Multi-Machine Path Coordination With Dynamic Wait Dependencies

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing systems for coordinating the paths of automated guided vehicles (AGVs) and other movable machines often result in unnecessarily long waiting times due to collision avoidance mechanisms, which can lead to inefficiencies and potential deadlocks.

Innovation Solution

A method for fully or partially automated coordination of machine paths that determines and establishes waiting dependencies between path points to avoid collisions, prioritizing paths based on quality criteria such as execution time, allowing for optimized traversal without endless waiting dependencies by adjusting wait dependencies to minimize overall runtime.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If vehicles with lower priority wait for higher priority vehicles to reach specific path points before leaving, then collisions are prevented, but waiting times become unnecessarily long

Engineering Contradiction:
Improvecollision preventionVSAvoidwaiting time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system dynamically determines wait dependencies by evaluating multiple alternative path arrangements and selecting the optimal one based on current traffic conditions and quality criteria, rather than using fixed priority-based waiting rules. This allows the coordination strategy to adapt in real-time, minimizing waiting times while ensuring collision-free operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the parameter of wait dependency relationships by evaluating alternative arrangements and selecting those that optimize quality criteria such as total travel time or throughput. This transforms the static priority-based waiting mechanism into a dynamic optimization process that adjusts waiting behavior based on overall system performance goals.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If fixed priority-based waiting rules are used for collision avoidance, then coordination is simple, but deadlocks and endless waiting dependencies can occur

Engineering Contradiction:
Improvecoordination complexityVSAvoiddeadlock-free operation
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The system incorporates feedback by evaluating the consequences of different wait dependency arrangements, including detecting potential deadlocks, and adjusting the coordination strategy accordingly. This feedback mechanism allows the system to identify and avoid deadlock-prone configurations while maintaining relatively simple coordination rules.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary evaluation of alternative path arrangements and wait dependencies before executing the coordination, identifying and eliminating potential deadlock scenarios in advance. This preliminary analysis prevents deadlocks from occurring while keeping the actual coordination mechanism straightforward.

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If multiple machines are successively coordinated with default priority given to existing paths, then path arrangement is simplified, but newly added machines experience long waiting times

Engineering Contradiction:
Improvepath arrangement complexityVSAvoidwaiting time for new machines
Core Design Contradiction:
Device complexityVSLoss of time

Solution Approach 1:

The system changes the priority parameter dynamically by evaluating alternative wait dependencies and selecting arrangements that minimize the impact on newly added machines. Instead of always giving default priority to existing paths, the system optimizes the wait dependency configuration to balance simplicity with fair treatment of all machines regardless of when they were added.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3491473B1Coordination of paths of a plurality of movable machines
Publication Date: 2021.11.03 KUKA DEUT GMBH
  • EP3491473B1 patent drawingFigure 1
  • EP3491473B1 patent drawingFigure 2(a)~2(b)
  • EP3491473B1 patent drawingFigure 3

AI summary

A method according to the invention for the at least partially automated coordination of a path arrangement of a machine arrangement, having a path (P1) of at least one first movable machine (R1) in the machine arrangement and an additional path (P2) of at least one second movable machine (R2), comprises the step of: determining (S90) at least one waiting dependence (W2; W3) between a path point (K13; K14) of a path (P1) of a first machine (R1) in the machine arrangement and a path point (K23; K23) of the additional path (P2) in order to avoid a collision between the second machine (R2) and this first machine (R1) provided that a quality criterion (T) for jointly leaving the path arrangement (P1) and the additional path (P2) while complying with this waiting dependence (W2; W3) is not worse, in particular is better, than when complying with an alternative inverse waiting dependence (W1; W4) between a path point (K15; K12) of the path (P1) of the first machine (R1) and a path point (K21; K25) of the additional path (P2) in order to avoid the same collision.