Basic zone control performance determination in FTS design

U radu je izložena procedura za procenu vremena blokiranja vozila u kontrolnim zonama, koja predstavlja mali deo postupka za određivanje vrednosti promenljivih performansi sistema i elementarnih podsistema u projektovanju fleksibilnih transportnih sistema (FTS). Procedura je završni korak Integralnog analitičkog modela (IAM) za projektovanje i određivanje performansi FTS-a, čiji je generalni algoritam, takođe, predstavljen. Predložena strategija analitičkog modeliranja znatno poboljšava nivo tačnosti predviđanja performansi sistema i elementarnih podsistema FTS-a.This paper presents procedure for estimation of vehicle control zone blocking times as an only a small part of system and elementary subsystems performance variables calculation in a flexible transport system (FTS) design. Procedure is a final step of an Integral analytical model (IAM) for FTS design and performances determination, whose general algorithm is shown. Some results of sensitively analyses performed by IAM are also presented. Proposed analytical modeling strategy substantially increases the level of accuracy of system and elementary subsystem performance predicting

A survey of literature on shuttle based storage and retrieval systems

Prethodna decenija donela je pravi procvat u oblasti automatskih skladišnih sistema (SBS/RS) baziranih na šatl tehnologiji u mnogim industrijama. Njihova superiornost u odnosu na 'mini-load' automatske skladišne sisteme ogleda se prvenstveno u mogućnosti većeg protoka skladišnih jedinica kroz sistem, velikoj fleksibilnosti proširenja sistema i mnogo boljoj energetskoj efikasnosti, koja je rezultat manje potrošnje energije i sposobnosti regeneracije velike količine energije. Sveobuhvatan pregled literature SBS/RS prikazan u ovom radu ukazuje na glavne specifičnosti, ključne pretpostavke i aproksimacije u razvijenim modelima za procenu vrednosti performansi sistema ili strategijama za upravljanje sistemom, i ističe najvažnije zaključke izvedene iz dobijenih rezultata. Predstavljeni pristupi u modeliranju sistema mogu biti koristan alat za projektante SBS/RS prilikom procene efikasnosti sistema u početnoj fazi projektovanja.The last decade brought the blooming of the shuttle-based automated storage and retrieval system (SBS/RS) in many industrial applications. They proved the superiority over the mini-load automated storage and retrieval system mainly due to higher throughput capacity, high flexibility of future extension, much better energy efficiency resulting from lower energy consumption and high energy regeneration capability. A comprehensive literature review on SBS/RS given in the paper pointed out main specifics and crucial approximations and assumptions of the developed system performance estimation models or control strategies, as well as the main conclusions resulting from the obtained results. Presented modeling approaches could be a valuable tool for SBS/RS designers and other related decision makers to estimate the system efficiency in the starting phase of SBS/RS design activities

Design of automaded storage and retrieval systems in pharmaceutical industry

U radu su predstavljene neke osnovne smernice za projektovanje automatskih skladišta u farmaceutskoj industriji: vrsteskladištenog materijala, uslovi čuvanja materijala, osnovne karakteristike podsistema za prijem materijala, osnovne karakteristike podsistema za komisioniranje i zahtevani ambijentalni uslovi. Predstavljen je analitički model za određivanje očekivanih vremena ciklusa dizalice kod automatskih skladišta opsluživanih dizalicama sa regalima dvostruke dubine, budući da je ovo, verovatno, najčešće korišćena tehnologija skladištenja u podsistemu glavnog skladišta u farmaceutskim fabrikama. Usled izuzetne važnosti ispunjenja savremenih zahteva za distribucijom malih, frekventnih porudžbina, predstavljeni su analitički modeli za određivanje očekivanih vremena ciklusa kod automatskih skladišta za male terete opsluživanih dizalicama i automatskih skladišta za male terete opsluživanih skladišnim vozilima, koja definišu protok transportnih jedinica kroz sistem. Svi navedeni modeli mogu poslužiti projektantima i inženjerima koji se ovim problemima bave u praksi, kao i proizvođačima ovih sistema, da odrede meru uspešnosti projektnih rešenja, odnosno, da garantuju potencijalnim korisnicima najvažnije performanse sistema.The paper addresses some basic guidelines for the automated storage and retrieval systems design in pharmaceutical industry: types of pharmaceutical materials, materials storage keeping conditions, receiving subsystem main characteristics, order picking subsystem main characteristics and requested environment conditions. Analytical travel time model for the estimation of cycle times for the unit-load double-deep automated storage and retrieval systems is presented as it is the most common automated storage and retrieval systems type in main warehouse subsystem in pharmaceutical industry. Due to the great importance of very frequent small orders distribution in oday's logistic, analytical travel time model for the computation of travel cycle times for mini-load multi-shuttle automated storage and retrieval system and shuttle based storage and retrieval systems are presented. All models could help designers, professionals in practice even a producers of these systems to estimate successions of offered solutions or to guarantee most important system performance achievement

