A cross-entropy method for optimising robotic automated storage and retrieval systems. Issue 19 (2nd October 2018)

• Record Type: Journal Article
• Authors: Foumani, Mehdi; Moeini, Asghar; Haythorpe, Michael; Smith-Miles, Kate
• Is Part Of: International journal of production research. Volume 56:Issue 19(2018)
• Page Start: 6450
• Page End: 6472
• Publication Date: 2018-10-02
• Subjects: warehousing -- automated storage and retrieval systems -- scheduling -- cross-entropy method -- travelling salesman problem; Factory management -- Periodicals; 658.57
• DOI: 10.1080/00207543.2018.1456692
• Languages: English
• ISSNs: 0020-7543

Abstract

Abstract : In this paper, we consider a robotic automated storage and retrieval system (AS/RS) where a Cartesian robot picks and palletises items onto a mixed pallet for any order. This robotic AS/RS not only retrieves orders in an optimal sequence, but also creates an optimal store ready pallet of any order. Adapting the Travelling Salesman Problem to warehousing, the decision to be made includes finding the optimal sequence of orders, and optimal sequence of items inside each order, that jointly minimise total travel times. In the first phase, as a control problem, we develop an avoidance strategy for the robot (or automatic stacker crane) movement sequence. This approach detects the collision occurrence causing unsafe handling of hazardous items and prevents the occurrence of it by a collision-free robot movement sequence. Due to the complexity of the problem, the second phase is attacked by a Cross-Entropy (CE) method. To evaluate the performance of the CE method, a computational analysis is performed over various test problems. The results obtained from the CE method are compared to those of the optimal solutions obtained using CPLEX. The results indicate high performance of the solution procedure to solve the sequencing problem of robotic AS/RSs.