【作者】 金海松；

【导师】 李刚炎；

【作者基本信息】 武汉理工大学 ， 机械设计及理论， 2005， 博士

【摘要】 现代轿车电子控制单元多为相互独立的系统,各单元间又往往存在着关联性和时序性的控制需求。如何对这些电子控制系统实施有效、有序和安全方便的集中控制,综合利用它们的信息己成为将电子技术应用于轿车上和轿车技术发展迫切需要解决的理论和应用问题。 本文以多个项目为支撑,特别是在法国洛林国家信息及其应用研究实验室(LORIA:Laboratoire Lorrain de Recherche en Informatique et ses Applications)实验室的技术支持下,针对轿车电子控制系统存在的问题,立足于提高轿车整体性能,基于将轿车中各种独立的功能系统关联信息集中传递和控制的思路,采用当前先进的车载网络,研究轿车信息集中控制系统(CICCS:Car InformationCentral Control System)及其主要关键技术。 在研究CICCS定义、特征和构建准则的基础上,构建CICCS的总体结构和节点结构,通过比较分析,确定了CICCS结构中的网关模型。 提出了CICCS的控制方法——基于规则和分级递阶的控制方法。对于带有轿车信息集中控制器的CICCS两种方法都可以采用;而对于在网关中没有集成轿车信息集中控制功能的系统,只能采用分级递阶控制方法。 在对轿车行驶外控因素进行分类分析的基础上,对交通环境进行了分类,建立了CICCS控制规则的层次结构;在对制动过程进行合理的分解后,研究了轿车直线行驶和坡路行驶时的安全制动距离:提出了轿车撞车、火灾事件的控制规则;以环型交叉路口和非环型交叉路口为例,研究了轿车转向的控制规则,从而说明了CICCS控制规则的产生过程与主要方法。 在对CICCS实时性分析的基础上,结合Bosch公司开发的供不同等级网络通信用的通用工作负荷特性表,设计了若干状态下CICCS需要传递的信息;分别采用RM算法和DM算法分配信息优先级,依此计算出系统的worst-case响应时间,并进行了对比分析。结果显示,当高速CAN(ControllerArea Network)上的速率达到500Kbit/s,低速CAN上的速率达到100 Kbit/s时,不论是采用RM(Rate Monotonic)算法还是采用DM(Deadline Monotonic)算法,所有的信息都能满足其截止期要求。 采用分布式实时系统的可靠性技术分析了CICCS的故障类别和可靠性要求,提出了CICCS的可靠性体系,得出了CICCS的可靠度计算公式。 选用Kvaser Navigator作为CICCS性能分析仿真平台,面向事例,对CICCS进行了实时性和可靠性仿真。其结果验证了CICCS的可行性、实时性和可靠性。对比了下坡行驶时驾驶员和CICCS制动的安全制动距离。计算结果显示,在同等条件下,采用CICCS制动能明显改善轿车的制动情况。更多还原

【Abstract】 There are many kinds of Electronic Control Units (ECUs), which are mostly independent in a modern car. However, there frequently exist correlative and time sequence control requirements between them. How to centrally control these ECUs in an effective, orderly, safe and convenient way and how to synthetically use their information have already become theoretical and applied problems that must be solved urgently in the course of applying electronic technologies to cars and development of the car’s technologies.This dissertation is supported by several projects, especially technically supported by Laboratoire Lorrain de Recherche en Informatique et ses Applications (LORIA). In order to improve the holistic performances of a car, aiming at solving the existing problems of the ECUs, based on central transmission and control correlative information from various independent car ECUs, adopting advanced in-vehicle network, the author of this dissertation researches the Car Information Central Control System (CICCS) and its key technologies.After researching the definition, features and forming rules of CICCS, the author builds the whole structure of CICCS and the structure of its nodes. By compare, gateway model of CICCS is determined.Rule-based control method and hierarchically control method of CICCS are put forward. To CICCS with a car information central controller, both methods could be used. To CICCS without a car information central controller, only hierarchically control method could be adopted.Based on the classification of a car’s outer factors in the course of driving and classification of traffic environment, hiberarchy of control rules in CICCS is built. After division of braking process, safe braking distances during drive beeline, decline and ascent are calculated. Control rules of collision and fire are brought forward. Steering round a cross-road and steering round a traffic circle as examples, control rules during steering are researched. Thus produce process and main ways of control rules in CICCS are demonstrated.On the basis of the analysis of CICCS real-time, combined with universal working load characteristic table for different level network communication developed by Bosch, information need to be transmitred under some condition in CICCS is designed. Adopting Rate Monotonic (RM) and Deadline Monotonic (DM)scheduling to assign information priorities, worst-case response time in CICCS are calculated. The results show, when the bit rate of high-speed CAN reaches 500Kbit/s and the speed of low-speed Controller Area Network (CAN) is 100Kbit/s, all the messages meet their timing constraints under both RM and DM.Adopting dependability of distributed real time system, fault classes and dependability requirements in CICCS are analyzed, dependability system is presented and its reliability is deduced.Choosing Kvaser Navigator as the simulation flat of CICCS performance analysis, event oriented, real time and dependability simulations of CICCS are conducted. The results validate its availability, real time and dependability. The author compares the safe braking distance while a car brakes by driver during decline with the value when a car brakes through CICCS. The results show that under the same conditions, brake performance of the car by CICCS could be improved remarkably.更多还原