Train Control Speed Pattern Adjustment for Seamless Safety System Changeover
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Solution Overview
Problem
Conventional train control systems often result in unplanned brakes during safety system changes due to unconsidered differences in speed patterns between systems, leading to potential brake outputs even when the train's speed is close to the new system's pattern.
Innovation Solution
A train control system that adjusts the speed pattern to ensure the speed limit at a specific position within the overlapping control section is equal to or lower than the new system's speed limit before switching safety systems, preventing unplanned brakes by ensuring the train's speed does not exceed the new system's limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the speed pattern of the first safety system is changed to prevent unplanned brakes, then the train's ride comfort is improved, but the control complexity increases due to speed pattern adjustment requirements
Solution Approach 1:
The system performs preliminary adjustment of the first speed pattern before the safety system changeover occurs. By predicting the speed pattern competition condition and pre-adjusting the speed limit at the second position, the system prevents unplanned brakes from occurring during the transition to the second safety system.
Solution Approach 2:
The speed pattern is made dynamic and adjustable based on the train's position and the upcoming safety system changeover. The system modifies the speed limit parameters in real-time within the overlapping control section, transforming the static speed pattern into a dynamic one that adapts to prevent harmful brake outputs.
2Object-affected harmful factors
If the speed limit at the second position is adjusted to be equal to or lower than the second speed pattern limit, then unplanned brakes are prevented, but the train's productivity decreases due to speed restrictions
Solution Approach 1:
The speed pattern adjustment is applied locally only within the overlapping control section where the safety system changeover occurs. The speed limit at the second position is specifically modified in this localized area, while other sections maintain their original speed patterns, thus minimizing the impact on overall train productivity.
Solution Approach 2:
The system changes the speed limit parameter of the first speed pattern at the second position to match or be lower than the second speed pattern limit. This parameter adjustment is precisely controlled and applied only where necessary to prevent brake activation, rather than reducing speed throughout the entire route.
3Loss of time
If the safety system changeover is performed without speed pattern adjustment, then the system switches quickly, but unplanned brakes occur when train speed exceeds the new system's speed pattern
Solution Approach 1:
The speed pattern adjustment is performed in advance before the safety system changeover is executed. By preparing the first speed pattern modification beforehand, the system ensures that when the changeover occurs, the train's speed will already be compliant with the second safety system's requirements, preventing unplanned brakes.
Solution Approach 2:
The system monitors the train's position, current speed pattern, and the relationship between overlapping speed patterns to determine when adjustment is needed. This feedback mechanism ensures that speed pattern modification is applied at the appropriate moment and only when necessary, maintaining both quick changeover and reliable speed compliance.
Data Source
Figure 1
Figure 2
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AI summary
This train control system 1 controls a train 104 according to a speed pattern showing the relationship between a traveling position and a limit speed. When the train control system 1 changes over a safety system from a first safety system to a second safety system at a first position (position A) in a control section (change-over section 110) where control regions 108, 109 of the respective safety systems are overlapped with each other, if the limit speeds of a first speed pattern 300 and a second speed pattern 301 compete with each other at the first position, the train control system 1 changes the first speed pattern 300 such that the limit speed at a second position (position C) preceding the first position becomes less than or equal to the limit speed of the second speed pattern 301, and changes over the safety system from the first safety system to the second safety system after applying the changed first speed pattern 304.