A novel optimization technique for optimizing the damper top mount characteristics to improve vehicle ride comfort and harshness is developed. The proposed optimization technique employs a new combined objective function based on ride comfort, harshness, and impact harshness evaluation. A detailed and accurate damper top mount mathematical model is implemented inside a validated quarter vehicle model to provide a realistic simulation environment for the optimization study. The ride comfort and harshness of the quarter vehicle are evaluated by analyzing the body acceleration in different frequency ranges. In addition, the top mount deformation is considered as a penalty factor for the system performance. The influence of the ride comfort and harshness weighting parameters of the proposed objective function on the optimal damper top mount characteristics is studied. The dynamic stiffness of the damper top mount is used to describe the optimum damper top mount characteristics for different optimization case studies. The proposed optimization routine is able to find the optimum characteristics of the damper top mount which improve the ride comfort and the harshness performances together. 1. Introduction Damper top mounts are used in the vehicles not only to provide ideal Noise-Vibration-Harshness (NVH) performance but also to improve ride comfort, driving safety, and handling. The ride comfort and harshness can be considered as the vibration response of the vehicle body at different frequency ranges. Vehicle ride comfort can be evaluated by using vertical acceleration of the body up to 20？Hz while the harshness can be considered as the body vertical acceleration in the frequency range over 20？Hz until 100？Hz [1]. Another type of the vehicle harshness is the impact harshness (IH) which also affects the subjective impression of ride comfort. This type of harshness involves the vibration response of the vehicle which is referred to as IH events [2–5]. The driver and the passengers are always in contact with different parts of the vehicle chassis during the operation of the vehicle. Therefore, it is expected that reducing the acceleration response of the vehicle body will improve ride comfort and harshness. Some previous studies have shown that the ride comfort and harshness performance of the vehicle can be improved by optimizing the characteristics of the suspension system components [5–13]. A numerical procedure for finding the optimum values of the vehicle suspension system parameters has been studied by Pintado and Benitez [6]. The vehicle is modeled as a
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