Browsing by Author "Lerher, Tone"

Now showing 1 - 3 of 3

Citation - WoS: 30
Citation - Scopus: 33
Method for Evaluating the Throughput Performance of Shuttle Based Storage and Retrieval Systems
(Univ Osijek, Tech Fac, 2016) Lerher, Tone; Ekren, Banu Y.; Sari, Zaki; Rosi, Bojan
In this paper a method for throughput performance calculation of shuttle based storage and retrieval systems (SBSRS) is presented. SBS RS represent a new technology in automated storage and retrieval systems. Since it is important to design SBS RS right the first time due to the relative inflexibility of the physical layout, we provide a proposed method for the throughput performance calculation of these systems. The performance of the system is considered as a throughput capacity of the SBS RS as a whole.
Citation - WoS: 65
Citation - Scopus: 70
Multi-Objective Optimisation Model of Shuttle-Based Storage and Retrieval System
(Vilnius Gediminas Tech Univ, 2017) Borovinsek, Matej; Yetkin Ekren, Banu; Burinskiene, Aurelija; Lerher, Tone
This paper presents a multi-objective optimisation solution procedure for the design of the Shuttle-Based Storage and Retrieval System (SBS/RS). An efficient SBS/RS design should take into account multi-objectives for optimization. In this study, we considered three objective functions in the design concept which are the minimization of average cycle time of transactions (average throughput time), amount of energy (electricity) consumption and total investment cost. By also considering the amount of energy consumption as an objective function for minimization, we aimed to contribute to an environmentally friendly design concept. During the optimization procedure, we considered seven design variables as number of aisles, number of tiers, number of columns, velocities of shuttle carriers, acceleration/deceleration of shuttle carriers, velocity of the elevators lifting tables and acceleration/deceleration of the elevators lifting tables. Due to the non-linear property of the objective function, we utilized the Non-Dominated Sorting Genetic Algorithm II (NSGA II) genetic algorithm for facilitating the solution. Lastly, we searched Pareto optimal solutions to find out the optimum results. We believe that this study provides a useful and a flexible tool for warehouse planners and designers, while choosing a particular type of SBS/RS at the early stage of the warehouse design.
Citation - WoS: 92
Citation - Scopus: 126
Travel Time Model for Shuttle-Based Storage and Retrieval Systems
(Springer London Ltd, 2015) Lerher, Tone; Yetkin Ekren, Banu; Dukic, Goran; Rosi, Bojan
This paper presents analytical travel time model for the computation of travel (cycle) time for shuttle-based storage and retrieval systems (in continuation SBS/RS). The proposed model considers the operating characteristics of the elevators lifting table and the shuttle carrier, such as acceleration and deceleration and the maximum velocity. Assuming uniform distributed storage rack locations and using the probability theory, the expressions of the cumulative distribution functions with which the mean travel time is calculated, have been determined. The proposed model enables the calculation of the mean travel (cycle) time for the single and dual command cycles, from which the performance of SBS/RS can be evaluated. The approximation model and a simulation model of SBS/RS have been used to compare the performances of the proposed analytical travel time model. The analysis shows that regarding all examined types of SBS/RS, the results of proposed analytical travel time model for SBS/RS correlate with the results of simulation models of SBS/RS.