الفهرس 
Chapter 1 : IntroductionOnly 14 pages are availabe for public view
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Abstract
Several researchers had studied vehicle stability either theoretically via the simulation software like the MATLAB/Simulink or experimentally including both the laboratory and on-field experiments. Dynamic stability of vehicles depends on varies maneuver conditions such as traction, braking, and cornering. knowingly, both the yaw rate and lateral acceleration are usually used to represent and investigate the theoretical handling performance for vehicle models which defined the stability region under varies maneuver features.
The main aim of thesis study is to investigate the effect of vehicle parameters design and operative on vehicle handling and stability. Also, the effect of tire load fluctuating on vehicle handling and stability. The fluctuating in tire load was depend on suspension system improvement. According to that, a two different vehicle model (linear and non-linear model) are proposed to investigate vehicle handling and stability improvement due to vehicle parameters variation and the influence of utilizing active or semi-active suspension system.
A two degree of freedom linear vehicle model is proposed to investigate dynamic vehicle stability under varies vehicle maneuvers. The simulation is developed using MATLAB/Simulink application program to predict the vehicle dynamic stability under different maneuvers. To investigate vehicle stability, the steering wheel angle is chosen to be the primary model input for the analysis procedures. The developed model is validated via Step steer input. Moreover, a new typical steer wheel angle is developed to examine highway predicted vehicle output within its maneuver. The vehicle dynamic outputs, namely, yaw rate and lateral acceleration are adopted for all the investigated maneuvers. It is found that the vehicle design parameters such as changing the vehicle center of gravity (CG) position, vehicle mass, tire cornering stiffness and vehicle speed have a significant influence on the vehicle dynamic stability.
The effects of vehicle vertical vibrations on the tires/road cornering forces, and then consequently on vehicle lateral dynamics are studied. This is achieved through a ride model and a handling model linked together by a non-linear tire model. The ride model is a half vehicle with four degrees of freedom (bounce and pitch motions for vehicle body and two bounce motions for the two axles). The front and rear suspension are a controlled by proposed LQR (Linear Quadratic Regulator) control strategy to predict active suspension system and a Four state switchable damper to predict semi-active suspension system. Vehicle lateral dynamics is modeled as two degrees (yaw and lateral motions) incorporating a driver model. The tire non-linearity is represented by the Magic Formula tire model. The ride vibration control, vehicle lateral dynamics and tire/road cornering forces are interlinked together in order to study the effect of vertical vibration control on the vehicle lateral stability with a driver model.