Page 104 - Neural Network Modeling and Identification of Dynamical Systems
P. 104

CHAPTER
                                                                   3




                           Neural Network Black Box Approach to

                           the Modeling and Control of Dynamical

                                                             Systems







                                3.1 TYPICAL PROBLEMS                   Situation = External-Situation (Environment) +
                                     ASSOCIATED WITH                            Internal-Situation (Object).
                                     DEVELOPMENT AND                     The main problem is that, due to the pres-
                                      MAINTENANCE OF                   ence of uncertainties, the current situation for
                                    DYNAMICAL SYSTEMS                  the dynamic system under consideration may
                                                                       change significantly and unpredictably. This cir-
                            As noted earlier, the object of our research is  cumstance we have to take into account both in
                          a controlled dynamical system, operating under  modeling the system and in controlling its be-
                          conditions of various uncertainties.         havior.
                            Among the main types of uncertainties that   In Chapter 1, the dynamical system S was de-
                          need to be considered when solving problems  fined as an ordered triple of the following form:
                          related to controlled dynamical systems are the
                          following:                                                  S = U,P,Y ,            (3.1)
                          • uncertainties generated by uncontrolled dis-  where U is the input to the simulated/con-
                            turbances acting on the object;            trolled object, P is the simulated/controlled ob-
                          • incomplete and inaccurate knowledge of the  ject (plant), and Y is a response of the object to
                            properties and characteristics of the simu-  the input signal. In this definition:
                            lated object and the conditions in which it
                                                                       • the input actions U are the initial conditions,
                            operates;
                          • uncertainties caused by a change in the prop-  controls, and uncontrolled external influences
                            erties of the object due to failures of its equip-  on the object P;
                            ment and structural damage.                • the simulated/controlled object P is an air-
                                                                         craft or another type of controllable dynam-
                            As shown in Chapter 1, the behavior of the   ical system;
                          system is largely determined by the current  • the outputs Y of the dynamical system S are
                          and/or predicted situation, including external  the observed reactions of the object P to the
                          and internal components, i.e.,                 input actions.


                          Neural Network Modeling and Identification of Dynamical Systems
                          https://doi.org/10.1016/B978-0-12-815254-6.00013-7  93        Copyright © 2019 Elsevier Inc. All rights reserved.
   99   100   101   102   103   104   105   106   107   108   109