Optimization analysis of rollover index of multi axle special vehicles

DOI:	10.11809/bqzbgcxb2023.09.017
Keywords:	special vehicle; rollover dynamics model; rollover indicator;lateral load transfer rate; warning threshold
Abstract:	In order to explore the lateral dynamic characteristics of multi axle special vehicles, more accurate rollover evaluation indexes are established as the basis for vehicle stability control. Taking the heavy 5 axle special vehicle as the research object, based on the established rollover dynamics model of special vehicle, the dynamic analysis of two common vehicle rollover evaluation indexes (the lateral load transfer rate (LTR) and the zero moment point (ZMP) theory) are carried out.The LTR is optimized, and a new optimized lateral load transfer rate (LTRo) is proposed, which considers the influence of the roll moment of the sprung mass and the unsprung mass. Then, taking LTRo as the vehicle rollover evaluation index, a calculation method that can adaptively determine the rollover warning threshold (LTRt) according to the vehicle speed and road adhesion coefficient is explored based on data fitting. Through Trucksim vehicle dynamics model simulation and real vehicle test, the calculation accuracy of LTRo is compared with the early warning effect of LTRt. The results show that the calculation accuracy of LTRo is about 6.3% and 12.4% higher than that of LTR and ZMP, respectively.The evaluation of vehicle rollover risk is more accurate. LTRt can adjust adaptively according to the changes of vehicle speed and road environment, so that rollover indicators are not only applicable to tripping rollovers, but also applicable to non tripping rollovers. Under high ambient conditions, compared with the warning under a fixed warning threshold, the warning under LTRt can reserve more time for vehicle rollover control.
Published:	2023-09-28
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