Model reference adaptive control for systems with unknown relative degrees

A design method of model reference adaptive controllers for systems with unknown relative degrees, is presented in this paper. Contrary to the previous researches where the relative degrees of controlled systems are exactly known, the relative degrees in the present paper are partly unknown; that is, the relative degrees are known to be r, r + 1, or r + 2 with known r. It is shown that single adaptive schemes can deal with such uncertainties of relative degrees and that no switching of controllers exists.