Multi Objective Optimization of a Quarter Car Model Fitted with an MR Damper

Abstract

In this paper, an MR-damper fitted to a non-linear quarter car model to obtain the optimum voltage required to handle the MR-damper during the vehicle passing over a bump. Macpherson strut suspension system is implemented for the study. The optimum voltage was obtained depending on ride comfort which was the vertical vehicle RMS acceleration and displacement. The analysis was done by using a genetic algorithm in MATLAB/SIMULINK software. GA is implemented to minimize both the vertical RMS acceleration and displacement of the sprung mass. The results are compared to the passive suspension system. The RMS acceleration is reduced by 71 % and 11% at velocities of 10 and 70 km/hr respectively while the displacement is reduced by 36.6% and 40% at the same velocities after the transient period. A pareto front was obtained at different vehicle velocities to demonstrate the effect of vehicle velocity on vehicle vertical acceleration and displacement and gives more flexibility to choose optimum solution as the designer requirement’s. Keywords— Macpherson, genetic algorithm, Multi Objective Optimization, MR-damper, pareto front.