Real-time Ethernet Research Articles

Microsecond-level Real-time Ethernet Deterministic Bus (REDBUS): Architecture and motor control experiments

Microsecond-level Real-time Ethernet Deterministic Bus (REDBUS): Architecture and motor control experiments

End-to-End Real-Time Service Provisioning Over a SDN-Controllable Analog mmWave Fiber -Wireless 5G X-Haul Network

The current work presents the first experimental demonstration of real-time Ethernet (ETH) trial services and 4K-Ultra High Definition (UHD) video application transmission over a 2λ Wavelength Division Multiplexing (WDM) analog Fiber-Wireless (FiWi) mmWave X-haul network, supporting dynamic flexible capacity allocation through an integrated silicon photonic Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> Reconfigurable Optical Add Drop Multiplexer (ROADM) and 60 GHz wireless transmission across a 7 m V-band link distance, while controlled by a Software Defined Network (SDN) controller based on Open Daylight. Analog X-haul transport of the radio signals is based on an Intermediate Frequency over Fiber (IFoF) scheme centered at 1.5 GHz using an Orthogonal Frequency Division Multiplexing (OFDM) radio-waveform with a bandwidth of 204 MHz, generated by a Field Programmable Gated Array (FPGA)-based RF System-on-Chip (SoC) processor that converts on-the-fly the real-time ETH downlink traffic to analog radio and vice-versa for the uplink. Dynamic allocation of the X-haul traffic capacity is handled through the use of the 802.1Q Virtual Local Area Network (VLAN) tag-mechanism, which controls the forwarding operation to the proper DAC and InP EML for optical modulation using Intensity Modulation/Direct Detection (IM/DD) schemes, while the wavelength routing operation is handled by the low-loss four-port Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> ROADM featuring only 2.5 dB fiber-to-fiber losses based on a cascaded MZI-interleaver design on the TriPleX platform, routing the real-time traffic to a second mmWave antenna site. Detailed measurements and traffic statistics indicate end-to-end latency of less than 260 μs and a packet loss less than 0.0054% across a dynamic range of at least 6.5 dB in the optical domain, while the high user bandwidth and signal quality are validated by an uninterrupted 4K-UHD video transmission across the FiWi X-haul mmWave transport network. The current work aims to shape a complete technology roadmap for Point-to-Multipoint FiWi transport network architectures with high spectral efficiency X-haul transport for dense areas and 5G/6G hotspots of future mmWave Centralized Radio Access Networks (C-RANs).

An Adaptive Confidentiality Security Service Enhancement Protocol Using Image-Based Key Generator for Multi-Agent Ethernet Packet Switched Networks

Conventional network Security Protocols provide different types of security services that establish secure connections between network nodes making them robust against different security threats. The security establishment process depends on sharing security keys between connected devices. The level of security provided by such security protocols is static and irrelevant to the status of the network. In this paper, we propose an adaptive security-aware lottery-EDF scheduler for limited resources Ethernet packet switched networks using GAIA multi-agent approach. The proposed system adopts a periodic non-shared cryptographic key-generation process of different sizes (i.e., 64 bits, 128 bits, 160 bits, and 512 bits) using the textural features of digital images stored on a central image-server. The proposed system deploys a security enhancement unit that adaptively enhances the confidentiality security-service level for the real-time packets according to feedback from a congestion control scheme that is based on network resource estimation technique, hence making the network robust against the spoofing security threat while preserving the overall network performance metrics (NPMs). By simulating a real-time Ethernet packet switched network, extensive simulation results show the efficiency of the adaptive proposed protocol over the static-security and IPSec protocols in guaranteeing the QoS requirements for the real-time flows in terms of destination’s buffer consumption and average total packet delays.

