Approximated stable inversion for nonlinear systems with nonhyperbolic internal dynamics

A technique to achieve output tracking for nonminimum phase nonlinear systems with nonhyperbolic internal dynamics is presented. The present paper integrates stable inversion techniques (that achieve exact-tra@ing) with approximation techniques (that modify the internal dynamics) to circumvent the nonhyperbolicity of the internal dynamics this nonhyperbolicity is an obstruction to applying presently available stable inversion techniques. The theory is developed for nonlinear systems and the method is applied to a two-cart with inverted-pendulum example.