Computation of a variable steering ratio with a fuzzy logic method

This research project presents a system of fuzzy adaptation of the steering ratio. This study fits into the scheme of the current manufacturers which is to improve the comfort and the security of the passengers. The tendency is with the generalization of the electrification in automotive vehicles, and this with an aim of acting more quickly and of freeing themselves from the significant mechanical constraints hitherto. This study deals more particularly with ´variable steering ratio´ (steering angle/wheels angle), and will try to answer the following questions : according to which information the steering ratio must be determined without disturbing the driver´s behavior? what must be the transition strategy from a value to another according to the driving situation? The results reported in this paper are obtained on the basis of fuzzy mathematics through simulations and implementation on a vehicle control laws.