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The objective of this study is to develop a Model Reference Control (MRC) strategy for active suspension System. The MRC strategy employs both the suspension look-ahead preview and wheelbase preview concepts, and the methodology of the MRC based on the ideal hybrid skyhook-groundhook concept. The study performed using a 13 degree-of-freedom (DoF) vehicle vertical dynamics model including the active suspension actuators masses. The engine mass, driver seat and anti-roll bar are considered in the model. The MRC strategy uses eight Proportional-Integral-Derivative (PID) controllers for both body and wheel control. A gradient-based optimization algorithm is applied to obtain the controller parameters using a cost function including both ride comfort and road holding performance.

Semi-active suspension offers variety of damping force range which demands greater need to optimize the top mount to ensure multiple objectives of ride comfort, harshness and safety can be achieved. For this purpose, this paper proposes a numerical optimization procedure for improving the harshness performance of the vehicle through the adjustment of the damper top mount characteristics of the semi-active suspension system. The proposed optimization process employs a frequency dependent combined objective function based on ride comfort and harshness evaluation. A detailed and accurate damper top mount mathematical model is implemented inside a validated full vehicle model to provide a realistic simulation environment for the optimization study. The semi-active suspension system employs a Rule-Optimized Fuzzy-Logic controller. The ride comfort and harshness of the full vehicle are evaluated by analyzing the body acceleration in different frequency ranges.

This paper presents experimental and theoretical investigations for ride comfort performance of compressed natural gas fuelled car. A compressed natural gas and gasoline fuel are used to run the engine car and its effect on the vehicle ride comfort is evaluated. The ride comfort performance in terms of experimental Root Mean Square (RMS) values of the vertical acceleration at near driver's feet on the floor, on the front and back seat for the same passenger car fuelled by gasoline and natural gas is evaluated. Furthermore, seven degrees of freedom vehicle mathematical model is developed, and validated through laboratory tests. The validation process is performed by comparing the predicted RMS values of the vertical accelerations with the measured RMS values. Furthermore, the optimum values of vehicle suspension parameters are obtained through the validated vehicle model.

The interest of the highway engineer and researchers are focused on road roughness and vehicle vibrations in the frequency range of interest, which corresponds to a wave number range appropriate for the prevailing traffic speed. Road profile is an important step for studying vehicle ride comfort. The aim of this work is to investigate the effect of road roughness on the ride comfort and rolling resistance for passenger cars. Mathematical models of a half vehicle for passive and semi-active suspension systems are developed to evaluate vehicle ride comfort in terms of suspension performance criteria. The ride performance, power consumed in rolling resistance and power dissipation in suspension for passive and semi-active suspension systems are finally evaluated

Following the developments in controlled suspension system components, the studies on the vertical dynamics analysis of vehicles increased their popularity in recent years. The objective of this study is to develop a semi-active suspension system controller using Adaptive-Fuzzy Logic control theories together with Kalman Filter for state estimation. A quarter vehicle ride dynamics model is constructed and validated through laboratory tests performed on a hydraulic four-poster shaker. A Kalman Filter algorithm is constructed for bounce velocity estimation, and its accuracy is verified through measurements performed with external displacement sensors. The benefit of using adaptive control with Fuzzy-Logic to maintain the optimal performance over a wide range of road inputs is enhanced by the accuracy of Kalman Filter in estimating the controller inputs. A gradient-based optimization algorithm is applied for improving the Fuzzy-Logic controller parameters.

Due to the importance of the fast transportation under every circumstance, the transportation process may require a high speed heavy vehicle from time to time, which may turn the transportation process more unsafe. Due to that fact the truck safety during braking and the ride comfort during long distance travelling with high speeds should be improved. Therefore, the aim of this work is to develop a control system which combines the suspension and braking systems. The control system consists of three controllers; the first one for the active suspension system of the truck body and cab, the second one for the ABS and, the third for the integrated control system between the active suspension system and the ABS. The control strategy is also separated into two strategies.