Fault-tolerant control of discrete-event systems with lower-bound specifications

2015-06-01
Moor, Thomas
Schmidt, Klaus Verner
Fault-tolerant control addresses the control of dynamical systems such that they remain functional after the occurrence of a fault. To allow the controller to compensate for a fault, the system must exhibit certain redundancies. Alternatively, one may relax performance requirements for the closedloop behaviour after the occurrence of a fault. To achieve fault tolerance for a hierarchical control architecture, a combination of both options appears to be advisable: on each individual level of the hierarchy, the controller may compensate the fault as far as possible, and then pass on responsibility to the next upper level. This approach, when further elaborated for discrete-event systems represented by formal languages, turns out to impose a hard lower-bound inclusion specification on the closed-loop behaviour. The present paper discusses the corresponding synthesis problem and presents a solution.

Suggestions

Abstraction-based supervisory control for recon-gurable manufacturing systems ?
Khalid, Harith M.; Kirik, Mustafa Sancay; Schmidt, Klaus Verner (2013-10-21)
Reconfiguration control for discrete event systems (DES) is concerned with the realization of different system configurations by modification of the supervisory control loop. In this paper, we study the reconfiguration supervisor design for reconfigurable manufacturing systems (RMS) that comprise multiple components. We construct a modular supervisor for each configuration and system component in order to realize each active configuration and to quickly change between configurations. Different from the exis...
Hierarchical multitasking control of discrete event systems: Computation of projections and maximal permissiveness
Schmidt, Klaus Verner; Cury, José E.r. (null; 2010-12-01)
This paper extends previous results on the hierarchical and decentralized control of multitasking discrete event systems (MTDES). Colored observers, a generalization of the observer property, together with local control consistency, allow to derive sufficient conditions for synthesizing modular and hierarchical control that are both strongly nonblocking (SNB) and maximally permissive. A polynomial procedure to verify if a projection fulfills the above properties is proposed and in the case they fail for a g...
Adaptive output feedback control with reduced sensitivity to sensor noise
Kutay, Ali Türker; Hovakimyan, N (2003-01-01)
We address adaptive output feedback control of uncertain nonlinear systems with noisy output measurements, in which both the dynamics and the dimension of the regulated system may be unknown, and only the relative degree of the regulated output is assumed to be known. Given a smooth reference trajectory, the problem is to design a controller that forces the system measurement to track it with bounded errors. A recently developed method proposes the use of a linear error observer that estimates the tracking ...
Discrete event supervisor design and application for manufacturing systems with arbitrary faults and repairs
Acar, Ayşe Nur; Schmidt, Klaus Verner (2015-10-07)
This paper considers the supervisory control of discrete event systems (DES) that are subject to faults. To this end, an existing method for the fault-recovery and repair of single faults is extended to the case of different faults. As a result, we obtain a supervisor that follows the specified nominal system behavior in the fault-free case, converges to a desired degraded behavior for each fault type and recovers the nominal behavior after repair. The results of the paper are illustrated by a small example.
Redundant tasks in multitasking control of discrete event systems
Schmidt, Klaus Verner (null; 2009-12-01)
This paper addresses the control of multitasking DES that allow for dealing with liveness properties in the case where multiple classes of tasks have to be independently completed by the system. Colored marking generators (CMG) have been previously introduced as a model to consider multitasking control. The computational cost of the supervisor synthesis for multitasking DES grows with the number of classes of tasks. In this paper we investigate conditions under which removing tasks of the DES model does not...
Citation Formats
T. Moor and K. V. Schmidt, “Fault-tolerant control of discrete-event systems with lower-bound specifications,” 2015, vol. 28, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/35767.