Feedforward stabilization of nonlinear nonminimum phase system

The nonlinear-inversion based output tracking had been successfully introduced in the output tracking control for the nonlinear nonminimum phase system. In this paper, motivated by the nonlinear inversion idea, the partial feedforward control approach is proposed. Since this approach requires a reference trajectory, some preliminary propositions for the existence of a reference trajectory are presented and sufficient conditions for these conditions are derived. Then, this reference trajectory is combined with the original system, and the sufficient conditions are derived for the system to have arbitrary small states and input at the end of the control. The developed controller design schemes are applied to the examples and the system performance is evaluated through the simulations.