A system for controlling nonlinear plants which may be effected with gain
scheduled feedback controllers. Several linear sub-controllers having
various gains may be put together as one unit. The overall controller may
be changed by switching from one sub-controller to another according to
an exogenous or endogenous parameter. The signal to the switch may
reflect operational ranges of the plant occurring at certain times and
indicate the gain desired from the system relative to the output and
input signals of the plant at those times. The advantages of the present
approach may include a guarantee of nominal and robust stability both
global and local, a permitting of the use of control structures that are
familiar to industrial practitioners, and no requirement of advanced
mathematical techniques for its implementation.