Flexible Material Handling System Research Articles

A multi-agent based approach to dynamic scheduling with flexible processing capabilities

A multi-agent based system is proposed to simultaneous scheduling of flexible machine groups and material handling system working under a manufacturing dynamic environment. The proposed model is designed by means of \(\hbox {Prometheus}^{\mathrm{TM}}\) methodology and programmed in \(\hbox {JACK}^{\mathrm{TM}}\) agent based systems development environment. Each agent in the model is autonomous and has an ability to cooperate and negotiate with the other agents in the system. Due to these abilities of agents, the structure of the system is more suitable to handle dynamic events. The proposed dynamic scheduling system is tested on several test problems the literature and the results are quite satisfactory because it generates effective schedules for both dynamic cases in the real time and static problem sets. Although the model is designed as an online method and has a dynamic structure, obtained schedule performance parameters are very close to those obtained from offline optimization based algorithms.

Anytime heuristic search for scheduling flexible manufacturing systems: a timed colored Petri net approach

Given the fluctuations in demand, diversity in products, production flexibility requirements, and tight customer due dates, obtaining optimal production schedules is considered a complex research problem. This can drastically affect the survival of some manufacturing companies in today’s fiercely competitive global market. In a very demanding decision-making environment, scheduling problems are dealt with in a short-term horizon, in which computation time is a critical factor. Producing optimal solutions is practically impossible given the time limitations and the nondeterministic polynomial (NP)-hard nature of scheduling problems. This paper presents an anytime-heuristic search approach based on a simulation-optimization framework that combines evaluation methods (simulation) and search methods (optimization) through the reachability analysis (or state space) of timed colored Petri net models to schedule flexible manufacturing systems (FMS). The anytime search algorithm is capable of finding a first suboptimal solution very quickly and continuously improves the solution quality over time. If given enough computation time, the algorithm eventually converges to an optimal solution. The proposed approach is aimed at obtaining optimal or near-optimal solutions to FMS scheduling problems in relatively short computation times with the objective of minimizing the makespan. Its effectiveness is highlighted with excellent results that outperform previous methods on benchmark examples with flexible material handling systems, machine, and routing configurations. The approach can also serve as a decision support tool to assist production schedulers that require rapid and almost real-time responses to time-critical production scheduling on the shop floor.

IEC 61499 as Enabler of Distributed and Intelligent Automation: State-of-the-Art Review

This review paper discusses the industrial and research activities around the IEC 61499 architecture for distributed automation systems. IEC 61499 has been developed to enable intelligent automation where the intelligence is genuinely decentralized and embedded into software components, which can be freely distributed across networked devices. With the recent emergence of professionally made software tools and dozens of hardware platforms, IEC 61499 is getting recognition in industry. This paper reviews research results related to the design of distributed automation systems with IEC 61499, the supporting tools and the aspects related to the execution of IEC 61499 on embedded devices. The promising application areas of IEC 61499 include flexible material handling systems, in particular airport baggage handling, flexible reconfigurable manufacturing automation, intelligent power distribution networks and SmartGrid, as well as the wide range of embedded networked systems.

Economic feasibility analysis of flexible material handling systems: A case study in the apparel industry

Abstract Flexible material handling systems (MHS) have been widely used to enhance productivity involved with product proliferation, and thus far, only fixed-track MHSs such as Eton systems in the apparel industry are commonly used. This paper explores the economic feasibility of a flexible MHS using free-ranging automated guided vehicles (AGV) with a local positioning system (LPS) for the apparel industry. A component-based and modified activity-based costing methodology is proposed to estimate the additional cost of adopting flexible MHSs, and then the internal rate of return (IIR) and payback periods are applied to evaluate the project economic performance. Results show that adopting flexible MHSs has a promising IIR which is larger than 30%.

