Robust Adaptive Control: Conditions for Local Stability

The question is examined of when an adaptive control system is robust to modeled dynamics and unknown bonded disturbances. Conditions are presented that insure the existence of such robustness properties, but only locally; i.e., restrictions are placed on the behavior of signals in the ideal, perfectly tuned adaptive system. Local L¿-stability is investigated when the tuned signals are assumed to be small, slowly varying, and/or persistently exciting.