A Comparison of Different Mathematical Bus Dynamics Models to Evaluate Road Roughness and Ride Comfort Teron Nguyen 1(&) , Patrick Swolana 2 , Bernhard Lechner 2 , and Yiik Diew Wong 3 1 Rapid Road Transport, TUMCREATE, 01 Create Way, #10-02 CREATE Tower, Singapore 138602, Singapore teron.nguyen@tum-create.edu.sg 2 Technische UniversitätMünchen, Baumbachstraße 7, 81245 Munich, Germany 3 Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore Abstract. 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. Keywords: Bus dynamics Á Ride comfort Á Bus lanes Á Road roughness Á Mathematical simulation 1 Introduction Vehicle dynamics models have long been developed for different purposes such as to design and optimise suspension system [1], to evaluate passenger ride comfort and vehicle handling [2], and to evaluate road roughness conditions [3]. The most commonly-used vehicle models are quarter-car-simulation (QCS), half-car-simulation (HCS) and full-car-simulation (FCS), of which the QCS has been used most often due to its simplicity. A comprehensive summary of current approaches to evaluating road roughness has shown that there are eight QCS, two HCS and one FCS models which have been used to develop various indices [4]. In another study of car dynamics [5], the FCS gave the most accurate results with errors within 10% of ride comfort indicator as © Springer Nature Switzerland AG 2020 M. Klomp et al. (Eds.): IAVSD 2019, LNME, pp. 1683–1690, 2020. https://doi.org/10.1007/978-3-030-38077-9_191