Showing papers by "Zhiwei Gao published in 2003"

New results on doubly coprime fractional representations of generalized dynamical systems

Abstract: This note first points out that the main results by Wang and Balas regarding the doubly coprime fractional representations for generalized dynamical systems have severe limitation in their applications, that is, the doubly coprime factorization obtained by Wang and Balas cannot characterize the parameterization of all properly stabilizing controllers when a system is singular, therefore, truly generalized. To remedy those results, two new doubly coprime factorizations have been developed that will parameterize all properly stabilizing controllers for single-input or single-output cases. In addition, the new results can characterize the parameterization of all corresponding causal properly stabilizing controllers. Finally, the extension to the multiple-input-multiple-output case is presented.

On parameterization design for linear observers

Abstract: In this paper, the design of observers is further investigated via the parameterization technique. Two new observer parameterizations are addressed related to nonminimal reduced-order state observers. The known results in the references available can be obtained as particular results from the present parameterizations. For plants with input disturbances, parameterizations of estimation error dynamics are derived, providing useful tools for the design of robust optimal observers. An illustrative example is given for describing the parameterization procedure.