Improvement of ride performance with an active suspension based on fuzzy logic control

Abstract

The physiological and psychological effect of vehicle vibrations on passengers is still a challenging problem. Therefore, the passenger ride comfort, which depends on a combination of vehicle displacement (heave) and angular displacement (pitch), has been one of the major issues of vehicle design. This paper proposes a fuzzy logic control (FLC) strategy for active vehicle suspension system which is utilized to generate counter-force to isolate vibration from the rough ground. A four degree-of-freedom (DOF) half car mathematical model is firstly presented. And a “decoupling transformation” is applied to the translation and pitch motion. The hydraulic actuator is then introduced as well. Last the ADMAS control module is used to render co-simulation between ADAMS and MATLAB to verify efficiency of FLC and decoupling transformation. Compared with passive suspension system, it is indicated that the proposed active suspension system is very effective in reducing peak values of vehicle body accelerations, especially within the most sensitive frequency range of human response. The root mean square of vehicle vertical and pitch angle accelerations is reduced. Therefore, the ride comfort is improved.