Supervisory Control of AGV’s for Flexible Manufacturing Cells

Manufacturing systems are undergoing a noticeable evolution due to an intense technological progress in industrial robotics. Serial production has evolved into the concept of Flexible Manufacturing Systems (FMS), which encapsulate processes in automatic equipment that are capable of executing different operations, that before be performed in several stages and diverse equipments. Automated Guided Vehicle (AGV) systems have been frequently used as material handling equipment in manufacturing systems since the last two decades. Particularly, AGV´s with trailers are, and will continue to be, the backbone of the material transport industry. The use of these systems has taken the attention of experts and researchers. They are numerous studies concerning AGV with trailers systems in literature; few of them deal with the adaptation of these systems into FMS. In this paper, a study of the trajectories and a simulation model of a hypothetical system, which included a FMS environment, were developed. In addition, a potential field's method was explored in order to improve the ability of detecting obstacles in AGV´s with trailers moving through stations.

Iranian Journal of Science and Technology Transaction B Engineering, 2012

Automated Guided Vehicles (AGV) have been a conventional solution and choice made by many manufacturing enterprises as means for Flexible Material Handling Systems (FMHS). In recent years, a considerable number of these vehicles have been installed on shop floors worldwide, effectively proving the usefulness of material handling systems. However, the increasing complexity of demand as well as a need for "make to order" rather than "make to stock" policy implies usage of more intelligent material handling solutions. This paper discusses the usage of an intelligent AGV as means for FMHS which should have Intelligent Material Handling System (IMHS) as the final outcome. This paper presents the experimental results of hybrid robotic control architecture. To evaluate the performance of the architecture, a mobile robot built on LEGO ® Mindstorms NXT technology was used. Some of the architectural modules are based on the implementation of Artificial Neural Networks in order to achieve the needed robustness in exploitation. Then, through simulation using AnyLogic ® 6 software, the performance in terms of manufacturing system effectiveness and workstation utilization is analyzed. Based on the experimental results, the proposed IMHS can have significant advantages over conventional material handling systems.

IJST, 2012

Automated Guided Vehicles (AGV) have been a conventional solution and choice made by many manufacturing enterprises as means for Flexible Material Handling Systems (FMHS). In recent years, a considerable number of these vehicles have been installed on shop floors worldwide, effectively proving the usefulness of material handling systems. However, the increasing complexity of demand as well as a need for "make to order" rather than "make to stock" policy implies usage of more intelligent material handling solutions. This paper discusses the usage of an intelligent AGV as means for FMHS which should have Intelligent Material Handling System (IMHS) as the final outcome. This paper presents the experimental results of hybrid robotic control architecture. To evaluate the performance of the architecture, a mobile robot built on LEGO ® Mindstorms NXT technology was used. Some of the architectural modules are based on the implementation of Artificial Neural Networks in order to achieve the needed robustness in exploitation. Then, through simulation using AnyLogic ® 6 software, the performance in terms of manufacturing system effectiveness and workstation utilization is analyzed. Based on the experimental results, the proposed IMHS can have significant advantages over conventional material handling systems.

In this paper, we study the design and control of automated guided vehicle (AGV) systems, with the focus on the quayside container transport in an automated container terminal. We first set up an event-driven model for an AGV system in the zone control framework. Then a number of layouts of the road network (guide-path) are carefully designed for the workspace of the AGVs in a container terminal. Based on our zone control model, a traffic control strategy is proposed, which decouples the motion conflict resolution among the AGVs from the routing problem. A routing algorithm is also constructed with the goal of minimizing the vehicle travel distances and the transportation time. The efficiency of the integrated design and control is demonstrated by computer simulations in terms of a set of defined measures of system performance. Lastly, we point out several possibilities towards improving our current results.

The International Journal of Advanced Manufacturing Technology, 2017

Decentralized coordination and route planning face the challenges such as scalability, dynamic changes (disturbances) in the environment, continuous planning, and coordination issues (i.e., deadlock and livelock situations). Self-organized delegate multi-agent systems (D-MASs) have proven to be effective decentralized coordination mechanisms for coordination and control (C&C) applications. However, the use of such coordination mechanisms becomes more challenging, compared to the previous studies, in which the coordinated entities are one-directional automated guided vehicles (AGVs), with restricted movement, situated in a highly dynamic production environment. To address these challenges, there were several problematic situations identified dealing with issues such as the originally proposed functionalities of D-MASs, restricted movement, priority parameter settings, and simulated failures of AGVs. Solutions (coordination rules) to these situations were proposed, also described examples were provided and, finally, the approach was verified by simulation in the 3D environment, involving five AGV agents (AGVAs). Simple indicators of such intralogistics system were proposed to outline the system performance. Simulations were performed with as well as without simulated failure states. Simulation results show that the proof-of-concept was reached, and that by the combination of the proposed coordination rules and D-MAS, one-directional AGVAs were able to generate a short-term forecast for the near future and thus anticipate and avoid coordination issues as well as to cope with simulated failures.

