Deployment of an Distributed Strategic Material Flow Control for Automated Material Flow Systems Consisting of Autonomous Modules

Poster 1

Deployment of an Distributed Strategic Material Flow Control for Automated Material Flow Systems Consisting of Autonomous Modules

The modularisation of hardware and software is one approach to handle the demand for increasing flexibility and changeability of automated material flow systems that are, for example, utilised in flexible production systems. In such automated material flow systems, autonomous modules communicate with each other to coordinate and execute transport tasks. In this paper a strategic material flow control is introduced, which is distributed on several modules realised with a multi-agent system. The strategic material flow control agent coordinates transport tasks with advanced logistical requirements, such as sequencing. A transport task states for a transport unit the system source and sink together with arrival criteria at the sink, e.g. sequence In order to fulfil the arrival criteria the strategic material flow agent selects additional destinations within the automated material flow system to buffer a transport unit. For the selection of suitable buffer modules, several strategies are proposed and evaluated in a simulation study

An Approach to Data-Based Standardization of Automatic Miniload Warehouses

Automatic miniload warehouses with stacker cranes are used in intralogistics processes to decouple demand from supply. However, these systems are highly complex, requiring an extensive planning phase. By identifying the commonalities among these warehouses, our research presents an approach to reduce the complexity of the planning process of automatic miniload warehouses with stacker cranes

SIMULATION-BASED EVALUATION OF RESERVATION MECHANISMS FOR THE TIME WINDOW ROUTING METHOD

Automated warehouses operated by a fleet of robots offer great flexibility, since fleet size can be adjusted easily to throughput requirements. Furthermore, they provide higher redundancy compared to common solutions for automated storage and retrieval systems.On the other hand, these systems require more complex control strategies to run robustly and efficiently. Special routing and deadlock handling strategies are necessary to avoid blocking and collisions among the robots.In this contribution, we focus on the time window routing method, an approach for avoiding deadlocks byreserving routes in advance. We present and discussdifferent reservation mechanisms that are evaluated bythe means of simulation.Automated warehouses operated by a fleet of robots offer great flexibility, since fleet size can be adjusted easily to throughput requirements. Furthermore, they provide higher redundancy compared to common solutions for automated storage and retrieval systems. On the other hand, these systems require more complex control strategies to run robustly and efficiently. Special routing and deadlock handling strategies are necessary to avoid blocking and collisions among the robots. In this contribution, we focus on the time window routing method, an approach for avoiding deadlocks by reserving routes in advance. We present and discuss different reservation mechanisms that are evaluated by the means of simulation

Design, Application and Evaluation of a Multi Agent System in the Logistics Domain

The increasing demand for flexibility of automated production systems also affects the automated material flow systems (aMFS) they contain and demands reconfigurable systems. However, the centralized control concept usually applied in aMFS hinders an easy adaptation, as the entire control software has to be re-tested, when manually changing sub-parts of the control. As adaption and subsequent testing are a time-consuming task, concepts for splitting the control from one centralized to multiple, decentralized control nodes are required. Therefore, this paper presents a holistic agent-based control concept for aMFS, whereby the system is divided into so-called automated material flow modules (aMFM), each being controlled by a dedicated module agent. The concept allows the reconfiguration of aMFS, consisting of heterogeneous, stationary aMFM, during runtime. Furthermore, it includes aspects such as uniform agent knowledge bases through metamodel-based development, a communication ontology considering different information types and properties, strategic route optimization in decentralized control architecture and a visualization concept to make decisions of the module agents comprehensible to operators and maintenance staff. The evaluation of the concept is performed by means of material flow simulations as well as a prototypical implementation on a lab-sized demonstrator.Comment: 13 pages, https://ieeexplore.ieee.org/abstract/document/9042827

Model-Based Systems Engineering for the Design of an Intermodal High-Speed Freight Train Terminal

