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- state constraints (3)
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- nonlocal radiation interface conditions (2)
- second-order sufficient conditions (2)
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- Lavrentiev type regularization (1)
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A Lavrentiev type regularization technique for
solving elliptic boundary control problems with pointwise state
constraints is considered. The main concept behind this
regularization is to look for controls in the range of the adjoint
control-to-state mapping. After investigating the analysis of the
method, a semismooth Newton method based on the optimality
conditions is presented. The theoretical results are confirmed by
numerical tests. Moreover, they are validated by comparing the
regularization technique with standard numerical codes based on the
discretize-then-optimize concept.
The numerical solution of the Dirichlet boundary optimal control problem of the Navier-Stokes equations in presence of
pointwise state constraints is investigated. Two different regularization techniques are considered. First, a Moreau-Yosida
regularization of the problem is studied. Optimality conditions are derived and the convergence of the regularized solutions
towards the original one is proved. A source representation of the control combined with a Lavrentiev type regularization
strategy is also presented. The analysis concerning optimality conditions and convergence of the regularized solutions is
carried out. In the last part of the paper numerical experiments are presented. For the numerical solution of each
regularized problem a semi-smooth Newton method is applied.
An optimal control problem arising in the context of 3D electromagnetic induction heating is investigated. The state equation is given by a quasilinear stationary heat equation coupled with a semilinear time-harmonic eddy current equation. The temperature-dependent electrical conductivity and the presence of pointwise inequality state-constraints represent the main challenge of the paper. In the first part of the paper, the existence and regularity of the state are addressed. The second part of the paper deals with the analysis of the corresponding linearized equation. Some sufficient conditions are presented which guarantee the solvability of the linearized system. The final part of the paper is concerned with the optimal control. The aim of the optimization is to find the optimal voltage such that a desired temperature can be achieved optimally. The corresponding first-order necessary optimality condition is presented.
This paper is concerned with a PDE-constrained optimization problem of induction heating, where the state equations consist of 3D time--dependent heat equations coupled with 3D time--harmonic eddy current equations. The control parameters are given by finite real numbers representing applied alternating voltages which enter the eddy current equations via impressed current. The optimization problem is to find optimal voltages so that, under certain constraints on the voltages and the temperature, a desired temperature can be optimally achieved. As there are finitely many control parameters but the state constraint has to be satisfied in an infinite number of points, the problem belongs to a class of semi--infinite programming problems. We present a rigorous analysis of the optimization problem and a numerical strategy based on our theoretical result.
This paper is devoted to an optimal control problem of Maxwell's equations in the presence of pointwise state constraints. The control is given by a divergence--free three--dimensional vector function representing an applied current density. To cope with the divergence--free constraint on the control, we consider a vector potential ansatz. Due to the lack of regularity of the control--to--state mapping, existence of Lagrange multipliers cannot be guaranteed. We regularize the optimal control problem by penalizing the pointwise state constraints. Optimality conditions for the regularized problem can be derived straightforwardly. It also turns out that the solution of the regularized problem enjoys higher regularity which then allows us to establish its convergence towards the solution of the unregularized problem. The second part of the paper focuses on the numerical analysis of the regularized optimal control problem. Here the state and the control are discretized by N\'ed\'elec's curl--conforming edge elements. Employing the higher regularity property of the optimal control, we establish an a priori error estimate for the discretization error in the $\boldsymbol{H}(\bold{curl})$--norm. The paper ends by numerical results including a numerical verification of our theoretical results.
A state-constrained optimal boundary control problem governed by a linear elliptic equation is considered. In order to obtain the optimality conditions for the solutions to the model problem, a Slater assumption has to be made that restricts the theory to the two-dimensional case. This difficulty is overcome by a source representation of the control and combined with a Lavrentiev type regularization. Optimality conditions for the regularized problem are derived, where the corresponding Lagrange multipliers have $L^2$-regularity. By the spectral theorem for compact and normal operators, the convergence result is shown. Moreover, the convergence for vanishing regularization parameter of the adjoint state associated with the regularized problem is shown. Finally, the uniform boundedness of the regularized Lagrange multipliers in $L^1(\O)$ is verified by a maximum principle argument.
We consider a control- and state-constrained optimal control problem
governed by a semilinear
elliptic equation with nonlocal interface conditions.
These conditions occur during the
modeling of diffuse-gray conductive-radiative heat transfer.
The nonlocal radiation interface condition and the pointwise state-constraints
represent the particular features of this problem. To deal with the
state-constraints, continuity of the state is shown which allows to
derive first-order necessary conditions. Afterwards, we establish second-order
sufficient conditions that account for strongly active sets and
ensure local optimality in an $L^2$-neighborhood.
A state-constrained optimal control problem with nonlocal radiation interface conditions arising from the modeling of crystal growth processes is considered. The problem is approximated by a Moreau-Yosida type regularization. Optimality conditions for the regularized problem are derived and the convergence of the regularized problems is shown. In the last part of the paper, some numerical results are presented.
Sensitivity analysis (with respect to the regularization parameter)
of the solution of a class of regularized state constrained
optimal control problems is performed. The theoretical results are
then used to establish an extrapolation-based numerical scheme for
solving the regularized problem for vanishing regularization
parameter. In this context, the extrapolation technique provides
excellent initialization along the sequence of reducing
regularization parameters. Finally, the favorable numerical
behavior of the new method is demonstrated in a nested iteration
environment.
The numerical solution of the Dirichlet boundary optimal control problem of the Navier-Stokes equations in presence of
pointwise state constraints is investigated. A Moreau-Yosida regularization of the problem is proposed to obtain regular
multipliers. Optimality conditions are derived and the convergence of the regularized solutions towards the original one is
presented. The paper is ended with a numerical experiment.