A new approach for nonlinear process identification using orthonormal bases and ordinal splines

► A new gray-box method for nonlinear process identification has been presented. ► Use of Hammerstein, Wiener and the more general N-L-N block-oriented structures for identification has been detailed. ► Unique aspect to this approach, the construction of two particular bases functions. ► Both bases allow for the direct inclusion of a priori information. ► This formulation implicitly accommodates nonlinear dynamics.