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Road humps are considered as one of the best design propositions to control running vehicle speeds, in many roads they are randomly installed depending on the resident's requirements. In this paper, Genetic Algorithm (GA) optimization technique is used to design an active suspension based on force cancellation concept when the vehicles crossing road humps. A longitudinal half vehicle model is used to represent passenger's car and truck models. These models are used to evaluate the performance of active suspension over the road speed humps. The force cancellation concept is employed to isolate the force between the sprung and unsprung mass. Virtual damper and skyhook damper concepts are also used for reducing the sprung mass acceleration and tire dynamic loads. GA is adopted to obtain the better coefficients of a virtual damper and a skyhook damper for its effective searching ability.

Heavy trucks are becoming more common in use for international transportations, with longer highways and long driving hours contributing corresponding increases in driver's fatigue that is related to accidents. In this paper a detailed procedure is proposed to improve a highway truck seat. A dynamic model of an on-highway truck seat is simulated using Simulink toolbox in MATLAB. The seat suspension including the cushion is mounted on the cab floor of a half truck model and excited by a rapid excitation of step input. The seat suspension system controller is designed to improve the ride quality of the driver. Genetic Algorithms (GA) is used to obtain the coefficients of the control parameters. In addition, model outputs comparison of the proposed design to a conventional passive seat suspension using the maximum overshoot and the root mean square (RMS) values of both, the driver acceleration and the seat suspension working space.

The number of speed humps (sleeping policemen) has seen a global increase in the last decade. This paper addresses the geometric requirements of these humps using Genetic Algorithms optimization techniques to control the speed, stability, and ride feel of the traversing vehicles. The interaction between road hump profile and the modeled vehicles (passenger and a two-axle truck) are studied with a dynamic model. The shape of the proposed profile is described by numbers of amplitudes of harmonic functions. The extreme acceleration of the drivers’ seats of the vehicles traversing the hump is set as multiobjective function for the optimization process, taking into consideration the road-holding ability represented by the tire lift-off speed. The results show that hump geometry can be improved while fulfilling the requirements of speed control and vehicle dynamic responses.

Vibration ride comfort of combat vehicles is essential subject because these vehicles operate at different environments. Improving the comfortability enables the solders to drive for a long time at critical situations with full activity. This paper looks at the ride performance of multi-axles combat vehicles driven at varies speeds over terrain profile. Three configurations of these vehicles, two axles, three axles and four-axles-vehicles, have been studied and compared. The results showed that at a wide range of speeds there is a significant improvement to be gained by using four axles over the three axles and two axles when emphasis is placed on the vehicle body vertical acceleration and dynamic tyre loads.

In this paper, a continuously controlled semi-active suspension system is designed for trucks main suspension. Using a linearized seven degrees of freedom mathematical model equipped with hydraulic and hydro-pneumatic components, the optimal damping forces for truck front and rear suspensions are designed based on optimal control theory using Linear Quadratic Regulation (LQR) to improve the ride comfort and dynamic tyre loads. The practical limitation for the damping forces and the time lag for system controllable elements are taken into account. The results are generated considering the suspension components non-linearity and the model is excited by statistically random road. The frequency domain results as power spectral density and the root mean square values are compared with those obtained from conventional passive suspension system.