High-bay Warehouse Research Articles

Experimental behaviour of ductile diagonal connections for rack supported warehouses

Steel racking systems are widely adopted for storage purposes: they are thin-walled structures composed of consecutive trusses, connected with beams on which the palletized goods are stored. Their geometry and structural configuration strongly depend on market and operator necessities, and, in modern applications, racks can also function as the supporting structure of the warehouse itself in the form of Rack Supported or High-Bay Warehouses. With the increase of the overall geometric dimensions and the global weight of the stored material, the seismic action becomes more relevant for the design. Along these lines, the development and experimental testing of a dedicated seismic design approach for ductile steel racks is here presented, with particular attention to Rack Supported Warehouses. This approach exploits the ductility of trusses introduced via the plastic ovalization mechanism of the diagonal-to-upright connections while a tailored capacity design is used to assure the elastic behaviour of the rest of the structure and to keep the brittle failure mechanisms at bay.

A New Method for the Determination of Fire Risk Zones in High-Bay Warehouses

Considering that the determination of fire hazard zones in warehouses is not sufficiently researched and studied, this paper aims to present a new methodological approach concerning the mentioned issue. Based on the COPRAS multi-criteria decision-making method, a new method was developed for the precise determination of potential zones where there is a risk of fire. The advantage of the described method is that it allows the quick and easy determination of all-orientation fire risk zones. The method requires fewer hardware resources compared to the existing ones and enables the display of the warehouse space in the form of a 3D model with calculated fire hazard zones. The mentioned procedure represents the first step when planning the layout and arrangement in the warehouse itself. The effectiveness of the proposed method was confirmed through a suitable numerical example.

The Concept of an Autonomous Mobile Robot for Automating Transport Tasks in High-Bay Warehouses

The Concept of an Autonomous Mobile Robot for Automating Transport Tasks in High-Bay Warehouses

The ENBIS‐21 quality and reliability engineering international special issue

The ENBIS-21 Quality and Reliability Engineering International Special Issue is related to the contributions to the 21st Annual Conference of the European Network for Business and Industrial Statistics (ENBIS) held online from 13 to 15 September, 2021. The topics covered by the 12 papers included in this special issue fall within the scope of ENBIS, whose ultimate goal is to bridge the gap between methodology and application in the field of business and industrial statistics and foster networking between statisticians in academic and commercial settings. It becomes evident from the papers on this issue that classical methods of industrial statistics are still having a wide range of applications and expansions towards complex and big data structures as well as they are increasingly cross-fertilized by artificial intelligence and machine learning perspectives and approaches. The issue is opened by the contribution of Yang et al.1 in the Statistical Process Monitoring (SPM) of data in the form of tensors. The authors develop a hierarchical in-situ process monitoring approach for anomaly detection, which is applied to thermal video streams acquired during a metal additive manufacturing process for highly complex parts. A more traditional SPM approach based on generalized likelihood ratio (GLR) control charts is elaborated by Rizzo and Di Bucchianico2 to set up tailor-made monitoring for high-purity (high-quality) processes and deals with issues arising in GLR control charts for discrete processes. Along the line of developing statistical methods for complex data structures, Gril et al.3 set up a tensor-on-tensor regression model able to dynamically predict repetitive human motions helpful in avoiding unwanted collisions at the interface with robots in industrial assembly tasks. Chuquin et al.4 present a straightforward extension of the K-means clustering to spatially correlated functional data, with an application in the analysis of the normalized difference vegetation index in a large region of Ecuador. From a more general perspective, Vanacore et al.5 address the problem of assessing prediction performance in the multi-class classification of imbalanced data sets. In the optimal Design of Experiments (DoE) Pesce et al.6 offer new results that are oriented to bias reduction in large datasets and protection against confounders. Whereas, Kirchhoff et al.7 use DoE as the initial solution for the optimization of shift planning in high-bay warehouse operations based on Gaussian process models with low-rank correlation kernels. Risk assessment and management is the topic of the following three papers. Testik and Unlu8 compare traditional and fuzzy failure modes and effect analysis to rank risks in different areas of testing and calibration laboratories. Meynaoui et al.9 deal with an accidental scenario in a sodium-cooled fast nuclear reactor by means of a global sensitivity analysis of the input parameter distribution used in numerical simulator outputs to model physical phenomena. Lai and Zwetsloot10 offer a data-driven ensemble ranking system of product quality, which is validated in the identification of high-risk manufacturers in a solar industry case study. The final two papers are devoted to the Reliability and Maintenance of repairable systems. El-Aroui and Gaudoin11 propose a general goodness-of-fit test for imperfect repair models that has the favorable property of being asymptotically distribution-free for renewal and power law processes. Fouladirad et al.12 develop a new bounded transformed gamma process model to describe and predict degradation phenomena by relaxing the typical assumption that the degradation level can grow indefinitely, which is often unrealistic for technological units. The proposed model is also applied to a set of wear measures of cylinder liners that equip a diesel engine for marine propulsion. We are deeply grateful to the journal staff for their professional assistance in the editorial process, as well as to the anonymous referees for the time and effort spent to provide careful and constructive comments, and to all the authors, who made revisions on a very tight timescale.

