eng Science and Education Publishing American Journal of Mechanical Engineering 2328-4110 2019-09-24 7 4 151 157 10.12691/ajme-7-4-1 AJME2019741 article Nouby M. Ghazaly 1 Mostafa Makrahy 2 Ahmad O. Moaaz 3 Mechanical Engineering Department, Faculty of Engineering, South Valley University, Qena, Egypt Automotive Engineering Department, Faculty of Engineering, Minia University, Minia-Egypt Mechanical Engineering Department, Faculty of Engineering, Beni-suef University, Beni-suef, Egypt The main purpose of the vehicle suspension system is to induce more comfortable riding and well handling with the road inputs. The principal objective of this research paper is to reduce vibration and improve passenger comfort of car suspension through the sliding mode controller. The mathematical model of passive and active suspensions mechanism for a quarter car model that subjects to excitation from road profiles is obtained. The active suspension system is developed through sliding mode control for a quarter car model. The performance of the sliding mode control is evaluated through a simulation approach using MATLAB and SIMULINK toolbox. The simulated results plotted in the time domain and root mean square values. It is concluded that the active suspension using a sliding mode controller improves the ride comfort and reduces vibration. http://pubs.sciepub.com/ajme/7/4/1/ajme-7-4-1.pdf quarter car model active suspension system sliding mode control road profile