Multi-AGV Route Replanning for Deadlock-Free Travel

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Solution Overview

Problem

Conventional traveling systems with multiple automatic traveling devices often experience deadlocks due to interference, leading to decreased travel efficiency.

Innovation Solution

A traveling system that includes a management server with processing units to set and adjust travel routes based on interference evaluation values, changing routes when the influence level exceeds a threshold to prevent deadlocks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If multiple automatic traveling devices operate on preset travel routes, then the system achieves automated transport functionality, but interference between devices occurs leading to deadlocks

Engineering Contradiction:

Improveautomated transport functionalityVSAvoiddeadlock occurrence

Core Design Contradiction:

Extent of automationVSReliability

Solution Approach 1:

The patent implements dynamic route adjustment by allowing automatic traveling devices to change their travel routes in real-time based on interference detection. When a device detects potential deadlock conditions, the system dynamically recalculates and assigns alternative routes, transforming the static route-following behavior into adaptive dynamic navigation that prevents deadlocks while maintaining automated operation

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system employs feedback mechanisms where each automatic traveling device monitors the positions and movements of other devices, detects interference conditions, and reports back to the management server. The management server processes this feedback information and adjusts routes accordingly, creating a closed-loop control system that continuously prevents deadlock situations

Inventive Principle:

Principle #23Feedback

2Reliability

If virtual obstacles are set on travel routes to prevent interference, then device collision is avoided, but travel efficiency decreases due to route restrictions

Engineering Contradiction:

Improveinterference avoidanceVSAvoidtravel efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

Instead of using static virtual obstacles that permanently block certain areas, the system uses dynamic virtual obstacles that are temporarily created only when interference conditions are detected. These virtual obstacles appear only in specific time windows and locations where conflicts are anticipated, allowing devices to use previously blocked routes when safe, thereby maintaining higher travel efficiency while still preventing interference

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the parameters of route restrictions by making virtual obstacles time-dependent and condition-dependent rather than permanent. The presence, position, and duration of virtual obstacles are adjusted based on real-time system state, allowing the same physical space to be accessible at different times under different conditions, thus balancing safety with efficiency

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If fixed travel routes are assigned to each device, then route management is simplified, but deadlock occurs when devices block each other's paths

Engineering Contradiction:

Improveroute management complexityVSAvoiddeadlock prevention

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The system performs preliminary actions by predicting potential deadlock situations before they occur. The management server calculates anticipated interference based on current device positions, speeds, and planned routes, and proactively adjusts routes to prevent deadlocks before they happen, rather than reacting after devices are already blocked

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The management server acts as an intermediary between automatic traveling devices, mediating route conflicts by calculating and assigning alternative routes when interference is detected. This intermediary role allows the system to maintain simple fixed routes for normal operation while introducing complexity only when necessary to resolve conflicts, balancing route management simplicity with deadlock prevention

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS12554258B2Traveling system, traveling method, and recording medium recording traveling program

Publication Date: 2026.02.17 SHARP KK

AI summary

This traveling system includes: a setting processing unit that sets a travel route corresponding to each of the plurality of automatic traveling devices; a calculation processing unit that, when a first automatic traveling device interferes with a travel of other automatic traveling devices, calculates an evaluation value representing an influence level that the first automatic traveling device imposes on the travel of the other automatic traveling devices; and a change processing unit that, when the evaluation value calculated by the calculation processing unit is greater than or equal to a threshold, changes the travel route that is set to the first automatic traveling device by the setting processing unit.