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以汽车动力学模型和汽车制动稳定性控制原理为基础,通过分析汽车两侧车轮在路面附着系数相差较大的对开路面上的紧急制动状况进行理论分析,提出运用主动转向技术控制汽车的方向稳定性,并使汽车在制动驶偏后能快速通过转向控制恢复到正确的行驶车道。 相似文献
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为减小SUV车型在人车碰撞中对行人小腿的伤害,文章对SUV车型前保险杠造型进行了优化。分析了上支撑与下支撑布置和材料对小腿碰撞伤害值的影响,结果表明,当前保险杠上支撑安装位置处于小腿上部质心以下时,上支撑与小腿上部质心距离及上支撑材料对胫骨加速度值影响较大,上支撑与下支撑距离与下支撑材料对剪切位移影响较大。采用优化后的前保险杠防撞系统有效地控制了行人小腿伤害值,有利于该车型行人保护性能的提升,为以后SUV车型行人保护前保险杠防撞系统设计提供一些参考。 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(11):871-885
This article presents a model for solving solid–fluid interactions in vehicles carrying liquids. A tractor–semitrailer model is developed by incorporating suspension systems and tire dynamics. Owing to the solid–fluid interaction, equations of motion for the vehicle system are coupled. To simplify the complicated solution procedure, the coupled equations are solved separately using two different codes. Each code is analyzed separately; but as the parameters of the two codes depend on each other, the codes must be connected at the end of each time step. To determine the dynamic behavior of the system, different braking moments are applied. As the braking moments increase, braking time decreases. However, it turns out that increasing the braking moment to more than a certain level produces no significant results. It is also shown that vehicles carrying fluids need a greater amount of braking moments in comparison to vehicles carrying solids during braking. In addition, as the level of the fluid inside the tanker increases, from one-third to two-third of the tanker’s volume, the sloshing forces applied to the tanker’s walls increase. It was also concluded that the strategy used in this article to solve for the solid–fluid interaction by incorporating vehicle dynamic effects represents an effective method for determining the dynamic behavior of vehicles carrying fluids in other critical maneuvers. 相似文献
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Toshiyuki Yamamoto Jean-Loup Madre Ryuichi Kitamura 《Transportation Research Part B: Methodological》2004,38(10):905-926
The French government has implemented a periodical vehicle inspection program, which aims at maintaining proper functioning of the vehicle and ensuring the emissions control systems installed on the vehicle work properly. Also, an incentive program for scrapping old vehicles was introduced in 1994 through 1996 to promote the replacement of those vehicles with higher emissions by newer vehicles with lower emissions. A hazard-based duration model of household vehicle transaction behavior has been developed in this study to examine the effects of the inspection program and the grant for scrappage on vehicle transaction timing. The model is developed as a competing risks model assuming the following three types of competing risks: replacing one of the vehicles in the household fleet, disposing of one vehicle in the fleet, and acquiring one vehicle to add to the fleet. The empirical analysis is carried out using the panel data of French households' vehicle ownership from 1984 to 1998, obtained by the panel survey called Parc-Auto, which has been conducted by a French marketing firm, SOFRES, since 1976. The long panel observation period facilitates the introduction of macro-economic indicators into the model, enabling the analysis to distinguish the effects of policy measures from macro-economic factors. The empirical results indicate that the expected vehicle holding duration becomes 1.3 years longer under the inspection program than before the program commenced, given that the vehicle is replaced by another vehicle at the end of the holding duration; and that the conditional probability of replacing a vehicle aged 10 years and over becomes 1.2 times higher, and the average holding duration becomes shorter by 3.3 years, when the grant for scrappage is available. 相似文献
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