Abstract
The conflict between ride and handling in a passive suspension system is extremely difficult to solve. A wide range of controllable suspension system have been developed varying in effectiveness, action principle and cost. Among these systems semi-active suspension are receiving considerable attention because of their competitive performance and low cost. By means of an adjustable damper, a semiactive suspension is only capable of storing and dissipating energy. According to the damper configuration used, dampers with a controllable orifice are the most common forms of semi active suspension and commercial products are already available.
In this paper, the determination of the structure parameters of the automotive semi active suspension is presented. The suspension system is optimized with respect to ride comfort, road holding, working space and control effort of the suspension. The Linear Quadratic Gaussian (LQG) algorithm is therefore utilized and seems to be efficient to deal with this multi-target optimization problem. The optimal structure parameters are obtained for a semi active suspension system which is modeled by a four degree of freedom car model (4DOF). Obtained results show a strong impact of parameters (ρ1, ρ2, ρ3, ρ4) on the suspension efficiency. The performance of optimal semi active suspension system is also given in comparison with passive system (zero control force).
Keywords: suspension system, set of structure parameters, swing quality, damping coefficient, damping ratio, spring stiffness, optimization theory, LQG, 4DOF