A Mechatronics and Material Handling Systems Laboratory: Experiments and Case Studies

Industrial mechatronic systems integrate technologies from a variety of engineering disciplines to create solutions to challenging manufacturing problems. The material handling industry utilizes mechatronics to move, track, and manipulate items in factories and distribution centers. Material handling systems are a logical choice of study, due to their use of multiple mechatronic elements. This article describes mechatronic experiments and projects in a new course. Topical coverage includes sensors, actuators, PLCs, robotics, pneumatics, hydraulics, human factors, teamwork, leadership, and project management. A series of eight laboratory experiments have been created to introduce PLCs, robotics, electric circuits, and data acquisition fundamentals. In-depth case studies synthesize the technologies and interpersonal skills together to create a flexible material handling system. The most significant student outcome is the successful completion of a course project that required individuals to apply mechatronics concepts and technology in a multi-disciplinary team setting to solve industrial material handling tasks.

Interfaced multidirectional small-scaled modules for intralogistics operations

This article examines options of an innovative design of intralogistics systems by interfacing small-scaled modules. Current intralogistics systems are usually customized for unique solutions and small production lots. In most cases, these systems feature a central main control. To offer highly individual solutions, thus meeting the demand of shorter life cycles, there is a need for more flexible material handling systems. Hence, identical small-scaled modules with integrated intelligence present a promising approach. In the research presented here, a systematic process for the analysis of requirements and options is suggested as a prerequisite for the successful development of a small-scaled module, which in turn serves as standardized building blocks for flexible intralogistics systems. Most essential for a small-sized module is functional flexibility to allow configuring individual intralogistic solutions. Thus, these modules have to combine a variety of functions to provide not only a material flow function but also sorting and distributing functions, for instance. Furthermore, an easy extension of the system in any plane direction should be possible. Approaches based on existing technology, such as roller conveyors or belt conveyors, are considered along with new solutions concerning this ambitious challenge. A further development of swivel wheel technology and some new ideas like a swivel disk present promising solutions. With a flexible mechanical solution, we can design modules that can be developed into self-controlling elements.

Development of a flexible AGV for flexible manufacturing systems

PurposeThe paper aims to describe the design and development of an automated guided vehicle (AGV) that incorporates artificial intelligence techniques to increase its autonomy and flexibility. The aim is developing a flexible AGV that operates as a flexible material handling system (MHS) in dynamic industrial environments.Design/methodology/approachIntroduces the entire on‐board control system including hardware and software designs. The sensory system consists of a laser navigation system for localisation and a security laser scanner for sensing the environment. The software architecture is instantiated in a CPU that is connected to low level controllers through a CAN bus. Simplicity, flexibility, robustness and safety were concerned in the design process.FindingsThe developed prototype is able to operate in partially structured and dynamic environments, is easily configured using an approximated description of the workplace and is able to adapt when slight floor layout modifications. This development shows that current technology permits introducing intelligent vehicles in complex manufacturing systems.Practical implicationsThe prototype is successfully tested in a real factory, operating as a flexible MHS, transporting pallets between production and storage lines.Originality/valueA novel flexible AGV is designed and developed to operate as a flexible MHS in dynamic industrial environments. The system satisfies the safety and robustness requirements of industrial applications. The flexible MHS results especially suitable for manufacturing systems that suffers from cyclic and seasonal variations and for flexible manufacturing systems where the possibility of choosing alternative routes is a must.

Modeling Distributed Transportation Systems Composed of Flexible Automated Guided Vehicles in Flexible Manufacturing Systems

This paper proposes a methodology for modeling and controlling a flexible material handling system (MHS), composed of multiple automated guided vehicles (AGVs), suitable for Flexible Manufacturing Systems (FMSs). The AGVs incorporate artificial intelligent techniques to: i) facilitate the configuration and adaptation when there are layout modifications and ii) simplify the interaction between them using simple coordination models. In order to achieve higher flexibility, the MHS makes use of a decentralized navigation control, which increases autonomy and scalability, and a distributed Petri net for solving task allocation and traffic control problems. In order to facilitate the integration with the manufacturing processes, tasks dispatched by manufacturing cells are allocated by the MHS itself, taking into account pending transportation tasks and the system's performance. The whole system has been tested in a real factory and is currently in operational use.

