【作者】 吴春阳；

【导师】 张丹红；

【作者基本信息】 武汉理工大学 ， 控制科学与工程， 2012， 硕士

【摘要】 电子技术在汽车上的广泛应用使得智能传感器、电子执行器和电控单元急剧增加,各种通信设备陆续地在汽车上得到应用。随之而来,在汽车中的电气配线以及各种信号线越来越多,导致系统运行的可靠性下降、故障率增加。为了实现各个单元状态信息的共享、提高系统的可靠性,各种网络技术被引入到汽车中,车载网络技术成为研究热点之一。因此,本文开展嵌入式车载网络系统的研究与设计。经典CAN总线网络能够很好地实现传输速率在500kbps以下的电控单元之间的信息交换；近几年发展迅速的LIN总线主要是针对简单的传感器-执行器之间数据传输而设计的一种总线,适合于在传输数据量更小、速率要求更低的设备之间传输数据；新型MOST总线非常适合汽车媒体设备应用环境的要求,汽车行业已经把MOST技术作为将来汽车媒体系统的一个标准。本文重点分析了目前广泛使用的LIN总线、CAN总线以及MOST总线,结合各自总线的特点,设计了基于以上三种总线的车载网络系统。在本车载网络系统中,三种总线各自的分工如下：对于低速的传感器-执行器装置使用LIN总线；对于实时性要求高的汽车电子装置使用CAN总线；对于高速传输数据、要求严格的车载电子装置使用MOST总线。基于以上思路,设计了基于ARM的嵌入式车载网络控制器。该系统的硬件平台主要由以下几部分组成：核心处理器S3C2440、扩展存储器SDRAM和NAND-Flash、LIN总线驱动器MC33661、CAN总线控制器SJA1000与收发器PCA82C250、MOST总线控制OS8104与光纤收发器MIT401/MIR401。根据嵌入式系统软件设计的一般方法并结合硬件电路,完成了系统各部分硬件的底层驱动。详细论述了嵌入式Linux内核的移植,Yaffs根文件系统的制作、LCD显示设备驱动程序、LIN总线、CAN总线以及MOST总线驱动程序的实现方法。针对车载网络中三种网络总线,论述了这些总线应用软件的实现,重点介绍总线数据帧格式的制定、一些重要函数的实现以及对远程诊断程序进行调试。更多还原

【Abstract】 The widespread application of car electronic technology to automobile causes the smart sensor, the electronic actuator and electrically controlled unit to grow sharply, and every kind of communication equipments are applied to automobile one after another. Subsequently, more and more electrical wires as well as a variety of signal lines in automobile causes the operational reliability of system to drop, the failure rate to increase. In order to achieve each unit status information sharing, improve system reliability, a variety of network technologies have been introduced into the car, vehicle networking technology to become one of the research focus. Therefore, this paper thoroughly researched and designed embedded automotive network system.Classic CAN bus network can be a good solution to control the electronic controlled unit, the transmission rate of which is less than500kbps. The rapidly developed LIN bus in recent years is a kind of bus which is designed for data transmission between simple sensors and actuators, effectively improving the utilization rate of the CAN bus. The new MOST bus is very suitable for the requirement of the vehicle media device application environment, the MOST technology has been regarded as a standard of car media system in the future by automotive industry.This paper focuses on the current widely used LIN bus, CAN bus and MOST bus, designs a vehicle network system based on the above three bus in connection with their respective requirement for application. For the three bus of this vehicle network system, their respective division of work are as follows:LIN bus is used for low-speed sensor-actuator device; CAN bus is used for automotive electronic devices requiring better real-time; the MOST bus is used for automotive electronic device requiring high-speed transmission of data.ARM-based embedded vehicle network controller is designed based on the above classification structure of vehicle bus. The hardware platform of this system consists of the following parts:core processor S3C2440, extended memory SDRAM, NAND-Flash, the LIN bus drive MC33661, CAN bus controller SJA1000, transceiver PCA82C250, MOST bus controller OS8104and optic fiber transceiver MIT401/ MIR401.Bottom divers of various parts of hardware in this system are completed according to the general method of software design of the embedded system as well as hardware circuitry. The transplantation of embedded Linux kernel, production of Yaffs root file system, LCD display driver, the realizing method of driver of LIN bus, CAN bus and MOST bus are discussed in detail.In connection with the three network bus in vehicle network, the realization of these bus application software is discussed, the formulation of the bus data frame format, realization of some important functions as well as debugging remote diagnosis program are emphasized.更多还原