Since rail traffic is the mode of mass transport with minimal transportation-related greenhouse gas emissions, it plays a key role in achieving the sustainability targets of the transportation sector. To enable a modal shift from road to rail the German Aerospace Center has developed the Next Generation Train CARGO, a high-speed freight train concept targeted to ship so-called Low-Density High Value goods on existing railway infrastructure. Studies have revealed that an intermodal transshipment terminal is key to a successful integration of the concept in current logistics networks. Driven by high requirements regarding handling, reliability, and time, the terminal is a complex intralogistics system strongly depending on the particular good that shall be handled. This work uses the principles and methods of Model-Based Systems Engineering in a tailored modeling approach to specify a generic terminal system architecture. Based on this generic architecture an exemplary good-specific variant of the terminal is derived with focus on intralogistics freight handling. The chosen design approach is further evaluated regarding its suitability in context of intralogistics system design. The results of this work demonstrate that Model-Based Systems Engineering is capable of successfully guiding architecture specification in the novel application domain of complex intralogistics facilities and further contributes to a consistent and comprehensive terminal design

DNA double strand breaks as predictor of efficacy of the alpha-particle emitter Ac-225 and the electron emitter Lu-177 for somatostatin receptor targeted radiotherapy

Key biologic effects of the alpha-particle emitter Actinium-225 in comparison to beta-particle emitter Lutetium-177 labeled somatostatin analogue DOTATOC in vitro and in vivo were studied to evaluate the significance of H2AX-foci formation and its downstream effects. To determine relative biological effectiveness (RBE) between the two isotopes somatostatin expressing AR42J cells were incubated with Ac-225-DOTATOC and Lu-177-DOTATOC up to 48 h and viability was analyzed using the MTT assay. DNA double strand breaks were quantified after immunofluorescence staining of H2AX. Cell cycle was analyzed by flow cytometry. In vivo, uptake of both radiolabeled somatostatin-analogues into subcutaneous AR42J tumors and number of cells displaying H2AX-foci were measured. Therapeutic efficacy was assayed by monitoring tumor growth after treatment with activities translated from in vitro cytotoxicity. Ac-225-DOTATOC was synthesized with specific activities between 0.2-0.4 MBq/µg and radiochemical purity of > 90%. ED50 values were 30 kBq/ml after 24 h and 14 kBq/ml after 48 h. Lu-177-DOTATOC displayed radiochemical purity of >95% and ED50 values of 10 MBq/ml after 48 h. Number of DNA double strand breaks increased with increasing concentration of Ac 225 DOTATOC and Lu-177-DOTATOC similarly, if a factor of approximately 700 of Lu-177 activities over Ac-225 activities was applied. Already 24 h after incubation with 2.5, 5, and 10 kBq/ml Ac 225 DOTATOC cell cycle studies showed an increment of the percentage of tumor cells in G2/M phase up to 60%. After 72 h an apoptotic subG1 peak was also detectable. Tumor uptake for both radio peptides at 48 h was identical with 7.5 %ID/g, though overall number of cells with H2AX-foci was higher for tumors treated with 48 kBq Actinium-225-DOTATOC than tumors treated with 30 MBq Lutetium-177-DOTATOC (35% vs. 21%). Tumors with a mean volume of 0.34 ml reached exponential tumor growth after 25 days (44 kBq Ac-225-DOTATOC), after 21 days (34 MBq Lu-177-DOTATOC) and after 5 days (control). Thus H2AX-foci displayed the key parameter after irradiation with similar downstream effects for beta and alpha irradiation.JRC.E.5-Nuclear chemistr

SYNERGY BETWEEN SHUTTLES AND STACKER CRANES IN DYNAMIC HYBRID PALLET WAREHOUSES: CONTROL STRATEGIES AND PERFORMANCE EVALUATION

This article considers two dynamic hybrid pallet warehouses obtained hybridizing a shuttle-based warehouse with stacker cranes. We begin by describing their design and characteristics. Afterwards, we explain the control algorithms that were developed for them. Next, we illustrate the modalities of the discrete event simulation study we ran to investigate their performance. In conclusion, we discuss the results in terms of throughput of the simulation study to individuate the field of application for the two layouts of dynamic hybrid pallet warehouses in comparison to stacker crane-based and shuttle-based warehouses.This article considers two dynamic hybrid pallet warehouses obtained hybridizing a shuttle-based warehouse with stacker cranes. We begin by describing their design and characteristics. Afterwards, we explain the control algorithms that were developed for them. Next, we illustrate the modalities of the discrete event simulation study we ran to investigate their performance. In conclusion, we discuss the results in terms of throughput of the simulation study to individuate the field of application for the two layouts of dynamic hybrid pallet warehouses in comparison to stacker crane-based and shuttle-based warehouses

