Sortation System Conveyor Speed Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Material-handling systems face challenges in matching the product supply rate from merge assemblies to sorter assemblies due to differing performance curves, leading to either excess or insufficient product being sorted, especially when handling a range of product sizes.
Innovation Solution
A sortation system with a control system that monitors product flow and adjusts the speed of conveyors and accumulators to balance the supply rate, using product detectors and position transducers to determine a fullness parameter, which controls the operation of conveyors and accumulators to maintain optimal product flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the merge assembly supplies product at a high rate, then the productivity of the material-handling system is improved, but the sorter assembly cannot sort the product fast enough leading to product backlog
Solution Approach 1:
The system performs preliminary accumulation of product at the accumulator before sorting. Product is accumulated in advance during periods when the sorter is operating below maximum capacity, then released during peak sorting demand. This preliminary action smooths out the mismatch between merge assembly supply rate and sorter processing rate, preventing product backlog while maintaining high productivity.
Solution Approach 2:
The control system continuously monitors the accumulator fullness parameter and uses this feedback to dynamically adjust the conveyor speed. When the accumulator is nearly full, the conveyor speed is reduced to prevent overflow. When the accumulator is empty or low, the conveyor speed is increased to maintain productivity. This closed-loop feedback control resolves the contradiction by automatically balancing supply rate with sorting capacity.
2Productivity
If the conveyor speed is increased to match sorter capacity, then the productivity is improved, but the accumulator becomes overloaded with excess product
Solution Approach 1:
The control system uses real-time feedback from the fullness parameter sensor on the accumulator to dynamically adjust conveyor speed. When the accumulator reaches a predetermined fullness level, the feedback signal automatically reduces conveyor speed to prevent overload. This maintains productivity at optimal levels while preventing excessive product accumulation.
Solution Approach 2:
The conveyor speed is made dynamic rather than fixed. The system continuously adjusts conveyor speed based on real-time accumulator conditions, varying the supply rate to match the actual sorting capacity. This dynamic adjustment prevents both accumulator overload and underutilization of sorting capacity, resolving the contradiction between maintaining high productivity and preventing product backlog.
3Adaptability or versatility
If the system handles a range of product sizes, then the adaptability is improved, but the performance curves of merge and sorter assemblies become mismatched
Solution Approach 1:
The accumulator acts as an intermediary buffer between the merge assembly and sorter assembly. This intermediary decouples the performance curves of the two assemblies, allowing them to operate at different rates without directly affecting each other. The accumulator absorbs the variability caused by different product sizes, maintaining reliable rate matching even when handling diverse product ranges.
Solution Approach 2:
The control system dynamically changes the conveyor speed parameter based on real-time system conditions and product characteristics. By adjusting this key parameter, the system adapts to different product sizes and sorting demands, maintaining reliable rate matching between merge and sorter assemblies across a wide range of operating conditions.
Data Source
AI summary
A sortation system and method of sorting product includes providing a sorter assembly and a supply system supplying product that is received by the sorter assembly. Product supplied to the sorter assembly is monitored and a parameter is determined that is indicative of the relationship between product supplied to the sorter assembly and product being sorted by the sorter assembly. The supply system is controlled as a function of a value of the parameter.