An Idle Speed Controller using Analytically Developed Fuzzy Logic Control Law 2002-01-0138

Fuzzy control is based on either expert knowledge or experimental data and, therefore, it possesses intrinsic qualities like robustness and ease of implementation. The mathematical modeling for fuzzy control systems has been attempted, but until now many models that have been developed do not extend beyond the application for which they were developed. A general class of fuzzy linguistic control algorithms that can be formulated analytically and can capture the nonlinear aspect of a given fuzzy control scheme has been formulated using interpolating functions. The interpolating functions map the process error and its rate or it's a cumulative sum into control action. The systematic approach makes it more desirable to be used in the control of nonlinear dynamics systems. The analytical method developed in previous wok conducted by Langari (1992) and modified by the authors is employed in this practical example to design a controller for an idle speed control system. This study aims to show that the analytically developed fuzzy control law can be used in practical application such as the idle speed control problem provided that certain modifications and assumptions are taken into consideration in the derivation and the application of the control law.

The following sections present a discussion of the control law, in addition to the design process and the simulation results of the idle speed control system.