Multivariable MRAC Design Without Gain Symmetry Conditions Using a Stabilizing Multiplier

A new multivariable MRAC design for plants of arbitrary relative degree, which does not require a stringent symmetry assumption related with the plant high frequency gain matrix, is presented. In contrast to previous results, the new solution does not involve additional parametrization and filtering, being thus close in structure and complexity to conventional solutions. Instead of the fragile symmetry assumption, a less restrictive and robust condition is required, which can be achieved using a multiplier.