Comparison of routing algorithms for storage and retrieval mechanism in cylindrical AS/RS

The objective of this research is to propose new routing algorithms for the Storage and Retrieval Mechanism (SRM) in the Cylindrical Automated Storage and Retrieval System (C-AS/RS) and contribute to the system conceptualization by investigating the maximum achievable retrieval request rates for different routing algorithms and system parameters. For this purpose, flexible and detailed simulation model was developed and investigated for 2 SRM types, 3 routing algorithms and a feasible set of system movement and load transfer time parameters. Based on the simulation output, the regression models for different SRM types and routing algorithms were developed for predicting the maximum retrieval request rate. The differences of the average maximum retrieval request rate were evaluated for various system configurations and routing algorithms. The alternative to optimal routing algorithm was proposed, reducing the system performance only by 1.4÷2.4% on average, but requiring significantly less calculations when planning the SRM tour. In addition, the system analysis indicated that SRM vertical velocity and load transfer time have the highest impact on the system performance and for different SRM types the average maximum retrieval request rates differ by 22.2÷31.8%. First published online: 14 Jan 201

Corrigendum

"Corrigendum." Transport, 31(1), p.

The simulation of dynamic systems using combined modelling

The new approach to the problems of dynamic systems simulation is proposed. The analytical and imitation modelling of non‐linear complex dynamic systems which comprise simulation of continuous and discrete processes with constant and variable parameters, are investigated. The aggregate mathematical modelling scheme [1] and the method of control sequences for discrete systems specification and simulation are used as well as the dynamic mathematical modelling scheme for continuous process formalization and modelling. According to them the investigated systems are presented as the set of interacting piecewise linear aggregates, which can include processes described with differential equations. The above mentioned approach is used in developing software for the construction and research of the models. The modelling of the dynamic systems’ control is also analyzed and developed software for the dynamic systems’ simulation is presented. It is related to the proposed combined modelling methodology. The developed dynamical simulation system ADPRO (Automatic Differentiation PROgram) extends applicability of the system SIMAS (SIMulation of the Aggregate Systems) [2] with dynamical simulation means realized with APL2 (A Programming Language 2) and based on automatic differentiation [3]. The created model of service process and its control can be used as a base for other models of wide class complex dynamics’ systems [4], the parts of which are described with differential equations. Dinaminių sistemų kombinuotas modeliavimas Santrauka Darbe nagrinejamas naujas dinaminiu sistemu modeliavimo metodas. Ištirti analitiniai ir imitaciniai sudetingu dinaminiu sistemu modeliavimo būdai, tirti tolydieji ir diskretieji procesai. Pateikta nauja dinaminio matematinio modeliavimo schema, skirta tolydžiu procesu formalizavimui ir modeliavimui. Sukurta programine iranga, leidžianti sudaryti ir tirti tokio tipo matematinius modelius. Taip pat tirtas dinaminiu sistemu valdymo modeliavimas bei sukurta atitinkama programine iranga. First Published Online: 14 Oct 201

Cравнение работы автоматизированных цилиндрических систем складирования С-AS/RS с разными погрузочно-разгрузочными устройствами

This paper proposes the concept of a new type of Cylindrical Automated Storage and Retrieval system (C-AS/RS), which consists of the octagonal shape rack, system input/output (I/O) positions, load storage and retrieval mechanism (SRM), which rotates and moves simultaneously and contains a number of load handling devices (LHDs). Physical structure of the single and multi-LHD systems, control algorithms and the performance measures were presented. Simulation modelling techniques, descriptive statistics and analysis of variance were used in this research to identify the effects of different location of I/O positions, the number of LHDs on the SRM and the retrieval request rates to the performance of the C-AS/RS system.В данной работе описывается концепция aвтоматизированных цилиндрических систем складирования нового типа (англ. Cylindrical Automated Storage and Retrieval Systems - C-AS/RS), которая состоит из стеллажа восьмиугольной формы, системы локализации ввода / вывода (англ. input/output-I / O), механизма сбора и хранения груза (англ. Storage Retrieval Mechanism - SRM), который вращается и движется одновременно и содержит ряд погрузочно-разгрузочных устройств (англ. Load Handling Device - LHD). Также была представленф физическая структура моно и мульти-LHD системы, алгоритмы управления и показатели эффективности. В данном исследовании были использованы методы иммитационного моделирования, дискриптивной статистики и дисперсионного анализа для определения влияния различных I/O локализаций, количества LHDs на SRM и интенсивности потока выбора груза на производительность системы C-AS/RS