Real-time performance of periodic data transmission in EPA industrial Ethernet

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.

A hybrid genetic algorithm to optimize device allocation in industrial Ethernet networks with real-time constraints

With the advance of automation technology,the scale of industrial communication networks at field level is growing.Guaranteeing real-time performance of these networks is therefore becoming an increasingly difficult task.This paper addresses the optimization of device allocation in industrial Ethernet networks with real-time constraints (DAIEN-RC).Considering the inherent diversity of real-time requirements of typical industrial applications,a novel optimization criterion based on relative delay is proposed.A hybrid genetic algorithm incorporating a reduced variable neighborhood search (GA-rVNS) is developed for DAIEN-RC.Experimental results show that the proposed novel scheme achieves a superior performance compared to existing schemes,especially for large scale industrial networks.

Distribution of combustible gas alarm based on embedded Ethernet technology

One kind of combustible gas alarms based on industrial Ethernet was designed to prevent the gas leakage in industrial production sites, The alarm adopted the high performance microprocessor LPC2214 as the main chip. The embedded operating system μC/OS-Ⅱand TCP/IP protocol stack uIP running on LPC2214 constitute a development platform of application of the combustible gas alarm, The test shows that it can automatically and continuously detect combustible gas in industrial production sites in several positions;it can give out sound-light alarm and take protective measures immediately against the gas leakage; and it can send the detected data to PC through the Ethernet interface to realize the remote detection. The designed project provides a reference to design industrial devices based on industrial Ethernet

一类活动发射平台驱动控制系统网络设计

In order to ensure that a mobile launch platform is able to transport a launch vehicle which is assembled vertically on a complex orbit,a communication network for the drive control system was designed.Based on the char-acteristics of equipment of the drive control system and its position,Industrial Ethernet and Profibus were selected.To meet the requirements for reliability and maintainability of aerospace products,the communication network featured a hot redundant to avoid single point failure risk,so that if any point in the system fails,the control strategy of standby switches using heartbeat detection and parity check would ensure the normal communication and failure diagnostics,which could enable the transport mission of the launch vehicle to be completed smoothly.

Time-stamped predictive functional control for networked control systems with random delays

The random delays in a networked control system (NCS) degrade control performance and can even destabilize the control system.To deal with this problem,the time-stamped predictive functional control (PFC) algorithm is proposed,which generalizes the standard PFC algorithm to networked control systems with random delays.The algorithm uses the time-stamp method to estimate the control delay,predicts the future outputs based on a discrete time delay state space model,and drives the control law that applies to an NCS from the idea of a PFC algorithm.A networked control system was constructed based on TrueTime simulator,with which the time-stamped PFC algorithm was compared with the standard PFC algorithm.The response curves show that the proposed algorithm has better control performance.

Present situation and developing trend of coal mine automation and communication technology

Introduced developing process of coal mine automation and communication technology,analyzed present features and characteristics of coal mine automation and communication technology,and put forward a few key technical problems needed to be solved.

Research on Testing Technologies of Network System in Smart Substations

The network structures of smart substations and the characteristics of industrial Ethernet switches are analyzed.The testing technologies of network systems based on smart substations are specifically elaborated.A viewpoint is proposed that special testing policy&method of smart substation networks should be followed,so that the results can reveal the real network data exchange performance of the whole station.This view ensures the safety and stability of smart substations and lays a foundation for future upgrades and expansions.

The Parallel Redundancy Protocol over Wide Area Networks

To accomplish the safety-critical mission of transmission and distribution automation, high availability and stability are always required in the industrial communication networks. The IEC 62439 Standard (Industrial communication networks-High availability automation networks) Part 3 defines the Parallel Redundancy Protocol (PRP) and High-availability Seamless Redundancy (HSR) protocols. Both redundancy protocols target the process bus described in IEC61850 9-2 [1] and support only Local Area Networks (LANs). It has become an active research area to extend the redundancy protocols to the Wide Area Network (WAN) communication with existing network infrastructure. This paper offers a novel solution, namely the parallel redundancy protocol over the wide area networks (PRPW), to enable PRP over WANs with no added overheads to the data frame, while retaining full compatibility. Moreover, PRPW also strengthens the cyber security against spoofing attacks by maintaining a comprehensive list of remote communication units.