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Wireless sensor networks (WSNs) have recently extended application areas to numerous sectors such as industrial automation, military applications, transportation systems, building management, and environment surveillance. In particular, WSNs provide flexible, reliable, cost-effective solutions to monitor the real-time status of automated manufacturing facilities. A facility-specific WSN for reliable monitoring and efficient management of industrial facilities is called the facility sensor network (FSN). In general, industrial facilities run various electromagnetic devices causing electromagnetic interference (EMI), which disturbs wireless data communication. To obtain accurate and reliable data in such environments, the FSN needs to deal with the EMI by proper deployment of sensor nodes and their validation and fusion. This paper proposes a data processing protocol, called Interfered Sensor Data Processing Protocol (ISDPP) to handle the EMI affecting wireless communication. ISDPP is developed with a data fusion algorithm and an exponentially weighted moving average/fuzzy logic-based error detection method to obtain reliable information from the FSN. To evaluate the performance, experiments in various settings are performed in a test-bed manufacturing facility. The experimental results indicate the interfered data, and outliers can be filtered out even if unexpected interferences occur in the facility. The FSN with the ISDPP can provide efficient real-time monitoring solutions for various industrial applications. [ABSTRACT FROM AUTHOR]

This paper presents a time synchronization method to achieve high-precision distributed clocks in real-time Ethernet-based computer numerical control (CNC) systems with a ring topology. The proposed synchronization method adopts the frequency compensation and peer-to-peer transparent clock mechanisms, and utilizes a real-time synchronization protocol to embed the time synchronization into the real-time communication cycle. An optimal proportional-integral controller is then designed for the frequency compensation mechanism based on the model and analysis of the time synchronization process. Besides, the hardware implementation of this time synchronization strategy is described. Finally, a real time Ethernet-based CNC system with a ring topology is built, and experiments are conducted to verify the performance of the presented synchronization scheme. The experimental results demonstrate that the proposed time synchronization method achieves high synchronization precision. The peak-to-peak jitters are measured to be only 42.42 and 95.5 ns for one and four hops, respectively. [ABSTRACT FROM AUTHOR]

To compete in the current interconnected world, manufacturing companies shall explore varied forms of collaboration in order to maintain the creation of value-added goods and services. The extended enterprise is one of the proposed approaches to improve collaboration among individual enterprises. Such paradigm is based on the fact that core capabilities must be shared by participating firms so they can exploit jointly the best resources and practices each firm provides. Nevertheless, data exchange is not carried fluently due to poor coordination among the firms. We claim that business processes help define the dynamics of data exchange associated to core capabilities being the basis to establish a communication protocol among software agents. The resultant multi-agent system coordinates data flow among organizations. Agents are given autonomy and intelligence to make decisions regarding the data that is either needed or offered, as defined by the corresponding business process. We present a case study to validate our proposal. [ABSTRACT FROM AUTHOR]

This paper deals with a multi-agent architecture of agile manufacturing system and a hybrid strategy for shop floor scheduling. Firstly, it proposes a distributed multi-agent-based manufacturing structure, which has characteristics of self-determination and distribution grounded on multi-agent as well as control and harmony grounded on hierarchical structure or dynamic logical unit. Then, based on the fuzzy theory and method, it studies a hybrid shop floor scheduling strategy that combines fuzzy programming with fuzzy contract net protocol. The hybrid strategy has both virtues of precision of static programming and flexibility of contract net protocol. [ABSTRACT FROM AUTHOR]

The growth in the development of distributed manufacturing systems necessitates increases in efficient technologies in order to facilitate management of the networked resources. Systems such as manufacturing automation protocol (MAP) already exist which were specifically designed for managing networked manufacturing devices. However, MAP has been criticised for being over-complex and expensive for small–medium sized enterprises. The simple network management protocol (SNMP) was designed for managing TCP/IP networks, and we argue that it can also be used for managing networked manufacturing devices. However, SNMP, like MAP, is based upon a client/server architecture, and both have scalability issues. We also investigate the use of mobile agent (MA) technology as a means of managing a domain of manufacturing devices. An integrated network management framework based on MA technology is developed to direct the research into the investigation of aligning network management paradigm to the strategic management decision. [ABSTRACT FROM AUTHOR]