【作者】 徐超；

【导师】 曾锃；

【作者基本信息】 湖南大学 ， 计算机应用技术， 2011， 硕士

【摘要】 近年来，CAN总线因其实时性强、安全性好、便于扩展等优点，逐渐成为现场总线的主流。目前，除在一贯使用良好的汽车领域外，CAN总线在过程自动化、楼宇自动化、制造自动化等领域也都有广泛的使用。随着CAN总线的不断成熟，工业微波控制领域因规模不断扩大而带来的温度控制不够精准、磁控管输出不稳定、规模不宜扩展以及数据传输拥堵等问题，都可借用CAN总线的优势解决。本文首先介绍了LamC系统（大阵列磁控管控制系统）和CAN总线的相关背景以及它们的应用现状。详细分析了CAN总线的通信模型、传输机制及报文滤波与屏蔽等技术原理，基于CAN总线的这些技术原理，结合LamC系统要求的灵活控制、便于扩展、安全可靠等特点，提出基于CAN总线的LamC系统的硬件和软件需求及其架构。确定需求后，通过比较CAN总线现有的应用层协议的优缺点，提出一种新的、完全符合本系统使用特点的应用层协议——MWCPro。该协议结构简单，便于理解，且具备CAN总线的实时性好、安全性高和便于扩展等优点。通过在开发板上对该协议进行功能验证，发现该协议简单可靠。最终参照MWCPro的软、硬件的需求，自主设计13.5千瓦的中型微波设备控制系统的软硬件，测试结果显示基于CAN总线及MWCPro的微波控制系统的设计达到了预期的目标：在线从机的检测、实时传送数据、无数据拥堵和丢包现象产生且报警及时安全可靠。在大阵列磁控管控制系统（LamC系统）中，只需采用CAN2.0B的扩展标识符以及网控器便可进行节点扩展，过程简单可靠。不仅如此，通过修改命令协议指令，MWCPro还可用于其它较为简单和独立的自动化控制系统。更多还原

【Abstract】 Recent years, CAN bus is becoming more and more popular in the field offieldbus, because of its real-time interactive responsiveness, safety, scalability andperformance. At present, CAN bus is also used in process automation, constructionautomation, manufacturing automation, and so on, in addition to it, the bus is widelyuse in automotive field. It is hard to control the temperature precisely and expand thescale along with the industrial microwave control fields’ development constantly. Inthe other aspects, the magnetrons output unstable and the data transmissioncongestion problems are the problems too. But now, the advantages of CAN bus cansolve these things.This paper first introduces the related background and application status of thelarge array magnetrons control system and CAN bus. Then it analyzes the details ofCAN bus communication model, transmission mechanism, packet filtering andblocking technology principle. This paper puts forward the hardware and softwarerequirements and architecture of LamC system based on CAN bus theory whileaddressing the problems related to flexible control, scalability, safety and reliabilitycharacteristic. After conforming to the requirements and a careful comparativeanalysis of pros and cons of existing application layer protocol for the CAN, wepropose a new application-layer protocol---MWCPro, which fully complies with thissystem’s features. This protocol is simple in structure, easy to understand, and hasmultiple advantages like real-time response, high safety and scalability, etc. Throughthe functional verification of the protocol on the CAN bus development board, wefound that this protocol is simple and reliable. Finally, according to the software andhardware requirements of this protocol, we designed the hardware and software of themedium-sized microwave control system by ourselves, the ultimate test results showthat LamC system based on CAN bus and MWCPro is expected to reach the designgoal: online machine detection, real-time transmission of data, zero data congestionand minimal lost package phenomenon, alarm prompt, reliability. In the LamC system,we just need to do the two things to extend the control system; CAN2.0B extendedidentifier and network access controller. And the process is simple, reliable. MWCPromay be used in the simple and independent automotive control systems.更多还原