The warehouse reshuffling problem with swap moves and time limit

In this paper, we study the warehouse reshuffling problem, where pallets in a storage have to be rearranged in an efficient way. A high-bay warehouse with an automated storage and retrieval system is considered, which is equipped with a twin shuttle stacker crane. This twin shuttle is designed to perform swap moves, where the pallet at a storage location is swapped with the pallet currently loaded on the stacker crane. We study a new problem variant, where the time for reshuffling is limited, and the desired assignment of pallets to storage locations is not given as input. The objective is to store the frequently accessed pallets closely to the input/output-point to keep the warehouse operations efficient. After proposing necessary and sufficient optimality conditions for assignments of pallets to storage locations, we present algorithms to deal with the time limit. Moreover, we prove NP-hardness of two special cases, introduce lower bound procedures, several construction heuristics and a simulated annealing algorithm. Finally, we present computational results on randomly generated instances based on a real-world company setting.

Scheduling the tasks of multiple AGVs in a fault-tolerant control way

The paper concerns a development of an approach for implementing fault-tolerant control (FTC) of automated guided vehicles (AGVs). The main challenge considered in the article is the way of taking into account in the scheduling algorithm the delays occurring in the system resulting from the use of transport means. Mostly, multiple AGVs are designed and implemented as a firm real-time system in which delays are treated as faults. The proposed framework allows to compensate the faults in the real time. In the paper a multiple AGVs that transport item from an output of a production system to a high bay warehouse is presented. The article presents the non-deterministic nature of a multi-AGV system and includes a mathematical description of the system using (max, +) algebra. Having a analytical description of AGVs system, a new FTC strategy is proposed. Moreover, in the paper an illustrative case study showing the performance of the developed approach is presented.

New high bay warehouse as a result of a general logistics study

New high bay warehouse as a result of a general logistics study

Analysis of the use of artificial intelligence in the management of Industry 4.0 projects. The perspective of Polish industry

Abstract Artificial Intelligence (AI) supports project management in industry projects increasingly more often. The article documents research results regarding the use of AI in Industry 4.0 projects. The aim of the article is to define the range of AI use in Industry 4.0 projects throughout their entire life cycle and to indentify the main stages of AI development in project management. Additionally, the article indicates the main barriers to AI use in project management identified in the studied projects. In order to identify and systemise the range of AI use, the Conceptual Framework of Using AI in Project Management presented in literature is applied. Research results indicate that we are in the early stages of AI use in projects. The studied projects use AI mainly in project administration, i.e. to complete the following tasks: simple automation of routine activities, support, and, to a very limited extent, in the area of project management, i.e. in identifying anomalies and predicting the phenomena where the anomalies will occur. The research uses the case study method, where four projects were studied: an ERP system upgrade, an implementation of an IT system supporting high-bay warehouse management, an implementation of an IoT as a data-collection sensor platform and an E-learning platform implementation. The study was conducted between 2019 and 2021, and covered the entire project life cycle, including its three stages, i.e. preparation, implementation and operation.

Analiza ryzyka jako element zarządzania bezpieczeństwem w łańcuchu dostaw

W trakcie badań dokonano identyfikacji zagrożeń i analizy ryzyka w łańcuchu dostaw pracownika zatrudnionego w magazynie wysokiego składowania. W badaniach podjęto próbę wartościowania ryzyka w celu określenia jego poziomu akceptowalności. Wyznaczono kategorię ryzyka z zastosowaniem metody risc score. Określono środki profilaktyczne obniżające ryzyko zawodowe na stanowisku pracy magazyniera. Z przeprowadzonej oceny ryzyka wynika, że wózek widłowego stanowi największe źródło zagrożenia w łańcuchu dostaw surowców, produktów, komponentów stanowi ryzyko nieakceptowalne na poziomie R = 540, co oznacza, że bez zastosowania środków profilaktycznych pracodawca nie może w sposób bezpieczny dopuścić pracowników do pracy. W ramach działań obniżających kategorię ryzyka zastosowano nowoczesne metody dodatkowego wyposażenia wózków widłowych m.in. w sygnalizacje świetlną informującą o nadjeżdżającym wózku za pomocą blue light oraz oznaczenia czerwonej strefy pracy wózka (red zone) jako niebezpiecznej. Z przeprowadzonych badań wynika, że po zastosowaniu środków profilaktycznych ryzyko dla stanowiska pracy magazyniera zostało ocenione w przedziale 0< = R <70 na poziomie akceptowalnym.

