Rail Brake Valve Opening Time Correction Device

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Solution Overview

Problem

Existing pneumatic brake systems in rail vehicles face issues with inaccurate valve opening times due to imprecise design specifications and parameterization, leading to increased switching cycles, reduced control accuracy, and instability, especially in modular systems with various component variants.

Innovation Solution

A brake system with a valve opening time correction device that uses a signal input interface to detect pressure differences and adjust the effective valve opening time based on a reference system's pneumatic properties, allowing for real-time correction of valve opening times to achieve the desired pressure changes efficiently.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If model-based pressure control is used with predetermined valve opening times, then control speed is improved, but control accuracy deteriorates due to inaccurate design specifications and parameter settings

Engineering Contradiction:
Improvecontrol speedVSAvoidcontrol accuracy
Core Design Contradiction:
SpeedVSMeasurement precision

Solution Approach 1:

The patent implements a feedback mechanism where the actual pressure development in the pneumatic system is continuously monitored and compared with the desired pressure trajectory. Based on this comparison, the valve opening time is dynamically adjusted to compensate for deviations caused by inaccurate design specifications. This closed-loop control ensures that the actual pressure follows the desired pressure curve accurately, resolving the contradiction between fast control speed and accurate control.

Inventive Principle:
Principle #23Feedback

2Device complexity

If characteristic parameters are determined based on design data, then device complexity is reduced, but reliability deteriorates due to deviations from actual pneumatic system properties

Engineering Contradiction:
Improveparameter determination complexityVSAvoidpressure control reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent dynamically adjusts the characteristic parameters of the pneumatic system based on actual measured pressure values during operation. Instead of relying solely on fixed design data, the system adapts parameters such as volume and pneumatic conductance to match the actual system behavior. This parameter adaptation ensures reliable pressure control even when there are deviations between design specifications and actual system properties.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If valve opening time is increased to compensate for slow pressure changes, then pressure change accuracy is improved, but switching cycles increase reducing productivity

Engineering Contradiction:
Improvepressure change accuracyVSAvoidbraking system responsiveness
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent implements dynamic adjustment of the valve opening time based on the actual pressure development rate. When pressure changes slowly, the valve opening time is extended; when pressure changes rapidly, the valve opening time is reduced. This dynamic adaptation allows the system to achieve accurate pressure control without unnecessarily increasing switching cycles, thereby maintaining high productivity and braking system responsiveness.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3724046B1Braking system having a correction device for correcting an opening time of a valve and method for correcting the opening time of the valve
Publication Date: 2022.03.09 KNORR BREMSE SYST FUR SCHIENENFAHRZEUGE GMBH
  • EP3724046B1 patent drawingFigure 1
  • EP3724046B1 patent drawingFigure 2

AI summary

The invention relates to a braking system having a correction device (1) for correcting an opening time of a valve (103), which braking system comprises a signal input interface for a signal of a most recently input effective valve opening time (154), a signal input interface for a pressure (156) before the valve (103) after the most recently input effective valve opening time (154), a signal input interface for a pressure difference (125) between a pressure after the valve (103) before and after a current specification of the effective valve opening time (153), a valve opening time determination apparatus, which determines an effective reference system valve opening time (160) from the pressure difference (125) after the valve (103), the pressure (156) after the most recently input specification of the effective valve opening time (154) before the valve (103) and a parameter of the reference system (111) defining the pneumatic properties of a reference system (111), a correction time determination apparatus (127), which determines a correction time (162) as a difference between the most recently input effective valve opening time (154) and the effective reference system valve opening time (160), an addition apparatus (129), which adds up the correction times (162) after a current effective valve opening time (152) to form a summed correction time (164), and a signal output for the summed correction time (164), by means of which summed correction time the current effective valve opening time (153) is corrected.