ASRS Personnel Access Zones With Selective Rover Shutdown
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Automated storage and retrieval systems (ASRS) face challenges in integrating secure and controlled personnel access zones without disrupting system efficiency, particularly due to high rover speeds, dynamic distribution, and dense storage configurations, which complicate safe and secure human interaction within the storage and transport spaces.
Innovation Solution
The integration of controlled, shielded, and secure personnel access zones within the ASRS architecture, utilizing a control system with a secure access zone PLC, rover accountant, and presence sensors to manage rover movement and secure shutdown of automated vehicles, ensuring safe access for personnel while maintaining system operation and compliance with SIL-3 category criteria.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high rover speeds and dynamic distribution are implemented to increase storage throughput efficiency, then productivity is improved, but the difficulty of ensuring personnel safety and controlling access increases
Solution Approach 1:
The system divides the storage array into multiple independently controllable access zones. Each zone can be isolated and secured independently, allowing personnel access to specific areas without shutting down the entire system. This segmentation enables maintained productivity in active zones while ensuring safety in zones under maintenance or personnel access.
Solution Approach 2:
The system performs preliminary actions by pre-positioning barriers and pre-securing rovers before personnel enter access zones. The control system commands all rovers to evacuate or secure themselves prior to zone access approval, ensuring that safety measures are already in place before personnel exposure to potential hazards.
2Ease of operation
If personnel access zones are integrated into the storage array, then ease of operation for human interaction is improved, but the device complexity increases
Solution Approach 1:
The control system performs multiple functions: it manages normal rover operations, monitors access zone status, commands rover evacuation, secures barriers, and authorizes personnel access. This multi-functionality consolidates what could be separate complex systems into a unified control architecture, managing complexity while providing comprehensive access control.
Solution Approach 2:
The access control system is nested within the existing ASRS control architecture. Access zone controllers are integrated into the overall system controller, which already manages rover operations. This nested structure allows personnel access functionality to be added without creating entirely separate complex systems, leveraging existing control infrastructure.
3Reliability
If barriers and access control mechanisms are added to secure personnel zones, then reliability of personnel protection is improved, but productivity of the storage system deteriorates
Solution Approach 1:
By segmenting the storage array into multiple access zones with independent control, the system allows personnel access to one zone without affecting operations in other zones. Barriers and security mechanisms are localized to specific zones, so productivity loss is confined to only the zones under maintenance or personnel access, while the remainder of the system continues full operations.
Solution Approach 2:
The access control system is dynamic rather than static. Barriers can be opened or closed, and zone access permissions can be changed in real-time based on operational needs. This dynamic control allows the system to optimize the balance between personnel protection and productivity by minimizing the impact of access control on overall system throughput.
Data Source
Figure 1
Figure 2
Figure 2A
AI summary
A transportation system having a transportation space including destinations distributed in the transportation space, multiple independent automated vehicles configured for free roving through the transportation space to and between the destinations so that the vehicles are dynamically distributed through the transportation space, a control system communicably connected via a remote communication link to each of the vehicles and having a system controller that addresses each vehicle to different destinations, and the control system having a vehicle accountant controller separate and distinct from the system controller and configured to independently register a dynamic location of at least one of the vehicles, selected from the multiple vehicles in the transportation space, and command shutdown, via the remote communication link, to only the selected at least one vehicle at the registered location if the registered location corresponds to a predetermined location.