Transformation of a nonlinear system into an augmented linear system

This paper presents a method of formal linearization by augmenting state variables for nonlinear systems. Introducing a sequence of linearly independent functions and regarding each of them as a new state variable, the original nonlinear system is transformed into an augmented linear system. Based on this linearization, the paper also derives an observer and a suboptimal controller for nonlinear systems. The examples indicate that the linearization has excellent characteristics and greatly improves the performances.