Motorbike Vibrations Induced by Surface Irregularities in Road Pavements

The author proposes a multi–axis equivalent mechanical system with two degrees of freedom on the horizontal plane and five degrees of freedom along the vertical axis to evaluate the accelerations on a motorbike’s seat using the state- space representation. The experimental investigations evaluate three types of routes to analyze the comfort vibrational of the motorcycle: paved roads with poor maintenance, road surface with crushed stone, and a road with an artificial bump. Experimental processing considers the gyroscopic and accelerometric signals to deduce the Euler angles. The error analysis evaluates the discrepancy between the accelerations predicted, using the calibrated multi-axis mathematical model, and those obtained in the experimental investigations. The multi–axis model estimates the vibrations on the seat induced by surface irregularities in road pavements. The mathematical prediction obtained by the multi–axis model and experimental investigations analyzes the accelerations in the resonance frequencies of the human spine between 4–12 Hz.