Robust adaptive LQ control schemes

The certainty equivalence principle is used to combine a robust adaptive law with a control structure derived from the linear quadratic (LQ) control problem. The resulting adaptive control scheme is applicable to minimum and nonminimum phase continuous-time plants and is robust with respect to unmodeled dynamics and bounded disturbances. The computational complexity of the continuous-time adaptive LQ control scheme is improved by using a hybrid adaptive law which requires the solution of an algebraic Riccati equation at each interval of time rather than at each time t