Before revision: .. A separation principle also exists for the control of high gain observers used for state estimation of nonlinear systems , a class of nonliear observers known as cubic observers when used in combination with linear state feedback and control of quantum systems.
After revision: .. The separation principle also holds forof a class high gain observers used for state estimation of nonlinear systems , a class of nonliear observers known as cubic observers when used in combination with linear state feedback and control of quantum systems.