We define flat inputs for discrete-time systems and carry over a input based observer design strategy non-integrable nonlinear continuous-time to the case. This approach allows observers that cannot be transformed into canonical form, i.e., conventional strategies fail. is illustrated by two examples.

This paper proposes two methods for nonlinear observer design which are based on a partial nonlinear observer canonical form (POCF). Observability and integrability existence conditions for the new POCF are weaker than the well-established nonlinear observer canonical form (OCF), which achieves exact error linearization. The proposed observers provide the global asymptotic stability of error dy...

Recently, the author has proposed a methodology for the design of nonlinear observers based on the dissipative theory. This methodology offers a systematic approach to the observer design providing great flexibility and generality. For example, several well known observer design methods, as the High-Gain and the Lipschitz Observers, can be treated and generalized in a unified manner by the Diss...