Abstract: A speed profile for an entire train trip includes a maximum allowable speed at each point of the entire trip, taking into account the ability of the train to comply with speed reductions encountered during the trip. The speed profile includes a braking curve that gradually reduces from a higher speed to a lower speed starting at a point at which the train must begin braking in order to be traveling at the lower speed when the train reaches the point at which the lower speed limit begins. The speed profile is generated on multiple wayside computers, cross checked, and then vitally transmitted to an onboard locomotive control system. The onboard control system includes redundant speed sensors with redundant vital circuits, and also includes redundant speed comparators to ensure that the train doesn't exceed the speed profile. A GPS receiver may be used for greater reliability.

Abstract: A speed profile for an entire train trip includes a maximum allowable speed at each point of the entire trip, taking into account the ability of the train to comply with speed reductions encountered during the trip. The speed profile includes a braking curve that gradually reduces from a higher speed to a lower speed starting at a point at which the train must begin braking in order to be traveling at the lower speed when the train reaches the point at which the lower speed limit begins. The speed profile is generated on multiple wayside computers, cross checked, and then vitally transmitted to an onboard locomotive control system. The onboard control system includes redundant speed sensors with redundant vital circuits, and also includes redundant speed comparators to ensure that the train doesn't exceed the speed profile. A GPS receiver may be used for greater reliability.

Abstract: A speed profile for an entire train trip includes a maximum allowable speed at each point of the entire trip, taking into account the ability of the train to comply with speed reductions encountered during the trip. The speed profile includes a braking curve that gradually reduces from a higher speed to a lower speed starting at a point at which the train must begin braking in order to be traveling at the lower speed when the train reaches the point at which the lower speed limit begins. The speed profile is generated on multiple wayside computers, cross checked, and then vitally transmitted to an onboard locomotive control system. The onboard control system includes redundant speed sensors with redundant vital circuits, and also includes redundant speed comparators to ensure that the train doesn't exceed the speed profile. A GPS receiver may be used for greater reliability.

Abstract: An identification tag reader reads identification tags on vehicles of a train consist. Identification tag identifiers are used to retrieve weights and lengths of the vehicles, and the weight and length information is used by an onboard train control system either to verify weight and length information already stored in the system or input the information initially, in either case for use in controlling the train such as in the calculation of braking curves. In another embodiment, an identification tag reader is paired with a sensor capable of detecting a condition on a train vehicle requiring maintenance, and the condition and an identification tag identifier are transmitted to maintenance personnel. The identification tag is preferably an AEI tag.

Abstract: An identification tag reader reads identification tags on vehicles of a train consist. Identification tag identifiers are used to retrieve weights and lengths of the vehicles, and the weight and length information is used by an onboard train control system either to verify weight and length information already stored in the system or input the information initially, in either case for use in controlling the train such as in the calculation of braking curves. In another embodiment, an identification tag reader is paired with a sensor capable of detecting a condition on a train vehicle requiring maintenance, and the condition and an identification tag identifier are transmitted to maintenance personnel. The identification tag is preferably an AEI tag.

Abstract: A speed profile for an entire train trip includes a maximum allowable speed at each point of the entire trip, taking into account the ability of the train to comply with speed reductions encountered during the trip. The speed profile includes a braking curve that gradually reduces from a higher speed to a lower speed starting at a point at which the train must begin braking in order to be traveling at the lower speed when the train reaches the point at which the lower speed limit begins. The speed profile is generated on multiple wayside computers, cross checked, and then vitally transmitted to an onboard locomotive control system. The onboard control system includes redundant speed sensors with redundant vital circuits, and also includes redundant speed comparators to ensure that the train doesn't exceed the speed profile. A GPS receiver may be used for greater reliability.

Abstract: A method and system for compensating for wheel wear uses position and/or speed information from an independent positioning system to measure some distance over which the train has traveled. Wheel rotation information is also collected over the distance. The wheel rotation information and distance and/or speed information are then used to determine the size of the train wheels. The method is performed periodically to correct for changes in wheel size over time due to wear so that the wheel rotation information can be used to determine train position and speed in the event of a positioning system failure.

Abstract: Position reports from GPS receivers can be made vital through a variety of techniques including relative differential GPS corrections and a technique in which a train traveling on a fixed path is provided with a database that includes positions on fixed paths or data from which positions on fixed paths can be determined. Position reports from GPS receivers located on the vehicle are compared to the positions of the fixed paths in the database. If the distance from the position reported by the GPS receiver to the nearest point on the nearest fixed path is greater than the stated accuracy of the GPS receiver, the position report is discarded or other corrective action is taken. A second technique involves cross-checking position reports from two GPS receivers separated by a known distance, preferably mounted on a single vehicle. Still other techniques may be used.

