基于DO-178C的民用飞机二级配电系统的软件开发(硕士)

基于DO-178C的民用飞机二级配电系统的软件开发(硕士)(论文42000字)
SOFTWARE DEVELOPMENT FOR CIVIL AIRCRAFT SECONDARY POWER DISTRIBUTION SYSTEM BASED ON DO-178C
摘要
随着航空电力系统在整个飞机的功能扩大，大量电力设备逐渐开始取代传统的电气系统并且拥有了许多新的功能。传统的集中式配电变得难以维护和实施，系统重量的问题，布线的复杂性，可重组性，以及额外的监控和维护的需要。这些问题都成为了影响成本和安全的障碍。在国外，航空业者提出了多电飞机和固态配电这些新技术。随着固态配电系统成熟应用在B787、A380等飞机上，许多传统飞机的电力系统的问题得到了解决。固态配电技术的自身优势使其迅速成为现代飞机发展的必然趋势。本文以某民用飞机机型项目的二级配电系统项目为背景，采用了固态通道控制技术、航空CAN总线技术和过载保护技术，研发了一个符合民用机载软件开发流程的机载软件。该软件根据国际机载软件研发流程DO-178C中定义的B级（危害级）进行研制，符合中国民用航空规章第25部：运输类飞机适航标准。
本文首先对国内外研究现状进行调研，综述了固态配电技术、ARINC-825航空CAN总线技术和过载保护技术。在深入分析DO-178C标准的基础上，详细描述了基于DO-178C标准的软件需求、设计与实现的开发目标和开发过程。
本文软件需求和软件设计均采用自上而下的迭代方式进行。软件需求来源于分配给软件的系统需求，一些必要的且不能直接追踪至系统需求的将标记为衍生需求。本文对二级配电系统中的通道控制、过载保护和CAN总线通讯三个关键功能进行了深入的需求分析，并定义了相应的软件非功能需求。二级配电系统的软件由配电控制单元软件和通道控制单元软件两个构件组成，本文对两个构件分别进行了架构设计，包括软件总体结构、软件总体数据流图、软件数据结构设计和软件模块接口设计。在此基础上，对软件中关键的通道控制模块、过载保护模块、CAN通讯模块进行了详细设计与实现。刻画了一个满足机载软件设计流程要求和技术要求的二级配电系统软件。
目前，本系统已通过原型机测试，并已交付。系统功能测试与非功能测试的结果表明，本系统的通道控制、CAN通讯和过载保护功能已经实现，采样精度达到+/-10%，通道响应时间为10毫秒，已符合设计预期。原型机测试为下一步交付蓝标件、红标件和首飞件打下了良好的基础。

关键词DO-178C，固态配电，通道控制，ARINC-825，过载保护
        
SOFTWARE DEVELOPMENT FOR CIVIL AIRCRAFT SECONDARY POWER DISTRIBUTION SYSTEM BASED ON DO-178C
ABSTRACT
With the expansion of aeronautical power system in the whole aircraft, a large number of power equipment gradually began to replace the traditional electrical system and have many new functions.Traditional centralized power distribution becomes difficult to maintain and implement because of the problem of system weight, the complexity of wiring, reconfigurability, and the need for additional monitoring and maintenance. These problems have become obstacles to the economy and security. In foreign countries, the aviation industry has put forward the new technology of the multi-electric aircraft and solid-state power distribution. With the mature application of solid-state power distribution system in B787, A380 and other aircraft, many traditional aircraft power system problems have been solved. Solid-state power distribution technology's advantages make it quickly become the inevitable trend of modern aircraft development. In this thesis, we study how to use solid-state channel control technology, ARINC-825 CAN bus technology and over-current protection in secondary power distribution system (SPDU) of a civil aircraft project. The software will be developed according to the level B (hazard) defined in the DO-178C to comply with CCAR-25: Transport Category Airplanes.
This thesis first investigates the current research status at domestic and foreign, and summarizes the solid-state distribution technology, the ARINC-825 CAN bus technology and the over-current protection technology. Based on the in-depth analysis of the DO-178C standard, the development goals and development process of software requirements, design and implementation based on the DO-178C standard are described in detail.
In this thesis, both software requirements and software design are carried out from top-down iteration. Software requirements come from the system requirements assigned to the software, and some necessary and not directly traced to the system requirements will be labeled as derived requirements. This thesis makes an in-depth analysis of the three key functions of channel control, over-current protection and ARINC-825 CAN bus communication in the SPDU, and defines the corresponding software non-functional requirements.The software of SPDU consists of the SPDUs control software and channel control software two components. In this thesis, the architecture of the two components is designed, including the software block diagram overview, the software data flow chart, and the design of the software data structure and the interface design of the software module. On this thesis, the channel control module, over-current protection module and CAN communication module are in detail design and implementation, and depicts the software which both meets the airborne software design process and SPDU technology requirements.
At present, the system has passed prototype testing and has been delivered. The results of the system function test and non-functional test show that the channel control, CAN communication and over-current protection function of the system have been realized, the channel sampling precision reaches +/-10%, the channel response time is 10 milliseconds, which is in line with the design expectation. The prototype lays a good foundation for the next delivery of blue label, red label and first flying.

Keywords DO-178C, SPDU, Channel Control, ARINC-825, Over-current Protection
 
目录
1 绪论    1
1.1研究背景及意义    1
1.2国内外研究现状    1
1.2.1传统配电电气系统    2
1.2.2固态配电电气系统    3
1.2.3传统配电系统与固态配电系统的比较    4
1.3研究目标与研究内容    6
1.4论文的组织结构    7
2相关技术    8
2.1基于DO-178C的机载软件开发过程    8
2.2固态配电技术    9
2.3通道过载保护    10
2.4航空CAN总线    10
2.5本章小结    12
3二级配电系统的软件需求分析    13
3.1二级配电系统    13
3.1.1飞机电源系统    13
3.1.2系统通讯网络架构    14
3.1.3系统外部交联环境    14
3.1.4功率板卡硬件结构    15
3.2软件需求过程与工具    16
3.2.1基于DO-178C的软件需求过程    16
3.2.2 软件需求工具    18
3.3软件需求分析    19
3.3.1通道控制需求    19
3.3.2 过载保护需求    25
3.3.3 CAN总线通讯需求    30
3.3.4非功能需求    33
3.4本章小结    35
4二级配电系统的软件设计与实现    36
4.1 软件设计与实现的过程与工具    36
4.1.1基于DO-178C的软件设计过程    36
4.1.2基于DO-178C的软件实现过程    38
4.1.3软件设计与实现工具    39
4.2软件架构设计    40
4.2.1 SPDUApp架构设计    40
4.2.2 ChannelApp架构设计    46
4.3关键模块的设计与实现    50
4.3.1 SPDUApp通道控制模块    50
4.3.2 SPDUAppCAN通讯模块    53
4.3.3 ChannelApp过载保护模块    58
4.4 软件集成    61
4.5本章小结    62
5二级配电系统的原型机测试    63
5.1 原型机系统测试环境    63
5.2 原型机系统功能测试    67
5.3 原型机系统非功能测试    72
5.4 测试结论    76
5.5本章小结    76
6总结与展望    77
6.1 总结    77
6.2展望    78
参考文献    79
致谢    81