Adaptive dual controller for systems with unmodelled effects

An adaptive pole placement controller with dual modification is applied to a dynamic plant which is described by an unknown nonlinear model. Stability of the suggested dual controller, applied together with a robust adaptatio n scheme, is proved for this system. It is demonstrated that after the inse rtion of the dual controller, the robust adaptive system remains stable. Ho wever, some known assumptions about the unmodelled residuals of the nonline ar plant model should be modified. It is also demonstrated that in the case of no residuals in the plant model, the closed-loop system converges to th e model defined by the desired pole positioning. The derived controller is applied to real-time control of hydraulic drive.