Dynamic right coprime factorization and observer design for nonlinear systems

The output behavior of nonlinear control system depends not only on its input but also on its initial conditions. These two factors have to be considered simultaneously in nonlinear systems design. This paper presents a new definition, called dynamic right factorization, for nonlinear dynamic control systems. This factorization takes the initial conditions as well as the system input into account. Coprimeness and fundamental properties of dynamic right coprime factorization are investigated. Its relations to the system observability and the observer design problem are discussed. An example is given to illustrate the procedure of obtaining the dynamic right factorization and designing an observer for a given nonlinear dynamic system.