . The detection device according to  claim 1 , wherein the friction pad further comprises at least one groove arranged in the lower surface in the longitudinal direction, the at least one groove emerging on the at least one cavity. 
     
     
         6 . The detection device according to  claim 1 , wherein the friction pad is assembled to the rail vehicle by a suspension provided with means for fixed maintenance of a constant transverse position of at least one collection of sensors relative to the wagon. 
     
     
         7 . The detection device according to  claim 1 , wherein the friction pad is assembled to the rail vehicle by a suspension provided with means for maintenance by slaving of a constant transverse position of the at least one collection of sensors relative to an edge of the rail. 
     
     
         8 . The detection device according to  claim 1 , further comprising an electronic processing device for information provided by the sensors, said device comprising at least one electronic detector for spatial coordinates and at least one on board controller, said electronic detector and said on board controller being secured to the rail vehicle, said on board controller being connected to the electronic detector and to the collection of sensors. 
     
     
         9 . The detection device according to  claim 7 , wherein the processing device includes several on board controllers secured to a same rail vehicle or several different rail vehicles, each on board controller being connected to a collection of sensors, the processing device further comprising a centralized logic controller provided with means for communicating with each of the on board logic controllers. 
     
     
         10 . An operating method for a detection device according to  claim 1 , said method including the following steps:
 moving the rail vehicle along the rail;   during said movement, measuring the distance between the sensors of the at least one collection and an upper surface of the rail; and simultaneously detecting spatial coordinates and the speed of the vehicle; then   developing a first spatial representation of the upper surface of the rail; then   comparing said first spatial representation with reference representations in order to identify defects of the upper surface; then   generating an alert in case of identified defect.   
     
     
         11 . The method according to  claim 10 , further comprising a step for comparing the first spatial representation with a second spatial representation previously stored in a data memory, so as to lead to tracking of the evolution of the defects of the upper surface. 
     
     
         12 . The method according to  claim 10 , wherein the reference representations comprise several types of defects associated with spatial characteristics and in which the comparison step comprises determining analysis windows corresponding to said spatial characteristics.