Nonlinear modeling and control of I.C. engine idle speed

Presented in this paper is the nonlinear modeling and control of the idle speed of a Ford 4.6L-2 valve V-8 fuel injected engine. The nonlinear model is of the Hammerstein type model and is identified through input-output data without a priori knowledge of the system dynamics. The nonlinear model is utilized in the development of an H_∞ controller with a nonlinear gain that maintains the idle speed within a prespecified output tolerance despite system nonlinearities, an external disturbance, and an actuator saturation constraint. The allowable output tolerance is asymmetric.