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Electro-Hydraulic Vibratory Exciter for Investigating Vehicle Vibration Effects on Humans
Željko Despotović Svetlana Despotović Srđan Sudarević
This paper presents a realization of an electronically controlled two-axis hydraulic vibratory exciter used for studying the behavior of the human body under the influence of vibrations. It deals particularly with the influence of vibrations that occur in motor vehicles. Regarding vehicle oscillatory comfort, understanding the transmission mechanism of vibrations through the human body and their influence on psycho-physiological abilities are very important for automotive design. In armored and transport vehicles, military personnel are also exposed to a high level of whole-body vibrations. Since command and control operations are likely to become more mobile in the future, it is of interest to understand the effects of vibrations on the human body and hearing and cognitive performances in particular. The presented vibratory exciter is based on the hydraulic servo drive control and a high-performance reference signal generator. The control system of the vibratory exciter is designed to provide continual amplitude adjustment in a range of 0-50mm and the frequency tuning in a range of 0.1-50Hz. The implemented control system provides the generation of different waveforms (sine, triangle or square waves) at a given frequency as well as the generation of stochastic signals, which is of utmost importance. The experimental results of the displacement of the vibratory exciter (oscilloscopic waveforms and spectra in the frequency domain) are also presented for both perpendicular axes and real mass load. Key words: vibrations, vibration excitation, vibration exciter, electro hydraulic platform, influence of vibrations, effects on the human body, vibrations of vehicles, signal generation.
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