53,032 research outputs found
Modular and Hierarchical Discrete Control for Applications and Middleware Deployment in IoT and Smart Buildings
International audienceIn the Internet of Things (IoT) and Smart Homes and Buildings, sensors and actuators are controlled through a management software, that runs on a distributed network of heterogeneous processors. Such management systems have to be self-adaptive w.r.t. different aspects, at applications level (functionalities) as well as deployment level (software tasks, execution platform). Holding a well-mastered and safe behaviour of the overall system, in presence of these concurrent adaptations, is a complex control problem. We approach this problem by applying techniques from the area of Supervisory Control for Discrete Event Systems (DES), where the space of configurations at the different levels are modeled with automata. We use programming language support tools, Heptagon/BZR and ReaX, to build up a design environment for the considered application domain. This paper contributes with (i) generic behavioural models for both the applicative and deployment aspects of systems; (ii) applications of Discrete Controller Synthesis (DCS) to design controllers, especially modular and hierarchical control structures; (iii) an implemented case study
Supervisory control of fuzzy discrete event systems with applications to mobile robotics
Fuzzy Discrete Event Systems (FDES) were proposed in the literature for modeling and control of a class of event driven and asynchronous dynamical systems that are affected by deterministic uncertainties and vagueness on their representations. In contrast to classical crisp Discrete Event Systems (DES), which have been explored to a sufficient extent in the past, an in-depth study of FDES is yet to be performed, and their feasible real-time application areas need to be further identified. This research work intends to address the supervisory control problem of FDES broadly, while formulating new knowledge in the area. Moreover, it examines the possible applications of these developments in the behavior-based mobile robotics domain. An FDES-based supervisory control framework to facilitate the behavior-based control of a mobile robot is developed at first. The proposed approach is modular in nature and supports behavior integration without making state explosion. Then, this architecture is implemented in simulation as well as in real-time on a mobile robot moving in unstructured environments, and the feasibility of the approach is validated. A general decentralized supervisory control theory of FDES is then established for better information association and ambiguity management in large-scale and distributed systems, while providing less complexity of control computation. Furthermore, using the proposed architecture, simulation and real-time experiments of a tightly-coupled multi-robot object manipulation task are performed. The results are compared with centralized FDES-based and decentralized DES-based approaches. -- A decentralized modular supervisory control theory of FDES is then established for complex systems having a number of modules that are concurrently operating and also containing multiple interactions. -- Finally, a hierarchical supervisory control theory of FDES is established to resolve the control complexity of a large-scale compound system by modularizing the system vertically and assigning multi-level supervisor hierarchies. As a proof-of-concept example to the established theory, a mobile robot navigation problem is discussed. This research work will contribute to the literature by developing novel knowledge and related theories in the areas of decentralized, modular and hierarchical supervisory control of FDES. It also investigates the applicability of these contributions in the mobile robotics arena
Supervisory Control Synthesis of Discrete-Event Systems using Coordination Scheme
Supervisory control of discrete-event systems with a global safety
specification and with only local supervisors is a difficult problem. For
global specifications the equivalent conditions for local control synthesis to
equal global control synthesis may not be met. This paper formulates and solves
a control synthesis problem for a generator with a global specification and
with a combination of a coordinator and local controllers. Conditional
controllability is proven to be an equivalent condition for the existence of
such a coordinated controller. A procedure to compute the least restrictive
solution is also provided in this paper and conditions are stated under which
the result of our procedure coincides with the supremal controllable
sublanguage.Comment: 29 pages, 11 figure
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