Interfaced multidirectional small-scaled modules for intralogistic operation

Logistics Journal, Vol. 01, Iss. 01 - This article examines options of an innovative design of intralogistic systems by interfacing small-scaled modules. Current intralogistic systems are quite customized with unique solutions and small production lots. In most cases these systems feature a central main control. To offer highly individual solutions, thus meeting the demand of shorter life cycles, there is a need for more flexible material handling systems. Hence, identical small-scaled modules with integrated intelligence present a promising approach. Requirements and options are analyzed to develop a small-scaled module as a basis for a flexible intralogistic system. An essential requirement for a small sized module is functional flexibility to allow configuring individual intralogistic solutions. Thus, these modules have to combine a variety of functions to provide not only a material flow function but also sorting and distributing functions, for instance. Furthermore, an easy extension of the system in any plane direction should be possible. Approaches based on existing technology, such as roller conveyors or belt conveyors are considered along with new solutions concerning this ambitious challenge. A further development of swivel wheel technology and some new ideas like a swivel disk present promising solutions. With a flexible mechanical solution we can design modules that can be developed into self controlling elements.

Performance analysis of flexible material handling systems for the apparel industry

Flexible material handling systems (FMHS) have been widely used to enhance productivity involved with product proliferation, and thus far, only fixed-track material handling systems such as Eton systems in the apparel industry are commonly used. This paper explores the potential advantages of a FMHS using free-ranging automated-guided vehicles with a local positioning system for the apparel industry. First, the free-ranging FMHS (FRMHS) for the apparel industry has been designed. Then, through Monte Carlo simulation and analytical models, the performance in terms of manufacturing system effectiveness, workstation utilization, and the total transportation distance of the FRMHS are compared with those of the fixed-track system. Based on our analysis, the current proposed FRMHS can have significant advantages over the fixed-track system.

A random key-based genetic algorithm for AGV dispatching in FMS

Automated Guided Vehicle (AGV) is a mobile robot used highly in industrial applications to move materials from point to point. AGV helps to reduce cost of manufacturing and increases efficiency in a manufacturing system. In this paper, we focus on the dispatching of AGVs in a Flexible Manufacturing System (FMS). A FMS environment requires a flexible and adaptable material handling system. To overcome the complex system constraints of AGV dispatching in FMS, we model an AGV system by using network structure. We also propose an effective evolutionary approach for solving this problem as a network optimisation problem by Random Key-based Genetic Algorithm (RKGA). The objective is minimising the time required to complete all jobs (i.e. makespan). Numerical experiments for case study show the effectiveness of the proposed approach.

An agent-based dynamic routing strategy for automated material handling systems

An agent-based dynamic routing strategy for a generic automated material handling systems (AMHS) is developed. The strategy employs an agent-based paradigm by which the control points of a network of AMHS components are modelled as cooperating node agents. With the inherent features of route discovery, route selection and fault management of these node agents, their performance is investigated through simulation study. A generic AMHS network is modelled with a simulation tool that represents a highly flexible material handling system in a typical distribution centre where simulation studies are performed under normal and exception operating conditions. The performance of the proposed dynamic routing strategy is benchmarked with a number of static and dynamic routing strategies including the shortest distance, round robin, widest shortest route and shortest widest route strategies. The results of the simulation experiments are presented and their performance compared under a number of performance indices including the cycle time, utilization and ability to balance network loading.

Now That's Smart!

This article describes the features and development of intelligent machines and concentrates on their information processing infrastructure. IEC 61499 function blocks have been used in these experiments as the driving vehicle to achieve important features of the intelligent machines such as reconfigurability. Information infrastructure of intelligent machines is based on the IEC 61499 architecture . The function block architecture of IEC 61499 provides a new degree of flexibility in managing embedded control and information processing systems through the lifetime of industrial automation products. The requirements of flexible manufacturing and material handling systems, such as rapid integration and reconfiguration, as well as the growing information intensity of the production environments imply that manufacturing equipment is becoming more autonomous and intelligent.

