Nonlinear modeling and identification of a spark ignition engine torque

The identification of mathematical models typically nonlinear systems is vital in many fields of engineering. This study presents nonlinear modeling and identification of spark ignition engine torque from input–output measurement. Nonlinear models for the system are obtained for identification purposes. The Hammerstein nonlinear system approach is used for identification of the nonlinear system model. Identification of nonlinear system models is performed using the recursive least squares method. The nonlinear system identification with fifth order linear dynamics gives the best result. And also selection of the second order nonlinearity gives the best result. The results are numerically and graphically presented.

► Nonlinear modeling and identification of spark ignition engine torque from input–output measurement. ► Nonlinear models for the system are obtained for identification purposes. ► The Hammerstein nonlinear system approach is used for identification of the nonlinear system model. ► Identification of nonlinear system models is performed using the recursive least squares method. ► The nonlinear system identification with fifth order linear dynamics and second order nonlinearity gives the best result.