### Journals Information

**
Mathematics and Statistics Vol. 8(2), pp. 187 - 202 DOI: 10.13189/ms.2020.080215 Reprint (PDF) (295Kb) **

## Solvability, Completeness and Computational Analysis of A Perturbed Control Problem with Delays

**Ludwik Byszewski ^{1}, Denis Blackmore ^{2}^{,*}, Alexander A. Balinsky ^{3}, Anatolij K. Prykarpatski ^{1}^{,4}, Mirosław Lu´styk ^{4}**

^{1}Institute of Mathematics at Cracow University of Technology, ul.Warszawska, Poland

^{2}Department of Mathematical Sciences at NJIT, University Heights, Newark NJ 07102, USA

^{3}Mathematics Institute,Cardiff University, Cardiff CF24 4AG, Great Britain

^{4}Department of Applied Mathematics,AGH University of Technology, Cracow 30-059, Poland

**ABSTRACT**

As a ﬁrst step, we provide a precise mathematical framework for the class of control problems with delays (which we refer to as the control problem) under investigation in a Banach space setting, followed by careful deﬁnitions of the key properties to be analyzed such as solvability and complete controllability. Then, we recast the control problem in a reduced form that is especially amenable to the innovative analytical approach that we employ. We then study in depth the solvability and completeness of the (reduced) nonlinearly perturbed linear control problem with delay parameters. The main tool in our approach is the use of a Borsuk–Ulam type ﬁxed point theorem to analyze the topological structure of a suitably reduced control problem solution, with a focus on estimating the dimension of the corresponding solution set, and proving its completeness. Next, we investigate its analytical solvability under some special, mildly restrictive, conditions imposed on the linear control and nonlinear functional perturbation. Then, we describe a novel computational projection-based discretization scheme of our own devising for obtaining accurate approximate solutions of the control problem along with useful error estimates. The scheme effectively reduces the inﬁnite-dimensional problem to a sequence of solvable ﬁnite-dimensional matrix valued tasks. Finally, we include an application of the scheme to a special degenerate case of the problem wherein the Banach–Steinhaus theorem is brought to bear in the estimation process.

**KEYWORDS**

Perturbed Linear Control Problem, Delay, Solvability, Stability, Computational Scheme, Convergence

**Cite This Paper in IEEE or APA Citation Styles**

(a). IEEE Format:

[1] Ludwik Byszewski , Denis Blackmore , Alexander A. Balinsky , Anatolij K. Prykarpatski , Mirosław Lu´styk , "Solvability, Completeness and Computational Analysis of A Perturbed Control Problem with Delays," Mathematics and Statistics, Vol. 8, No. 2, pp. 187 - 202, 2020. DOI: 10.13189/ms.2020.080215.

(b). APA Format:

Ludwik Byszewski , Denis Blackmore , Alexander A. Balinsky , Anatolij K. Prykarpatski , Mirosław Lu´styk (2020). Solvability, Completeness and Computational Analysis of A Perturbed Control Problem with Delays. Mathematics and Statistics, 8(2), 187 - 202. DOI: 10.13189/ms.2020.080215.