Modeling development method for slave controller of real-time ethernet fieldbus

Modeling development method for slave controller of real-time ethernet fieldbus

Design of real-time ethernet bus controller

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A Novel Heterogeneous Parallel System Architecture Based EtherCAT Hard Real-Time Master in High Performance Control System

EtherCAT is one of the preferred real-time Ethernet technologies. However, EtherCAT is not applicable in high-end control fields due to real-time constraints. Clock synchronization and cycle time are the most representative limitations. In this paper, a novel Heterogeneous Parallel System Architecture (HPSA) with features of parallel computation and hard real-time is presented. An HPSA-based EtherCAT hard real-time master is developed to significantly improve clock synchronization and shorten cycle time. Traditional EtherCAT masters feature serial processing and run on a PC. This HPSA-based master consists of two parts: EtherCAT master stack (EMS) and EtherCAT operating system (EOS). EMS implements the parallel operation of EtherCAT to realize the shorter cycle time, and EOS brings a hard real-time environment to the HPSA-based master to improve clock synchronization. Furthermore, this HPSA-based master operates on a heterogeneous System-on-a-chip (SoC). EMS and EOS form a heterogeneous architecture inside this SoC to achieve low-latency process scheduling. Experimental results show that in our HPSA-based EtherCAT hard real-time master, the cycle time reaches the sub-50 μs range, and the synchronization error reduces to several nanoseconds. Thus, this HPSA-based master has great application value in high-performance control systems.

A Low-Cost Online Data Acquisition and Processing System for Industrial Pollutants’ Monitoring

Recently, the prevention and control of industrial pollution has attracted extensive attention. Many studies based on emission data have achieved great success, but there are relatively few studies on the emission data acquisition. To this end, we propose a data acquisition and processing system (DAPS) for online monitoring of industrial pollutants. The system receives real-time emission data through the RS485, automatically generates periodic data, and saves it in the SQL Server database. Real-time Ethernet (RTE) is used to transmit control signals between the system and programmable logic controllers (PLCs). Emission data is transmitted to local industrial control systems and remote monitoring centers (RMCs) via a wireless network. We tested the acquisition function and communication function of the system through experiments and evaluated the overall performance of the system by observing the memory and CPU usage. The system is characterized by simple implementation and versatility and can be applied to continuous monitoring of various industrial pollutants.

Versatile unsupervised anomaly detection method for RTE-based networks

Reliability and dependability are critical demands of the fourth industrial revolution that Real-time Ethernet (RTE) networks have to meet. The use of anomaly detection and prevention techniques can further enhance existing RTE networks. This work presents a general and efficient anomaly detection strategy based on machine learning techniques. The proposal is of general purpose since only normal (i.e not anomalous) traffic data and statistical features are used during the training phase of the classifier. These features are derived from data sets extracted from unsupervised traffic data using a sliding window algorithm. The efficiency of the proposal depends on the proper selection of the sliding window algorithm’ parameters. In this work, an optimization strategy appropriately selects the algorithm’s step and window size. An Adapted Correlation based on Feature Selection indicates the most relevant features reducing the data dimensionality, improving classifier performance and efficiency. Finally, a One-Class Support Vector Machine algorithm is trained and used for classifying the traffic data sets. The authors applied the proposed anomaly detection strategy in real network data (PROFINET and Ethernet/IP Networks). The results demonstrate the proposal’s efficiency and accuracy.

TSN-Based Backbone Network of Train Control Management System

Time-sensitive network (TSN), as one of the latest real-time Ethernet techniques, has achieved great success in several scenarios that require strict communication latency and packet loss. This paper reviews the state-of-the-art in time-sensitive networks and investigates the drawbacks of current vehicle networks. By introducing TSN into the TCMS backbone network, next-generation smart vehicles can achieve high-quality data transmissions. This paper also analyzes the priority of the vehicle data and calculates the time-aware shaper slot to ensure that the control data is not affected by the multimedia data. Using the proposed structure, experimental results suggest that the network efficiency can be improved in the rail transit systems.

