【作者】 果艳红；

【导师】 刘淑敏； 冯晓东；

【作者基本信息】 北京化工大学 ， 检测技术与自动化装置， 2008， 硕士

【摘要】 TTCAN协议在CAN协议基础之上将事件触发机制与实时性更高的时间触发机制相结合,提高了网络实时性,满足对安全性要求苛刻的实时系统以及总线日益增长的信息负载的需求。CAN总线技术的研究为TTCAN协议总线技术研究奠定了很好的软硬件基础。文章介绍了TTCAN协议较CAN协议的改进、协议的基本要素及调度算法的研究现状。针对TTCAN协议调度算法研究不足的现状,以汽车控制系统为应用实例,首先结合遗传算法和一维装箱算法对TTCAN协议的静态调度表进行了研究和改进。其次为了克服静态调度算法在实际应用中灵活性差的问题,通过在线生成矩阵周期的方法实现了TTCAN协议的动态调度算法。最后利用Matlab中的Stateflow工具对该算法进行仿真研究,并按照ISO11898—4标准的要求,利用现有的硬件资源,搭建TTCAN网络通信的硬件平台。仿真结果较好的验证了TTCAN协议在通信实时性和带宽利用率方面的优势,并且有效的提高了在实际应用中的灵活性。仿真模型的成功建立为TTCAN协议应用在通信可靠性要求较高的硬实时通讯环境中提供了重要的参考价值。更多还原

【Abstract】 Based on the CAN protocol, TTCAN protocol combines event-triggered with time-triggered which improves the real-time performance of the network and makes the communication meet the demand of security critical real-time system and the increasing bus load;At the same time, the research on CAN makes good software and hardware environment for TTCAN.This paper introduces the improvements of the protocol TTCAN than CAN, the basic elements of the protocol and the research condition of scheduling algorithm. In order to deal with the insufficient research condition of TTCAN scheduling algorithm, as an example in automobile control system, firstly, combined with the characteristics of one-dimensional packing algorithm and genetic algorithm, the TTCAN static scheduling of the table were studied and improved.Secondly,in order to overcome the poor flexibility that the static scheduling algorithm used in the practical application, carry out TTCAN dynamic scheduling algorithm through creating matrix cycle online. Finally, the simulation model of the scheduling algorithm is implemented in the state flow tools of Matlab. And according to ISO11898-4, makes use of the existing hardware resources, and then structures the hardware platforms of the TTCAN communication network.The simulation results prove that the algorithm of TTCAN has the advantage of real-time transmission of signal and bandwidth utilization ratio, and also enhance the flexibility of practical application effectively. The successful establishment of simulation model provides an important reference value for TTCAN protocol which is applied in the hard real-time communication environment requiring higher communication reliability.更多还原