Network model and effective evolutionary approach for AGV dispatching in manufacturing system

Automated guided vehicles (AGVs), are the state-of-the-art, and are often used to facilitate automatic storage and retrieval systems (AS/RS). In this paper, we focus on the dispatching of AGVs in a flexible manufacturing system (FMS). A FMS environment requires a flexible and adaptable material handling system. We model an AGV system by using network structure. This network model of an AGV dispatching has simplexes decision variables with considering most AGV problem’s constraints, for example capacity of AGVs, precedence constraints among the processes, deadlock control. Furthermore, these problems can be solved by using a lot of heuristic algorithms as network optimization problems. We are also proposed an effective evolutionary approach for solving a kind of AGV’s problems in which minimizing time required to complete all jobs (i.e. makespan) and minimizing the number of AGVs, simultaneously. For applying an evolutionary approach for this multicriteria case of AGV problem, priority-based encoding method and Interactive Adaptive-weight GA (i-awGA) were proposed. Numerical analyses for case study show the effectiveness of proposed approach.

Material Transport System by Cooperation of Conveyor-Loaded AGVs.

A new transport module for constructing an efficient and flexible material handling system are proposed in this paper : an AGV (Automated Guided Vehicle) module loaded a conveyor in which it is possible to hand over a transported object between two modules. The operation can solve a deadlock problem among AGVs in the process of material handling. Prototype modules are created and hand-over experiments are made to measure three kinds of hand-over costs of the modules. Control strategy is proposed and transport simulations are made for a model plant layout by using the cost values in the former experiments. The results show the effectiveness of the proposed module and control strategy in comparison with singleloop and unidirectional type transportation.

A Petri net model for the operational design and analysis of segmented flow topology (SFT) AGV systems

Designing flexible manufacturing systems in general, and flexible material handling system in particular, is a complex problem, typically approached through several stages. Here the focus is on the conceptual design stage during which valid approximation-based methods are needed. The segmented flow topology (SFT) AGV systems were developed to facilitate control of complex automated material handling systems. This paper introduces a decomposition method, directly derived from timed Petri nets (TPN) theories, to calculate the expected utilization of AGVs (as servers of SFT systems) and to derive simple operational decision rules leading to maximum system productivity at steady state, for a given deterministic routeing of discrete material through the manufacturing system.

Combinatorial optimization models for production scheduling in automated manufacturing systems

Production planning and scheduling models arising in automated manufacturing environments exhibit several features not encountered in models developed for traditional production systems. For instance, models of automated facilities typically include tooling constraints which reflect the possibility for a machine to use different tools in order to perform successive operations, within limits imposed by the size of the tool magazine. Also, these models often account for the existence of flexible material handling systems whose activities must be synchronized with the machining operations in order to optimize system utilization. In this paper, we describe a few interesting combinatorial optimization problems proposed in this framework, we point to their relationships with models investigated in seemingly remote areas, and we identify a number of challenging open problems.

An object‐oriented and flexible material handling system

Examines research work aimed at exploring and developing a new, object‐oriented system design and operation concept, and new system software and hardware design concepts which could be used to design and build an open, flexible and reconfigurable material handling system in a Computer Integrated Manufacturing [CIM] environment that could cope with changes imposed by the market on today’s manufacturing industries. Looks at the design of a reconfigurable and flexible conveyor system and outlines the benefits of using a 3‐D CIM reference model when developing CIM hardware and software control. Concludes that the proposed new conveyor system helps resolves the need for an assembly system which can achieve rapid and flexible responses to meet the challenge set by changing customer requirements.

Theoretical and experimental design of LIM in automated manufacturing systems

A theoretical and experimental study was conducted to assess the feasibility of employing linear induction motors (LIMs) for automated manufacturing systems as the drive for fully flexible material handling systems (MHSs). Two double-sided linear induction motors with 17 and 9 A starting currents were designed and built to operate with two AC adjustable-frequency motor drives. The motors were intended for use as carts to transfer parts between the three cells in a physical simulator consisting of a load/unload cell, a manufacturing cell, and a turning cell. Experience with a working model confirms that the use of LIMs shows substantial promise for achieving cost and productivity gains in a wide variety of manufacturing systems. The physical simulator is used to demonstrate the advantages of the LIM system over the existing MHS.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>