Crossover Measuring Device Using Monocular Image Processing

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Solution Overview

Problem

Existing methods for measuring the position and deviation of trolley wires at crossovers, such as those used in electric railroads, are inadequate as they require contact with the pantograph and often fail to accurately determine the three-dimensional position without multiple cameras, especially when temperature variations cause trolley wires to move closer to the pantograph, potentially leading to entanglement.

Innovation Solution

A crossover measuring device utilizing a single camera with a line sensor and image processing techniques, including discrimination analysis binarization, noise removal, and edge detection, to calculate the height and deviation of the crossover, using a sodium lamp and band pass filter to enhance image quality and accuracy, allowing non-contact measurement and operation at high speeds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single camera is used for measurement, then device complexity is reduced, but measurement precision deteriorates due to inability to perform stereo measurement

Engineering Contradiction:
Improvenumber of camerasVSAvoidthree-dimensional position measurement accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces the mechanical/optical stereo measurement system (multiple cameras) with an image processing-based monocular measurement system. By using discrimination analysis binarization and edge detection algorithms, the system can determine three-dimensional position information from a single two-dimensional image, substituting complex hardware with sophisticated software processing.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the measurement parameters by using image intensity distribution and edge characteristics instead of stereoscopic depth information. By analyzing the binarized image data and edge positions, the system derives height and deviation information without requiring multiple viewing angles, thus maintaining measurement precision while reducing device complexity.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If contact measurement with pantograph is used, then measurement precision is improved, but reliability deteriorates due to collision risk with trolley wire

Engineering Contradiction:
Improveposition measurement accuracyVSAvoidcollision risk
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces contact-based mechanical measurement with non-contact optical measurement using a camera. The image processing system captures and analyzes visual information of the trolley wire and pantograph from a distance, eliminating physical contact and associated collision risks while maintaining measurement precision through advanced image analysis techniques.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces an optical intermediary (camera and image processing system) between the measurement device and the trolley wire. This intermediary captures visual information without requiring direct contact, serving as a safe mediator that prevents collision while enabling precise position measurement through image analysis.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If existing image processing methods are used, then ease of operation is improved, but measurement precision deteriorates due to inability to measure non-contacting objects

Engineering Contradiction:
Improveoperation simplicityVSAvoidnon-contact measurement capability
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent replaces conventional contact-based measurement methods with an advanced image processing system that can measure non-contacting objects. By using discrimination analysis binarization and edge detection, the system extracts precise position information from visual data alone, enabling measurement of trolley wires and pantographs without physical contact while maintaining operational simplicity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

Enables precise, non-contact measurement of the three-dimensional position and deviation of trolley wires using a single camera, allowing for continuous monitoring without collision risks and improved accuracy by filtering out ambient light, thus preventing entanglement and ensuring proper positioning within regulatory limits.

Implementation Method 1

an illuminating member installed on the roof of the vehicle to illuminate the crossover

Methodology Applied
Scientific EffectLight emission: Light

Implementation Method 2

band pass filter arranged to transmit only a wavelength of the light emitted from the sodium lamp ins, mounted on the crossover line sensor

Methodology Applied
Scientific EffectBand pass filter: Filter (optical)

Data Source

PatentEP2244056B1Crossover measuring device
Publication Date: 2016.11.30 MEIDENSHA CORP
  • EP2244056B1 patent drawingFigure 1~2B
  • EP2244056B1 patent drawingFigure 3~5
  • EP2244056B1 patent drawingFigure 6

AI summary

A crossover measuring device includes an illuminating member, a line sensor image forming section to form line sensor images respectively by lining up, in time series, luminance signals obtained by the crossover line sensor and the pantograph line sensor, and to store as input images; a discrimination analysis binarizing section to form a binary line sensor image in which the crossover part is emphasized by a discrimination analysis binarization of the line sensor image; a noise removing section to remove the noise of the binary line sensor image; a crossover part edge detecting section to detect edges of the crossover part in the binary line sensor image; a crossover part height calculating section to determine a width of the crossover part on the image, and to determine a height of the crossover; a crossover part deviation calculating section to determine a value of a center of the edges of the crossover, as a center of gravity of the crossover, and to determine a deviation of the center of the gravity from a center; a pantograph height and position calculating section to determine a height and a position of the pantograph; and a pantograph and crossover relative position calculating section to determine a relative position between the pantograph and the crossover.