Highway crossing control system for railroads utilizing a communications link between the train locomotive and the crossing protection equipment
First Claim
1. The method for controlling the operation of crossing protection equipment guarding a highway crossing for railroad tracks along which trains travel, said equipment having first and second states in which highway traffic across said tracks is allowed and disallowed respectively, said method comprising the steps of establishing a communications link between a train approaching said crossing and the equipment, interchanging messages over said link from said approaching train to said equipment and from said equipment to said approaching train, respectively, as to the speed of said approaching train and its distance from said crossing and as to the time when said transmission of a next successive message from said approaching train is required, computing a minimum time for said equipment to be disposed in said second state when said link is first established upon receipt of a first of said messages from said approaching train, and updating said minimum time upon each interchange of messages from said equipment to said train and from said train back to said equipment.
2 Assignments
0 Petitions
Accused Products
Abstract
Highwasy crossing protection equipment which operates warning lights or crossing gates is controlled from the train locomotive which enters into an interchange of messages via a radio link with the controller at the crossing. Communications between the train and the crossing controller is initiated when the locomotive passes a trackside beacon transponder located beyond a safe braking distance from the crossing. The crossing controller transmits a message addressed to the train acknowledging the receipt of the train signal. The interchange of messages can be repeated a plurality of times; each time the minimum time being updated so that traffic flow across the crossing is handled efficiently with minimum interference. All communications are handled through vital communications logic which activates the protection equipment to its safe condition or sets alarms or brakes in the train in the event of errors or failures in the messages being handled in the crossing controller or in the train equipment, respectively. Wayside signals may also be used to warn the train driver to stop the train unless the communication link has been established. The crossing protection equipment is responsive to successive occupancy and unoccupancy of the crossing.
39 Citations
29 Claims
- 1. The method for controlling the operation of crossing protection equipment guarding a highway crossing for railroad tracks along which trains travel, said equipment having first and second states in which highway traffic across said tracks is allowed and disallowed respectively, said method comprising the steps of establishing a communications link between a train approaching said crossing and the equipment, interchanging messages over said link from said approaching train to said equipment and from said equipment to said approaching train, respectively, as to the speed of said approaching train and its distance from said crossing and as to the time when said transmission of a next successive message from said approaching train is required, computing a minimum time for said equipment to be disposed in said second state when said link is first established upon receipt of a first of said messages from said approaching train, and updating said minimum time upon each interchange of messages from said equipment to said train and from said train back to said equipment.
- 16. Apparatus for controlling the operation of crossing protection equipment guarding a highway crossing for railroad tracks along which trains travel, said equipment having first and second states in which highway traffic across said tracks is allowed and disallowed respectively, said apparatus comprising means for establishing a communications link between a train approaching said crossing and the equipment, means for interchanging messages over said link from said approaching train to said equipment and from said equipment to said approaching train, respectively, as to the speed of said approaching train and its distance from said crossing and as to the time when said transmission of a next successive message from said approaching train is required, means for computing a minimum time for said equipment to be disposed in said second state when said link is first established upon receipt of a first of said messages from said approaching train, and means for updating said minimum time upon each interchange of messages from said equipment to said train and from said train back to said equipment.
Specification