Nonlinear robust controller for a class of nonlinear uncertain systems

The authors present an alternative control design approach for nonlinear uncertain systems that do not satisfy the generalised matching conditions. The control design scheme is a combination of the backstepping design technique, along with a dynamic recursive control design. The controller yields global stability of uniform ultimate boundedness, and requires only the knowledge of the bounding function of the uncertainty along with the system states. The form of the controller is a nonlinear nonhomogenous ordinary differential equation where its solution yields the control to be injected into the system model. This unique feature is recursively structured so that the control is generated in real time as the system solution is computed. The control design is applied to an air breathing tail controlled vehicle model to demonstrate the applicability of the control design to real world systems