Warehouse Task Routing via Local PLC Mediation to Cut WAN Latency
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Solution Overview
Problem
In distributed warehouse management systems, network latency between the warehouse management hub and programmable logic controllers (PLCs) leads to inefficiencies and errors due to the distance between locations, causing delays in message exchange and routing decisions, which can result in incorrect path choices for handling units and reduced automated warehouse efficiency.
Innovation Solution
Implementing a distributed system with warehouse management devices that are connected via a local area network to PLCs, allowing them to autonomously handle requests and reduce network latency by determining the appropriate PLC for task processing and routing instructions, thereby minimizing reliance on direct communication with the warehouse management hub.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If a centralized warehouse management hub communicates directly with PLCs via wide area network, then system management functions can be performed centrally, but network latency causes delays in message exchange and routing decisions
Solution Approach 1:
The patent introduces warehouse management devices as intermediary components between the centralized warehouse management hub and the PLCs. These devices are deployed at individual warehouse locations and handle local communication with PLCs via LAN, while maintaining connection to the hub via WAN. This intermediary layer resolves the contradiction by enabling centralized control architecture while eliminating the need for direct long-distance communication between the hub and PLCs, thus reducing network latency for time-critical operations.
Solution Approach 2:
The patent segments the warehouse management system into hierarchical layers: a centralized management hub for high-level coordination, multiple distributed warehouse management devices for local operations, and PLCs for equipment control. This segmentation allows the system to maintain centralized management capabilities while distributing time-critical communication functions to local devices, thereby resolving the conflict between centralized control and network latency.
2Loss of time
If full WMS functionality is deployed at each warehouse location, then network latency is eliminated, but system complexity and cost increase
Solution Approach 1:
The patent implements partial decentralization where warehouse management devices possess only the specific functionality needed for local PLC communication and routing decisions, rather than deploying complete WMS functionality at each location. These devices handle time-critical tasks locally while relying on the centralized hub for comprehensive warehouse management functions, thus achieving fast response times without the full complexity and cost of distributed WMS installations.
Solution Approach 2:
The patent assigns different functional qualities to different system components: the centralized hub provides comprehensive warehouse management capabilities, while local warehouse management devices provide specialized functions for rapid PLC communication and routing. This differentiation of local qualities allows each component to be optimized for its specific purpose, achieving fast local response times without requiring full WMS functionality everywhere.
Data Source
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AI summary
A computer-implemented method, a computer program and a distributed warehouse system for distributing a warehouse task from a warehouse management hub to a programmable logic controller are provided. The method comprises receiving at least one warehouse task at a warehouse management hub, the warehouse task including attributes for physically transferring at least one product into a warehouse, out of the warehouse or within the warehouse. The method further comprises determining, by the warehouse management hub and based on the attributes of the warehouse task, one of a plurality of warehouse management devices for processing the warehouse task. The warehouse management hub is communicably connected to each of the warehouse management devices via a wide area network. The method further comprises sending, by the warehouse management hub, the warehouse task to the determined warehouse management device. The method further comprises identifying, by the determined warehouse management device and based on the attributes of the warehouse task, a first one of a plurality of programmable logic controllers, wherein the determined warehouse management device is communicably connected to each of the programmable logic controllers via a local area network. The method further comprises sending, by the determined warehouse management device, a message including information for carrying out the warehouse task to one of the programmable logic controllers based on the identification of the first one of the programmable logic controllers.