Model reference adaptive control system hyperstability analysis

The stability of the model reference adaptive control system with external disturbance and unmodeling is discussed. Instead of Lyapunov's method, more general results have been acquired for the analysis of hyperstability. It is shown that if only the linear forward block can be made strictly positive real, then the globally asymptotical hyperstability of the error model structure will be guaranteed with no regard to the characteristic of nonlinear feedback block. The original model reference adaptive control system will also be globally asymptotically hyperstable.