A multi-objective optimization model for minimizing investment expenses, cycle times and co2 footprint of an automated storage and retrieval systems

A new optimization model of Automated Storage and Retrieval Systems (AS/RS) containing three objective and four constraint functions is presented in this paper. Majority of the researchers and publications in material handling field had performed optimization of different decision variables, but with single objective function only. Most common functions are: minimum travel time, maximum throughput capacity, minimum cost, maximum energy efficiency, etc. To perform the simultaneous optimization of objective functions (minimum: "investment expenses", "cycle times", "CO2 footprint") the Non-dominated Sorting Genetic Algorithm II (NSGA II) was used. The NSGA II is a tool for finding the Pareto optimal solutions on the Pareto line. Determining the performance of the system is the main goal of our model. Since AS/RS are not flexible in terms of layout and organizational changes once the system is up and running, the proposed model could be a very helpful tool for the warehouse planners in the early stages of warehouse design

Alternative energy sources for forklifts – a way to make intralogistics green

Growing awareness of environmental problems, and in particular with well-published issues such as acid rain, chlorofluorocarbons (CFCs) and global warming, “greenness” become a catchword in logistic as a heart of modern transport systems since early of 1990s. To overcome these problems new field of logistic research is emerging, focusing on the adaptation of logistical systems and supply chains to climate change. Therefore, it is a trend in intralogistics sector in recent years to invest more in green technologies. In the last few years, the success from fuel cell demonstrations has moved rapidly into commercial forklift operations. This paper addresses the potential benefits in using the fuel cells and triple hybrid drives in forklift trucks as a field of potential improvements in intralogistic

A multi-objective optimization model for minimizing cost, travel time and Co2 emission in an AS/RS

U predstavljenom radu, diskutovano je i vršena je evaluacija višeciljne optimizacije automatskih skladišnih sistema. S obzirom da je većina istraživača u oblasti manipulacije materijalom i logistici, vršila optimizaciju promenljivih samo sa jednom funkcijom cilja (najčešće je to funkcija minimalno vreme ciklusa, maksimalni intenzitet opsluživanja, minimalna cena, tj. troškovi, maksimalna energetska efikasnost, itd.), predložen je model višeciljne optimizacije (sa trima funkcijama cilja: minimalni troškovi - minimalno vreme ciklusa - minimalna emisija CO2, odnosno maksimalna energetska efikasnost). Za optimizaciju promenljivih u funkcijama cilja, korišćeni su genetski algoritmi. Da bismo pronašli optimalna Pareto rešenja, upotrebili smo NSGA II genetske algoritme. Glavni zadatak našeg doprinosa jeste da se utvrde performanse automatskog skladišnog sistema, u skladu sa procedurom višeciljne optimizacije. Rezultati predloženog modela, mogu biti od koristi projektantima u ranim fazama projektovanja automatskog skladišnog sistema.A multi-objective optimization of automated warehouses is discussed and evaluated in the present paper. Since most of the researchers in material handling community had performed optimization of decision variables with single objective function only (usually named with minimum travel time, maximum throughput capacity, minimum cost, maximum energy efficiency, etc.), the multi-objective optimization (cost - travel time - CO2 emission/ energy efficiency) will be presented. For the optimization of decision variables in objective functions, the method with genetic algorithms was used. To find the Pareto optimal solutions, the NSGA II genetic algorithm was used. The main objective of our contribution is to determine the performance of the system according to the multi-objective optimization technique. The results of the proposed model could be useful tool for the warehouse designer in the early stage of warehouse design

