To evaluate and improve the real-time performance of Ethernet for plant automation（EPA） industrial Ethernet,the real-time performance of EPA periodic data transmission was theoretically and experimentally studied.By...To evaluate and improve the real-time performance of Ethernet for plant automation（EPA） industrial Ethernet,the real-time performance of EPA periodic data transmission was theoretically and experimentally studied.By analyzing information transmission regularity and EPA deterministic scheduling mechanism,periodic messages were categorized as different modes according to their entering-queue time.The scheduling characteristics and delivery time of each mode and their interacting relations were studied,during which the models of real-time performance of periodic information transmission in EPA system were established.On this basis,an experimental platform is developed to test the delivery time of periodic messages transmission in EPA system.According to the analysis and the experiment,the main factors that limit the real-time performance of EPA periodic data transmission and the improvement methods were proposed.展开更多
Considering the increasing use of information technology with established standards, such as TCP/IP and XML in modem industrial automation, we present a high cost performance solution with FPGA （field programmable ga...Considering the increasing use of information technology with established standards, such as TCP/IP and XML in modem industrial automation, we present a high cost performance solution with FPGA （field programmable gate array） implementation of a novel reliable real-time data transfer system based on EPA （Ethemet for plant automation） protocol and IEEE 1588 standard. This combination can provide more predictable and real-time communication between automation equipments and precise synchronization between devices. The designed EPA system has been verified on Xilinx Spartan3 XC3S1500 and it consumed 75% of the total slices. The experimental results show that the novel industrial control system achieves high synchronization precision and provides a 1.59-ps standard deviation between the master device and the slave ones. Such a real-time data transfer system is an excellent candidate for automation equipments which require precise synchronization based on Ethemet at a comparatively low price.展开更多
In order to optimize the embedded system implementation for Ethernet-based computer numerical control （CNC） system, it is very necessary to establish the performance analysis model and further adopt the codesign met...In order to optimize the embedded system implementation for Ethernet-based computer numerical control （CNC） system, it is very necessary to establish the performance analysis model and further adopt the codesign method from the control, communication and computing perspectives. On the basis of analyzing real-time Ethemet, system architecture, time characteristic parameters of control-loop ere, a performance analysis model for real-time Ethemet-based CNC system was proposed, which is able to include the timing effects caused by the implementation platform in the simulation. The key for establishing the model is accomplished by designing the error analysis module and the controller nodes. Under the restraint of CPU resource and communication bandwidth, the experiment with a case study was conducted, and the results show that if the deadline miss ratio of data packets is 0.2%, then the percentage error is 1.105%. The proposed model can be used at several stages of CNC system development.展开更多
EPA(Ethernet for Plant Automation)通过微网段划分和确定性调度策略解决了以太网的非确定性问题,实现了信息的实时传输。作为一种实时网络控制系统,网络时延特性是影响EPA控制性能的关键因素。在分析EPA信息结构和信息传输规律的基础...EPA(Ethernet for Plant Automation)通过微网段划分和确定性调度策略解决了以太网的非确定性问题,实现了信息的实时传输。作为一种实时网络控制系统,网络时延特性是影响EPA控制性能的关键因素。在分析EPA信息结构和信息传输规律的基础上,研究了EPA微网段中信息传输网络时延的构成和各部分子时延的特性。通过分析确定性调度策略,对网络时延各部分中最重要的通信调度管理实体排队时延部分进行了重点研究,推导了周期报文和非周期报文排队时延的数学表达式,还建立了确定周期报文发送时间片和非周期报文发送时间片的数学模型。最后通过一个实例对相关分析进行了验证,找到了制约EPA网络时延特性的关键因素并提出了解决方案。展开更多
Real-time Ethernet(RTE) control systems with critical real-time requirements are called fast real-time(FRT) systems.To improve the real-time performance of Ethernet for plant automation(EPA),we propose an EPA-FRT sche...Real-time Ethernet(RTE) control systems with critical real-time requirements are called fast real-time(FRT) systems.To improve the real-time performance of Ethernet for plant automation(EPA),we propose an EPA-FRT scheme.The minimum macrocycle of EPA networks is reduced by redefining the EPA network frame format,and the synchronization process is modified to acquire higher accuracy.A multi-segmented topology with a scheduling scheme is introduced to increase effective bandwidth utilization and reduce protocol overheads,and thus to shorten the communication cycle significantly.Performance analysis and practical tests on a prototype system show the effectiveness of the proposed scheme,which achieves the best performance at small periodic payload in large scale systems.展开更多
基金Supported by the National High Technology Research and Development Program of China (2006AA040301-4,2007AA041301-6)
文摘To evaluate and improve the real-time performance of Ethernet for plant automation（EPA） industrial Ethernet,the real-time performance of EPA periodic data transmission was theoretically and experimentally studied.By analyzing information transmission regularity and EPA deterministic scheduling mechanism,periodic messages were categorized as different modes according to their entering-queue time.The scheduling characteristics and delivery time of each mode and their interacting relations were studied,during which the models of real-time performance of periodic information transmission in EPA system were established.On this basis,an experimental platform is developed to test the delivery time of periodic messages transmission in EPA system.According to the analysis and the experiment,the main factors that limit the real-time performance of EPA periodic data transmission and the improvement methods were proposed.
