On the robustness of continuous-time indirect adaptive controller

Proposes a robust certainty equivalence based indirect adaptive control algorithm with internal persistence of excitation. The parameter adaptation law using gradient least squares dead zone estimator is robust to avoid the corruption of the uncertain dynamics. It is shown that operation of the adaptive control algorithm with internal persistence of excitation will guarantee that the plant input and output are uniformly bounded, and drive the parameter errors and tracking error to a residual set whose size can be directly related to the uncertain dynamics explicitly