Patent ID: 8725761
Filing Date: 2014-05-13
Classification: B61L

Abstract:
1. A chainage calculation system for calculating the chainage distance using Positive Train Control (PTC) messages, the system receiving a PTC Current Position message and a PTC Train Route message, wherein the PTC Current Position message provides an absolute position of the train head end in relation to both a stored track database and the PTC Train Route message, wherein the PTC Train Route message includes a track segment ID field, and wherein the messages are wirelessly received on board a locomotive, wherein the system utilizes data included in the received PTC Current Position message to determine a last direction of travel for the train when such data is available and compares an existing linked list with data received in the PTC Train Route message to determine whether the PTC Train Route message includes any matches to the linked list if it is determined that the received PTC Train Route message is not a first PTC Train Route message received and a last direction of travel for the train is not known, wherein each node of the existing linked list includes a track segment ID field, wherein the system adds or deletes nodes of the existing linked list based on the comparison of the existing linked list with the data received in the PTC Train Route message to produce an updated linked list and deletes a linked list and calculates an updated linked list if the received PTC Train Route message is the first PTC Train Route message received, the PTC Train Route message is not the first PTC Train Route message but the last direction of travel for the train is known, or it is determined that the Train Route message does not include any matches to the existing linked list, wherein the chainage distance is re-calculated based on the comparison of the existing linked list with the data received in the PTC Train Route Message if an updated linked list is calculated, wherein the chainage distance calculation is optionally omitted based on the comparison, and wherein the system is implemented in at least one computer processing unit coupled to a memory that stores computer instructions for controlling operations of the at least one computer processing unit to perform operations for calculating the chainage distance.