A Survey of Real-Time Ethernet Modeling and Design Methodologies: From AVB to TSN

With the development of real-time critical systems, the ever-increasing communication data traffic puts forward high-bandwidth and low-delay requirements for communication networks. Therefore, various real-time Ethernet protocols have been proposed, but these protocols are not compatible with each other. The IEEE 802.1 Working Group developed standardized protocols named Audio Video Bridging (AVB) in 2005, and renamed it Time-Sensitive Networking (TSN) later. TSN not only adds new features but also retains the original functions of AVB. Proposing real-time Ethernet modeling and design methodologies is the key to meeting high-bandwidth and low-delay communication requirements. This article surveys the modeling from AVB to TSN, mainly including: (1) AVB and TSN modeling; (2) end-to-end delay modeling; (3) real-time scheduling modeling; (4) reliability modeling; and (5) security modeling. Based on these models, this article surveys the recent advances in real-time Ethernet design methodologies from AVB to TSN: (1) end-to-end delay analysis from AVB to TSN; (2) real-time scheduling from AVB to TSN; (3) reliability-aware design for TSN; and (4) security-aware design for TSN. Among the above four points, the last two points are only for TSN, because AVB lacks reliability and security mechanisms. This article further takes the automotive use case as an example to discuss the application of TSN in automobiles. Finally, this article discusses the future trends of TSN. By surveying the recent advances and future trends, we hope to provide references for researchers interested in real-time Ethernet modeling and design methodologies for AVB and TSN.

A general optimization-based approach to the detection of real-time Ethernet traffic events

One of the most used technologies in industrial automation is industrial Ethernet. RTE protocols can cope with the requirements of the Industry 4.0 frameworks. However, the broader use of industrial Ethernet also generates discussion about its vulnerabilities. In this sense, this work proposes anomaly detection methods. These methods are usually time-consuming and limited in scope since they are derived for addressing a single protocol. Thus, this work proposes a general and accurate anomaly detection technique suitable for any protocol based on RTE. ANN-based and SVM-based classifiers are used for classifying data traffic events based on the most relevant features extracted from data sets. An optimal sliding window approach is used for extracting these data sets, which improves the accuracy of the proposal. Seven different classifiers are investigated. Firstly, a Perceptron Neural Network is applied for verifying if the data sets are linearly separable. If this first classifier is unable to reach the required accuracy, three ANN-based classifiers with different activation functions and three SVM-based classifiers with different kernels are employed. The use of several classifiers not only improves the accuracy but also eliminates the need for advanced knowledge about communication dynamics. The generality and accuracy of the proposal are evaluated for detecting traffic events using real traffic data of a real automotive plant. PROFINET, Ethernet/IP, and SERCOS III networks have been analyzed, showing that some traffic events can be classified using the Perceptron while others require the use of more complex classifiers achieving accuracy greater than 98%.

Anomaly Detection and Attack Classification for Train Real-Time Ethernet

Real-time Ethernet has been applied to train control and management system (TCMS) of 250km/h Fuxing Electric Multiple Units (EMUs) and some urban rail vehicles. The openness of the Ethernet communication protocol poses a risk of intrusion attacks on the train communication network. It is, therefore, necessary that a safety protection technology is introduced to the train communication network based on real-time Ethernet. In this paper, a train communication network intrusion detection system based on anomaly detection and attack classification is proposed. Firstly, the paper built an anomaly detection model based on support vector machines (SVM). The particle swarm optimization-support vector machines (PSO-SVM), and genetic algorithm-support vector machines (GA-SVM) optimization algorithms are used to optimize the kernel function parameters of SVM. Secondly, the paper built two attack classification models based on random forest. They are iterative dichotomiser3 (ID3) and classification and regression tree (CART). And then, the built intrusion detection and attack classification model is tested by using the public data set knowledge discovery and data mining-99(KDD-99) and the data set of the simulation train real-time Ethernet test bench. PSO-SVM improves the intrusion detection accuracy from 90.3% to 95.75%, GA-SVM improves the detection accuracy from 90.3% to 95.85%. The training time of the PSO-SVM algorithm was higher than that of the GA-SVM algorithm, and much higher than that of the SVM, without optimization. Both ID3 and CART models are verified valid in the attack classification, while the ID3 algorithm obtained 100% accuracy on the training set, and only 32.89% accuracy on the test set, ID3 has a poor classification accuracy of the data outside of the training set. Also, the classification time is very long for ID3 compared with CART. So the comprehensive experimental results show that the intrusion detection system of train real-time Ethernet can use the GA-SVM model for detection of abnormal data. After passing the normal data, the CART model can be used to distinguish between the types of attacks to better complete subsequent responses and operations. Compared with the anomaly detection model based on SVM, the proposed model improves intrusion detection accuracy. And the proposed attack classification algorithm based on CART can improve the computing speed while ensuring the precision of classification.

