الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
The development of automobile suspension systems has been evolved due to benefit from simulation tools and coevolution of electronics and microprocessor control to get the most efficient and appropriate suspension system for cars.
This research involves both analytical modeling, simulation and experimental study of a hydro-pneumatic suspension system. The motivation behind this work is to build a fully controlled and stable suspension system to increase ride comfort and to obtain excellent performance in rough terrains as well as the ability to harvest energy during system operation. Suspension systems are generally classified into passive, semi-active, or active. The active suspension one is selected to investigate. The active hydro-pneumatic suspension system used in this study is 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 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.
A PI-controller is selected and tuned to control the manipulating current supplied to proportional valve in order to adjust the car displacement to be with reference position in all modes of operation. 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 better conformity for a different excitation road profile. The maximum displacement resulting from the simulation and experimental results of the hydro-pneumatic system are within ± % of the reference value.