A Comparison of Different Mathematical Bus Dynamics Models to Evaluate Road Roughness and Ride Comfort

Improving ride comfort for bus passengers experiencing vibrations under the excitation of road roughness is a meaningful solution to attract more public transport ridership. While many research studies have been conducted to simulate car and truck dynamics, few studies have studied bus dynamics. This study developed multi-degrees-of-freedom (3-DOF quarter, 5-DOF half and 9-DOF full) mathematical bus models in Matlab/Simulink and compared these models in calculating passenger ride comfort on buses operating along urban bus lanes. The comparison results have shown that the 9-DOF full bus model is the best alternative to measure passenger ride comfort within the error of 2%, as compared to 5-DOF half and 3-DOF quarter bus model with 7% and 20% error, respectively. However, the modelling complexity is much higher in cases of half and full bus models. The widely used quarter vehicle model for designing vehicle suspension and for evaluating road roughness are reasonable and pragmatic to minimise the complexity.