Wireless Train Control System Using Time-Delayed Track Circuit Signals
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Solution Overview
Problem
The existing wireless train control systems face challenges in maintaining stable operation when both wireless-control compliant and noncompliant trains coexist on the same track, due to transmission delays that can lead to erroneous recognition of the current train position and subsequent emergency stops.
Innovation Solution
The system sets a stop limit point for the wireless-control compliant train using a track circuit where the tail end position of the wireless-control noncompliant train is present, and employs a time-element-added track-circuit state signal to differentiate between the train's presence and track circuit turn-offs, preventing unnecessary updates of the stop limit point.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a wireless-control compliant train and a wireless-control noncompliant train coexist on the same track, then the system can support mixed train types, but the ground control device cannot accurately recognize the tail end position of the noncompliant train, leading to erroneous stop limit point calculations
Solution Approach 1:
The patent introduces track circuit information as an intermediary to indirectly detect the presence and position of noncompliant trains. Since the ground control device cannot directly obtain position data from noncompliant trains, it uses track circuit occupancy signals as a mediator to infer the tail end position of noncompliant trains, thereby resolving the measurement precision issue while maintaining coexistence capability
Solution Approach 2:
The patent segments the track into multiple track circuits and independently monitors the occupancy status of each segment. By dividing the track into discrete detectable units, the system can accurately track the position of noncompliant trains through sequential track circuit activations, improving position recognition accuracy without requiring direct communication from noncompliant trains
2Speed
If the stop limit point is updated based on real-time track circuit state signals, then the system responds quickly to train movements, but transmission delays cause erroneous recognition of current train position leading to unstable operation
Solution Approach 1:
The patent performs preliminary validation by checking whether the track circuit state change is consistent with the train's current position and movement direction before updating the stop limit point. This preliminary check prevents erroneous updates caused by transmission delays, maintaining reliable operation while still responding quickly to legitimate train movements
Solution Approach 2:
The patent implements a feedback mechanism where the system continuously monitors track circuit state changes and compares them against expected train positions. When a discrepancy is detected due to transmission delays, the feedback loop prevents incorrect stop limit point updates, ensuring stable operation while maintaining responsive tracking of actual train positions
3Measurement precision
If the system uses track circuit state signals to determine stop limit points, then it can detect train presence, but it cannot distinguish between track circuit turn-off caused by the train itself versus external factors, leading to unnecessary stop limit point updates
Solution Approach 1:
The patent uses the train's own wireless transmission signals as an intermediary to verify the cause of track circuit state changes. By cross-referencing wireless position reports with track circuit occupancy signals, the system can determine whether a track circuit turn-off is caused by the train itself or external factors, preventing unnecessary stop limit point updates while maintaining accurate train presence detection
Solution Approach 2:
The patent merges multiple information sources including track circuit state signals, wireless train position reports, and train identification data into a unified determination process. This combination allows the system to accurately distinguish between track circuit turn-offs caused by train presence versus external factors, resolving the information loss problem while maintaining precise train presence detection
Data Source
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AI summary
To provide a wireless train control system that can perform a stable operation. The wireless train control system controls a wireless-control compliant train 41 following a wireless-control noncompliant train 42 by a ground control device 10. A stop limit point of the wireless-control compliant train 41 is set by a track circuit in which a tail end position of the wireless-control noncompliant train 42 is present. By using a track-circuit state signal indicating that the track circuit is turned on or turned off and a time-element-added track-circuit state signal indicating turn-off at a timing delayed by a set time after the track-circuit state signal has indicated turn-off, when the track-circuit state signal indicates turn-off and the time-element-added track-circuit state signal indicates turn-on, it is determined that turn-off indicated by the track-circuit state signal is caused by the wireless-control compliant train 41 that is a train itself being present, and the stop limit point is not updated.