Wave Conveyor Sequencing for AS/RS Throughput
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Solution Overview
Problem
The vertical lift mechanism in Automated Storage and Retrieval Systems (AS/RS) is often the limiting factor in throughput and is costly, making it inefficient for high-capacity operations, especially when additional lifts are required to increase throughput.
Innovation Solution
Implementing a wave conveyor system that replaces traditional vertical lifts, allowing for simultaneous sequencing and handling of multiple pallets or orders across multiple aisles, with independent buffer and transfer positions, and optional vertical lifts for backup or surge capacity, to maintain high throughput without the need for additional vertical lifts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional vertical lifts are used in AS/RS systems, then vertical movement is achieved, but throughput is limited and system cost increases
Solution Approach 1:
The system divides vertical movement into discrete levels with independent buffer positions at each level. Instead of using a single vertical lift mechanism, the conveyor is segmented into multiple levels (e.g., Level 1, Level 2, Level 3) that can operate independently, allowing simultaneous loading and unloading at different heights without requiring complex vertical lift coordination.
Solution Approach 2:
The patent transitions from vertical movement (single dimension) to horizontal movement across multiple levels (adding a level dimension). The conveyor moves horizontally along each level while serving multiple vertical stories, effectively converting vertical transport challenges into horizontal conveyor operations that can be managed more efficiently and cost-effectively.
2Productivity
If additional vertical lifts are added to increase throughput, then capacity increases, but system cost increases significantly
Solution Approach 1:
The multi-level conveyor system serves multiple functions: it can load items onto shuttles at different levels, unload items from shuttles at different levels, provide buffer storage at each level, and sequence items for outbound delivery. This single conveyor structure replaces what would traditionally require multiple vertical lifts, each performing specialized functions, thereby reducing overall system complexity and cost while maintaining or increasing throughput capacity.
3Productivity
If vertical lift mechanism is used, then item retrieval is possible, but sequencing rate is reduced
Solution Approach 1:
The conveyor operates continuously in one direction along each level, eliminating the reciprocating motion required by vertical lifts. Items are conveyed forward through buffer positions and onto shuttles without stopping or reversing, maintaining continuous productive action. The shuttle itself handles the reciprocating movement to and from storage locations, while the conveyor maintains steady forward motion for sequencing operations.
Data Source
Figure 1A
Figure 1B~1C
Figure 2
AI summary
A material handling system (100) has an automated storage and retrieval system (AS/RS) (102) with vertically spaced levels storing articles (108). Each level has at least one pickup and deposit (P/D) station (120) serviced by a shuttle (114) and that is horizontally positioned to define a ramped orientation with a wave conveyor (106) to move products (108) selectively in at least one flow direction to each of the P/D (120) stations. An article transfer mechanism at each P/D station (120) respectively moves an article (108) in a selected at least one direction between the wave conveyor (106) and the respective P/D station (120). A controller selectively moves the selected articles onto the wave conveyor (106) by respective article transfer mechanisms in coordination with movement of the wave conveyor (106) to create a sequenced flow of selected articles (108). An order preparation system can receive the sequenced flow.