CNC Job Scheduling Using Genetic Algorithm Evaluation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional scheduling methods for computer numerical control machines are rule-based and lack clear evaluation criteria, making it difficult to produce optimized schedules that satisfy complex constraints in production environments where thousands of product types are fabricated, leading to inefficient job distribution.

Innovation Solution

A method and apparatus using machine learning, specifically a genetic algorithm, to generate and evaluate multiple schedules based on performance indices such as deadline adherence, delay times, and end times, iteratively improving schedules until a target evaluation index is reached, ensuring optimized job assignment while satisfying production constraints.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If rule-based scheduling methods are used, then scheduling can be performed according to simple conditions, but clear evaluation criteria are lacking and performance evaluation becomes ambiguous

Engineering Contradiction:
Improvescheduling operationVSAvoidperformance evaluation
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent transforms the scheduling system from rule-based to evaluation-index-based by changing the fundamental parameters used for scheduling decisions. Multiple quantitative evaluation indices (deadline adherence rate, average delay time, machine utilization rate) replace subjective rule-based criteria, enabling precise measurement and comparison of different scheduling schemes.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical rule-based scheduling system with a machine learning-based intelligent system. The genetic algorithm and evaluation index system substitute traditional manual or rule-based scheduling mechanisms, enabling automated optimization without relying on predefined rules that lack clear evaluation criteria.

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

2Speed

If conventional rule-based scheduling is used, then scheduling can be performed quickly, but optimized schedules satisfying complex production constraints cannot be generated

Engineering Contradiction:
Improvescheduling speedVSAvoidproduction efficiency
Core Design Contradiction:
SpeedVSProductivity

Solution Approach 1:

The patent introduces dynamic optimization through iterative genetic algorithm operations. Instead of static rule-based assignments, the system dynamically generates and evolves scheduling schemes across multiple generations, adapting to complex constraints and continuously improving solution quality through selection, crossover, and mutation operations.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback mechanisms through the evaluation index system. Each scheduling scheme is evaluated against multiple quantitative criteria, and this feedback drives the genetic algorithm's selection process. The system uses evaluation results to guide subsequent generations toward better solutions, creating a closed-loop optimization process that balances speed and quality.

Inventive Principle:
Principle #23Feedback

3Manufacturing precision

If multiple evaluation indices are calculated for schedule optimization, then schedule quality improves, but calculation complexity and time consumption increase

Engineering Contradiction:
Improveschedule optimization qualityVSAvoidevaluation system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent segments the complex evaluation process into distinct, modular indices: deadline adherence rate, average delay time, and machine utilization rate. Each index independently evaluates a specific aspect of schedule quality, making the complex evaluation system manageable and interpretable while maintaining comprehensive assessment capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent creates a universal evaluation framework that can assess multiple scheduling schemes simultaneously using the same set of indices. This multi-functional evaluation system works across different production scenarios and constraint types, providing consistent quality measurement without requiring separate complex evaluation systems for each case.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Productivity

If genetic algorithm operations are performed repeatedly to generate new schedules, then schedule optimization improves, but computational time increases

Engineering Contradiction:
Improveschedule optimizationVSAvoidcomputational time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent applies partial action by performing genetic algorithm operations iteratively but with controlled generations. Rather than exhaustively searching all possible schedules, the system performs a sufficient number of iterations to achieve acceptable optimization, balancing computational effort with solution quality through practical convergence criteria.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS10496436B2Method and apparatus for automatically scheduling jobs in computer numerical control machines using machine learning approaches
Publication Date: 2019.12.03 PUSAN NAT UNIV IND UNIV COOPERATION FOUND
  • US10496436B2 patent drawing
  • US10496436B2 patent drawing
  • US10496436B2 patent drawing

AI summary

The method includes collecting a schedule job list from a database, generating a plurality of schedules for a schedule job to be processed with respect to the schedule job list, calculating an evaluation index for the plurality of generated schedules, determining whether the calculated evaluation index for the plurality of schedules has reached a target evaluation index, selecting a schedule corresponding to two evaluation indices when the calculated evaluation index does not reach the target evaluation index and generating two new schedules using a genetic algorithm, and setting a selection probability so that a schedule having the highest evaluation index is selected and returning the selection probability to a user when the calculated evaluation index reaches the target evaluation index.