In recent years, people become more concerned about the vibration seeking more comfortable environment. As traveling increases, the drivers are more exposed to vibration mostly originating from the interaction between the road and vehicle. Vibration will make them feel discomfort and fatigue sometimes along with injury. It is important to know how the vibration is transmitted through the human body before we try to manage it. On the other hand, Kingdom of Saudi Arabia is now pay great attentions in civilization health, one of which is the human-body health. Therefore, this project’s aims to affirm this keen interest by studying most recent human rider comfort that used in the field of rider whole-body vibration. This helps in the development in both scientific research and industry application in KSA.
This project presents an optimization of vehicle suspension system to determine a set of parameters to achieve the best comfort of the driver. The main objective of this project is to develop a mathematical modeling of vertical biodynamic response-characteristics of seated vehicle-driver using genetic algorithms. A genetic algorithm was applied to solve the optimization problem. The optimization results are compared through step and sinusoidal excitation of the seat suspension system for the optimal and currently used suspension systems. A genetic algorithm was applied to search for the optimal parameters of the seat and vehicle suspension. The desired objective is proposed as the minimization of a multi-objective function formed by the combination of seat suspension working space (seat suspension deflection), head acceleration, and seat mass acceleration to achieve the best comfort of the driver. With the aid of Matlab/Simulink software, a simulation model is achieved. In solving this problem, the genetic algorithms have consistently found near-optimal solutions within specified parameters ranges for several independent runs. For validation, the solution obtained by GA was compared to the ones of the passive suspensions through sinusoidal excitation of the seat suspension system for the currently used suspension systems.
The results of optimal linear seat suspension characteristics showed that, to obtain the best vibration isolation, the stiffness of the spring tends to be near to lower boundary. The results indicated that optimal linear seat suspension system is less oscillatory, and have lower values of maximum over shoots than passive suspension system. This is directly related to driver fatigue, discomfort, and safety. Step excitation input causes more dangerous on whole body parts (Head, upper torso, lower torso, pelvic, seat, and sprung mass) than those produced by sinusoidal excitation input. The numerical results and the plots indicate that optimal system is less oscillatory, and have lower values of maximum over shoots than passive suspension system. This is directly related to driver fatigue, discomfort, and safety. These results are encouraging and suggest that genetic algorithm can be easily used in other complex and realistic designs often encountered in the engineering.