Multi-agent framework based on smart sensors/actuators for machine tools control and monitoring

Throughout the history, the evolutions of the requirements for manufacturing equipments have depended on the changes in the customers' demands. Among the present trends in the requirements for new manufacturing equipments, there are more flexible and more reactive machines. In order to satisfy those requirements, this paper proposes a control and monitoring framework for machine tools based on smart sensor, on smart actuator and on agent concepts. The proposed control and monitoring framework achieves machine monitoring, process monitoring and adapting functions that are not usually provided by machine tool control systems. The proposed control and monitoring framework has been evaluated by the means of a simulated operative part of a machine tool. The communication between the agents is achieved thanks to an Ethernet network and CORBA protocol. The experiments (with and without cooperation between agents for accommodating) give encouraging results for implementing the proposed control framework to operational machines. Also, the cooperation between the agents of control and monitoring framework contributes to the improvement of reactivity by adapting cutting parameters to the machine and process states and to increase productivity

Reactive scheduling using a multi-agent model: the SCEP framework

Multi-agent systems have been successfully applied to the scheduling problem for some time. However, their use often leads to poorly unsatisfactory disappointing results. A new multi-agent model, called supervisor, customers, environment, producers (SCEP), is suggested in this paper. This model, developed for all types of planning activities, introduces a dialogue between two communities of agents leading to a high level of co-operation. Its two main interests are the following: first it provides a more efficient control of the consequences generated by the local decisions than usual systems to each agent, then the adopted architecture and behaviour permit an easy co-operation between the different SCEP models, which can represent different production functions such as manufacturing, supply management, maintenance or different workshops. As a consequence, the SCEP model can be adapted to a great variety of scheduling/planning problems. This model is applied to the basic scheduling problem of flexible manufacturing systems, andit permits a natural co-habitation between infinite capacity scheduling processes, performedby the manufacturing orders, and finite capacity scheduling processes, performed by the machines. It also provides a framework in order to react to the disturbances occurring at different levels of the workshop

Impact Evaluation of Interoperability Decision Variables on P2P Collaboration Performances

This article deals with the impact evaluation of interoperability decision variables on performance indicators of business processes. The case of partner companies is studied to show the interest of an Interoperability Service Utility (ISU) on business processes in a peer to peer (P2P) collaboration. Information described in the format and the ontology of a broadcasting entity is transformed by ISU into information with the format and the ontology of the receiving entity depending on the available resources of interoperation. These resources can be human operators with defined skill level or software modules of transformation in predefined languages. A design methodology of a global simulation model for estimating the impact of interoperability decision variables on performance indicators of business processes is proposed. Its implementation in an industrial case of collaboration shows its efficiency and its interest to motivate an investment in the technologies of enterprise interoperability

Design methodology for smart actuator services for machine tool and machining control and monitoring

This paper presents a methodology to design the services of smart actuators for machine tools. The smart actuators aim at replacing the traditional drives (spindles and feed-drives) and enable to add data processing abilities to implement monitoring and control tasks. Their data processing abilities are also exploited in order to create a new decision level at the machine level. The aim of this decision level is to react to disturbances that the monitoring tasks detect. The cooperation between the computational objects (the smart spindle, the smart feed-drives and the CNC unit) enables to carry out functions for accommodating or adapting to the disturbances. This leads to the extension of the notion of smart actuator with the notion of agent. In order to implement the services of the smart drives, a general design is presented describing the services as well as the behavior of the smart drive according to the object oriented approach. Requirements about the CNC unit are detailed. Eventually, an implementation of the smart drive services that involves a virtual lathe and a virtual turning operation is described. This description is part of the design methodology. Experimental results obtained thanks to the virtual machine are then presented

A distributed architecture to implement a prognostic function for complex systems

The proactivity in maintenance management is improved by the implementation of CBM (Condition-Based Maintenance) principles and of PHM (Prognostic and Health Management). These implementations use data about the health status of the systems. Among them, prognostic data make it possible to evaluate the future health of the systems. The Remaining Useful Lifetimes (RULs) of the components is frequently required to prognose systems. However, the availability of complex systems for productive tasks is often expressed in terms of RULs of functions and/or subsystems; those RULs have to bring information about the components. Indeed, the maintenance operators must know what components need maintenance actions in order to increase the RULs of the functions or subsystems, and consequently the availability of the complex systems for longer tasks or more productive tasks. This paper aims at defining a generic prognostic function of complex systems aiming at prognosing its functions and at enabling the isolation of components that needs maintenance actions. The proposed function requires knowledge about the system to be prognosed. The corresponding models are detailed. The proposed prognostic function contains graph traversal so its distribution is proposed to speed it up. It is carried out by generic agents

