M-MRAC backstepping for systems with unknown virtual control coefficients

The paper presents an over-parametrization free certainty equivalence state feedback backstepping adaptive control design method for systems of any relative degree with unmatched uncertainties and unknown virtual control coefficients. It uses a fast prediction model to estimate the unknown parameters, which is independent of the control design. It is shown that the system´s input and output tracking errors can be systematically decreased by the proper choice of the design parameters. The benefits of the approach is demonstrated in numerical simulations.