
25-1
25.1 Introduction
e parameters and also the nature of the controlled drive systems can change with the operating con-
ditions. If classical controllers with xed parameters are used, then such change can introduce a dif-
ference in dynamic behavior of the drive. It can result in weaker or stronger damping, and thus in a
tendency to instability or in an increase of system response rising time. If the specications of the drive
system do not admit such behavior, then adaptive controllers must be used [L85,BSS90,KT94]. It is
demanded of an adaptive controller that the control system shall satisfy a dened control index inde-
pendently of pa