Robust adaptive control: stability and asymptotic performance

Systems containing both compact real parametric uncertainty and frequency-weighted bounded operator uncertainty are addressed. It is shown that any parameter-adaptive control system is robustly stable provided only that: the unknown parameters lie in a known compact convex set; the control design rule is Lipschitzian; the control design rule would produce a robust controller if given perfect parameter information; and a specified robust parameter estimation algorithm is applied in lieu of perfect parameter information. It is also shown that the asymptotic robust performance level may be made arbitrarily close to that of the nonadaptive design which would result from parameter information