Istraživanje srednje vrednosti potrebne energije, performansi i referentnih ciklusa slagačkih kranova

Automated storage and retrieval systems (AS-RS) are commonly used in intralogistic facilities and are often operated by stacker cranes. These stacker cranes are used in high-bay warehouses to move small load carriers, pallets and special load carriers. This paper presents an approach for the determination of the mean energy demand of stacker cranes, using a reference cycle. The examination of the reference cycles is based on a large scale simulation experiment with randomly generated stacker crane and rack configurations and operation tasks. The results permitted an analysis of the correlations between various parameters e.g. energy demand and performance of stacker cranes. Subsequently, three different reference cycles which allow an easy and fast calculation of the mean energy demand are developed and evaluated.

Razvijanje metode za određivanje energetske efikasnosti dizalice za slaganje robe u automatizovanim visokoregalnim skladištima

Modern intralogistic facilities fulfil important tasks within today's supply chains. Many different influences must be taken into account in their planning and construction. Current trends and circumstances show a strong tendency to build energy efficient and therefore environmentally friendly warehouses. This applies to the building technology of a warehouse and the intralogistic system used. Intralogistic facilities with an automated high-bay warehouse are very common and often operated by stacker cranes. This storage technology allows goods to be stored in a very volume and energy-efficient manner. The performance and energy demand of stacker cranes are influenced by a large number of parameters. To determine their energy efficiency is therefore complex. In this paper we present a method based on a simulation study which could be a possible solution for this problem.

Vertical Expansion: A Solution for Future Container Terminals

Container terminals play a major role in the growth of international trade. They need to accommodate the increasing number of containers although their space is limited, particularly close to major cities. One approach, often used in practice, is horizontal expansion through expensive land reclamation projects. In contrast, vertical expansion uses the available land more efficiently by storing containers in high-bay warehouses. In this paper, we study a next-generation container terminal consisting of container storage towers. A container tower is a cylindrical structure that consists of multiple levels of storage locations, lifts, and input/output (I/O) points (or depots). The lifts can rotate and can move containers horizontally and vertically to transport containers between the storage locations and the I/O points. We investigate several design questions: (1) What is the optimal configuration of a container tower? (2) How does a container tower compare with a traditional container block of the same storage capacity in terms of throughput capacity? (3) Is a container tower financially feasible compared with an existing container block of the same storage capacity? (4) What are the impacts of varying design parameters on the container tower performance and its financial feasibility? Question 1 is answered by obtaining closed-form expressions for the tower travel time, formulating the problem as a nonlinear optimization model, and deriving closed-form expressions for the tower optimal configuration. Questions 2 and 3 are answered by using closed-form expressions to compare the performance of two systems. Question 4 is answered by a sensitivity analysis for the design parameters of the container tower. The results show that, compared with a traditional container block, the container tower can increase the annual throughput while saving on the required footprint at competitive investment costs. In particular, the container tower can increase the annual throughput up to 120% compared with a container block of the same storage capacity.

Comparison of the order picking processes duration based on data obtained from the use of pseudorandom number generator

Abstract In this paper a simulation model of a part of logistics facility, i.e. an order picking area in a high-bay warehouse, is considered. The construction of this model was preceded by the development of a conceptual model as a result of the study for selected warehouses of this type. The researched simulation model is not a reflection of a logistics facility functioning in reality. This facility is a hypothetical warehouse. The simulation model includes generators of pseudorandom numbers, which, among other things, serve to obtain and introduce randomly generated picking orders (picking lists) into the model. And at the same time these generators reflect and provide the real, often unforeseen, size of orders. This allows, among other things, to analyze the capacity of the considered facility. The paper presents a comparison of results obtained with use of simulation model for pseudorandom number generator with different data at the input to these model.

Multiple AGV fault-tolerant within an agile manufacturing warehouse

The current trend towards Industry 4.0 leads to several important aspects that concern future warehouse systems. The holistic digitalization efforts behind this trend may enable sustainable and resilient processes within warehouses and may increase their agility, but require elaborate control and diagnosis systems. This paper concentrates on one prominent means for increasing the agility - the employment of multiple automated guided vehicles (AGVs). Due to the complexity of a system with multiple AGVs, model predictive control (MPC) algorithms are required for effective and efficient operation. In industrial reality, uncertainties cannot be avoided, it is therefore highly desirable that these algorithms can handle such uncertainties and minor inconsistencies. The precedent necessities led to a strategy based on a fault-tolerant control framework, which is based on max-plus algebra with a model predictive control scheme. The applicability of this strategy is validated on the example of the feedings system of an high-bay warehouse.

