Abstract Estimates of the Rate of Convergence for Optimal Control Problems

1997 ◽  
Vol 36 (1) ◽  
pp. 109-123
Author(s):  
T. Kärkkäinen ◽  
T. Räisänen
Keyword(s):  
Optimal Control ◽  
Rate Of Convergence ◽  
Optimal Control Problems ◽  
Control Problems

scholarly journals Superior properties of the PRESB preconditioner for operators on two-by-two block form with square blocks

2020 ◽  
Vol 146 (2) ◽  
pp. 335-368
Author(s):  
Owe Axelsson ◽  
János Karátson
Keyword(s):  
Optimal Control ◽  
Rate Of Convergence ◽  
Large Scale ◽  
Optimal Control Problems ◽  
Iterative Solution ◽  
Control Problems ◽  
Block Form ◽  
Solution Methods ◽  
Preconditioned Matrix ◽  
Iterative Solution Methods

Abstract Matrices or operators in two-by-two block form with square blocks arise in numerous important applications, such as in optimal control problems for PDEs. The problems are normally of very large scale so iterative solution methods must be used. Thereby the choice of an efficient and robust preconditioner is of crucial importance. Since some time a very efficient preconditioner, the preconditioned square block, PRESB method has been used by the authors and coauthors in various applications, in particular for optimal control problems for PDEs. It has been shown to have excellent properties, such as a very fast and robust rate of convergence that outperforms other methods. In this paper the fundamental and most important properties of the method are stressed and presented with new and extended proofs. Under certain conditions, the condition number of the preconditioned matrix is bounded by 2 or even smaller. Furthermore, under certain assumptions the rate of convergence is superlinear.

Improved Gradient-Type Algorithms for Zero Terminal Gradient Optimal Control Problems

1987 ◽  
Vol 109 (4) ◽  
pp. 355-362
Author(s):  
Chung-Feng Kuo ◽  
Chen-Yuan Kuo
Keyword(s):  
Optimal Control ◽  
Rate Of Convergence ◽  
Optimal Control Problems ◽  
Control Variable ◽  
Transformation Method ◽  
Control Problems ◽  
Final Time ◽  
Time Problem ◽  
Gradient Type ◽  
Improved Algorithm

Difficulties often arise when we apply the gradient type algorithms employing penalty functions to optimal control problems with variable final time. There is another class of optimal control problems for which the necessary conditions for optimality require a zero gradient at the final time. This causes the gradient-type algorithms, in their standard forms, to become incapable of changing the terminal value of the control variable at each iteration and the rate of convergence is adversely affected. In this paper, we first apply a new transformation method developed by Polak [19] which transforms the variable final time problem into a fixed final time problem. Second, an improved gradient-type algorithm is developed to overcome the zero terminal gradient problem. It is shown that, by applying this transformation and improved algorithm to four examples, not only the variable final time and zero terminal gradient problems are solved and the control vector updated in the correct direction but the rate of convergence of the improved algorithm is faster than that of the traditional gradient-type algorithms.

On closed-loop equilibrium strategies for mean-field stochastic linear quadratic problems

2020 ◽  
Vol 26 ◽  
pp. 41
Author(s):  
Tianxiao Wang
Keyword(s):  
Optimal Control ◽  
Closed Loop ◽  
Optimal Control Problems ◽  
Mean Field ◽  
Open Loop ◽  
Time Inconsistency ◽  
Control Problems ◽  
Linear Quadratic ◽  
Linear Quadratic Optimal Control ◽  
Equilibrium Strategies

This article is concerned with linear quadratic optimal control problems of mean-field stochastic differential equations (MF-SDE) with deterministic coefficients. To treat the time inconsistency of the optimal control problems, linear closed-loop equilibrium strategies are introduced and characterized by variational approach. Our developed methodology drops the delicate convergence procedures in Yong [Trans. Amer. Math. Soc. 369 (2017) 5467–5523]. When the MF-SDE reduces to SDE, our Riccati system coincides with the analogue in Yong [Trans. Amer. Math. Soc. 369 (2017) 5467–5523]. However, these two systems are in general different from each other due to the conditional mean-field terms in the MF-SDE. Eventually, the comparisons with pre-committed optimal strategies, open-loop equilibrium strategies are given in details.

Sweep Algorithm for Solving Discrete Optimal Control Problems with Three-point Boundary Conditions

2008 ◽  
Vol 40 (7) ◽  
pp. 48-58 ◽  
Author(s):  
Fikret Akhmed Ali Ogly Aliev ◽  
Rena Takhir kyzy Zulfugarova ◽  
Mutallim Mirzaakhmed ogly Mutallimov
Keyword(s):  
Optimal Control ◽  
Boundary Conditions ◽  
Optimal Control Problems ◽  
Control Problems ◽  
Point Boundary ◽  
Discrete Optimal Control ◽  
Sweep Algorithm
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