Design and implementation of EtherCAT Master based on Loongson

Abstract With the gradual development and competition among enterprises, the products of motion control system are diversified and the performance difference is bigger. The technology of motion control system is monopolized by a few foreign professional manufacturers. The development of motion controller in China is relatively late, and the number with independent research and development ability is still in the minority. Compared with foreign countries, some developed countries still restrict the export of high-end products to China. This paper will use Loongson 3A3000 processor to realize open motion controller. Loongson series processor is a general domestic processor developed by Institute of computing technology, Chinese Academy of Sciences. It uses MIPS instruction system. At present, Loongson is gradually catching up with and surpassing the world advanced level. The communication module of motion controller uses EtherCAT real-time Ethernet, which has the characteristics of high efficiency, flexible topology and short refresh cycle. At present, there are few cases of open motion controller based on domestic CPU Loongson, which provides a typical case for independent innovation in China.

Cost-Effective Hot-Standby Redundancy With Synchronization Using EtherCAT and Real-Time Ethernet Protocols

When designing and manufacturing industrial computer systems, many different issues must be considered. The most important of these are the temporal characteristics and real-time operation. Another factor is the distribution of the system, usually over a wide area, operation in harsh environments, and, finally, the system’s dependability. When addressing the last issue, redundancy is commonly employed. This can be applied in many ways, e.g., by providing redundant communication links (buses and communication modules) and redundant sensors, input/output modules. This article considers systems that have computing unit redundancy, for which programmable logic controllers (PLCs) are often used. On the one hand, systems of this kind should be reliable and capable of real-time operations. On the other hand, they should be economically attractive. There are many solutions available on the market for the implementation of systems with redundancy. However, they are always rather expensive. Of course, the price is for a robust solution with dedicated hardware and many built-in features that are crucial in highly reliable systems, such as autodiagnostics. Nevertheless, such powerful products are not always required. This article presents an example of a cost-effective implementation of an industrial controller with hot-standby redundancy using regular devices and an Ethernet communication interface for the needs of synchronization of the computing units. For this purpose, EtherCAT and real-time Ethernet protocols were used. Note to Practitioners—This article is motivated by the problem of high cost of application of systems with computing units redundancy based on dedicated components, such as the latest S7-1500R/H Redundant System by Siemens or PACSystems Profinet System Redundancy by Emerson (former GE IP). The above solutions are powerful and sophisticated. However, sometimes, simpler solutions would suffice. This article shows how a system with computing unit redundancy could be built in a cost-effective way and, at the same time, provide all the basic features expected from systems with redundancy, i.e., fault detection, automatic switchover, and synchronization. All this is done with a common embedded programmable device and an open Ethernet-based communication network.

Cyber–Physical Codesign of Field-Level Reconfigurations in Networked Motion Controllers

To be successful in the quickly evolving future of machine building and meet the increasingly complex requirements of manufacturers, equipment manufacturers face challenges of reconfigurability on the motion controller. This article proposes a cyber-physical codesign approach to enable plug-and-play of field devices via real-time Ethernet in controllers. In our proposal, we first design a modular runtime framework to facilitate auto-discovery and self-configuration of servo drives with EtherCAT. Then, we implement a self-adaptive period synthesis method for real-time scheduling. The method can automatically attain a combination of minimized periods for communication and control task during startup and achieve dynamic compensations of drifts and jitters occurred in the network. Through experiments, we show that for various combinations of cyber-physical settings, our proposal can ensure low jitters ($<; $10 μs) and stable latencies with a 125 μs cycle time and achieve runtime reconfiguration with a 250 μs or larger cycle time.

