Ride comfort quality improvement for a quarter car semi-active suspension system via state-feedback controller

The objective of this study is to simulate the road disturbance toward suspension in a quarter car system. This suspension system consists of springs, shock absorbers and linkages that connects a vehicle to its wheel and allows relative motion between the car body and the wheel. This paper shows the mathematical modeling in order to design a quarter car suspension system using Simulink and Matlab software. The work shows the effect of suspension travel in quarter car system toward road profile by using state-feedback controller. The purpose of this state-feedback controller is to decrease the continuous damping in suspension system. The inconsistency condition of the road is the main element that affects the ride comfort, which in this paper is represented by different heights of road profile. In suspension principles, the road wheels and vehicle body produce vertical forces in rotational motions direction. Therefore, state-feedback controller must be able to reduce body deflection caused by the road disturbance to achieve the ride comfort of driver and passengers. The results show that the proposed controller is capable to simulate road disturbance whereby the system shows vibration reduction of suspension after experiencing the bumps with different heights.