A Survey of Research on Industry 4.0 in Intralogistics

This paper presents the research, development and application of Industry 4.0 in Intralogistics in the last five years. The progress made in Intralogistics, using Industry 4.0, is presented. An overview of the basic principles and elements of Industry 4.0 as well as its impact in the field of Intralogistics is given. Intralogistics is a field that is still being researched and has great potential for further development. Finally, the aim of this paper is to focus on sustainability parameters, technology and elements that still need to be worked on

Discrete element modelling of screw conveyor-mixers

Pužni transporteri se veoma intenzivno koriste u industriji za proizvodnju i preradu hrane, plastike, mineralnih sirovina, u poljoprivrednoj proizvodnji kao i u prerađivačkoj industriji za podizanje i/ili transport rasutih materijala na kratkim i srednjim rastojanjima. Uprkos njihovoj očiglednoj konstrukcionoj jednostavnosti, sam čin transporta je veoma složen za razumevanje i konstruktori se često oslanjaju na iskustvene podatke pri konstruisanju i izradi. Osobine pužnih transportera su određene radnim uslovima (kao što su: brzinu rotacije vratila puža, ugao pod kojim je nagnut pužni transporter, nivo zapreminskog punjenja puža, itd.). U ovom radu je opisano nekoliko horizontalnih puževa, konstantne dužine koraka, pri čemu su geometrije pužnih spirala neznatno izmenjene radi ispitivanja procesa mešanja tokom transporta, korišćenjem metode diskretnih elemenata (Discrete Element Method - DEM). Ispitivani su uticaji geometrijskih izmena na osobine pužnog transportera, različita konstrukciona rešenja pužne spirale su međusobno poređena, kao i efekti geometrijskih izmena na mešanje u toku transporta. Tokom transporta u pužnom transporteru, čestice padaju sa vrha pužne spirale na prvu sledeću slobodnu površinu pužne spirale i taj segment putanje čestice može da bude iskorišćen za dopunsko mešanje materijala tokom transporta. Putanja čestice se drastično povećava ugradnjom tri dodatne zavojne površine usmerene u istom pravcu kao i pužna spirala (1458,2 mm u poređenju sa 397,6 mm u slučaju pužnog transportera sa jednom spiralom). Skraćivanjem dodatnih zavojnica, koje su usmerene u istom smeru kao i pužna spirala, unekoliko se smanjuje putanja čestice, na dužinu od 1728,8 mm (usled prekidanja zavojnice na sredini pužnog transportera). Putanja čestice se produžava na 1764.4 mm, kada se ugrade dodatne zavojne površine koje su usmerene u suprotnom pravcu od pravca pužne spirale. Ugradnjom tri dodatna pravolinijske letve, dobijena je najduža putanja čestice: 2061,6 mm.Screw conveyors are used extensively in food, plastics, mineral processing, agriculture and processing industries for elevating and/or transporting bulk materials over short to medium distances. Despite their apparent simplicity in design, the transportation action is very complex for design and constructors have tended to rely heavily on empirical performance data. Screw conveyor performance is affected by its operating conditions (such as: the rotational speed of the screw, the inclination of the screw conveyor and its volumetric fill level). In this paper, horizontal, several single-pitch screw conveyors with some geometry variations in screw blade were investigated for mixing action during transport, using Discrete Element Method (DEM). The influence of geometry modifications on the performance of screw conveyor was examined, different screw designs were compared, and the effects of geometrical variations on mixing performances during transport were explored. During the transport, the particle tumbles down from the top of the helix to the next free surface and that segment of the path was used for auxiliary mixing action. The particle path is dramatically increased with the addition of three complementary helices oriented in the same direction as screw blades (1458.2 mm compared to 397.6 mm in case of single flight screw conveyor). Transport route enlarges to 1764.4 mm, when installing helices oriented in the opposite direction from screw blades. By addition of straight line blade to single flight screw conveyor, the longest particle path is being reached: 2061.6 mm

