Rail Geometry Detection Using Matched Filters
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Solution Overview
Problem
Current methods for inspecting short-wave track geometry in railways are inefficient, as they require manual checks, are prone to maintenance issues, and indirect measurements based on axle load are inaccurate, leading to safety concerns and high personnel costs.
Innovation Solution
A method using matched filters to separate short-wave and long-wave track geometry components from spatially equidistant vertical track position signals, employing FIR and IIR high-pass filters to isolate short-wave components without information loss, allowing for automated and accurate detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual inspection methods are used to detect short-wave track geometry, then measurement precision is improved, but productivity deteriorates due to high time and personnel expenditure
Solution Approach 1:
The patent replaces manual mechanical inspection methods with an automated optical measurement system mounted on a rail vehicle. The system uses optical sensors to detect track geometry deviations automatically during train operation, eliminating the need for manual inspection while maintaining high measurement precision for short-wave track geometry.
Solution Approach 2:
The measurement system utilizes the rail vehicle's own movement and the existing track infrastructure to perform inspections. The system automatically captures geometric deviations during normal train operation without requiring separate inspection crews or route closures, making the inspection process self-contained and efficient.
2Productivity
If optical measurement systems are used to detect short-wave track geometry from vehicles, then productivity is improved, but reliability deteriorates due to high maintenance requirements
Solution Approach 1:
The patent uses optical sensors to capture geometric deviations as signal copies rather than direct physical measurements. The system records the optical signals during train operation and processes them to determine track geometry, avoiding direct contact with the track while maintaining measurement accuracy and reducing maintenance requirements.
3Productivity
If indirect assessment of track geometry based on axle load measurements is used, then productivity is improved, but measurement precision deteriorates due to dependency on boundary conditions
Solution Approach 1:
The patent introduces optical sensors as an intermediary measurement device that directly detects track geometry deviations independent of axle load conditions. The optical measurement system captures geometric deviations through light-based detection, providing accurate measurements that are not influenced by the vehicle's load state or speed variations.
Data Source
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AI summary
The method involves completely compensating phase distortion and reverse signal sequence by filtering with seven filters. Characteristic filter critical frequency and filter slew rate are determined from measured local equidistant vertical rail position signals. The long-wave and/or short-wave unit of the signals is determined depending on selection of the filters such that another associated short-wave and/or long-wave unit is determined by dual subtraction of doubly filtered rail position signal by an original rail position.