Parametric analysis of vehicle suspension based on air spring and MR damper with semi-active control

Abstract

Three strategies are used in this paper to investigate suspension systems behaviour. Firstly, the steel coil passive spring (conventional spring) is replaced by air spring, which comprised of an airbag, a connection pipe with a control valve, and a reservoir tank system. The influence of air spring pressure, reservoir volume and connection pipe diameter on suspension system behaviour are investigated. Secondly, a logic control scenario for the oscillation mass of air between spring airbag and the reservoir is applied by using on/off valve controller to study the controlling valve influence on the whole vehicle dynamics responses. Thirdly, the MR damper is used to introduce a variable damping coefficient as a semi-active control (skyhook) strategy of the suspension system. To represent the suspension system with the earlier mentioned strategies, a mathematical model 2-DOF for a quarter car is adopted along with governing equations of the air spring and semi-active skyhook control under the Matlab/Simulink platform. The obtained result, i.e., suspension travel displacement, body acceleration, dynamic tire force, and damper dissipation energy, are calculated in terms of RMS to show up the dynamic behaviour of suspension system considering four configurations in various control styles. The models’ responses were examined versus two road excitations pattern, including harmonic excitation and random road excitation. The results show that using air spring is considerably increased suspension quality, furthered more the suspension system is significantly enhanced when semi-active strategies are applied on air spring and MR damper.