Signal aspect enforcement

Abstract

A signal aspect enforcement method for a rail vehicle includes determining, by an on-board controller on the rail vehicle, a position of the rail vehicle; determining, by the on-board controller, whether a first signal aspect for a signal matches a second signal aspect for the signal; and determining, by the on-board controller, at least one of a route of the rail vehicle or a speed limit of the rail vehicle when the first signal aspect matches the second signal aspect. The first signal aspect is determined from first data from first system on the rail vehicle, and the second signal aspect is determined from second data from a second system on the rail vehicle, which system is different from the first system used to determine the first signal aspect.

What is claimed is: 
     
         1 . A signal aspect enforcement method for a rail vehicle with an unknown position, the method comprising:
 determining, by an on-board controller on the rail vehicle, a position of the rail vehicle;   determining, by the on-board controller, whether a first signal aspect for a signal matches a second signal aspect for the signal; and   determining, by the on-board controller, at least one of a route of the rail vehicle or a speed limit of the rail vehicle when the first signal aspect matches the second signal aspect,   wherein:
 the first signal aspect is determined from first data from a first system on the rail vehicle, and 
 the second signal aspect is determined from second data from a second system on the rail vehicle, which system is different from the first system used to determine the first signal aspect. 
   
     
     
         2 . The method of  claim 1 , wherein:
 the first system is one of a camera system on the rail vehicle, a beacon/radio system on the rail vehicle, a LiDAR system on the rail vehicle, or a radar system on the rail vehicle, and   the second system is one of a camera system on the rail vehicle, a beacon/radio system on the rail vehicle, a LiDAR system on the rail vehicle, or a radar system on the rail vehicle, which system is different from the first system.   
     
     
         3 . The method of  claim 2 , wherein:
 data from the camera system is used to determine the first signal aspect, the camera system being a stereo camera system or multi-camera system, and   data from the LiDAR system or the radar system is used to determine the second signal aspect.   
     
     
         4 . The method of  claim 2 , wherein the first data includes a first identification of the signal,
 the method further comprising using the on-board controller to make a first determination of the position of the rail vehicle using the first identification of the signal.   
     
     
         5 . The method of  claim 4 , wherein the second data includes a second identification of the signal,
 the method further comprising using the on-board controller to made a second determination of the position of the rail vehicle using the second identification of the signal.   
     
     
         6 . The method of  claim 5 , wherein:
 the LiDAR system is used to generate third data including a third identification of the signal, and   the radar system is used to generate fourth data including a fourth identification of the signal,   the method further comprising:
 using the on-board controller to made a third determination of the position of the rail vehicle using the third identification of the signal; 
 using the on-board controller to make a fourth determination of the position of the rail vehicle using the fourth identification of the signal; and 
 providing a position of the rail vehicle only if the first, second, third, and fourth determinations of the position all match within certain predefined tolerance. 
   
     
     
         7 . The method of  claim 2 , wherein the on-board controller determines the position of the rail vehicle only if a position based on data from the camera system, a position based on data from the beacon/radio system, a position based on data from the LiDAR system, a position based on data from the radar system, and a position (if available) supplied by another independent positioning system all match within a predefined tolerance. 
     
     
         8 . The method of  claim 2 , wherein at least two of the camera system, the beacon/radio system, the LiDAR system, and the radar system on the rail vehicle are used to extract at least two rail tracks, the at least two rail tracks including a first track that the rail vehicle occupies and a second track nearby the first track. 
     
     
         9 . The method of  claim 2 , wherein data from the camera system, data from the LiDAR system, and data from the radar system are used to generate a map, the map including:
 a location of the signal on the map, and   an ego track the rail vehicle is on.   
     
     
         10 . The method of  claim 9 , wherein the on-board controller cross checks the generated location of the signal against a stored signal location, and raises an alarm if the generated location of the signal does not match the stored signal location. 
     
     
         11 . The method of  claim 2 , wherein the on-board controller uses data from the camera system to determine the first signal aspect. 
     
     
         12 . The method of  claim 11 , wherein the on-board controller uses data from the beacon/radio system to determine the second signal aspect. 
     
     
         13 . The method of  claim 12 , wherein the on-board controller accepts a signal aspect only if the first signal aspect based on the data from the camera system and the second signal aspect based on the data from the beacon/radio system match, and the signal aspect is a valid aspect in a database. 
     
     
         14 . The method of  claim 2 , wherein:
 data from the camera system includes an identification of the signal, an ego track, a nearby track, and an extracted path (trajectory), and   the on-board controller uses the identification of the signal, the ego track, the nearby track, and the extracted path (trajectory) together with a map to determine the position of the rail vehicle.   
     
     
         15 . The method of  claim 2 , wherein the on-board controller uses data from the camera system to determine a first along-tracks distance to the signal, uses data from the beacon/radio system to determine a second along-tracks distance to the signal, uses data from the LiDAR system to determine a third along-tracks distance to the signal, and uses data from the radar system to determine a fourth along-tracks distance to the signal. 
     
     
         16 . The method of  claim 15 , wherein the on-board controller determines an along-tracks distance to the signal only if all of the first through fourth along-tracks distances to the signal match within a certain tolerance. 
     
     
         17 . The method of  claim 1 , further comprising:
 receiving a speed measurement from a speed measuring device by the on-board controller, and determining a first speed of the rail vehicle;   determining if the first speed is less than a predetermined line-of-sight threshold speed;   receiving a grade measurement from a grade measuring device by the on-board controller and determining a first grade of a rail on which the rail vehicle is traveling;   determining a worst-case braking distance of the rail vehicle using the first speed and the first grade; and   outputting a brake request from the on-board controller when the first speed is greater than the predetermined line-of-sight threshold speed.   
     
     
         18 . The method of  claim 1 , wherein the on-board controller determines an ego track the rail vehicle is on, and an association of the ego track with the signal. 
     
     
         19 . A signal aspect enforcement method for a rail vehicle, the method comprising:
 determining, by an on-board controller, whether a first signal aspect for a signal matches a second signal aspect for the signal; and   determining, by the on-board controller, at least one of a route of the rail vehicle or a speed limit of the rail vehicle when the first signal aspect matches the second signal aspect,   wherein:
 the first signal aspect is determined from first data from a first system on the rail vehicle, and 
 the second signal aspect is determined from second data from a second system on the rail vehicle, which system is different from the first system used to determine the first signal aspect. 
   
     
     
         20 . The method of  claim 19 , wherein:
 the first system is one of a camera system on the rail vehicle, a beacon/radio system on the rail vehicle, a LiDAR system on the rail vehicle, or a radar system on the rail vehicle, and   the second system is one of a camera system on the rail vehicle, a beacon/radio system on the rail vehicle, a LiDAR system on the rail vehicle, or a radar system on the rail vehicle, which system is different from the first system.