ABSTRACT

The aim of vertical dynamics is the tuning of body suspension and damping to guarantee good ride comfort, respectively a minimal stress of the load at sufficient safety. The stress of the load can be judged fairly well by maximal or integral values of the body accelerations. The wheel load Fz is linked to the longitudinal force Fx and the lateral force Fy by the coefficient of friction. The degressive influence of Fz on Fx and Fy as well as nonstationary processes at the increase of Fx and Fy in the average lead to lower longitudinal safety can

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of the wheel load also reduce road damage. The comfort of a vehicle is subjectively judged by the driver and passengers. The vibration of a vehicle occurs in several directions, contains many frequencies, and changes over time. Via the seat it is transferred to all passengers. The driver is also exposed to the vibration of the steering wheel. Whole-body vibration may cause sensations (e.g., discomfort or annoyance), influence human performance capability, or present a health and safety risk. According to ISO-Directive 2631 [15], rootmean-square (r.m.s.) values of the body accelerations are used to judge the the effects of vibration on health and comfort. Because the human response to vibration is a function of frequency, the accelerations are filtered with frequency weighting curves. Different approaches of describing the human sense of vibrations by different metrics can be found in the literature [22].