Adaptive control of uncertain pure-feedback nonlinear systems

A novel adaptive control approach is proposed to solve the globally asymptotic state stabilization problem for uncertain purefeedback nonlinear systems in the pseudo-affine form. The pure-feedback nonlinear system under consideration is with nonlinearly parameterised uncertainties and possibly unknown control coefficients. Based on the parameter separation technique, a backstepping controller is designed by adopting the adaptive high gain idea. The rigorous stability analysis shows that the proposed controller could guarantee, for any initial system condition, boundedness of the closed-loop signals and globally asymptotic stabilization of the state. A numerical and a realistic examples are employed to demonstrate the effectiveness of the proposed control method.