A Multiagent System-Based Solution for Shipment Operations with Priorities in a Container Terminal

Abstract

This paper proposes the use of a multiagent system-based solution for a proposed robotic-based automation system for the shipment operations of containers with shipment priorities in the port terminal located in Rio Grande City, Brazil. We faced with a problem of optimal policy formulation for teams of resource-limited robotic loaders in stochastic environments, which is composed of two strongly-coupled sub problems: a resource allocation problem and a policy optimization problem. The containers are required to be shared between the loaders, considering the following constraints: the containers have different weights and shipment priorities, the loaders have a maximum load that they can support during a journey, and, due to several reasons (e.g: administrative rules, maintenance schedule), the loaders are made available to the shipping operation only sequentially. We show how to combine the two problems, by formulating a policy optimization problem over the loading/unloading operations for each loader, as it becomes available. To solve the problem of container allocation to the next available loader we use a reduction of the Knapsack Problem. Then, we use Markov Decision Processes to decide on the shipment operations preformed by that loader in the terminal yard. These two processes are connected, since the container allocation process determines the states of the Markov chain that each loader actually visits. We simulated the resulting shipment operations using Net Logo.