【作者】 司徒莉英；

【导师】 朱顺应；

【作者基本信息】 武汉理工大学 ， 交通运输规划与管理， 2010， 硕士

【摘要】 论文以国家自然科学基金——基于视觉光流率和边缘率的车速控制理论与方法研究(50778142)为依托。我国山地丘陵占总面积比重大,地貌条件复杂,生态环境制约大,山区公路往往存在坡度大、坡道长的连续长大下坡路段,而长大下坡路段车辆制动失效致使车速失控造成的事故数及伤亡人数常年处于高位,交通安全形势严峻。人们所掌握的外部世界信息有80%以上通过视觉获得,视觉信息是驾驶员重要的速度感知源,通过合理的视觉诱导能让驾驶员产生车速高估、车距低估效用,可引诱和强制驾驶员减速。若能从驾驶员视知觉出发,结合长大下坡车辆速度及制动温升特征,进行考虑制动器温升约束下的控速标线设计研究,有助于实现事前驾驶员自主控速,符合并适应我国长下坡事故率高、事故强度大、超载车多、车速过快及可控经济资源有限的具体国情。本文首先简述边缘率原始速度定义,从时间与空间频率角度简析边缘率在行车状态下对驾驶员主观车速感知的具体影响,总结边缘率在交通领域的创新应用表现形式,并选取边缘线单元个体间距作为边缘率控制参数。随后,总结国内外长大坡段描述,以我国近年下坡段事故统计数据为基础,从人因、车辆、车速、道路环境等角度分析下坡段事故致因,综合比对国内外研究现状及事故数据、路况、车辆性能差异性,选取制动器温升控制安全值及下坡段较为合理的速度控制阈值。结合相关分析及结论,提出下坡段边缘率控速设计思路,从具体国情出发,确定出控速设计具体研究车型,有机结合能量守恒、汽车动力学、物体运动学等,给出下坡段车辆驱动基本方程,并推导出减速制动下坡功率与制动热能转换的关系式,从能量变化构成的角度对其简化应用进行分析及描述。接下来,在现有基本理论基础上,总结分析现有研究对舒适减速度的取定及其适用范围,在文献实测数据基础上结合下坡特性确定纵坡行驶方向舒适减速度的取值范围,对恒定边缘率控速模型进行局部调整,在实路试验数据基础上总结得出货车敏感ER取值范围。然后,合理考虑应用控速模型减速时的制动功率与制动鼓温升关系变化,确定温升变化约束下的控速标线设计使用方法。最后,给出具体车型参数及预设相关参数下的视觉控速设计实例,在其基础上分析讨论具体车型车重、车速与制动鼓温度变化间的关系。更多还原

【Abstract】 Constrained by the complex landforms and ecological environment, There are often continuous long steep downgrades when the driver driving on the mountain road. And annual number of accidents and casualties remain high, which are caused by the brake failure resulted the fast speed that out of control. Traffic safety situation of the long steep downgrade is grim. People grasp the 80% outside world information through the vision, and the visual information is driver’s important speed sensation source. The reasonable visual induction can let the driver have the vehicle speed over-estimated feeling and under-estimated the effectiveness of distance between vehicles, distance between vehicles, then may guide and force the driver to decelerate. Embark on visual perception of the driver, combined with speed and braking temperature characteristics to analyze the driver visual speed controlling design method for the long steep downgrade, it helps to realize the driver can control speed consciously, and the driver visual speed controlling method is a effective measurement that adapt to the China situation with the high accident rate, the heavy accident intensity, more overloading of vehicles, the excessively quickly vehicle speed and the limited controllable economic resource.This paper briefly defined the edge rate, from the perspective of time and spatial frequency, analyzed the edge rate’s influence for the driver subjective perception of speed under driving condition, summarized the innovative applications of edge rate in transportation domain, and then selected the individual edge line unit spacing as the edge rate controlled variable. Subsequently, summarized the domestic and foreign description of the long steep downgrade, with the basis of downhill section accident statistics data of our country in recent years, analyzed the cause of the downhill accident from various aspects such as human’s reason, vehicles, speed and road conditions. Then synthesis compared to domestic and foreign research of accident data, and the difference of road conditions, vehicles performance, selected brake rising temperature security value and reasonable speed control threshold value for the long steep downgrade. According to related analysis and conclusions, proposed the driver visual speed controlling design conception for the long steep downgrade, from the specific national conditions, determine the vehicle type for the speed control design, combined with conservation of energy, automobile dynamics, object kinematics and so on, the basic drive equations was given, then deduced the mathematical formula about downhill deceleration power and braking energy conversion, and decrypted its simplified application from the sight of energy changes. Next, on the basis of the existing basic theory, summarized and analyzed existing research on the comfort retardation rate, based on the measured data in the literature and combined with downhill characteristics, determined value scope of the comfort retardation rate for the steep downgrade, then made a adjustment to the design model for speed control by using constant edge rate, obtained the sensitive value scope of the edge rate on the basis of real road test data. Considering the relationship of downhill deceleration power and braking energy conversion, determined the logical relation about using the new design model that combined with speed and braking temperature characteristics. Finally, the design example was given, then on the basis the example, analyzed the relationships about vehicle’s weight, speed and brake temperature.更多还原