A New Matching Condition for Robust Control Design

We study the control design problem for uncertain nonlinear systems. A new matching condition is presented. The main idea is to configure the possible route through which the uncertainty may affect the stability. Compared with the previous case, the current matching condition prescribes the route nonlinearly while the early matching condition is a special case of the linear description. The advantage is demonstrated. As an example, the number of required independent controls drops from three to one in a rotational rigid-body problem by using the new matching condition.