基于CAN总线的Bootloader研究与实现

发布时间：2018-02-12 00:08

本文关键词： 启动加载 ECU ISO15765协议总线负载率状态转移图　出处：《南京邮电大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着汽车ECU(电子控制单元)应用开发的快速发展,其功能越来越强大,实现也越来越复杂。如果应用软件后续需要进行功能升级,传统方法需要将零件从整车上拆卸下来,这将增加更新的工作量,并且容易对车辆本身造成损坏。而Bootloader(启动加载)可以通过车载网络传输数据,实现应用软件的在线更新,免除拆卸的麻烦。车载OBD(在线诊断)五大诊断标准之一的CAN(控制器局域网总线)总线,拥有高度的弹性调整能力,可以在既有的网络中增加节点而不用在软硬件上做任何修正与调整。因此,基于CAN网络的Bootloader的研究具有很大的实用价值。论文首先介绍了车载网络的发展历史,展望了其发展未来;在研究CAN总线协议的基础上,选择、设计了CAN通信模块和外围模块,实现了主控芯片和外部CAN的接口;详细研究了ISO15765协议,并针对STmin建立了数学模型;基于对ISO15765网络层的研究,得出UML描绘的状态转移图并加以实现;根据Bootloader的特点,重新设计Bootloader系统和工作流程,对系统各个模块进行详细的设计与实现,并提出多项改进;在实现Bootloader后,搭建软硬件环境对它的可行性和稳定性进行测试;最后,在证明Bootloader可以在高负载情况下正常工作的基础上,提出后续可能增加的功能等。测试结果分析表明:该系统不仅可以准确地完成应用程序自更新,而且能在高负载下正常工作;相比于传统的采用串口的Bootloader和其他基于CAN总线的Bootloader,该系统稳定性和兼容性更高,能够更好地完成程序更新的任务。研究结果表明该系统完全可以取代各大供应商的Bootloader系统,极大地降低了产品成本。课题的研究对Bootloader系统的设计与开发具有重要的指导作用和参考价值,对其的实际应用也具有很强的实用意义和商业价值。
[Abstract]:With the rapid development of automotive ECU (Electronic Control Unit) application, its function is becoming more and more powerful and its realization is becoming more and more complicated. This will increase the workload of updating and easily damage the vehicle itself, while Bootloader can transmit data through the onboard network to achieve online updates of the application software. Eliminate the trouble of disassembly. CAN (Controller LAN bus) bus, one of the five diagnostic criteria for on-board OBDs, has a high flexibility to adjust, Nodes can be added to the existing network without any modification and adjustment in software and hardware. Therefore, the research of Bootloader based on CAN network is of great practical value. Firstly, this paper introduces the development history of vehicular network. Based on the research of CAN bus protocol, the paper designs the CAN communication module and peripheral module, realizes the interface between the main control chip and the external CAN, studies the ISO15765 protocol in detail, and establishes the mathematical model for STmin. Based on the study of ISO15765 network layer, the state transition diagram described by UML is obtained and realized. According to the characteristics of Bootloader, the Bootloader system and workflow are redesigned, each module of the system is designed and implemented in detail, and several improvements are put forward. After the implementation of Bootloader, the feasibility and stability of Bootloader are tested by setting up a software and hardware environment. Finally, on the basis of proving that Bootloader can work normally under high load, The test results show that the system can not only finish the self-updating of application program accurately, but also work normally under high load. Compared with the traditional Bootloader with serial port and other Bootloader based on CAN bus, the system is more stable and compatible, and can complete the task of program update better. The research results show that the system can completely replace the Bootloader system of the major suppliers. The research on this topic has important guiding and reference value for the design and development of Bootloader system, and also has strong practical and commercial value for its practical application.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U463.6

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