Discrete element modelling of screw conveyor-mixers

Pužni transporteri se veoma intenzivno koriste u industriji za proizvodnju i preradu hrane, plastike, mineralnih sirovina, u poljoprivrednoj proizvodnji kao i u prerađivačkoj industriji za podizanje i/ili transport rasutih materijala na kratkim i srednjim rastojanjima. Uprkos njihovoj očiglednoj konstrukcionoj jednostavnosti, sam čin transporta je veoma složen za razumevanje i konstruktori se često oslanjaju na iskustvene podatke pri konstruisanju i izradi. Osobine pužnih transportera su određene radnim uslovima (kao što su: brzinu rotacije vratila puža, ugao pod kojim je nagnut pužni transporter, nivo zapreminskog punjenja puža, itd.). U ovom radu je opisano nekoliko horizontalnih puževa, konstantne dužine koraka, pri čemu su geometrije pužnih spirala neznatno izmenjene radi ispitivanja procesa mešanja tokom transporta, korišćenjem metode diskretnih elemenata (Discrete Element Method - DEM). Ispitivani su uticaji geometrijskih izmena na osobine pužnog transportera, različita konstrukciona rešenja pužne spirale su međusobno poređena, kao i efekti geometrijskih izmena na mešanje u toku transporta. Tokom transporta u pužnom transporteru, čestice padaju sa vrha pužne spirale na prvu sledeću slobodnu površinu pužne spirale i taj segment putanje čestice može da bude iskorišćen za dopunsko mešanje materijala tokom transporta. Putanja čestice se drastično povećava ugradnjom tri dodatne zavojne površine usmerene u istom pravcu kao i pužna spirala (1458,2 mm u poređenju sa 397,6 mm u slučaju pužnog transportera sa jednom spiralom). Skraćivanjem dodatnih zavojnica, koje su usmerene u istom smeru kao i pužna spirala, unekoliko se smanjuje putanja čestice, na dužinu od 1728,8 mm (usled prekidanja zavojnice na sredini pužnog transportera). Putanja čestice se produžava na 1764.4 mm, kada se ugrade dodatne zavojne površine koje su usmerene u suprotnom pravcu od pravca pužne spirale. Ugradnjom tri dodatna pravolinijske letve, dobijena je najduža putanja čestice: 2061,6 mm.Screw conveyors are used extensively in food, plastics, mineral processing, agriculture and processing industries for elevating and/or transporting bulk materials over short to medium distances. Despite their apparent simplicity in design, the transportation action is very complex for design and constructors have tended to rely heavily on empirical performance data. Screw conveyor performance is affected by its operating conditions (such as: the rotational speed of the screw, the inclination of the screw conveyor and its volumetric fill level). In this paper, horizontal, several single-pitch screw conveyors with some geometry variations in screw blade were investigated for mixing action during transport, using Discrete Element Method (DEM). The influence of geometry modifications on the performance of screw conveyor was examined, different screw designs were compared, and the effects of geometrical variations on mixing performances during transport were explored. During the transport, the particle tumbles down from the top of the helix to the next free surface and that segment of the path was used for auxiliary mixing action. The particle path is dramatically increased with the addition of three complementary helices oriented in the same direction as screw blades (1458.2 mm compared to 397.6 mm in case of single flight screw conveyor). Transport route enlarges to 1764.4 mm, when installing helices oriented in the opposite direction from screw blades. By addition of straight line blade to single flight screw conveyor, the longest particle path is being reached: 2061.6 mm

A multi-objective optimization model for minimizing investment expenses, cycle times and CO2 footprint of an automated storage and retrieval systems

A new optimization model of Automated Storage and Retrieval Systems (AS/RS) containing three objective and four constraint functions is presented in this paper. Majority of the researchers and publications in material handling field had performed optimization of different decision variables, but with single objective function only. Most common functions are: minimum travel time, maximum throughput capacity, minimum cost, maximum energy efficiency, etc. To perform the simultaneous optimization of objective functions (minimum: “investment expenses”, “cycle times”, “CO2 footprint”) the Non-dominated Sorting Genetic Algorithm II (NSGA II) was used. The NSGA II is a tool for finding the Pareto optimal solutions on the Pareto line. Determining the performance of the system is the main goal of our model. Since AS/RS are not flexible in terms of layout and organizational changes once the system is up and running, the proposed model could be a very helpful tool for the warehouse planners in the early stages of warehouse design