Adaptive Control for Non-Minimum Phase Systems Via Time Scale Separation

Adaptive control for non-minimum phase systems is a challenging problem. This paper proposes a method of adaptive control for systems that may be both nonlinear and non-minimum phase. This is accomplished by exploiting time scale separation between the internal and external dynamics. The original non-minimum phase control problem is reduced to two minimum phase control problems through a time scale analysis. The resulting adaptive control signals are fused via multiple time scale control techniques. Singular perturbation theory is used to prove the stability and convergence of the full-order system as an extension of the stability and convergence of the two reduced-order systems. The effectiveness of this method is validated on a nonlinear example system.