摘要: |
Predictive enforcement braking is one of the key concepts behind positive train control (PTC) systems. If a train is on the verge of overrunning a target stopping location, such as an authority limit, the system enforces a brake application to stop the train safely short of the limit. The concept depends on an algorithm that can predict the stopping distance of the train. Errors in stopping distance prediction can result in target overruns, target underruns, or unnecessary enforcements, which can negatively impact railroad safety or operations. Due to the uncertainty of many parameters that affect stopping distance, PTC enforcement algorithms have traditionally used a target offset to ensure that no trains overshoot the target. However, this can force the algorithm to be overly conservative and result in unnecessary or early warnings and enforcement. |