【作者】 姜秀柱；

【导师】 徐钊；

【作者基本信息】 中国矿业大学 ， 通信与信息系统， 2011， 博士

【摘要】 EPA是我国自主研发的工业实时以太网国际标准。微网段是EPA网络的基本组成部分,为了实现微网段的实时调度,微网段内节点数据的产生速率和传输时间必须满足一定的关系。本文以实时调度基本理论和经典调度算法可调度性定理为基础,证明了EPA微网段可调度的充要条件,完善了EPA网络实时调度算法的理论依据,为EPA技术的进一步发展研究奠定了坚实的基础。宏周期和偏移量是构成EPA网络实时调度算法中的两个关键参数,宏周期和偏移量的确定决定着EPA实时调度算法的实现。本文在对EPA微网段可调度的充要条件研究的基础上,提出了具有硬实时性能,经计算实时级别可达<10us级的复合周期EPA实时调度算法,并找到了满足复合周期调度的各节点复合周期条件,在证明该法可用的同时,给出了复合周期调度下的宏周期和偏移量计算方法。分时调度是以太网实现确定性传输的关键技术。EPA通过增加一个调度子层,在分布式精确时钟的支持下,采用静态优先级固定时隙分配的方法,实现分时调度。这种静态优先级固定时隙分配的方法,在煤矿环境下经常发生的网络结构变化、节点出现故障、节点增减变化或节点受干扰信息频繁重传等情况下,都会导致固定时隙分配策略的失效或固定分配时隙的浪费。为此,本文提出了基于EPA的煤矿EPA微网段自适应实时调度算法MEPA_SaSiS。该算法结合事件和时间共同驱动,能根据节点有无信息传输以及实际信息传输时间即时动态分配时隙。在保证EPA微网段实时能力的同时,可将信道使用率稳定到92.93%~99.26%,并使微网段的调度运行具有适应节点失效离线和在线恢复的容错能力。在煤矿工业控制网络中,跨网段周期数据传输是一种普遍需求,EPA的实时调度是基于微网段的,不能保证跨网段实时周期数据的传输,这是EPA自身存在的不足。本文在微网段自适应实时调度算法MEPA_SaSiS的基础上,通过对EPA跨网段传输过滤规则的改进,并结合协同优先级分配的思想,提出了一种可以根据跨网传输延迟的变化和不同网段时基差的波动自动调整跨网段周期数据发送时刻的煤矿EPA网络跨网段自适应实时调度算法MEPA_SaSaS,实现了跨网段周期数据的确定性传输。论文有图56幅,表1个,参考文献136篇。更多还原

【Abstract】 EPA ,Ethernet for Plant Automation, is a international standard about industrial real-time Ethernet,which was developed by our country itself.Micro-segment is an element part of EPA network. In order to implement the real-time scheduling in micro-segment, it is necessary that the rate to generate data in a node suits the delay to transmit it in the micro-segment. On the basis of the real-time scheduling theory and classical algorithm RM and EDF, the thesis proves the sufficient and necessary conditions for feasibility of EPA scheduling algorithm in a micro-segment, completes the theoretical basis of EPA scheduling algorithm and gives a solid foundation to develop EPA technology further.Micro period and the offset are two key parameters of EPA scheduling algorithm, how to determine them decides the implementation of EPA scheduling algorithm. The thesis gives a novel method to calculate the micro period of a micro-segment and offsets for every node in the micro-segment, which implements hard real-time with the help of multi-periods in a micro period and is proved feasibility theoretically by the author.Time division scheduling is a key technology to implement the real-time in Ethernet. EPA realizes the time division scheduling through adding a sub layer to schedule the time slice to nodes, under the support of a precise synchronous clock. EPA allocates the fix time slice to every node before running the network; therefore it does not suit a variation environment like coal mine, which has changes in time slice to transmit data and changes in number of nodes when networks work. Author comes up with a dynamic method, MEPA_SaSiS, to allocate time slice according to the practical need of every node, and put forward an idea to implement it using a event-driven way replaced to the time-driven way, so that attains a stable channel utility ratio of 92.93 to 99.26 percent. Furthermore author brings forward some measures to feel the fault nodes off and recover nodes up on line, so as to implement the fault-tolerant scheduling with the way of both the even-driven and the time-driven.In the industrial Ethernet of coal mine,it is general situation to transmit data from a node in a micro-segment to a node in another micro-segment. Because EPA real-time scheduling can only be realized in a micro-segment, author raises a new real-time scheduling algorithm , MEPA_SaSiS, to realize the transmit data across two micro-segment, which bases on EPA scheduling algorithm and changes the filter rules across segments in EPA scheduling algorithm.There are 56 figures, 1 table, and 136 literatures.更多还原