STS Inc | Date: 2013-03-13
A sequential monitoring system is for an interlocking logic system and a track circuit system including a plurality of track circuits. The sequential monitoring system includes an interface between the interlocking logic system and the track circuit system; and a processor structured to monitor a state of each of the track circuits, validate a sequence of state changes of the track circuits, and interrupt and correct invalid track circuit state indications between the track circuit system and the interlocking logic system. The interface normally passes inputs from the track circuit system to outputs to the interlocking logic system. When an out of sequence event occurs, the processor applies a quarantine to a minimum of three of the track circuits in a quarantined area, thereby inhibiting use of an unoccupied track circuit in the quarantined area.
STS Inc | Date: 2011-09-21
A method of testing a target electronic device implemented in a configurable integrated circuit device includes receiving a baseline design for the target electronic device in a hardware description language, establishing a fault model for the particular configurable integrated circuit device, synthesizing the fault model in the hardware description language, embedding the synthesized fault model into the baseline design to create a modified baseline design in the hardware description language which enables one or more targeted signals to be selectively corrupted, creating a fault model enabled target device on the particular configurable integrated circuit device using the modified baseline design, performing a number of fault injection experiments on the fault model enabled target device, wherein each fault injection experiment includes causing at least one of the one or more targeted signals to be corrupted within the fault model enabled target device.
STS Inc | Date: 2010-07-22
An autonomous vehicle collision/crossing warning system provides for simple, inexpensive and decentralized installation, operation and maintenance of a reliable vehicle collision/crossing warning system. The autonomous warning system preferably utilizes a single frequency TDM radio communication network with GPS clock synchronization, time slot arbitration and connectionless UDP protocol to broadcast messages among vehicles and components in the warning system. Adaptive localized mapping of components of interest within the warning system eliminates the need for centralized databases or coordination and control systems and enables new vehicles and warning systems to be easily added to the system in a decentralized manner. Preferably, stationary warning systems are deployed as multiple self-powered units each equipped to receive broadcast messages and to communicate with the other units by a low power RF channel in a redundant Master-Slave configuration. The communication schemes are preferably arranged for low duty cycle operation to decrease power consumption.
STS Inc | Date: 2011-09-20
A method of adjusting one or more of braking parameters used in a braking function to control braking of a train includes determining an adjustment factor based on a joint stopping distance probability distribution, the joint stopping distance probability distribution representing the composite effect on stopping distance of a plurality of predetermined train characteristic parameters, each of the predetermined train characteristic parameters being variable, and applying the adjustment factor to each of the one or more of braking parameters. Also, a method of adjusting braking parameters that includes determining an adjustment factor based on a nominal value, a worst case limit value and a best case limit value of each of a plurality of predetermined train characteristic parameters, each of the predetermined train characteristic parameters being variable, and applying the adjustment factor to each of the one or more of braking parameters.
STS Inc | Date: 2011-03-01
A railroad monitoring apparatus includes first and second diverse vital processing units, first and second current sensors configured to measure the current being provided to one or more signaling elements of an item of wayside signaling equipment, and means for measuring voltage levels being supplied to each of the signaling elements. The first processing unit receives a first current measurement from the first current sensor and the measured voltage levels, and the second vital processing unit receives a second current measurement from the second current sensor and the measured voltage levels. The vital processing units are each programmed to determine based on one or more of the first current measurement, the second current measurement and the measured voltage levels: (i) the state of the item of railroad wayside signaling equipment, (ii) failures within the item of railroad wayside signaling equipment, and (iii) failures within the monitoring apparatus itself.