【作者】 陈明；

【导师】 王建华；

【作者基本信息】 吉林大学 ， 车辆工程， 2011， 硕士

【摘要】 汽车主动防撞预警系统(Active Collision Warning System),是利用传感技术和现代信息技术获得的外界信息,在车况与路况的信息中综合判断是否存在安全隐患,自动采取相应措施对汽车进行控制,使得汽车能够主动避险,保证车辆行驶的安全,从而尽量减少或者减轻交通事故,提高交通安全性。主动防撞预警系统分为三个重要组成部分：行驶环境识别系统、安全判断系统、控制执行系统。行驶环境识别系统是用于识别车况参数(节气门位置信号、自车实时车速信号以及加速度信号等)和路况参数(路面类型、道路标志信号、其它车辆、前方行人及障碍物等),并会测量出相对速度信息,从而达到对汽车内外环境的识别。(2)安全判断系统：将行驶环境识别系统传输过来的各信号进行分析综合,将判断得出的结果以指令的形式向执行控制系统发出,该分析结果也将作为储存信息的一部分以方便驾驶员查询,该部分信息具有较实用的参考价值。(3)控制执行系统：接受安全判断系统的判断情况,在危险状态下向驾驶员发出警报,倘使驾驶员在一定时间内没有采用有效的避险措施,则系统将会避开驾驶员的操作直接过渡到自动控制状态,提高行驶安全性；当系统判断出所遇到的是无论如何也无法避免的危险时,防撞预警系统会自动选择最为妥当的被动安全控制策略。汽车主动防撞预警系统的行驶环境识别中比较关键的就是路况识别和车况识别,其中路况识别研究中最重要的就是路而类型的辨识,表达路面类型最典型的参数就是路面附着系数,而估算路面附着系数难度很大,路面附着系数直接关系到安全的制动距离的大小,而且在主动防撞预警系统中估算路面附着系数的目的也是为了计算制动距离,因此,本文研究的重心转移到建立制动距离模型上来。本文的核心内容就是建立驱动过程中的制动距离模型,首先需要建立整车动力学模型,在理想状态下设置整车参数,之后分别建立发动机模型、变速器模型、传动系统的模型、驱动轮动力学模型、从动轮动力学模型以及整车动力学模型；在整车动力学模型的基础上,建立驱动过程中的制动距离模型,并且设计仿真框图,根据运行结果进行仿真分析。更多还原

【Abstract】 Active Collision Warning System makes use of sensor technology and modern information technology to access external information, according to vehicle condition and road conditions which determines whether there are security risks. Then it will take the appropriate measures to control the car automatically and to make the vehicle avoid the risk and ensure the safety of vehicles, to minimize or reduce traffic accidents and improve traffic safety.Active Collision Warning System is divided into three major parts: Environment recognition system, Security status determination system, Control execution system. Environment recognition system is used to identify vehicle parameters(throttle position signal, the signal of the vehicle speed and acceleration signals in real, etc.) and road condition parameters (road type, road signs signals, other vehicles, pedestrians and obstacles in front of itself,etc). And it will measure the relative velocity information to achieve the identification of Internal and external environment. Security status determination system makes use of identified information environment recognition subsystem provided to determine the state of the vehicle, Mainly calculation and determination whose degree of the risk on the environment determines the model state the current dates fitted, to give directions to Control execution system, and to make the results of calculations and determinations to interact with the driver through Human Machine Interface, Or the driver can also transfer the information they need to Signal processing system for inquiring provide the driver with timely and effective state information as a reference. Controlling execution subsystem accepts judged information which the Security status determination subsystem has provided, and alert the driver in a dangerous state, If the driver have not any action in a certain pre-set period of time, to achieve the required state of Charged target by the system control mode automatically, and to avoid delaying the driver’s operation and to ensure traffic safety; If a collision is unavoidable, it will be called passive safety related measures.Road identification and condition identification are critical in Environment recognition subsystem of Active Collision Warning System, the recognition of road type is the most important in road Recognition, The most typical expression of road surface type parameters is the road adhesion coefficient, But it is difficult to estimate the road adhesion coefficient, Road adhesion coefficient is directly related to the size of braking distance, And the purpose of estimating the road friction coefficient is to calculate the braking distance in the Active Anti-collision Warning System. Therefore, this study’s focus is shifted to building up the braking distance model. The core content of this article is to establish a braking distance model in the drive process, First it needs to create dynamic model of vehicle, set vehicle parameters ideally, establish the engine model, Transmission model, Transmission system model, Driving wheel dynamics model, Driving wheel dynamics model and the vehicle dynamics model; which is Based on the vehicle dynamics model, establishing the braking distance model the process of driving, designing Block Diagram of simulation, analyzing the results of running simulation.更多还原