ASRS Vehicle Access Control for Blocked Target Cells
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In automated storage and retrieval systems, congestion occurs around frequently visited cells like ports due to container handling vehicles waiting for access, leading to delays as the position of blocking vehicles is not known until they pass a track crossing, causing inefficient traffic flow and bandwidth usage.
Innovation Solution
Implementing a proximity sensor system on container handling vehicles to detect when a blocking vehicle is beyond a predetermined distance, allowing the central control unit to command the waiting vehicle to move into the target cell without waiting for the blocking vehicle's new position to be transmitted, reducing queuing times and bandwidth usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the central control unit waits for the blocking vehicle's position to be transmitted before allowing the waiting vehicle to move, then collision safety is ensured, but queuing time increases and traffic efficiency decreases
Solution Approach 1:
The system performs preliminary detection of the blocking vehicle's position using proximity sensors before the waiting vehicle needs to move. By continuously monitoring and knowing the blocking vehicle's position in advance, the system can prepare authorization signals ahead of time, allowing the waiting vehicle to move immediately when the path is clear without waiting for position transmission delays.
Solution Approach 2:
Each container handling vehicle is equipped with its own proximity sensors and control unit that can independently detect blocking vehicles and determine when the target cell is accessible. This self-service capability allows vehicles to make real-time movement decisions without constant communication with the central control unit, reducing queuing time while maintaining safety through local intelligence.
2Reliability
If the central control unit continuously monitors and commands each vehicle movement, then system safety and coordination are maintained, but bandwidth usage and processing load increase
Solution Approach 1:
The control functionality is segmented between the central control unit and individual vehicle control units. The central unit handles high-level task assignment and coordination, while individual vehicles handle local navigation and collision avoidance using their proximity sensors. This segmentation reduces the communication bandwidth required between the central unit and vehicles, as only essential coordination signals need to be transmitted.
Solution Approach 2:
The system implements a feedback mechanism where vehicles report their status and the central control unit provides authorization signals only when necessary. The proximity sensors provide continuous local feedback about blocking vehicles, enabling the system to reduce central control communications to event-driven updates rather than continuous monitoring, thereby optimizing bandwidth usage while maintaining system coordination.
Data Source
Figure 1
Figure 2a~2b
Figure 3~4
AI summary
The invention concerns a method of operating an automated storage and retrieval system (1), wherein the method comprises: - detecting with the central control unit (14) that access of a first container handling vehicle (2) to a target cell (12), which is one of the plurality of grid cells, is blocked by a second container handling vehicle (2), - transmitting a data signal (16) from the central control unit (14) to the vehicle control unit (15) of the first container handling vehicle (2) commanding the first container handling vehicle (2) to move into the target cell (12) when the second container handling vehicle (3) is beyond said predetermined distance (D). Furthermore, the invention relates to an automated storage and retrieval system comprising container handling vehicles comprising a central control unit configured to perform the aforementioned method.