This paper involves both analytical modelling, simulation and experimental study of a hydro-pneumatic suspension system. The motivating behind this work was to build a fully controlled and stable suspension system to increase ride comfort and to obtain excellent performance in rough terrains. The active hydro-pneumatic suspension composed of a proportional directional valve, an accumulator attached to an actuator for the purpose of absorbing shock pulsation in addition to controlled system.
A PI-controller operates the valve to achieve the desired suspension performance. A mathematical model is derived and a simulation program was carried out using Matlab/Simulink software. To validate the simulation results, an experimental test rig of a quarter car suspension model is designed and examined. All the input signal and measured values are monitored and controlled using the Labview software that used to perform online simulation for the system. The program takes account of fluid mechanics, friction and nonlinearities of various sub-elements. The system behavior and oscillation rates are studied and tested for different kinds of terrains mathematically and experimentally. The comparison of results obtained from the simulation model and experimental test-rig shows a good conformity for different excitation road profile. The maximum displacement resulting from the simulation and experimental results of the hydro-pneumatic system are within ± 12 % of the reference value.
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