文摘Considering the increasing use of information technology with established standards, such as TCP/IP and XML in modem industrial automation, we present a high cost performance solution with FPGA （field programmable gate array） implementation of a novel reliable real-time data transfer system based on EPA （Ethemet for plant automation） protocol and IEEE 1588 standard. This combination can provide more predictable and real-time communication between automation equipments and precise synchronization between devices. The designed EPA system has been verified on Xilinx Spartan3 XC3S1500 and it consumed 75% of the total slices. The experimental results show that the novel industrial control system achieves high synchronization precision and provides a 1.59-ps standard deviation between the master device and the slave ones. Such a real-time data transfer system is an excellent candidate for automation equipments which require precise synchronization based on Ethemet at a comparatively low price.
基金Projects(50875090,50905063) supported by the National Natural Science Foundation of ChinaProject(2009AA04Z111) supported by the National High Technology Research and Development Program of China+2 种基金Project(20090460769) supported by China Postdoctoral Science FoundationProject(2011ZM0070) supported by the Fundamental Research Funds for the Central Universities in ChinaProject(S2011010001155) supported by the Natural Science Foundation of Guangdong Province,China
文摘In order to optimize the embedded system implementation for Ethernet-based computer numerical control （CNC） system, it is very necessary to establish the performance analysis model and further adopt the codesign method from the control, communication and computing perspectives. On the basis of analyzing real-time Ethemet, system architecture, time characteristic parameters of control-loop ere, a performance analysis model for real-time Ethemet-based CNC system was proposed, which is able to include the timing effects caused by the implementation platform in the simulation. The key for establishing the model is accomplished by designing the error analysis module and the controller nodes. Under the restraint of CPU resource and communication bandwidth, the experiment with a case study was conducted, and the results show that if the deadline miss ratio of data packets is 0.2%, then the percentage error is 1.105%. The proposed model can be used at several stages of CNC system development.
文摘EPA(Ethernet for Plant Automation)通过微网段划分和确定性调度策略解决了以太网的非确定性问题,实现了信息的实时传输。作为一种实时网络控制系统,网络时延特性是影响EPA控制性能的关键因素。在分析EPA信息结构和信息传输规律的基础上,研究了EPA微网段中信息传输网络时延的构成和各部分子时延的特性。通过分析确定性调度策略,对网络时延各部分中最重要的通信调度管理实体排队时延部分进行了重点研究,推导了周期报文和非周期报文排队时延的数学表达式,还建立了确定周期报文发送时间片和非周期报文发送时间片的数学模型。最后通过一个实例对相关分析进行了验证,找到了制约EPA网络时延特性的关键因素并提出了解决方案。
基金Project supported by the National High-Tech R&D Program (863) of China (No. 2008AA042602)the National Natural Science Foundation of China (Nos. 61075078 and 61074028)
文摘Real-time Ethernet(RTE) control systems with critical real-time requirements are called fast real-time(FRT) systems.To improve the real-time performance of Ethernet for plant automation(EPA),we propose an EPA-FRT scheme.The minimum macrocycle of EPA networks is reduced by redefining the EPA network frame format,and the synchronization process is modified to acquire higher accuracy.A multi-segmented topology with a scheduling scheme is introduced to increase effective bandwidth utilization and reduce protocol overheads,and thus to shorten the communication cycle significantly.Performance analysis and practical tests on a prototype system show the effectiveness of the proposed scheme,which achieves the best performance at small periodic payload in large scale systems.
