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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 a performance analysis study for the Rule-Optimized controller of a semi-active suspension system. The Rule-Optimized controller is based on a Fuzzy Logic control scheme which offers new opportunities in the improvement of vehicle ride performance. An eleven degree of freedom full vehicle ride dynamics model is developed and validated through laboratory tests performed on a hydraulic four-poster shaker. An optimization process is applied to obtain the optimum Fuzzy Logic membership functions and the optimum rule-base of the semi-active suspension controller. The global optima of the cost function which considers the ride comfort and road holding performance of the full vehicle is determined through discrete optimization with Genetic Algorithm (GA).

There is an increasing customer demand for adjustable chassis control features which enable adaption of the vehicle comfort and driving characteristics to the customer requirements. One of the most promising vehicle control systems which can be used to change the vehicle characteristics during the drive is the semi-active suspension system. This paper presents a Rule-Optimized Fuzzy Logic controller for semi-active suspension systems which can continuously adjust itself not only according to the road conditions but also to the driver requirements. The proposed controller offers three different control modes (Comfort, Normal and Sport) which can be switched by the driver during driving. The Comfort Mode minimizes the accelerations imposed on the driver and passengers by using a softer damping. On the other hand, the increased damping in Sport Mode provides better road holding capability, which is critical for sporty handling.

The integrated control between the vehicle chassis subsystems (suspension, brake, and steering) became one of the most important aspects for current developments to improve the dynamics of the vehicles. Therefore, the aim of this study is to investigate the influence of the preview control of the active suspension on the vehicle ride and braking performance. The vehicle performance was examined theoretically using a longitudinal half vehicle model with four degrees of freedom considering the rotational motion of the tires. The active suspension system model, tire-road interface model and braking system model are included in the vehicle model. In order to study the influence of the preview control on the vehicle ride and braking performance, an active suspension system control algorithm employing the lock-ahead preview information and the wheel-base time delay based on the optimal control theory is derived.

This paper presents a new and effective control concept for semi-active suspension systems. The proposed controller uses a Fuzzy Logic scheme which offers new opportunities in the improvement of vehicle ride performance. The Fuzzy Logic scheme tunes the controller to treat the conflict requirements of ride comfort and road holding parameters within a specified range of the suspension deflection. An eleven degree of freedom full vehicle ride dynamics model is constructed and validated through laboratory tests performed on a hydraulic four-poster shaker. A new optimization process for obtaining the optimum Fuzzy Logic membership functions and the optimum rule-base of the proposed semi-active suspension controller is proposed. Discrete optimization has been performed with a Genetic Algorithm (GA) to find the global optima of the cost function which considers the ride comfort and road holding performance of the full vehicle.

The paper deals with a theoretical study to present a new sort of the buses suspension systems employs a hydraulic connection between the front and rear dampers together with active suspension actuator at the front axle. The theoretical investigation based on a half vehicle model of the bus suspension system includes the engine mounting system. The hydraulic connection between the front and rear dampers is created according to the capillary tubes theory. Furthermore, the active suspension system control algorithm based on the optimal control theory is derived. The Genetic Algorithm optimization routine is applied to generate the active suspension control algorithm parameters. A comparison between the connected dampers suspension system, active suspension system, active-connected dampers suspension system, and the passive suspension system in terms of ride comfort and road holding at constant suspension working space is performed.

Hybrid electric vehicle (HEVs) represents a promising approach to reduce vehicle fuel consumption and exhaust emissions. However, due to the electric motor (EM) assistance, the engine load could be reduced and intermittent operation of engine is realizable in HEVs powertrain system. Consequently, the HEV powertrain heating-up process and engine fuel consumption will be changed accordingly. Therefore, the influences of the EM power and battery capacity on the hybrid powertrain heating-up process and the engine fuel consumption will be analyzed, and 2 methods for optimizing the heating-up process by applying the auxiliary heaters (AHs) and the modification of the energy management strategy are represented. The application of AHs can improve engine efficiency during heating-up; the controlling of the power flow from the AHs to the ICE cooling system is of special important.