Search results for "Distributed computing"
showing 10 items of 622 documents
High Level Planning of Reconfigurable Enterprises: a Game Theoretic Approach
2006
Reconfigurable Enterprises (REs) represent production networks made of different and geographically dispersed plants that, in case of unpredictable market changes, can be reconfigured in order to gather a specific production objective. However, REs effectiveness and efficiency depend on the extent to which global performance is obtained. Basically two approaches are available to reach coordination: centralised or decentralised planning tools. In this paper, the authors propose a novel cooperative game theoretical approach for distributed production planning at high level of a RE; the proposed approach has been benchmarked in front of both a distributed one, based on negotiation, and a centr…
Distributed intelligent control of exceptions in reconfigurable manufacturing systems
2003
In order to react to the continuous and unpredictable changes in product demand, in product variety, and in process technologies, reconfigurable manufacturing systems allow quick adjustment of production capacity and functionality by rearranging or changing their modular components. In this kind of system, operation management issues, such as exception handling policies, become more complex since correct reconfiguration strategies have to be selected. This paper explores the potential of the reconfigurability feature to be a basis for the development of new strategies to handle out-of-the-ordinary events in the production process; in particular, maintaining production flow when machine brea…
Charging Electric Vehicles Using Opportunistic Stopovers
2017
The diffusion of electric vehicles asks for efficient energy replenishment, which requires geographical and temporal coordination of shared charging resources. We introduce a novel charging methodology that exploits users’ opportunistic mobility. This paper focuses on vehicle stopovers detecting potential charg- ing opportunities. Our mobility-assisted methodology protects users privacy and permits a hybrid centralized/distributed ap- proach avoiding clashes with other potential users. A preliminary analysis on our charging system, obtained with mobility data from the field, shows that among the available charging stations, some are more relevant and have a key role in serving electric vehi…
A multi-agent system reinforcement learning based optimal power flow for islanded microgrids
2016
In this paper, a distributed intelligence algorithm is used to manage the optimal power flow problem in islanded microgrids. The methodology provides a suboptimal solution although the error is limited to a few percent as compared to a centralized approach. The solution algorithm is multi-agent based. According to the method, couples of agents communicate with each other only if the buses where they are located are electrically connected. The overall prizing system required for learning uses a feedback from an approximated model of the network. Based on the latter, a distributed reiforcement learning algorithm is implemented to minimize the joule losses while meeting operational constraints…
A CAN Fieldbus Based Architecture for Distributed Control Systems Implementation
2003
Abstract The application of distributed systems theory to the implementation of industrial control systems is one of the best options to develop simple, scalable and physically distributed control systems. Following this line, our group has proposed a new architecture based on Rule Nets (RN) as an HLP over CAN fieldbus for the implementation of Distributed Systems. This architecture has been applied to several control applications, obtaining excellent results. The most outstanding feature of the architecture was its simplicity in the control systems design, without any efficiency loss. New capabilities have been added to improve its features and develop new analysis tools, in order to incre…
Fifth Generation Networking Principles for a Service Driven Future Internet Architecture
2010
Published version of an article published in Wireless Personal Communications, vol. 57:393-411. Also available from the publisher at: http://dx.doi.org/10.1007/s11277-010-0076-7 The vision of all-IP networks where IP forms the simple common layer understandable across the whole network has undeniable advantages. However, such simplicity comes as a major hurdle to flexibility and functionality to the architecture. This is evident from the increasingly numerous and complex engineering solutions and optimizations required to accommodate essential qualities like mobility, security, realtime communication support etc or to mitigate the shortcomings inherent in the 'traditional Internet' architec…
A New HLA-Based Distributed Control Architecture for Agricultural Teams of Robots in Hybrid Applications with Real and Simulated Devices or Environme…
2011
The control architecture is one of the most important part of agricultural robotics and other robotic systems. Furthermore its importance increases when the system involves a group of heterogeneous robots that should cooperate to achieve a global goal. A new control architecture is introduced in this paper for groups of robots in charge of doing maintenance tasks in agricultural environments. Some important features such as scalability, code reuse, hardware abstraction and data distribution have been considered in the design of the new architecture. Furthermore, coordination and cooperation among the different elements in the system is allowed in the proposed control system. By integrating …
CVS: Using VLANs to Counteract the Effect of Topology Changes in Quasi-Static Mesh Access Networks
2006
Mesh networks are candidate to play the role of switched Ethernet LANs over extended areas and with a sensibly higher flexibility. Actually, mesh networks can exploit both Ethernet and wireless technologies, e.g. Wi-Fi and/or free-space optical links, to provide a high degree of redundancy in an access network, and to provide users with powerful means to connect with each other. By using such technologies, the mesh topology remains stable for hours, so that the mesh topology can be considered quasi-static. However, large meshes require a heavy overhead in the network control plane as for the management of end-to-end paths, which can change due to mobility of users and due to occasional fail…
LSOM: A Link State protocol Over MAC addresses for metropolitan backbones using Optical Ethernet switches
2003
This paper presents a new protocol named "Link State Over MAC" (LSOM) for Optical Ethernet switches to allow the use of active loop topologies, like meshes, in Metropolitan Area Networks (MAN) or even Wide Area Networks (WAN) backbone. In this respect, LSOM is an alternative to a ring topology as proposed in draft IEEE 802.17 Resilient Packet Ring (RPR) or a tree topology using IEEE802. 1D Rapid Spanning Tree Protocol (RSTP). LSOM provides higher scalability and is able to achieve better bandwidth utilization and lower latency than RSTP and RPR. Simulation results for 4-node and 9-node topologies show that LSOM can improve throughput over RPR by a factor of up to 1.7. Furthermore, full free…
A study of mobility and reachability in ad hoc networks using stochastic activity networks
2006
The integration of ad-hoc networks into real environments is now becoming more and more common and supervision and control systems are no exception. The efficiency of the communication in these networks as well as various other factors, are governed by the working area, the number of nodes, mobility, transmission power, etc. In this paper, the mobility and reachability of mobile nodes appearing spontaneously in a large installation such as can be found in a water purification system are studied. These nodes form an ad-hoc network and communicate between each other in order to finally reach a fixed node which can offer them information from the rest of the system in real time or act as a gat…