Emergency Brake Optimization Module for Rail Vehicles
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Solution Overview
Problem
Existing emergency brake systems in rail vehicles experience significant jerk and delayed response times due to the mechanical nature of hydraulic brakes, which compromises passenger comfort and safety, especially when software controls fail, as they rely on choke size for jerk reduction but this increases dead time and maintenance challenges.
Innovation Solution
The implementation of an emergency brake optimization module with a dead time caliper fill circuit and/or a secondary volume consumption circuit within the hydraulic brake system to regulate the application of the emergency brake, reducing dead time and jerk by providing initial fluid inflow and additional volume to minimize flow resistance and contamination risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a small choke size is used in the emergency brake circuit to reduce jerk, then jerk rate is reduced, but dead time increases and response time is delayed
Solution Approach 1:
The emergency brake circuit is segmented into two parallel paths: the original choke-containing path and a new bypass path with a larger choke. This segmentation allows fluid to flow through both paths simultaneously, combining the jerk-reducing effect of the small choke with the faster response of the large choke, thereby resolving the contradiction between jerk reduction and response time.
Solution Approach 2:
A bypass circuit is introduced as an intermediary element that provides an alternative fluid flow path. This bypass circuit contains a larger choke that allows faster fluid flow while the original small choke continues to regulate jerk. The bypass acts as a mediator that enables both fast response and jerk control to coexist.
2Object-generated harmful factors
If a small choke size is used to reduce jerk, then jerk rate is reduced, but maintenance efforts and expense increase due to fouling by debris
Solution Approach 1:
The circuit is segmented into two parallel choke elements, where the bypass circuit contains a larger choke that is less susceptible to fouling. This segmentation distributes the flow burden, reducing the clogging risk in the original small choke while maintaining its jerk-control function, thereby reducing maintenance requirements.
Solution Approach 2:
The choke size parameter is changed in the bypass circuit to be larger than the original choke. This parameter change makes the bypass choke less sensitive to debris fouling, reducing maintenance needs while the original small choke continues to control jerk through its restricted flow characteristic.
3Reliability
If mechanical emergency brake control is used to ensure safety after software failure, then safety integrity is maintained, but passenger comfort is compromised due to high jerk
Solution Approach 1:
The mechanical emergency brake system is enhanced by segmenting the fluid supply into two parallel paths with different choke characteristics. This segmentation allows the system to maintain its mechanical safety integrity while incorporating flow regulation elements that reduce jerk, thus improving passenger comfort without compromising safety.
Solution Approach 2:
The flow resistance parameter is modified by introducing a bypass circuit with a larger choke. This parameter change reduces the overall flow restriction, allowing smoother pressure buildup and reduced jerk during emergency brake application, while the mechanical safety function remains intact.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution effectively reduces emergency brake response time and jerk, enhancing passenger comfort and safety by minimizing dead time and eliminating choke-related limitations, while maintaining mechanical integrity and reducing maintenance efforts.
Implementation Method 1
The dead time caliper fill circuit may be configured to provide an initial inflow of hydraulic fluid to the brake supply line during a dead time period of fluid supply through the emergency brake valve
Implementation Method 2
an oversized choke, or optionally no choke, may be provided in the emergency brake circuit to decrease or eliminate flow resistance in the emergency brake circuit, and in turn minimize dead time experienced upon activation of the emergency brake, with jerk being controlled through consumption of excess hydraulic fluid by the secondary volume consumption circuit
Data Source
AI summary
Disclosed are systems and methods for regulating application of an emergency brake configured to minimize jerk for riders' comfort while assuring safe application of the emergency brake. An emergency brake optimization module may be provided and positioned in fluid communication with a standard hydraulic brake system to regulate the application of the emergency brake through (i) providing an initial inflow of hydraulic fluid through a dead time caliper fill circuit to the brake supply line during a dead time period of fluid supply through the emergency brake valve to reduce dead time in emergency brake application, (ii) providing an oversized choke, or optionally no choke, in the emergency brake circuit with jerk being controlled through consumption of excess hydraulic fluid by a secondary volume consumption circuit, and (iii) providing both a dead time caliper fill circuit and a secondary volume consumption circuit to more precisely control reduction in dead time and minimization of jerk during application of the emergency brake.