ROBUST PARAMETER ADJUSTMENT WITH NONPARAMETRIC WEIGHTED-BALL-IN-H-INFINITY UNCERTAINTY

Using a new parameter adjustment law, robust monotonic parameter error reduction is proven for a linear parameter estimation problem in which the signal is corrupted by the presence of nonparametric dynamical uncertainty. The nonparameterized dynamics are characterized by a known frequency-domain magnitude bound. A nonconservative bound on the finite-time energy of the nonparametric-dynamics output is constructed in real time. When the error signal energy is small enough to be due to nonparametric dynamics alone, the parameter adjustment is shut-off to avoid misadjustment. This represents an extension of existing adaptive control error-dead/one ideas to the case of frequency-domain bounded uncertainty. © 1990 IEEE