Implementation and testing of a service system with smart and modular special load carriers

Unter- und Überbestände, fehlende Ladungsträger und Sondertransporte sind Probleme, die unter anderem aufgrund von unzureichender Transparenz innerhalb einer Supply-Chain auftreten. Deshalb konzentrieren sich aktuelle Forschungsansätze im Bereich der Logis-tik auf intelligente Objekte und cyber-physische Sys-teme, die prozessrelevante Daten sammeln und so zu einer Erhöhung der Transparenz und Optimierung der Supply-Chain beitragen. Dieser Beitrag zeigt auf, wie eine Umsetzung von innovativen produkt- und daten-basierten Dienstleistungen (z. B. automatische Bestand-führung, Zustandsüberwachung) mithilfe von modula-ren, intelligenten und vernetzten Behältern gelingt. Die Erprobung des Service-Systems, der Architektur und der eingesetzten Hardware zeigen dabei die erzielba-ren Mehrwerte und technologiebedingten Grenzen auf. Unter anderem können mithilfe des Service-Systems manuelle Prozesse innerhalb des Behälterkreislaufs und notwendige Dokumentationen innerhalb der Supp-ly-Chain digitalisiert werden. Eine gesteigerte Trans-parenz hinsichtlich aktueller Bestände und Beschädi-gungen trägt darüber hinaus aktiv zu einer Verbesse-rung der Prozessqualität bei den an der Supply-Chain beteiligten Partnern bei.Under- and overstocks, missing load carriers and special transports are problems that occur due to insufficient transparency in a supply chain. Therefore, current re-search approaches in the field of logistics focus on smart objects and cyber-physical systems that collect process-relevant data and thus contribute to an in-crease in transparency and the optimization of the supply chain. This article shows how innovative prod-uct and databased services (e.g. automatic inventory management, condition monitoring) can be imple-mented using smart and modular special load carriers. The experiments with the service system, the architec-ture and the hardware show the achievable benefits and technology-related limits. Among other things, manual process steps within the container circuit and necessary documentations in the supply chain are dig-itized with the help of the service system. The increased transparency in current stocks and damaged goods al-so actively contributes to an improved process quality for the supply chain partners

Development of a generic simulation method for the time window routing of automated guided vehicles

Fahrerlose Transportfahrzeuge werden unter anderem zur Produktionsversorgung und in automatisierten Lagersystemen eingesetzt. Die Anzahl an Fahrzeugen, welche notwendig ist, um einen geforderten Durchsatz zu erzielen, kann auf analytischem Wege nur näherungsweise bestimmt werden. Sind exakte Aussagen über den Durchsatz in Abhängigkeit der Fahrzeuganzahl gefordert, ist die Durchführung einer Simulationsstudie notwendig. Die Erstellung eines Simulationsmodells ist jedoch aufwändig und erfordert Kenntnisse über Steuerungsalgorithmen, um ein ablauffähiges Simulationsmodell zu erhalten. Der Beitrag beschreibt vor diesem Hintergrund eine Methode zur Simulation von Fahrerlosen Transportsystemen, um eine aufwandsarme Leistungsbestimmung zu ermöglichen. Ein Fahrerloses Transportsystem wird allgemeingültig modelliert, damit es in eine Simulationsumgebung überführt werden kann. Es werden Strategien zum Routing und Deadlock-Handling beschrieben, welche in das Modell hinterlegt und auf beliebigen Layouts angewendet werden können. Somit entsteht ein ablauffähiges Modell, welches zur individuellen Systemanalyse herangezogen werden kann.Automated guided vehicles are used for the supply of production areas, in automated storage and retrieval systems and for the supply of picking areas in goods to person fulfillment systems. The number of vehicles, that is required to reach a given throughput cannot be calculated exactly in an analytical way. Therefore, the performance of a simulation study is necessary. Implementing the model in a simulation environment requires time and effort. Basic algorithms are needed in order to obtain an executable simulation model. In this work, we describe a method for the simulation of automated guided vehicle systems for the measurement of the throughput as a function of the number of vehicles. We model an automated guided vehicle system in order to transfer it into a simulation environment. We describe algorithms concerning the routing and deadlock-handling, that will be integrated into the model and could be used on different layouts. As a result we obtain an executable simulation model that can be used for the detailed analysis of individual automated guided vehicle systems