Dynamic robust recursive control design and its application to a nonlinear missile autopilot

A design method is proposed, dynamic robust recursive control, in order to obtain output tracking performance for a general class of nonlinear systems. Depending upon the relative degree of the system, this new approach generates static or dynamic controllers, whereas previous recursive design methods generate only static controllers. The dynamic recursive technique does not require any prior conditions on the system structure and hence overcomes the main limitation of the back-stepping method. Robust dynamic recursive design is extended to uncertain nonlinear systems which do not satisfy either the matching conditions or the generalized matching conditions. System uncertainty is modeled in the time domain, and the design of robust fictitious control terms in the recursive design process requires only that suitable bounding functions are imposed on the uncertainty. A detailed case study is developed to demonstrate the application of the dynamic robust recursive design method to a second order nonlinear “pitch plane” missile autopilot with structured uncertainties