Time-Space Rail Car Stacking for Classification Track Assignment

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Solution Overview

Problem

The manual process of assigning train blocks to classification tracks in railroad merchandise yards is inefficient and often leads to suboptimal decisions, resulting in increased operational time and resource consumption.

Innovation Solution

A time-space network based multi-objective system that utilizes multiple optimization models to automatically assign train blocks to classification tracks, considering constraints and objectives such as efficient utilization of bowl capacity, minimization of switch distance, and minimizing the number of trains spread across multiple pull leads, using a combination of first, second, third, and fourth optimization models to optimize assignments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If manual process is used to assign train blocks to classification tracks, then operational flexibility is maintained, but assignment efficiency deteriorates and suboptimal decisions are made

Engineering Contradiction:
Improveassignment efficiencyVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent replaces the manual mechanical decision-making process with an automated computer-based optimization system. The system uses mathematical models and algorithms to automatically assign train blocks to classification tracks, eliminating manual intervention and achieving optimal assignments that manual operators cannot achieve due to complexity and time constraints.

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

Solution Approach 2:

The system changes the approach from qualitative manual judgment to quantitative parameter optimization. It uses multiple objective functions (minimizing switch distance, optimizing bowl capacity utilization, reducing number of trains) and constraints (track capacity, train block requirements) to automatically determine optimal assignments, transforming the decision-making process into a systematic parameter optimization problem.

Inventive Principle:
Principle #35Parameter changes

2Loss of time

If manual train block assignment is used, then operational simplicity is maintained, but time required to form outbound trains increases

Engineering Contradiction:
Improvetime to form outbound trainsVSAvoidtrain formation efficiency
Core Design Contradiction:
Loss of timeVSProductivity

Solution Approach 1:

The system performs preliminary optimization calculations before actual train formation operations begin. By pre-determining the optimal assignment of train blocks to classification tracks based on future train schedules and current yard conditions, the system eliminates time-consuming manual decisions during the critical train formation window, allowing operations to proceed more efficiently.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The optimization system operates continuously to monitor yard conditions, train block arrivals, and outbound train schedules, maintaining optimal assignments in real-time. This continuous optimization ensures that the assignment decisions remain valid and optimal throughout the planning horizon, eliminating the need for repeated manual adjustments and ensuring continuous efficient operation.

Inventive Principle:
Principle #20Continuity of useful action

3Loss of energy

If manual stacking and swing operations are performed, then operational flexibility is maintained, but switching operations increase and fuel consumption rises

Engineering Contradiction:
Improvefuel consumptionVSAvoidoptimization system complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The system replaces manual operational decisions with automated optimization algorithms that calculate the most fuel-efficient switching paths. The mathematical models consider all possible switching operations and select the optimal sequence that minimizes fuel consumption while maintaining operational flexibility through constraint-based planning.

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

Solution Approach 2:

The system incorporates feedback mechanisms that continuously monitor actual yard conditions, train block positions, and switching operations. This feedback allows the optimization system to adjust assignments and switching sequences in real-time to minimize fuel consumption, learning from actual operational data to improve future optimization decisions.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS12358543B2Time-space network based multi-objective systems and methods for optimal rail car stacking at a railroad merchandise yard
Publication Date: 2025.07.15 BNSF RAILWAY COMPANY
  • US12358543B2 patent drawing
  • US12358543B2 patent drawing
  • US12358543B2 patent drawing

AI summary

A method for assigning train blocks at a railroad merchandise yard includes determining, using a first optimization model and outbound train schedule data, a first list of train block assignments for a planning horizon. The method further includes determining whether an unassigned train block volume from the first optimization model is greater than zero. The method further includes displaying the first list of train block assignments generated by the first optimization model on an electronic display in response to determining that the unassigned train block volume from the first optimization model is not greater than zero. The method further includes, in response to determining that the unassigned train block volume from the first optimization model is greater than zero: determining and then displaying on the electronic display a second list of train block assignments for the planning horizon using a second optimization model and the outbound train schedule data.