LOVAS, D. Stabilita zpětně-vazebních řízení dynamických systémů s časovým zpožděním [online]. Brno: Vysoké učení technické v Brně. Fakulta strojního inženýrství. 2020.
This thesis deals with control problems for basic models of mechanical oscillators. As the main goal of the thesis, various problems concerning stabilization and synchronization of given models via suitable time-delay feedback controls were discussed. Besides theoretical results answering these problems, the thesis presents also a lot of numerical and graphical experiments supporting these results. The topic of the thesis required the knowledge of a stability background for linear time-delay systems and the ability to convert the existing results into effective conditions for stabilization and synchronization of studied models of mechanical oscillators. Also, the knowledge of essentials of control theory was needed. In my opinion, the author met high demands put on the topic of his thesis. He succeeded in theoretical as well as computational analysis of the studied problems. The obtained results are applicable in control theory and follow current trends in the area of stabilization and synchronization of dynamical systems. Also, I would like to express my contentment with activity and responsibility of the author. He was interested not only in the topic itself, but also in many related issues from various areas. Some minor (mostly formal) inaccuracies has no substantial impact on a quality of the text. For the above reasons, I recommend this thesis to the final defence.
| Kritérium | Známka | Body | Slovní hodnocení |
|---|---|---|---|
| Splnění požadavků a cílů zadání | A | ||
| Postup a rozsah řešení, adekvátnost použitých metod | A | ||
| Vlastní přínos a originalita | A | ||
| Schopnost interpretovat dosažené výsledky a vyvozovat z nich závěry | A | ||
| Využitelnost výsledků v praxi nebo teorii | A | ||
| Logické uspořádání práce a formální náležitosti | B | ||
| Grafická, stylistická úprava a pravopis | B | ||
| Práce s literaturou včetně citací | A | ||
| Samostatnost studenta při zpracování tématu | A |
The thesis deals with stability analysis of dynamical systems under delay feedback control. The analysis is considered in a frame of a mechanical oscillator model and its variations, especially with respect to the control term form. The results are appropriately commented in this context. Several approaches are introduced and applied to obtain the asymptotic stability conditions, mainly the Pontryagin's method is employed in the thesis. The results in Section 4 are based on very recent paper [9], which illustrates the topicality of the investigated problems. The text is very well logically built and it provides detailed insight into the stability analysis of considered tasks. Numerical solution of delay differential equations in Matlab (dde23 solver) is illustrated in Section 6. There are several mistakes and misprints in the text, e.g. p. 15: call - > called; polynomial of order n -> polynomial of degree n; p. 29: "with a negative real part" -> "with a non-negative real part" p. 42: by stabilised -> be stabilised [p. 44 and p. 62]: sing -> sign p. 49: form -> from; will be introduce -> will be introduced There should be "Matsunaga H." instead of Hideaki M. in the paper [11] reference in the Bibliography. The overall impression of the thesis is very good: the introduced results are well commented, supported by suitable graphics, some open problems and possible thesis extensions are formulated in Conclusion.
| Kritérium | Známka | Body | Slovní hodnocení |
|---|---|---|---|
| Splnění požadavků a cílů zadání | A | ||
| Postup a rozsah řešení, adekvátnost použitých metod | A | ||
| Vlastní přínos a originalita | A | ||
| Schopnost interpretovat dosaž. výsledky a vyvozovat z nich závěry | A | ||
| Využitelnost výsledků v praxi nebo teorii | A | ||
| Logické uspořádání práce a formální náležitosti | A | ||
| Grafická, stylistická úprava a pravopis | A | ||
| Práce s literaturou včetně citací | A |
eVSKP id 125332