Utilizing flow rate and pressure data in and out of the mud circulation loop provides a driller with real-time trends for the early detection of well-control problems that impact the drilling efficiency. This paper pr...
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Utilizing flow rate and pressure data in and out of the mud circulation loop provides a driller with real-time trends for the early detection of well-control problems that impact the drilling efficiency. This paper presents state estimation for infinite-dimensional systems used in the process monitoring of oil well drilling. The objective is to monitor the key process variables associated with process safety by designing a model-based nonlinear observer that directly utilizes the available information coming from the continuous-time online process output measurements at the topside of the well. The observer consists of a copy of the plant plus output injection terms where the gain is computed analytically in terms of the Bessel function of the first kind. The design is tested using data from a real-field drilling commissioning test in the North Sea by Statoil Oil Company. The results show that the design estimates the flow and pressure accurately. (C) 2015, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.
An efficient approach to determine an activation policy for scanning sensor network monitoring a distributed process over some spatial domain is proposed. Given a finite number of potential sensor the scheduling probl...
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An efficient approach to determine an activation policy for scanning sensor network monitoring a distributed process over some spatial domain is proposed. Given a finite number of potential sensor the scheduling problem is defined so as to maximize a criterion defined on the Fisher information matrix associated with the estimated parameters. Then, applying an efficient continuous approximation of the the related combinatorial problem, the multi-exchange procedure adopting pairwise communication schemes is developed, which distributes the configuration process between the network nodes. Finally, the delineated approach is illustrated via simulations on a sensor network scheduling problem for a two-dimensional convective diffusion process.
The problem of estimating the initial state of 1D wave equations with globally Lipschitz nonlinearities from boundary measurements on a finite interval was solved recently by using the sequence of forward and backward...
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ISBN:
(纸本)9781479978861
The problem of estimating the initial state of 1D wave equations with globally Lipschitz nonlinearities from boundary measurements on a finite interval was solved recently by using the sequence of forward and backward observers, and deriving the upper bound for exact observability time in terms of Linear Matrix Inequalities (LMIs) [7]. In the present paper, we generalize this result to n-D wave equations on a hypercube. This extension includes new LMI-based exponential stability conditions for n-D wave equations, as well as an upper bound on the minimum exact observability time in terms of LMIs. The efficiency of the results is illustrated by a numerical example.
In this work we study the numerical approximation of the solutions of a class of abstract parabolic time optimal control problems. Our main results assert that, provided that the target is a closed ball centered at th...
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ISBN:
(纸本)9783952426937
In this work we study the numerical approximation of the solutions of a class of abstract parabolic time optimal control problems. Our main results assert that, provided that the target is a closed ball centered at the origin and of positive radius, the optimal time and the optimal controls of the approximate time optimal problems converge to the optimal time and to the optimal controls of the original problem. In order to prove our main theorem, we provide a nonsmooth data error estimate for abstract parabolic systems.
In this paper, the stabilization problem of a class of diffusion neural networks via periodically intermittent sampled-data control is studied. It is assumed that the measurement of the states are taken in a finite nu...
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ISBN:
(纸本)9789881563897
In this paper, the stabilization problem of a class of diffusion neural networks via periodically intermittent sampled-data control is studied. It is assumed that the measurement of the states are taken in a finite number of fixed sampling points in the spatial domain and continuous in time. In the proposed control method, sampled-data control is only activated in "work time", rather than during the whole time. A sufficient condition for the existence of periodically intermittent sampled-data controllers is derived in terms of linear matrix inequalities (LMIs). The obtained condition establishes a quantitative relation among the control period, the control width, and the upper bound on the spatial sampling intervals. Finally, a numerical example is provided to illustrate the effectiveness of the proposed theoretical result.
Dynamics modelling and control design for elastic rods with distributedparameters are under study. The constitutive laws are specified by an integral equality according with the method of integro-differential relatio...
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Dynamics modelling and control design for elastic rods with distributedparameters are under study. The constitutive laws are specified by an integral equality according with the method of integro-differential relations. A numerical algorithm is developed to solve direct and inverse dynamic problems in linear elasticity based on the Ritz met hod and finite element technique. The control problem is to obtain the rod motion from some initial state to terminal one at a fixed time with the minimal mean energy. exact solution is round with a specific triangular space-time mesh and a piecewise polynomial displacement input. (C) 2015, IFAC (Internalional Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.
A method based on controls and computational fluid dynamics for the estimation of a gaseous plume that results from gas released into the ambient atmosphere through a moving aerial source is presented. The estimation ...
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ISBN:
(纸本)9783952426937
A method based on controls and computational fluid dynamics for the estimation of a gaseous plume that results from gas released into the ambient atmosphere through a moving aerial source is presented. The estimation scheme, in the form of the Luenberger observer, utilizes concentration sensor measurements provided by an unmanned aerial vehicle (UAV). The estimator is in the form of an advection-diffusion equation and is solved in real-time by a finite volume method with total variation diminishing (TVD) limiter and dynamic grid adaptation. The control algorithm for the motion of the UAV is implemented via Lyapunov redesign methods and couples the UAV dynamics to the performance of the process estimator. Numerical examples are included to illustrate the performance of the method.
The paper discusses different abstract state-space representations for a class of linear distributed parameter systems of hyperbolic type defined on a one-dimensional spatial domain. It starts with the homogeneous sta...
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ISBN:
(纸本)9781479987016
The paper discusses different abstract state-space representations for a class of linear distributed parameter systems of hyperbolic type defined on a one-dimensional spatial domain. It starts with the homogeneous state equation including the unbounded formal state operator. Based on the semigroup approach, some theoretical results of well-posedness and internal stability for the considered systems are given here. Next, the boundary and observation operators are introduced, taking a typical boundary inputs configuration as well as pointwise observations of the state variables. Consequently, the homogeneous state equation is extended to the so-called boundary control state/signal form. Finally, the most classical state-space representation involving typical (A, B, C)-triple of state, input and output operators is considered together with the definition of the Pritchard-Salamon class of infinite-dimensional systems.
This paper presents the dynamic modeling and vibration control design of a floating wind turbine system. Two flexible mooring lines attached to a flexible wind turbine tower (taut-moored floating spar) are used to rep...
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ISBN:
(纸本)9788993215090
This paper presents the dynamic modeling and vibration control design of a floating wind turbine system. Two flexible mooring lines attached to a flexible wind turbine tower (taut-moored floating spar) are used to represent the dynamics of system. The wind turbine tower is modeled as an Euler-Bernoulli beam, and the mooring lines are modeled as two strings. The control laws are designed to suppress vibrations of both wind turbine tower and the mooring lines. Based on the construction of a physically motivated Lyapunov function, the bounded stability is proved with the proposed control. Numerical examples illustrate the performance of the control system.
This paper deals with the control of the preheating process of a casting mould formulated as a distributedparameter system and using a programmable logic controller (PLC). The control process is first optimized by a ...
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This paper deals with the control of the preheating process of a casting mould formulated as a distributedparameter system and using a programmable logic controller (PLC). The control process is first optimized by a simulation procedure using a distributedparameter control loop. The temporal part of the control synthesis is implemented on the PLC in order to control the preheating of the casting mould. A controlled preheating process is demonstrated on the experimental casting mould with embedded sensors and actuators.
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