الفهرس 
INTRODUCTION AND BACKGROUNDOnly 14 pages are availabe for public view
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Abstract
Riding quality is considered a key element in automotive industry which imposed a challenge on car manufacturers to develop a new alternatives control strategies for the classical suspension system. To this extent, many efforts have been done on developing several active or semi active suspension systems. In the past few years, the decreasing cost of electromechanical actuators has, however, opened new trends to face this challenge. Active Aerodynamic Surfaces Spoilers (AAS) represent an alternative and effective solution to the issue. Two contradicting criteria of good vehicle suspension performance are typically their ability to provide good road handling and increased passenger comfort. The main disturbance affecting these two criteria is terrain irregularities. Active suspension control systems reduce these undesirable effects by isolating car body motion from vibrations at the wheels. We are trying to investigate the use of Active Aerodynamic Surfaces on half car pitch oriented model to enhance ride comfort. AAS work as a virtual dynamic inertia which reduce these undesirable effects by resisting car body motion from the excitation. The aerodynamic forces represent one element that deeply influences the vehicle response, especially at high speed. At high speed starts from (150km/ hr.), the lift force (Spoiler) has a potential that may be used to attenuate the vibration and enhance ride comfort without affecting road holding. Also we investigated the usage of Active Aerodynamic Surfaces (AAS) to enhance ride comfort in sport vehicles for quarter car model. A proposed control scheme of one PID controller with inlet derivative filter is provided to keep the sprung mass vertical acceleration as minimum as possible. The controller gains are tuned through Genetic Algorithm (GA) for three different single objective functions and also using fast Non-dominating Genetic Algorithm (NSGA-II) for two different conflicting fitness functions. The controller provides an input controlled voltage signal to a DC servo motor to actuate the airfoil. The vehicle response is investigated under random road profile and shows that the lift force has a significant effect on the ride comfort without side effects on the road holding.