Robotic Sorting Systems: Performance Estimation and Operating Policies Analysis

Many distribution centers use expensive, conveyor-based sorting systems that require large buildings to house them. In areas with tight space, robotic offer a new type of solution sort parcels by destination. Such are highly flexible in throughput capacity and now gradually being introduced, particularly express companies. This paper studies system two layouts. The first layout has tiers: robots drive on the top tier destination spiral conveyors connected roll containers at lower tier. second single input output points located perimeter, robots. For each layout, we consider both shortest path topology via dual-lane aisles detour single-lane aisles. We build closed queueing networks for performance estimation, design an iterative procedure investigate robot congestion two-tier traffic flow function estimate single-tier layout. Random, closest, dedicated, shortest-queue robot-to-loading-station assignment rules examined. validate analytical models simulation real case Deppon Express analyze optimal size operating policies cost. results show is significantly affected topology, but it only slightly other systems. A square fits rectangular path. Both random rule superior number robots, whereas dedicated small apply these insights different allocations peak off-peak hours. Our analysis shows typically overall annual cost than traditional cross-belt when required not too large.