汽车动力学课件

An integrated 集 成
stability control
system can incorporate 合 并 both yaw stability横摆稳定 and roll stability侧倾稳定 control。
① The lower curve shows the trajectory轨迹 that the vehicle would follow in response响应 to a steering input from the driver if the road were dry and had a high friction coefficient摩擦系数 between the tire and road.
③ In the case of stability control systems as shown by the middle curve, if the speed was higher than some certain thresholds门限, the yaw control system 横 摆 控 制 系 统 would be brought into play with effect发挥作用 on holding the track轨迹 that vehicle should done.
The increasing worldwide use of automobiles has motivated促使 the need that develop vehicles to optimize优化 the use of highway and fuel resources, to provide safe and comfortable transportation and at the same time have minimal impact on the environment.
Stability control systems that prevent vehicles from skidding滑移 or spinning out 偏转 are often referred to as yaw stability control systems横摆稳定控制系统.
Stability control systems that prevent roll over侧翻 are referred to as roll stability control systems侧倾稳定控制系统.
VEHICLE DYNAMICS AND CONTROL 汽车动力学及控制
参考书目
1、R. Rojimani, Vehicle Dynamics and Control, SPRINGER . Ltd. 2 、 J.R. Ellis, Vehicle Dynamics, LONDON BUSINESS BOOK. Ltd. 3、喻凡，汽车系统动力学，机械工业出版社。 4、周云山，汽车电子控制技术，机械工业出版社。 5、张洪欣， 汽车系统动力学，同济大学出版社。 6、余志生，汽车理论，机械工业出版社。 7、靳晓雄，汽车振动分析 ，同济大学出版社
1.2 ACTIVE STABILITY CONTROL SYSTEMS 主动性稳定控制系统
Vehicle stability control systems稳定控 制系统 that prevent vehicles from spinning 偏转, drifting out侧滑 and rolling over侧 翻 have been developed and recently commercialized 商 业 化 by several automotive manufacturers.
1) Collision avoidance防碰撞 systems which automatically detect slower moving preceding 前 面 的 vehicles and provide warning and brake to assisted to the driver. 2) Adaptive Cruise Control自适应巡航 控制(ACC) systems which enhance提升 cruise control systems and enable preceding vehicles to be followed automatically at a safe distance.
1.1
DRIVER ASSISTANCE SYSTEMS 驾驶员辅助系统
On average, one person dies every minute somewhere in the world due to a car crash碰撞. In addition to the emotional toll惊人的费用 of car crashes, their actual costs in damages实际损害成本 equaled to 3% of the world GDP in 2000.
It is a great challenge to develop such vehicles that can satisfy these diverse不同 的 and often conflicting冲突 requirements.
To meet this challenge, automorelying on electromechanical systems机电一体化系统 that employ sensors传感器, actuators执行器 and feedback control反馈控制.
Advances进展 in solid state electronics 固态电子学, sensors, computer technology and control systems during the last two decades have also played an enabling role in promoting this trend.
A variety of driver assistance systems are being developed by automotive manufacturers to automate mundane乏味 driving operations, reduce driver’s burden 负担, and thus reduce highway accidents. Examples of such driver assistance systems under development include:
Data from the National Highway Transportation Safety Association (NHTSA) 美 国 高 速 公 路 交 通 安 全 协 会 show that 6.335 million accidents事故 occurred on US highways in 1998 (NHTSA, 1999). Data also indicates that, while a variety of factors contribute to 促 成 accidents, but human error accounts for over 90% of all accidents.
CHAPTER 1
INTRODUCTION 概论
The use of automobiles is increasing worldwidely. In 1970, 30 million vehicles were produced and 246 million vehicles were registered注册 on the world. By 2009, about 70 million vehicles have been produced and more than 800 million vehicles could be registered.
5) Vision enhancement or night vision 视 野 提 升 或 夜 视 systems for detecting obstacles障碍 and pedestrians 行人. 6) Driver condition monitoring驾驶员 状 况 监 视 systems which detect frequency of wink 眨 眼 and provide warning for driver drowsiness瞌睡.
It would travel on a trajectory轨迹 of larger radius 半 径 (smaller curvature 曲 率 ), and a significant yaw speed would make vehicle to spin with breaking away脱离 from ideal path.
This are partially succeeded部分地完成 by making the vehicle’s yaw rate横摆角速度 closer to the expected预期 nominal yaw rate.
A yaw stability control system is in action by helping to keep the vehicle on its intended预期 path and thus preventing the erratic不稳定 driver steering actions. There are also considerable works being done directly on the development of active rollover prevention systems主动防 侧 翻 系 统 , especially for Sport Utility Vehicles (SUV) and trucks.