Frequency-based controller design for a class of nonlinear systems

Presented in this paper is a frequency-based controller design methodology for a class of nonlinear systems that can be characterized by a class of Ha mmerstein models. The controller design is directed toward the disturbance rejection problem where the output performance specification appears as a t ime domain tolerance. The controller design process is executed in three st ages. First, the system nonlinearities are quasilinearized via describing f unction techniques. Second, the design methodology enforces a time domain t olerance \y(t)\ less than or equal to alpha via frequency domain constraint s on the quasilinearized closed-loop system. Finally, the controller is des igned via classical loop shaping of the quasilinearized system on the open- loop gain-phase plane. The design process is illustrated on the idle speed control of a Ford 4.6L-2 valve V-8 fuel injected engine. Copyright (C) 1999 John Wiley & Sons, Ltd.