Visualization systems for industrial automation systems

In currently designed industrial automation systems, a very important task is fulfilled by appropriate legible and properly designed system visualization. You cannot imagine, for example, a control room in a power station where there are lights, recorders and switches located on the walls. Currently, all power plants or, alternatively designated areas are controlled by automation systems with SCADA systems. These systems allow you to observe variables, change their status, record in real time as well as archiving variables, creating transparent charts, etc. operations [1-4,5,6]. The subject of the article is to present the real object of a high bay warehouse with a SCADA environment as a supervisory control. In the Proficy iFix environment, a visualization was made thanks to which the operator has the possibility to change the process of using the virtual buttons and manually entering setpoints. In addition, the amount of process data obtained is significantly increased, which facilitates and speeds up the operator’s decision making. The machine status data is presented in the form of virtual signaling lamps, displayed values of process variables, graphical representation of process variables, and animation of the high bay warehouse execution member reflecting the actual traffic.

Energy regeneration in automated high bay warehouse with stacker cranes

Energy regeneration in automated high bay warehouse with stacker cranes

Securing of safety by monitoring of technical parameters in warehouse racks, in high-bay warehouses and high storage warehouses - literature review of the problem

Securing of safety by monitoring of technical parameters in warehouse racks, in high-bay warehouses and high storage warehouses - literature review of the problem

The network control system of high-bay warehouse

Presentation of developing a method of automation of the storage process using electric drives with frequency converters, logic control and communication in industrial networks was the main purpose of this article. A connection structure was proposed to exchange information between devices that are part of a high-storage warehouse. It was assumed that modern communication protocols are used to synchronize the drives and to create a central control and information center in the PLC. The results of theoretical considerations were applied in practice by performing a laboratory model of a high storage warehouse with a developed automatic control system. Benefits of the proposed solutions was shown in the conclusions.

FISCHER FIXING SYSTEMS: MOVING FORWARD WITH THE WORKFORCE - CHANGE COMMUNICATION AT THE GLOBAL DISTRIBUTION CENTER

The investment decision was made last year, and after a time-consuming selection process and intensive negotiations, the contract with the general contractor was signed. The business segment Fixing systems of the fischer group of companies faced a significant investment in its logistics – the development of automation technology in the Global Distribution Center (GDC). According to the project schedule, the transition to the automated small parts storage with shuttle technology would take place in December of this year. It was mid-April, and therefore the right time for the Head of Logistics of the business segment fischer Fixing systems, Matthias Wehle, to describe the current status: Were all the important milestones achieved and would the subsequent steps ensure a smooth transition? The employees in the logistics got accustomed to changes over the years. Structural changes such as the introduction of SAP R/3 in early 2000 and the establishment of the automated high-bay warehouse in 2008 had been successfully implemented. It was the same with the continuous improvement process through the use of the fischerProzessSystem fPS. The introduction of pick-by-light technology for the picking of small sized products with high demand had worked well, too. But the last staff meeting about launch of the shuttle system had left with him a feeling of uncertainty. He could already feel the spirit of optimism from some of the employees triggered by the upcoming introduction of the new system. The majority, however, listened patiently and Mr. Wehle sensed insecurity among the employees – how does this change affect me? Up until now, management had used multiple channels to communicate information to the employees. But feedback from the workforce to those in charge was rather rare. And the logistics manager remembered that the use of pick-by-voice for picking had been stopped for a number of reasons. Now as a result of the largest investment in recent years, the GDC faced a drastic operational change. With this in mind, Mr. Wehle pondered over the issue of employee communication again and again. And they had eight more months in order to take action until December…

Routing orderpickers in a warehouse: a comparison between optimal and heuristic solutions

In this paper the problem of finding efficient orderpicking routes is studied for both conventional warehouses, where pickers have a central depot for picking up and depositing carts and pick lists, and modern warehouses, where orderpicking trucks can pick up and deposit pallets at the head of every aisle without returning to the depot. Such environments can be found in many warehouses where paperless picking is performed from pallet locations with pickers having mobile terminals receiving instructions one by one. In order to find orderpicking routes with a minimal length in both the situations of a central depot or decentralized depositing, we extend the well-known polynomial algorithm of Ratliff and Rosenthal [1] that considered warehouses with a central depot. In practice, the problem is mainly solved by using the so-called S-shape heuristic in which orderpickers move in a S-shape curve along the pick locations. The performance of the new algorithm and the S-shape heuristic are compared in three realistic orderpicking systems: (1) narrow-aisle high-bay pallet warehouse; (2) picking in shelf area with decentralized depositing of picked items; and (3) conventional orderpicking from wide-aisle pallet locations. The new algorithm gives a reduction in travel time per route of between 7 and 34%. It turns out that the reduction in travel time strongly depends on the lay-out and operation of the warehouse.