en کنترل Control پژوهشي Research In order to improve the safety and longitudinal stability of a vehicle equipped with standard ABS system, this paper, analyzes the basic principles of vehicles stability and proposes a control strategy based on fuzzy adaptive control which will adjust PID gain parameters, using genetic algorithm. A linear three-degree-of-freedom (DOF) vehicle model was set up in Simulink and the stability test was conducted utilizing jointly a joint established simulation platform with CarSim.<br> &nbsp;&nbsp; For controlling the brake length, traditional controllers have difficulty in guaranteeing performance and stability over a wide range of parameter changes and disturbances. Therefore, a 2 level controller by providing a modified Sliding Mode Control (SMC) will be used. Using this approach the flexibility increased and brake length and rotor temperatures decreases significantly. This results improvement of the vehicle&rsquo;s stability and brakes fatigue lifespan. ABS,Adaptive Fuzzy-PID, SMC, Longitudinal Stability 2895 2907 http://ase.iust.ac.ir/browse.php?a_code=A-10-355-1&slc_lang=en&sid=1 Majid Moavenian moaven@um.ac.ir 180031947532846002266 180031947532846002266 Yes Supervisor Sina Sadeghi namaghi sinasadeghi@programmer.net 180031947532846002267 180031947532846002267 No Ferdowsi university of Mashhad