Electronic Throttle Simulation Using Nonlinear Hammerstein Model

In this paper, a nonlinear Hammerstein model was used to represent the dynamic behavior of an electronic throttle body at different operating conditions. The structure of the Hammerstein model was nonlinear in its parameters. It consisted of a static nonlinear function representing the coulomb friction and limp-home return springs in series with dynamic piecewise-linear transfer functions. The mathematical modeling of the throttle body was derived in state-space discrete form. Separable least squares estimation and optimization methods were implemented as a means of simultaneously estimating and identifying both the linear and nonlinear elements to match the results obtained from the simulation of the nonlinear Hammerstein model and the experimental tests. The open- and closed-loop verification were carried out by integrating the nonlinear Hammerstein model and the controller into production electronic control unit software (TargetLink Block) using the rapid prototyping real-time system. The hardware-in-loop implementation and testing of the embedded control software with the nonlinear Hammerstein model and actual throttle body revealed that the open and closed-loop experimental results matched the simulation results.