A robust indirect adaptive regulation algorithm with self-excitation capability

A robust version of the adaptive control algorithm established by G. Kreisselmeier (1989) is presented. If the conventional dead-zone adaptive law is used in the adaptive system, it is troublesome that the size of the unmodeled dynamics, denoted by ∈, must be within the chosen dead-zone size for robustness. In this robust version, by introducing a positive design parameter, the robust stability can be achieved without this constraint. It is also shown that the plant output and control input will converge asymptotically within a certain bound. Moreover, in the ideal case, the plant output and control input will converge to zero under some condition