Evalution of Dynamic Seat Comfort and Driver's Fatigue 971573

This paper focuses on the evaluation of seat comfort when a sitting person is subjected to vertical excitations. Three seat models have been proposed to highlight the selection of seat design parameters when subjected to impulses, multi-frequency sinusoidal types of vibration, and random excitation. These selected models are commonly used to describe human body vibration. Stiffness and damping coefficients were selected as the variable parameters in order to most effectively reduce the transmissibility of the vibrations from the floor to the human body. The results indicate that in the case of impulsive and sinusoidal excitations, the isolated seats, with suspension characteristics obtained through an optimization in the frequency domain, reduce the acceleration and absorbed power of the human body much more so than the passive suspension and hard seats. In the case of random excitation, we see the same end results as in the other types of excitation inputs; however, the selection of the appropriate parameters for the cushion and seat suspension are not trivial. In all types of input excitation conditions, the absorbed power energy function showed that the hard seat and seat with cushion only are found to be the least desirable in human comfort and seat design.