Rail Profile Detection via Bogie Acceleration
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Solution Overview
Problem
Current methods for detecting rail surface defects like corrugation in railway tracks require multiple sensors and frequent maintenance, making them inefficient for busy lines, and existing in-service vehicle methods suffer from noise in acceleration signal processing.
Innovation Solution
A method using a single vertical acceleration sensor per rail to determine the rail surface profile by processing the signal through a simulation model of the bogie, incorporating a quarter-bogie model, and converting the signal from the time domain to the distance domain for accurate defect identification, with band-pass analysis and alert thresholds for corrugation detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple sensors and frequent maintenance are used to detect rail surface defects, then detection reliability is improved, but device complexity and maintenance requirements increase
Solution Approach 1:
The patent extracts and processes only the vertical acceleration component from the axle box, separating it from other sensor data. By focusing on this specific signal component and using it alone to determine the rail profile, the system reduces device complexity while maintaining detection reliability through targeted measurement rather than comprehensive multi-sensor monitoring.
Solution Approach 2:
The vertical acceleration signal from the axle box serves multiple functions: it directly indicates rail profile variations, enables defect detection, and provides the basis for maintaining track geometry. This multi-functional use of a single sensor type reduces the need for separate dedicated sensors for each function.
2Productivity
If in-service vehicle methods are used for rail monitoring, then productivity is improved, but noise in acceleration signal processing reduces measurement precision
Solution Approach 1:
The patent extracts the vertical acceleration signal specifically from the axle box location, which is known to be less noisy compared to other mounting positions. By selecting this specific extraction point and processing only this signal component, the system maintains measurement precision while enabling continuous in-service monitoring.
Solution Approach 2:
Instead of trying to filter out noise from the acceleration signal and work with the raw signal directly, the patent inverts the approach by integrating the acceleration signal to obtain velocity, then using this velocity information to directly determine the rail profile. This inversion of the processing sequence reduces the impact of noise accumulation.
3Measurement precision
If double integration of acceleration signal is performed to obtain vertical displacements, then measurement precision is improved, but noise in the processed signal increases
Solution Approach 1:
The patent inverts the traditional double integration approach by performing only single integration to obtain velocity, then using this velocity signal directly to determine the rail profile through the axle box acceleration relationship. This inversion reduces the cumulative noise that would result from double integration while maintaining sufficient measurement precision for defect detection.
Solution Approach 2:
The patent extracts the essential information from the acceleration signal by using it directly in the axle box acceleration relationship rather than converting it through double integration to displacement. This extraction approach maintains measurement precision for rail profile detection while avoiding the noise amplification that occurs during double integration.
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 approach provides a high-accuracy, noise-reduced method for identifying potentially harmful corrugations, enabling in-service vehicle monitoring with precise defect classification and location, thus enhancing maintenance efficiency.
Implementation Method 1
obtaining a vertical acceleration signal acc1, by measuring vertical acceleration of a bogie of a rail vehicle that runs on the rail surface
Implementation Method 2
processing the vertical acceleration signal acc1 to obtain a vertical velocity signal vel1; determining the vertical profile signal of the rail surface, by using the vertical acceleration signal acc1 and the vertical velocity signal vel1 as inputs to a simulation model of the bogie
Data Source
AI summary
The present invention defines a method of determining a vertical profile signal of a rail surface that includes, obtaining a vertical acceleration signal acc1, by measuring vertical acceleration of a bogie of a rail vehicle that runs on the rail surface; processing the vertical acceleration signal to obtain a vertical velocity signal; determining the vertical profile signal of the rail surface, by using the vertical acceleration signal and the vertical velocity signal as inputs to a simulation model of the bogie, the model having an unsprung mass connected to a sprung mass, the vertical acceleration signal acc1 represents the vertical acceleration of the unsprung mass; and measuring a linear velocity signal of the rail vehicle, the linear velocity signal is used in the step of determining to convert the vertical profile signal from the time domain to the distance domain.