Abstract: A method and system for compensating for wheel wear uses position and/or speed information from an independent positioning system to measure some distance over which the train has traveled. Wheel rotation information is also collected over the distance. The wheel rotation information and distance and/or speed information are then used to determine the size of the train wheels. The method is performed periodically to correct for changes in wheel size over time due to wear so that the wheel rotation information can be used to determine train position and speed in the event of a positioning system failure.

Abstract: A train control system includes a positioning system and consults a database to determine when the train is approaching a configurable device such as a switch or grade crossing gate. The system continuously interrogates the device to determine its status as the train approaches the device, and forces an engineer/conductor to acknowledge any detected malfunction. The train is forced to come to a complete stop before proceeding past the device or may be slowed down to a speed that will allow the engineer/conductor to visually determine whether it is safe to proceed past the device if the engineer/conductor acknowledges a message warning of the malfunction and will stop the train if the engineer/conductor fails to acknowledge the warning message.

Abstract: A train control system and method for ensuring that a train cannot be moved from a section of track not on a main line to a section of track on the main line until both a movement authority for the section of main line track and a circulation authority for the section of track not on the main line are received.

Abstract: A method and system in which a vehicle carries an on-board positioning system and has access to a database of information pertaining to a plurality of fixed paths. A vector between the position of the fixed path and a position of the vehicle as reported by the positioning system is calculated prior to arriving at a point of divergence (i.e., a point at which a path branches, such as a switch on a railroad track). After passing the path divergence, a second vector is calculated between the position of the vehicle as reported by the positioning system and at least one of the alternate paths, preferably the correct alternate path. The first vector is compared to the second vector, and a determination as to which path the vehicle is on is made based on the comparison.

Abstract: A train control system includes positioning systems at the end of the train and at the front of the train, allowing the conductor or engineer to unambiguously determine that no cars of the train have become detached. The positioning system at the end of the train is also used to verify that the entire train has cleared a block. This information can be relayed to a dispatcher, thereby eliminating the need for trackside sensing equipment. A control unit prevents the train from moving without an authorization that includes the train's current position.

Abstract: A train control system and method uses signal information from a next block to change a restrictive signal in a block currently occupied by the train to a less restrictive signal if it can be ascertained that the condition causing the more restrictive signal has changed. This may be accomplished by receiving signal information from the next block while still in the current block and, if the signal information from the next block is no more restrictive than the signal information in the current block, and the signal in the current block is of a type that can safely be modified, allowing the train to operate as if the signal information for the current block were less restrictive than the actual, previously received signal information for the current block.

Abstract: A train control system includes positioning systems at the end of the train and at the front of the train, allowing the conductor or engineer to unambiguously determine that no cars of the train have become detached. The positioning system at the end of the train is also used to verify that the entire train has cleared a block. This information can be relayed to a dispatcher, thereby eliminating the need for trackside sensing equipment. A control unit prevents the train from moving without an authorization that includes the train's current position.

Abstract: A train control system includes positioning systems at the end of the train and at the front of the train, allowing the conductor or engineer to unambiguously determine that no cars of the train have become detached. The positioning system at the end of the train is also used to verify that the entire train has cleared a block. This information can be relayed to a dispatcher, thereby eliminating the need for trackside sensing equipment. A control unit prevents the train from moving without an authorization that includes the train's current position.

Abstract: A train control system includes a control module that determines a position of a train using a positioning system and consults a database to determine when the train is approaching a portion of track monitored by a track circuit. When the train is near a track circuit, but while the train is still far enough away from the track circuit such that the train can be stopped before reaching the portion of track monitored by the track circuit, the train transmits an interrogation message to a transceiver associated with the track circuit. When the track circuit receives the interrogation message, a test is initiated. The test results are transmitted back to the train. The train takes corrective action if the track circuit fails to respond or indicates a problem.

Abstract: A train control system includes positioning systems at the end of the train and at the front of the train, allowing the conductor or engineer to unambiguously determine that no cars of the train have become detached. The positioning system at the end of the train is also used to verify that the entire train has cleared a block. This information can be relayed to a dispatcher, thereby eliminating the need for trackside sensing equipment. A control unit prevents the train from moving without an authorization that includes the train's current position.

Abstract: A train control system includes a positioning system and consults a database to determine when the train is approaching a configurable device such as a switch or grade crossing gate. The system continuously interrogates the device to determine its status as the train approaches the device, and forces an engineer/conductor to acknowledge any detected malfunction. The train is forced to come to a complete stop before proceeding past the device or may be slowed down to a speed that will allow the engineer/conductor to visually determine whether it is safe to proceed past the device if the engineer/conductor acknowledges a message warning of the malfunction and will stop the train if the engineer/conductor fails to acknowledge the warning message.

Abstract: A train control system includes positioning systems at the end of the train and at the front of the train, allowing the conductor or engineer to unambiguously determine that no cars of the train have become detached. The positioning system at the end of the train is also used to verify that the entire train has cleared a block. This information can be relayed to a dispatcher, thereby eliminating the need for trackside sensing equipment. A control unit prevents the train from moving without an authorization that includes the train's current position.