High Speed Train Safety Evaluation Using Complex Network SVM

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Solution Overview

Problem

Current high-speed rail safety evaluation methods, such as the frequency-consequence matrix method, are subjective and struggle with accurate multi-classification, particularly when dealing with complex environments like high-speed train systems, leading to unreliable safety judgments.

Innovation Solution

A complex network-based safety evaluation method using a combination of SVM and weighted kNN, where nodes represent components, and their connections are used to calculate functional attribute degrees and Mean Time Between Failures, enabling more objective safety level classification through a voting system and distance-based discrimination functions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the frequency-consequence matrix method is used for safety evaluation, then the evaluation process is simple and widely applicable, but the results are subjective due to reliance on expert experience

Engineering Contradiction:
Improveevaluation process simplicityVSAvoidevaluation objectivity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent replaces the manual expert judgment mechanism with an automated machine learning system. The SVM and kNN algorithms objectively calculate safety levels based on component failure data, eliminating subjective human factors while maintaining evaluation simplicity through automated processing.

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

Solution Approach 2:

The patent introduces complex network theory as an intermediary layer between raw component data and safety evaluation results. The network model calculates functional attribute degrees and identifies critical components, serving as an objective mediator that transforms component failure rates into system-level safety assessments without human intervention.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the SVM algorithm is used for multi-classification safety levels, then the structure is simple and learning speed is fast, but classification accuracy decreases when voting results are tied

Engineering Contradiction:
Improvelearning speedVSAvoidclassification accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent merges SVM with kNN to form a hybrid classification system. When SVM produces tied voting results, the kNN algorithm provides a secondary classification mechanism that considers k nearest neighbors, ensuring accurate safety level determination without sacrificing the fast learning speed of SVM.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements a feedback mechanism where kNN re-judges samples that cannot be classified accurately by SVM alone. This feedback loop ensures that classification accuracy is maintained for edge cases while preserving the efficiency of the primary SVM classification process.

Inventive Principle:
Principle #23Feedback

3Ease of operation

If traditional safety evaluation methods are used, then the evaluation process is straightforward, but component position importance and system reliability are not considered

Engineering Contradiction:
Improveevaluation process straightforwardnessVSAvoidsystem reliability consideration
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies local quality by calculating functional attribute degrees for individual components based on their positions in the complex network. Components in critical positions with higher connectivity receive higher functional attribute degrees, allowing the evaluation to account for local importance while maintaining overall system-level assessment.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent adds a new dimension to safety evaluation by incorporating complex network theory. This introduces the dimension of component connectivity and position importance, transforming the evaluation from a simple component-based approach to a multi-dimensional system-level assessment that considers both component failure rates and their structural importance.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS9630637B2Complex network-based high speed train system safety evaluation method
Publication Date: 2017.04.25 BEIJING JIAOTONG UNIV
  • US9630637B2 patent drawing
  • US9630637B2 patent drawing
  • US9630637B2 patent drawing

AI summary

The invention discloses a complex network-based high speed train system safety evaluation method. The method includes steps as follows: (1) constructing a network model of a physical structure of a high speed train system, and constructing a functional attribute degree of a node based on the network model; (2) extracting a functional attribute degree, a failure rate and mean time between failures of a component as an input quantity, conducting an SVM training using LIBSVM software; (3) conducting a weighted kNN-SVM judgment: an unclassifiable sample point is judged so as to obtain a safety level of the high speed train system. For a high speed train system having a complicated physical structure and operation conditions, the method can evaluate the degree of influences on system safety when a state of a component in the system changes. The experimental result shows that the algorithm has high accuracy and good practicality.