The just-in-time philosophy has been widely applied in production, especially when supplying parts to assembly lines. To supply parts, and to ensure the parts are fed to assembly units in time, automated transportation systems, such as the AGV system are used because they are widely considered to be an efficient transportation method. Most AGV systems use heuristic dispatching rules to control vehicle movement. However, there is no particular dispatching rule suitable for all cases. In this research we propose heuristic dispatching rules based on transportation time balanced for specific layout of an automotive assembly line environment with multiple vehicles. Simulation modeling of automotive industry assembly lines is developed in ARENA simulation environment. The facility layouts considered in the present study is flow-shop environment. In this paper, a simulation model of a hypothetical system which has a job shop environment and which is based on JIT philosophy was developed. I...

Computer Integrated Manufacturing Systems, 1997

To effectively manage the material handling in Flexible Manufacturing Systems (FMS), where a large amount of data is required in the dynamic decision-making, integrated control is needed to consider the overall production schedule. The focus of this research is on the development of an integrated Automated Guided Vehicle System (AGVS) control model that includes essential features like dynamic vehicle path determination and conflict-free routing. An object-oriented implementation of the AGVS model is proposed that forms the basis of systems integration with a production planning module such as MRI? Static and dynamic informational and functional models of the AGVS are developed. The system incorporates: (i) conflict-free shortest path routing procedures, and (ii) vehicle assignment rules or scheduling strategies. A prototype version of each of these has been developed for demonstrative purposes. This object-oriented. modelling methodology provides the capability of rapid development and change. The approach has been demonstrated for a real manufactured product through simulation studies which confirm the superior performance of anticipatory AGVS control rules, even in a production orderdriven environment. 0 1997 Elsevier Science Ltd. Production order-driven AGV control model: A4 Shah et al. 47 Davis, W J 'Real-time optimization in the automated research facility', in J White and I W Pence (eds), Progress in Material Handling I,ogistics ( 1989) 48 Production order-dtiven AGV control model: M Shah et al. 7 Jones, A and Mclean, C 'A proposed hierarchical control model for automated manufacturing systems', Journal of Manufacturing Systems, Vol 5 No 1 (1986) pp 15-25 8 Tirpak, T M, Deligiannis, S J and Davis, W J 'Real-time scheduling in flexible manufacturing', Manufacturing Review, Vol5 No 3 (1992) pp 193-212 9 Simpson, J A, Hocken, R J and Albus, J S 'The automated manufacturing research facility of the national bureau of stan-

2011

This paper presents the architecture of autonomous material handling vehicles. The centralized coordination of multiple vehicles and three-layer architecture (deliberative, sequencing, and reflexive layers) are adopted. The navigation controls, including configuration control, visual servoing, path tracking, and collision avoidance, are developed. The finite state machine (FSM) that supervises the control modules to complete the material handling task is elucidated. The experimental results of a forklift transporting a pallet from an initial to a desired goal configuration are demonstrated.

An Automated Guided Vehicle (AGV) is a set of cooperative driverless vehicle, used on manufacturing floor and coordinated by a centralized or distributed computer-based control system. AGVs-based Material Handling Systems (MHSs) are widely used in several Flexible Manufacturing Systems (FMS) installations. One of the challenge in MHSs is how flexible and adequate is the utilization. The key issue of the flexibility of MHSs is the routing system. It should be designed in a way that can be easily modified to become adaptable to new or replaced machines. The main focus of this study is to make an AGV with the convenient materials, simple and applicable routing system and more importantly reducing the cost and increasing the flexibility. For this propose an AGV is basically modeled and designed with CATIA software and developed with special specifications. Keywords: Fuzzy logic, steering system, programmable logic control (PLC), flexible manufacturing system (FMS), material handling system (MHS)

Automatic Guided Vehicle (AGV) has been widely applied in various applications in automatic logistics system. These systems provide the flexibility and effectiveness of logistics transportation systems. One of the applications of AGV is the use of AGV in container terminals. In this paper, is presented study of the design of multi automatic guided vehicle to be implemented in container terminal system. In this study is focused on the design of mechanism of vehicle and the supervisory control to give the task coordination to multi-agent AGV systems have so that it has the high effectiveness. Firstly, in this paper is reviewed some kind of mechanism AGV. Advantages and disadvantages of each mechanism will be compared. Secondly, several methods of control of the AGV and coordination method for multi-agent systems will be reviewed. Thirdly, it will be presented the models of container terminal logistics system and the possibility of applying multi-agent AGV system. Lastly, the results o...