Page 124 - Neural Network Modeling and Identification of Dynamical Systems

3.4 ANN-BASED CONTROL OF DYNAMICAL SYSTEMS 113

FIGURE 3.10 Comparison of the network operation with the preprocessing layer (with the stabilizer actuator model) and
the mathematical model (3.23). The solid line is model (3.23) output; the dotted line is the output of the neural network
model; V z is the component of the velocity vector along the Oy-axis; q is the angular velocity of the pitch; α is the angle of
(ref ) (ref )
attack; δ e is the deflection angle of the stabilizer; t is the time; EV z , Eq,and Eα are the differences |V z − V z |, |q − q |,
and |α − α (ref ) |, respectively (From [99], used with permission from Moscow Aviation Institute).

3.4.2.1 Basic Approaches to the Use of third approach (“compromise”) is a combination
ArtificialNeuralNetworksin of a conservative and radical approach, or more
Control Problems precisely, some compromise between them.
In the general case, the most effective (in
Thereare threemainapproaches totheuse of
terms of the applied problem) will, of course,
ANNs in control systems [83–86].
be a radical approach. However, a less pow-
In the first approach (“conservative”) the erful conservative approach not only has the
structural organization of the control system re-
right to exist, but, moreover, is more prefer-
mains unchanged, i.e., as it was obtained when
able at present for a variety of reasons, both
designing such a system using one of the tradi-
objective and subjective. Namely, following the
tional approaches. In this case, the ANN plays conservative approach, it is possible to quickly
the role of a module for correcting specific pa- achieve practically meaningful results, since this
rameters of the control system (for example, its approach is not about creating a new control sys-
gains) depending on the operating conditions of tem from scratch, but about upgrading existing
the system. In the second approach (“radical”), systems. Further, it is very difficult to imagine
the whole control system or a functionally com- now the situation when on board (for example,
pleted part is realized as an ANN system. The an airplane) a control system based entirely on