An automated storage and retrieval system optimization with MILP methods

Abstract

In this paper, we consider the problem of scheduling an automatic guided vehicle (AGV) in an automated storage and retrieval system (AS/RS). In this system, the AGV acts as a transfer station and performs the task of depositing and taking out goods. It is assumed that the number and location of shelves are known, as well as the number and type of goods on each shelf. The AGV performs transport tasks with decisions that include finding the optimal transport sequence between different shelves and the optimal sequence of goods within each shelf. Therefore, these decisions jointly minimize the total transport distance. Using mixed-integer linear programming (MILP), the AGV can not only complete the task with the shortest working route but also return to the sorting station with the shortest path after completing the task. Using MATLAB software to simulate the two cases, the results of obtaining the optimal solution verified the correctness of the algorithm. The results show that the algorithm has high performance for optimizing AS/RSs.