Vertical Vibrations of the Vehicle Excited by Ride Test

The influence of a rough road surface on vehicle vertical vibrations and on the driver and passengers is an important research among automotive manufacturers [3]. ISO international standard defines the terminology of vehicle dynamics and road holding ability. In addition, ISO international standard proposes the test procedures for steady-state circular driving behavior and lateral transient response characteris tics against step steering input, sinusoidal steering input, random steering input, and braking in a turn [6]. The standardized test procedure of a double-lane-change test as a severe lane-change maneuver is proposed [2]. In order to estimate the influence of vertical vibration on seated human body, the apparent mass of the human body is evaluated by mechanical lumped models [4]. In this research, a mechanical equiv alent model has been developed to characterize the response of the vehicle excited by road profiles. The mechanical equivalent model offers a quantitative evaluation of accelerations of vehicle along vertical axis in terms of natural frequencies and dissipative properties of vehicle. In order to calibrate the mathematical model, an experimental design has been developed by the ride test.