Stochastic adaptive control of non-minimum phase systems

The authors consider the problem of robust stochastic adaptive control of not necessarily minimum phase systems in the presence of unmodeled dynamics. Stochastic gradient algorithms with parameter projection and modified gain sequence are used for the estimation of the unknown controller parameters. Global stability of the adaptive system is achieved without requiring the strictly positive real condition and the persistency exciting condition to be satisfied. The self-stabilization mechanism inherent in adaptive control is verified analytically