Global Journal of Researches in Engineering, A: Mechanical & Mechanics, Volume 22 Issue 1

m 2 m 1 x 2 x 1 k s c s c t Switchable damper PID k t x t Figure 6: Semi-active suspension system of a quarter car model Figure 7: Free body diagram of semi-active system : 1̈ 1 = ( 2 − 1 ) + (̇ 2 −̇ 1 ) − ( 1 − ) − (̇ 1 −̇ ) 1̈ 1 + ( + ) ̇ 1 − ̇ 2 + ( + ) 1 − 2 = + ̇ : 2̈ 2 = − (̇ 2 −̇ 1 ) − ( 2 − 1 ) 2̈ 2 −̇ 1 + ̇ 2 − 1 + 2 = 0 : � 1 0 0 2 � �̈ 1̈ 2 � + � + − − � �̇ 1̇ 2 � + � + − − � � 1 2 � = � + ̇ 0 � f) Active Suspension System Fig. 9 shows the configuration of the active suspension system of a quarter car when the vehicle is travelling over a hump. The active suspension system is normally characterized by the presence of a linear actuator beside the suspension and the damper. The linear actuator force signals are received by the controller according to the body vertical acceleration. The equations of motion can be expressed as follow: Figure 8: Free body diagram of the active system Vibrational Behaviour of a Quarter Car Travelling over Road Humps with Different Suspension Systems © 2022 Global Journals Global Journal of Researches in Engineering (A ) Volume XxXII Issue I Version I 52 Year 2022 (8) (9)