Analysis of the vertical vibration effects on ride comfort of vehicle driver

Vehicle vibrations affect the health and comfort of the driver and passengers considerably. The aim of this study is to analyze the effects of vertical vehicle vibrations on the driver. To achieve this goal, a human biodynamic model with 11 degrees of freedom was incorporated into a full vehicle model and this combined human-vehicle model was subjected to the road disturbance. After dynamic analysis of the proposed model, root mean square (RMS) acceleration responses of the human body parts over a certain frequency range were obtained. Physiological effects of the vibrations on the human body were analyzed using the criteria specified in International Organization for Standardization (ISO) 2631. Then, in order to observe the effectiveness of a controller on the vibration isolation of human body, sliding mode controller was applied to the model. Comparison of the vibration effects for the uncontrolled and controlled cases of the human-vehicle model was presented. It can be concluded from the results that sliding mode controller considerably reduces whole body vibrations compared with the uncontrolled case and thereby improves the ride comfort satisfactorily.