Towards a distributed framework for transportation planning: A food supply chain case study

Distribution and remoteness of production sites of enterprise networks, remoteness and multiplicity of distribution centers, the explosion of e-commerce has led to an increase in the number of requests for transportation around the world. This increase in the volume of transport of goods and cargo added to the growing number of passenger trips has led to an increase in transportation means(cars, planes, boats, etc.), with a consequent increase in the capacity of communication channels, which reached saturation (highways, airlines, shipping lanes), an expansion of storage areas (ports, airports, warehouses, etc.), and an increase in pollution impacting the environment sustainability. In this context, organization, management and transportation planning, become crucial, favored the emergence of many specialized companies (3PL) offering a pooling of transport and centralized management. The objective of this paper is to present a distributed architecture planning of transportation activities aimed at better utilize transport resources by grouping several orders of transport for each effective displacement

A flood lamination strategy based on transportation network with time delay

Over the last few years, the frequency and intensity of floods has become more marked due to the influence of climate change. The engendered problems are related to the safety of goods and persons. These considerations require predictive management that will limit water height downstream. In the literature, numerous works have described flow modeling and management. The work presented in this paper is interested in quantitative management by means of flood expansion areas placed along the river and for which we have size and location. The performance of the management system depends on the time and height of gate opening, which will influence wave mitigation. The proposed management method is based on use of a transportation network with time delay from which the volume of water to be stored is calculated

Shared resources scheduling using a multi-agent model: the DSCEP framework

Recently, multi-agent systems have been successfully applied to the scheduling problem. A new multi- agent framework, called DSCEP (distributed, supervisor, customers, environment, producers), is suggested in this paper. This framework is developed base on the subsistent SCEP models, especial for shared resources scheduling activities. It introduces a dialogue between three kinds of evolved SCEP models leading to a high level of co-operation. It provides a more efficient control of the consequences generated by the local decisions than usual systems for each SCEP model. It also provides different algorithms in order to handle the disturbances occurring at different ranks in manufacturing process. As a consequence, the DSCEP framework can be adapted for various scheduling/planning problems. This model is applied to the shared resources scheduling problem of complex systems, and provide a natural cohabitation between infinite capacity scheduling processes, performed by the multi-site manufacturing orders, and finite capacity scheduling processes, performed by local or remote machines

Contribution to a flood situation management: a supervisory control scheme to reduce disaster impact

Inundations due to river overflows are becoming more frequent; management of flood is thus an important task belonging to the set of preventive measures allowing the protection of people and goods downstream. The flood situation management method proposed in this paper was designed to reduce the flood impact at its early arising stage. The river is supposed to be equipped with reservoirs in which water excess are stored and then released only when the flood episode ends. The supervisory control scheme allows calculating the water volumes through the use of a network flow. The management objectives such as the maximum discharge level allowed in the river, the order of priority for the reservoir storage or release; the measured levels and discharge in the river and in the reservoirs; and the assessed parameters such as time delays, are combined to configure the network flow. Then, the optimal flow in the network is computed and supplies the reservoirs’ gate opening setpoints. Finally, the method was applied to a simulated case for which the time delay during the flood varied and remained efficient for flood attenuation compared to the case when the gates were always open, thanks to the network configuration

Towards a generic prognostic function of technical multi-component systems taking into account the uncertainties of the predictions of their components

This article presents the first elements of a generic function that assesses the capacity of technical multi-component systems to accomplish the assigned productive tasks from production planning. This assessment is based on the prognostics of their components. It must so be able to process inaccuracies and uncertainties of these prognostics. For its implementation the aimed function combines the Dempster-Shafer theory combined and Bayesian inferences. The paper presents the multi-component system modeling and the inferences for the different identified structures as well as a general algorithm. The final aim of the proposed generic function is to compute decision supports for cooperative maintenance and production management