Multi-Objective Train Speed Curve Optimization

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Solution Overview

Problem

Current urban train operation optimization methods fail to effectively minimize energy consumption while ensuring safety, punctuality, and passenger comfort due to their focus on single-objective optimization and susceptibility to local optima, neglecting the complexities of actual route parameters and multi-objective considerations.

Innovation Solution

A method and system for multi-objective optimization of urban train operation that involves segmenting train sections into non-equal districts, constructing a longitudinal dynamics model, and using a multi-objective differential evolution algorithm to find a Pareto optimal solution set, which includes minimizing energy consumption, ensuring punctuality, and maximizing comfort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If single-objective optimization is used to minimize energy consumption, then energy saving is improved, but safety, punctuality, comfort and precise parking cannot be guaranteed simultaneously

Engineering Contradiction:
Improvetraction energy consumptionVSAvoidoperation safety and punctuality
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent segments the train operation process into multiple sections based on actual route parameters (slope, curvature, speed limits). Each section is optimized independently with section-specific constraints, allowing energy minimization in some sections while ensuring safety and punctuality constraints are met in critical sections. This segmentation enables multi-objective optimization by treating different operational requirements as separate optimizable units.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transforms the multi-objective optimization problem into a parameterized single-objective problem by introducing comprehensive evaluation indicators that combine energy consumption, punctuality, comfort and safety into weighted composite parameters. The optimization algorithm searches for optimal parameter combinations (speed curves, acceleration profiles) that minimize the composite indicator while satisfying operational constraints, thereby resolving the contradiction between energy saving and operational reliability.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If traditional numerical or analytical algorithms are used for optimization, then computational simplicity is improved, but the solution converges to local optima and cannot guarantee global optimality

Engineering Contradiction:
Improvealgorithm complexityVSAvoidoptimization convergence accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces traditional numerical/analytical algorithms with an intelligent optimization algorithm (such as genetic algorithm, particle swarm optimization, or simulated annealing). These intelligent algorithms use probabilistic search mechanisms and adaptive strategies to explore the solution space more effectively, avoiding local optima traps while maintaining reasonable computational complexity. The algorithm iteratively improves solutions through selection, crossover, and mutation operations, achieving global optimization without excessive computational burden.

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

3Device complexity

If ideal route conditions are assumed for optimization, then theoretical model simplicity is improved, but practical engineering application value is reduced due to ignoring actual route parameters

Engineering Contradiction:
Improvemodel construction complexityVSAvoidpractical engineering applicability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent applies local quality by incorporating actual route parameters (slope, curvature, speed limits, station locations) into the optimization model for each specific section of the train route. Instead of using uniform ideal conditions, the model adjusts optimization constraints and objective functions locally according to actual route characteristics. This enables the optimization results to be directly applicable to real-world operations while maintaining model tractability through section-by-section optimization.

Inventive Principle:
Principle #3Local quality

4Productivity

If multiple indicators are integrated into a single objective for optimization, then computational efficiency is improved, but the essential characteristics of multi-objective optimization are not fully reflected

Engineering Contradiction:
Improveoptimization computation efficiencyVSAvoidmulti-objective optimization capability
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent transforms multiple optimization indicators (energy consumption, punctuality, comfort, safety) into a parameterized comprehensive evaluation indicator system. Each indicator is assigned a weight and transformed into a standardized parameter, allowing the multi-objective problem to be solved as a single-objective problem with composite parameters. This approach maintains computational efficiency while preserving the multi-objective characteristics through the parameter transformation and weighting mechanism, enabling the algorithm to find solutions that balance all objectives simultaneously.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS11390306B1Method and system for multi-objective optimization of urban train operation
Publication Date: 2022.07.19 EAST CHINA JIAOTONG UNIVERSITY
  • US11390306B1 patent drawing
  • US11390306B1 patent drawing
  • US11390306B1 patent drawing

AI summary

Disclosed are a method and a system for multi-objective optimization of urban train operation. Firstly, speed limit information, slope information and curve radius information of a real train route are obtained, a section is segmented into non-equal sub-sections according to the above information about actual line characteristics, and then a longitudinal dynamics model of the train is constructed in combination with basic vehicle data of the train. Next, energy consumption of the train operation, section operation time, actual parking positions, and rates of acceleration change are calculated, so as to construct a multi-objective optimization model of train operation. Afterwards, a multi-objective differential evolution algorithm is used to solve the multi-objective optimization model, in order to obtain a Pareto optimal solution set of each operation district. Finally, an optimal solution is obtained which takes all objectives into comprehensive consideration, and an optimal train speed curve is generated.