9 research outputs found
A One Dimensional Elliptic Distributed Optimal Control Problem with Pointwise Derivative Constraints
We consider a one dimensional elliptic distributed optimal control problem
with pointwise constraints on the derivative of the state. By exploiting the
variational inequality satisfied by the derivative of the optimal state, we
obtain higher regularity for the optimal state under appropriate assumptions on
the data. We also solve the optimal control problem as a fourth order
variational inequality by a finite element method, and present the error
analysis together with numerical results
Finite Element Methods for One Dimensional Elliptic Distributed Optimal Control Problems with Pointwise Constraints on the Derivative of the State
We investigate finite element methods for one dimensional elliptic
distributed optimal control problems with pointwise constraints on the
derivative of the state formulated as fourth order variational inequalities for
the state variable. For the problem with Dirichlet boundary conditions, we use
an existing regularity result for the optimal state to
derive convergence for the approximation of the
optimal state in the norm. For the problem with mixed Dirichlet and
Neumann boundary conditions, we show that the optimal state belongs to
under appropriate assumptions on the data and obtain convergence for the
approximation of the optimal state in the norm
Explicit algorithms to solve a class of state constrained parabolic optimal control problems
We consider an optimal control problem of a system governed by a linear parabolic equation with the following features: control is dis-tributed, observation is either distributed or nal, there are constraints on the state function and on its time derivative. Iterative solution methods are proposed and investigated for the nite di erence ap-proximations of these optimal control problems. Due to explicit in time approximation of the state equation and the appropriate choice of the preconditioners in the iterative methods, the implementation of all constructed methods is carried out by explicit formulaes. Computational experiments con rm the theoretical results
Finite element approximation and iterative method solution of elliptic control problem with constraints to gradient of state
An optimal control problem with distributed control in the right-hand side of Poisson equation is considered. Pointwise constraints on the gradient of state and control are imposed in this problem. The convergence of nite element approxima-tion for this problem is proved. Discrete saddle point problem is constructed and preconditioned Uzawa-type iterative algorithm for its solution is investigated
A priori error analysis for state constrained boundary control problems. Part II: Full discretization
This is the second of two papers concerned with a state-constrained optimal control problems with boundary control, where the state constraints are only imposed in an interior subdomain. We apply the virtual control concept introduced in [26] to regularize the problem. The arising regularized optimal control problem is discretized by finite elements and linear and continuous ansatz functions for the boundary control. In the first part of the work, we investigate the errors induced by the regularization and the discretization of the boundary control. The second part deals with the error arising from discretization of the PDE. Since the state constraints only appear in an inner subdomain, the obtained order of convergence exceeds the known results in the field of a priori analysis for state-constrained problems. The theoretical results are illustrated by numerical computations
Quasi-best approximation in optimization with PDE constraints
We consider finite element solutions to quadratic optimization problems, where the state depends on the control via a well-posed linear partial differential equation. Exploiting the structure of a suitably reduced optimality system, we prove that the combined error in the state and adjoint state of the variational discretization is bounded by the best approximation error in the underlying discrete spaces. The constant in this bound depends on the inverse square-root of the Tikhonov regularization parameter. Furthermore, if the operators of control-action and observation are compact, this quasibest-approximation constant becomes independent of the Tikhonov parameter as the meshsize tends to 0 and we give quantitative relationships between meshsize and Tikhonov parameter ensuring this independence. We also derive generalizations of these results when the control variable is discretized or when it is taken from a convex set