Many physical processes are described by differential-algebraic equations. The numerical simulation of such models usually combines an ODE numerical method together with an optimisation algorithm. In this paper we giv...
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With the sustained increase of air traffic leading to airspace saturation, new flight maneuvering capabilities are expected for commercial aircraft. Among these, relative guidance of airliners, a set of maneuvers that...
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ISBN:
(纸本)3540279385
With the sustained increase of air traffic leading to airspace saturation, new flight maneuvering capabilities are expected for commercial aircraft. Among these, relative guidance of airliners, a set of maneuvers that doesn't require air traffic control support, appears as a. promising solution to ease air traffic controllers' workload. Relative guidance means path convergence of following aircraft to delayed position of leading ones and station keeping The convergence and station keeping phases are realized onboard the aircraft using their sensing and communication facilities, in a decentralized way, under aircraft maneuverability constraints due to safety and passenger comfort issues. Tu this paper, after introducing the relative positioning dynamics of two aircraft,, their flatness property is shown and a flat control law is proposed. Reference trajectories are designed in two steps: if the separation between aircraft is too small, the follower's trajectory is stretched by imposing a sinusoidal movement;at constant speed;in the opposite case, the follower copies the leader's delayed trajectory. The feedback tracking is done by feedback linearization. Simulation results, using a real scenario involving wide body aircraft in a merging situation are displayed and discussed.
This paper addresses the fuzzy control problem for a class of discrete-time nonlinear systems with disturbance. In case not all the system states are available, state observer is proposed. Consequently, the whole syst...
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An output-feedback Active Queue Management (AQM) scheme is presented for asymptotically stabilizing a class of TCP networks at a desired operating point. In order to design an AQM controller with only an output (queue...
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ISBN:
(纸本)9780780388345
An output-feedback Active Queue Management (AQM) scheme is presented for asymptotically stabilizing a class of TCP networks at a desired operating point. In order to design an AQM controller with only an output (queue size) measurement, a novel TCP window size observer is first proposed. Then, the control law is developed by applying an observer-based backstepping design technique. The amplitude limits on the control input is addressed, namely, packet dropping or marking ratio must fall between 0 and 1. An estimation of the domain of attractiveness is given with a Lyapunov level set [3].
Lightweight structures typically have low inherent structural damping. Effective vibration suppression is required, for example, in certain applications involving precision positioning. The present approach is based o...
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ISBN:
(纸本)3540279385
Lightweight structures typically have low inherent structural damping. Effective vibration suppression is required, for example, in certain applications involving precision positioning. The present approach is based on friction damping in semi-active joints which allow relative sliding between the connected parts. The energy dissipation due to interfacial slip in the friction joints can be controlled by varying the normal pressure in the contact;area using a piezo-stack actuator. This paper focuses on the optimal placement of semi-active joints for vibration suppression. The proposed method uses optimality criteria for actuator and sensor locations based on eigenvalues of the controllability and observability gramians. Optimal sensor/actuator placement;is stated as a nonlinear multicriteria optimization problem with discrete variables and is solved by a, stochastic search algorithm. At optimal locations, conventional rigid connections of a, large truss structure are replaced by semi-active friction joints. Two different, concepts for the control of the normal forces in the friction interfaces are implemented. In the first approach, each semi-active joint has its own local feedback controller, whereas the second concept uses a global, clipped-optimal controller. Simulation results for a 1.0-bay truss structure show the potential of the proposed semi-active concept.
This paper provides initial results on the use of formal power series parameterizations and summation methods for linear and nonlinear finite dimensional systems. The parameterizations prove to be suitable for system ...
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nonlinearcontroldesign is shown to be a critical enabler for robust model-based suppression of a flow instability. The onset of oscillatory vortex shedding is chosen as a well investigated benchmark problem of flow ...
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We consider the fixed interval smoothing problem for data from linear or nonlinear models where there is a priori information about the boundary values of the state process. The nonlinearities and boundary values prec...
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The presented model-based solution for the tracking control of switched reluctance (SR) servo-drives is an outcome of its differential flatness. The controller shows a cascade structure as commonly used in drive engin...
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We consider the constrained finite and infinite time optimal control problem for the class of discrete-time linear piecewise affine systems. When a linear performance index is used the finite and infinite time optimal...
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