Performance of synchronized master-slave closed-loop control of AC electric drives using real time motion over ethernet (RTMoE)

Multi-motor driving servomechanisms are widely used in modern industry for high-performance applications involving synchronized control of position, speed, acceleration and deceleration. Several synchronous control schemes have been developed to achieve good speed or position tracking regardless of various uncertainties and load torque perturbations. However, these solutions have some disadvantages, namely the costs associated with the necessary interfaces to transmit hardware synchronization signals between multiple drives and difficulty to integrate other tools and communication networks. Recently, Industrial Ethernet network-based control systems are becoming increasingly popular for industrial applications and factory automation. To overcome some of these disadvantages this paper proposes an approach that uses a real-time Ethernet applied to a dual-motor master-slave synchronization system, without introducing significant degradation of speed or position in the application performance. With this solution the position reference from the master encoder is transmitted by the real-time Ethernet instead of the classic hardware interface. This allows the integration of different tools and the explore of other functionalities of electric drives. The performance of the proposed solution was tested using industrial equipment through several practical experiments. It was also compared with an existing solution based on hardware interfaces, to identify advantages, limitations and cost savings of using real-time Ethernet networks solutions in synchronized AC electric drives.

Model-Based Stealth Attack to Networked Control System Based on Real-Time Ethernet

In this article, industrial control systems include networked control systems (NCS), which use real-time Ethernet (RTE) protocols since many years, well before the time sensitive networking initiative debut. Today, ethernet-based control systems are used all across Industry 4.0, including in critical applications, allowing for straight integration with information technology layers. Even if it is known that current RTE protocols do not have strong authentication or ciphering options, it is still very challenging to perform undetected cyber-attacks to these protocols while the NSC is in operation, in particular because such attacks must comply with very strict and small temporal constraints. In this article, a model-based attack is proposed for service degradation of NCS. The attack is carried out in real-time and it can remain undetected for the entire plant life. The attack can be applied to any RTE protocols and, without loss of generality, a detailed analysis of stealth techniques is provided for a specific real use case based on PROFINET. The experimental results demonstrate the feasibility of the proposed attack and its high effectiveness. The article also points out some possible future investigation directions in order to mitigate the attack.

Network Intelligence Empowered Industrial Robot Control in the F-RAN Environment

Industrial robots are widely adopted in modern industries, including automobile manufacturing, warehousing, and so on. The industrial robot with cellular network connection will be more flexible and intelligent than that without a network connection or with a conventional industrial communication network connection (e.g., fieldbus, real-time Ethernet, and WiFi). This is seen as the direction of development of the next generation of industrial robots. As a promising candidate for the next generation of cellular networks, fog radio access network (F-RAN) can provide artificial intelligence (AI) on the network edge, which is equipped with some computing and storage facilities, thus promoting the development of industrial robots in the future. In this article, we first propose a local-network cooperative control architecture for industrial robots in the F-RAN environment, which divides the robot controller into an onboard controller and a network controller, in order to decouple the basic control functions and application-dependent functions. The network controller is implemented on the fog access node (F-AP), and it possibly uses AI to bring advanced capabilities to the robot control. Then, based on the proposed architecture, a testbed for multiple automated guided vehicle (AGV) coordination in F-RAN has been designed and implemented, and a recurrent neural network (RNN)-empowered multi-AGV coordination policy is also developed. Finally, its performance is examined by several experiments. The results show that network intelligence deployed in F-RAN can improve the scheduling efficiency up to 35 percent, and the proposed control architecture can save huge backhaul traffic compared to the conventional cloud-based control architecture for industrial robots.

An Architecture for Highly Reliable Fault-Tolerant Adaptive Distributed Embedded Systems

With increased demand for carrying out critical operations in unpredictable environments, critical adaptive distributed embedded systems will play a key role in future cyberphysical systems. Based on a flexible real-time Ethernet network, we propose a complete architecture that includes mechanisms to deal with faults for high reliability.

Design and implementation of a three-dimensional simulation system for a humanoid table tennis robot

This paper designs and implements a simulation system that can verify the planning algorithms such as table tennis trajectory planning and robot leg movement planning. The simulation system and the humanoid robot’s control system are connected based on the RTnet real-time Ethernet protocol. The table tennis game of the humanoid robot is implemented using the simulation of the forward and inverse kinematics of the robot arm, the hitting planning, and the forward and inverse kinematics of the robot leg.