Stacker Crane Control for Interference Avoidance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional article storage facilities experience delays and inefficiencies due to the need for avoidance operations between stacker cranes, which can lead to reduced article throughput and increased operational complexity.

Innovation Solution

The system employs a control mechanism that detects the proximity of stacker cranes and only initiates interference avoidance when necessary, allowing cranes to operate without interruption and maintain efficient article transporting operations by positioning them at non-interfering locations based on detected travel and vertical positions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If avoidance operations are performed between stacker cranes to prevent interference, then safety and reliability are improved, but article throughput decreases and operational delays increase

Engineering Contradiction:
ImprovesafetyVSAvoidarticle throughput
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The control means continuously monitors travel positions and vertical positions of multiple stacker cranes through detection means, creating a feedback loop that enables real-time coordination. This feedback mechanism allows the system to maintain safety while minimizing unnecessary avoidance operations by only intervening when actual interference is detected or predicted.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control means determines whether travel positions are at mutually proximate positions where interference is predicted to occur before actual interference happens. By taking preliminary action to coordinate crane operations based on predicted proximity, the system prevents interference without requiring conservative avoidance maneuvers, thereby maintaining higher throughput.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If avoidance operations are initiated when stacker cranes are at mutually proximate positions, then interference is prevented, but operational complexity increases

Engineering Contradiction:
Improveinterference preventionVSAvoidoperational complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control means performs partial avoidance coordination only when cranes are at mutually proximate positions where interference is predicted, rather than implementing continuous or excessive avoidance operations. This selective approach reduces operational complexity while maintaining reliable interference prevention.

Inventive Principle:
Principle #16Partial or excessive action

3Measurement precision

If continuous monitoring of stacker crane positions is performed, then interference prediction accuracy is improved, but system complexity and detection requirements increase

Engineering Contradiction:
Improveinterference prediction accuracyVSAvoiddetection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The detection means serves multiple functions: it detects travel positions, detects vertical positions, and provides data for determining mutually proximate positions. This multi-functionality reduces the need for separate specialized detection systems, thereby improving measurement precision without proportionally increasing system complexity.

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

Data Source

PatentEP2332859B1Article storage facility and method of operating the same
Publication Date: 2016.01.06 DAIFUKU CO LTD
  • EP2332859B1 patent drawingFigure 1
  • EP2332859B1 patent drawingFigure 2
  • EP2332859B1 patent drawingFigure 3

AI summary

The object is to provide an article storage facility in which the facility can be downsized by minimizing the width of the travel path for a pair of stacker cranes, in which its configuration is simplified as much as possible, and in which its throughput can be efficiently improved. The control device is configured to perform a mutual avoidance vertical movement process in which both of the pair of vertically movable bodies (UD) are raised or lowered by a vertical movement operation for avoiding interference, which is different from the vertical movement operation in the article transporting operation to raise and lower the pair of vertically movable bodies, to the vertical positions for passing each other which are spaced apart in the vertical movement direction by a distance greater than or equal to the required separating distance which is defined as a separating distance which allows the pair of stacker cranes (3a, 3b) to pass each other without interfering with each other.