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Abstract: Mobile robots are physical agents that move and interact continuously while embedded in a dynamic environment. Communications can be one of the most difficult parts of building robot architecture because of the increasing complexity of sensor and actuator hardware, and the interaction between intelligent features and real-time constraints. Currently, hybrid architectures offer the most widespread solutions for controlling intelligent mobile robots. This paper deals with the communications framework necessary to design and implement these architectures. The main goal of this work 1 [1] This work has been partially funded with Spanish government project DPI2005-09327-C02-01/02. is to design a modular and portable architecture that allows the development of robot control systems. A multi-level and distributed architecture based on the reactive/deliberative paradigm is presented. Its main components are mobile software agents that interact through a distributed blackboard communications framework. These agents can be run on onboard processors, as well as on fixed workstations depending on their real-time restrictions. The presented control architecture has been tested in a real mobile robot and results demonstrate the effectiveness of distributing software agents to guarantee hard real-time execution. [Copyright &y& Elsevier]

Abstract: This paper is aimed at summarizing the current state-of-the-art in the development of agent-based solutions in three areas connected with industrial production, namely in holonic control, production management and virtual enterprises. This paper shows how the results in these three sub-areas are converging and discusses how the agent-oriented technologies could provide a good background for developing a unifying approach. Two industrial applications of agent-based systems are described in some detail. The paper also presents both the positive and negative aspects of applying agent-based technologies in industry. [Copyright &y& Elsevier]

Abstract: Remote access to industrial plants has proven a serious competitive advantage. However, building efficient and safe systems is not a trivial task. It requires the integration of diverse complex technologies at different levels. Even though these technologies are not extended in industrial environments, in the authors’ opinion, they are mature enough to be used in industrial applications. This paper proposes a systematic object-oriented methodology to build applications with remote access to industrial plants through Internet-like networks. The methodology guides the designer regarding key issues, such as security, concurrency, distribution of alarms and monitoring information to different kinds of users. A generic architecture for building remote access applications is proposed. The central components of the architecture are the so-called Application Servers (ASs). Each of them offers services to remote users and directly accesses to specific parts of the physical plants. The proposed methodology suggests the basic structure for these ASs, based on several reusable components, as well as mechanisms to determine the number of ASs required. The instantiation of the generic architecture as well as the stages of the methodology are validated through an industrial case study: a laboratory manufacturing cell. [Copyright &y& Elsevier]

Abstract: Emergent power and automation technologies provide new opportunities and challenges for multi-disciplinary ship design. In particular, these dynamically interdependent systems require dependable, fault-tolerant control to efficiently manage limited resources and to respond to casualty conditions. Design of an electric warship engineering and damage control system of systems is considered as an illustrative example. In this context, cost and survivability can be considered as either deterministic or probabilistic independent variables. In the stochastic formulation, design robustness is defined with respect to uncertainties including technology readiness, mission creep, and operational environment. [Copyright &y& Elsevier]

Increasingly, there is a move towards in-built intelligence for sensors and actuators in order to integrate these “smart” peripheral elements as part of a distributed control system. The utilisation of local intelligence to provide local fault detection and fault tolerance allows the incorporation of new variables into the structure of the system. The proposed approach is to integrate this information into the structure of the control law. Thus, the main goal is to integrate a decision-making procedure between peripheral elements and different control strategies. The reconfiguration of the control law, based upon local health measures, is decided by this procedure. [Copyright &y& Elsevier]

Mobile robotics development provides an excellent opportunity to experiment with various architectural solutions for distributed real-time systems. This is because of the increasing complexity of sensor and actuator hardware, and the interaction between intelligent features and real-time constraints. Currently, hybrid control structures seem to be the most widespread method of control. This paper describes a communications scenario resulting from hybrid structures. The YAIR robot and its communication infrastructure is described by addressing the control problems found and the solutions adopted. This paper presents a case study of implementing a hybrid communications system using the CAN bus. The worst-case message delay analysis for this bus is also presented, as well as the structure of identifiers defining its semantic possibilities. The deliberative part of the communication system is a developed object bus on TCP/IP protocol networks. The programming interface at this level takes the form of a distributed blackboard with extended properties such as a bind-notification mechanism and a temporal register recording the temporal firewall of information supplied. The overlap between both communication systems is a gateway service performing bi-directional mirroring over a set of CAN identifiers. Finally, a system test is presented. The test emphasises the intra-level gateway for validating performance and time expressiveness. [Copyright &y& Elsevier]