Thursday, 14:15 - 14:40 h, Room: MA 042

 

Torsten Gellert
Scheduling multiple cranes on a shared pathway

Coauthor: Rolf H. Möhring

 

Abstract:
In many logistics applications, transport requests are conducted in parallel by several vehicles moving along a fixed shared pathway. Examples include cranes mounted on a common rail, like gantry cranes loading and unloading containers in intermodal transportation, or forklifts moving along a narrow passageway in large warehouses.

In theory, assigning transport requests to the vehicles of such systems and scheduling their execution amounts to finding k tours on a common line, where tours may never cross each other in time - dynamic collision constraints need to be respected. The goal is to minimize the
makespan for a given set of transport requests.
This problem contains other challenging tasks like partitioning jobs and assigning starting times.

We present a model capturing the core challenges in transport planning problems of this type and prove NP-hardness for the problem.
The structural properties can be used to formulate a mixed integer program with starting time variables, but without any assignment of jobs to vehicles. Furthermore, we show some special cases where an optimal solution can be found in polynomial time.

 

Talk 3 of the contributed session Thu.2.MA 042
"Synchronization and collision avoidance" [...]
Cluster 13
"Logistics, traffic, and transportation" [...]

 

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