基于CAN总线和虚拟仪器技术的车载网络系统的研究

【作者】 颜剑；

【导师】 陈特放；

【作者基本信息】 中南大学 ， 信号与信息处理， 2007， 硕士

【摘要】 CAN总线由于具有可靠性高、成本低、容易实现、协议完全透明、可扩展性强、组建系统非常灵活等优点，在现场总线的实际工程应用中占据了较大的份额。CAN总线已经广泛应用于汽车电子、工业控制、小区智能监控等热点领域。本文研究了CAN总线在铁路养路机械(捣固车)电气控制系统上的应用，对一部原来没有CAN信号输出的捣固车电气控制系统进行了开发研究，使电气系统的各个模块实现了CAN网络的互连。本系统运用了DSP技术，设计了以TMS320F2812为主控制芯片的硬件平台，配以相应的外围驱动电路、信号处理电路、对F2812中CAN控制器开发，设计了一个CAN-bus互连的车载网络系统。系统软件是在DSP编译环境CCS下，用C语言实现的。参照CAN2.0B协议，制定了与之对应的各功能模块与上位机的通信协议。通过对DSP自带的CAN控制器的编程，实现了其CAN信号的发送和接收；并用虚拟仪器技术中的LABVIEW编写了CAN-bus中各节点的监控界面。NI公司的数据采集卡用来对捣固车原电气系统的作业信号进行采集并保存，与CAN-bus传输上来的信号进行了对比分析，结果证明CAN总线传输质量高，无掉包。最后，对整个车载网络进行了扩展设计，针对RS-232串行通讯数据格式，利用串口和PC机对节点的数据进行解包。界面是基于LabVIEW软件而设计的。方便用户利用PC机对CAN网络中单个节点信号采集与处理。通过各功能模块之间、各功能模块与上位机通讯试验和其它测试，结果证明本系统工作正常，信号稳定，抗干扰能力强，成功实现了电气系统各功能模块的互联。本系统在实际试验中取得了良好的效果，达到了设计目的；本系统的研究对CAN-bus和虚拟仪器技术在铁路养路机械电气控制系统的应用具有一定的意义。更多还原

【Abstract】 CAN-BUS is recognized to be one of the most developmental Fieldbus in the world and is becoming the leader pattern. With the features of high reliability, low cost, easy realization, thorough transparency, strong expansibility and flexibility of system setting up, it has occupied the leading position in the market and is widely used in automotive electron, industry control, and intellectualized community and so on.This paper studied the application of CAN-BUS in electrical control system of Railway Maintenance Machinery, in which every module was connected with the CAN network and Based on the input and output signals of all function models. This paper designed a hardware platform which used TMS320F2812 as main control chip and compounded corresponding periphery drive circuit and signal processing circuit adopting DSP technology. The system software was carried out by C language under DSP translate and edit environment CCS,including hardware configuration and control strategy realization.The system also constitute communication protocol between every function module and upper computer relatively according to CAN2.0B protocol. By programming CAN controller of DSP, this system implemented CAN signal’s transmitting and receiving, The data acquisition card of company NI was adopted to acquire and save the working data of formerly electrical control system, and validated the quality of data transmission.The interface of the system was designed by using the tool of LABVIEW, which was on the basis of CAN-BUS. The data was successfully displayed and the signal from the CAN network was compared with the one from the data acquisition card by the monitor interface. The results proved the efficiency and security of CAN-BUS transmission.Finally, the entire Vehicle-borne network was designed for the RS-232 serial communications data format by using serial port and PC to unpack the data at the node.The Interface based on LabVIEW software was designed,which is convenient for Users to acquire and process signal at the single node of CAN network. The experiments and tests of communication among every function module and between function module and upper computer, proved the system to work well and have stable signal and powerful interference immunity. The system gained good result in practical experiments and fulfilled the planning objective. It is beneficial for the application of CAN network in the Railway Maintenance Machinery electrical control system.更多还原