Fault-tolerant pitch-rate control augmentation system design for asymmetric elevator failures in a combat plane

summary:Combat planes are designed in a structured relaxed static stability to meet maneuver requirements. These planes are unstable in the longitudinal axis and require continuous active control systems with elevator control. Therefore, failures in the elevator can have vital consequences for flight safety. In this work, the performance of classical control approach against asymmetric elevator failures is investigated and it is shown that this approach is insufficient in the case of such a failure. Then, a fault-tolerant control system is proposed to cope with these failures and it is shown that this controller can successfully deal with such failures. The F-16 aircraft is taken as an example case. A detailed nonlinear dynamic model of this aircraft is presented first. In the F-16 aircraft, the elevator surfaces are in two parts, right and left, and can move independently. Therefore, to obtain a more realistic and difficult failure scenario, it is assumed that the elevator is asymmetrically defective. Two types of failures commonly observed on the elevator surfaces (freezing and floating) are aerodynamically modeled and it is shown that the pitch-rate control augmentation systems in the conventional structure cannot cope with these elevator failures. In order to overcome this problem, a fault-tolerant control system is proposed. It is shown that this controller can successfully cope with the aforementioned failures without any degradation in flight safety

Extension principle and controller design for systems with distributed time-delay

summary:Extension principle is defined for systems with distributed time-delay and the necessary and sufficient conditions for one system being an extension of the other are presented. Preservation of stability properties between two systems, one of which is an extension of the other is also discussed and it is shown that when the expanded system is an extension of the original system, (i) the original system is bounded-input bounded-output stable if and only if the expanded system is bounded-input bounded-output stable and (ii) the original system is exponentially stable if the expanded system is exponentially stable. Controller design using the extension principle is then considered. It is shown that, if the expanded system is an extension of the original system, then any controller designed for the expanded system can be contracted for implementation on the original system. Furthermore, if the controller designed for the expanded system stabilizes the expanded system and satisfies certain performance requirements, then the contracted controller stabilizes the original system and satisfies corresponding performance requirements for the original system. Finally, overlapping decompositions and controller design using overlapping decompositions are demonstrated. A highway traffic congestion control problem is then considered to demonstrate a possible application of the presented controller design approach

An intelligent control approach to decentralized routing and flow control in highways

1997 IEEE International Symposium on Intelligent Control -- JUL 16-18, 1997 -- ISTANBUL, TURKEY WOS: A1997BJ81K00046 A decentralized intelligent controller for routing in multi-destination transportation networks is presented. The controller is based on a dynamic congestion measure which was recently derived from the solution of an optimal control problem. The proposed controller is decentralized in the sense that all the on-line computations are done locally at the nodes with minimum information transfer from the adjacent downstream nodes. Furthermore, no synchronization among the nodes is needed. The controller avoids congestion on the links by not allowing any traffic higher than the capacity of a given link. Thus the controller also acts as a flow controller. An example is also presented to illustrate the design methodology and to assess the controller's performance in a typical case. IEEE Control Syst So

A decentralized routing controller for congested highways

34th IEEE Conference on Decision and Control -- DEC 13-15, 1995 -- NEW ORLEANS, LA WOS: A1995BE66Q00794 … IEEE, Control Syst So

A decentralized control approach for transportation networks

8th IFAC/IFORS/IMACS/IFIP Symposium on Large Scale Systems - Theory and Applications 1998 (LSS 98) -- JUL 15-17, 1998 -- RION, GREECE WOS: 000083105500054 A decentralized control approach for transportation networks to prevent traffic congestion is presented. The approach was developed by considering flow control and routing control together. The control algorithm is based on a previously proposed congestion measure. In this paper, in order to illustrate the performance of the proposed controller, some simulation results are presented. Copyright (C) 1998 IFAC. Int Federat Automat Control, Tech Comm Large Scale Syst, Tech Comm Mfg Modeling Management & Control, Tech Comm Adv Mfg Technol, Tech Comm Man Machine Syst, Int Federat Operat Res Soc, Int Assoc Math & Comp Simulat, Int Federat Informat Proc, Greek Minist Dev, Gen Secretariat Res & Dev, Tech Chamber Greece, European Commiss, DG III, Univ Patras, Res Comm, Greek Minist Culture, Greek Minist Edu

Supervisory controller design for timed-place Petri nets

summary:Supervisory controller design to avoid deadlock in discrete-event systems modeled by timed-place Petri nets (TPPNs) is considered. The recently introduced approach of place-stretching is utilized for this purpose. In this approach, given an original TPPN (OPN), a new TPPN, called the place-stretched Petri net (PSPN), is obtained. The PSPN has the property that its marking vector is sufficient to represent its state. By using this property, a supervisory controller design approach for TPPNs to avoid deadlock is proposed in the present work. An algorithm to determine the set of all the states of the PSPN which lead to deadlock is presented. Using this set, a controller for the PSPN is defined. Using this controller, a controller for the OPN is then obtained. Assuming that the given Petri net is bounded, the proposed approach always finds a controller in finite time whenever there exists one. Furthermore, this controller, when exists, is maximally permissive

Decentralized structural controller design for large-scale discrete-event systems modelled by Petri nets

summary:A decentralized structural controller design approach for discrete-event systems modelled by Petri nets is presented. The approach makes use of overlapping decompositions. The given Petri net model is first overlappingly decomposed into a number of Petri subnets and is expanded to obtain disjoint Petri subnets. A structural controller is then designed for each Petri subnet to avoid deadlock. The obtained controllers are finally applied to the original Petri net. The proposed approach significantly reduces the computational burden to design the controller. Furthermore, the controller obtained is decentralized and, hence, is easier to implement