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Despite significant advances in robotic technologies, few affordable robots for domestic applications are commercially available. This study aimed to develop an affordable yet practical mobile manipulator for use in household environments. The proposed mobile manipulator features a software-based real-time controller to control the motion of the manipulator and mobile base. The real-time controller was implemented on a single on-board Windows PC and can control the actuator and IO devices via EtherCAT communication. The major functionalities of the mobile manipulator include the pick-and-place of household objects and autonomous navigation within a domestic environment. For pick-and-place tasks, a deep neural network (DNN) was employed to recognize the object to pick up. For autonomous navigation, open-source ROS packages for SLAM and navigation were used along with the measurements from a LiDAR sensor and odometry. The feasibility of using the developed robot for domestic applications was experimentally evaluated.

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.

In industrial applications, EtherCAT control technology requires the use of TwinCAT control software with dedicated servos for real-time control. In order to solve the limitations of the practical application of EtherCAT, this experiment combines EtherCAT real-time control technology with Simulink Real-Time real-time control technology to design a new EtherCAT real-time control technology based on Simulink Real-Time. In the experiment, D2 delta robot is used as the control object, and the real-time control environment of Simulink Real-Time is set up to build the EtherCAT real-time communication model. The established real-time control model is added to the robot control system to realize the motion control of the robot.

Distributed control is the most popular control strategy for controlling numerous slave devices. However, the performance of slave devices is hard to improve because the control algorithm is handled by the commercial slave devices. Therefore, this paper proposes a hybrid control structure that follows the concept of centralized control strategy and handles part of the control loop on the master computer in a distributed control system through EtherCAT fieldbus. In this study, different advanced control methods such as robust control and learning control were applied to handle the position control loop of a scanning mirror system in a selective laser melting (SLM) system with stringent demand of position error around 40 µm based on EtherCAT fieldbus. By designing a proper controller, the experiment results showed that the tracking performance was significantly improved. The tracking error dropped by about 80% after the proposed hybrid control structure was applied. By applying the proposed hybrid control structure, one can improve the high-performance-requirement devices, while reducing the calculation burden of the master computer for other low-performance-requirement devices by retaining the benefit of distributed control.

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.

Ethernet-based motor drives are hard real-time control systems used to operate servomotors through the industrial Ethernet. Recently, Ethernet-based drives have drawn attention as a solution for industrial transport systems where numerous linear motor drives move magnetic shuttles individually or collectively to accurately position production parts. This paper presents the design and implementation of an Ethernet-based motor drive that enables delay analysis for synchronized motor actuation and sensing to build a scalable and precise industrial transport system. Our software design constructs the drive function using periodic tasks run by a rate-monotonic real-time scheduler and performs worst-case response analysis to determine the end-to-end delay required for the control host to actuate or sense the motor in the drive. Based on the calculated drive delays, clock-based I/O using Ethernet-provided global time realizes synchronized motor operation across multiple drives. In the Ethernet-networked control system, different phases of the host cycle with respect to the drive cycle can result in different actuation and sensing delays. To reduce the delay, we propose a phase-shifted loop method and present a heuristic to find the best phase that minimizes the normalized drive delays. Experimental results obtained using a prototype EtherCAT drive show that the phase-shifted loop significantly reduces the difference between the commanded and feedback currents while properly managing tracking errors. Performance evaluations are performed to investigate the impact of different Ethernet technologies on delays. Elaborated delay models are developed for EtherCAT and Ethernet Powerlink, and a comparative study of delay performance is conducted for various parameters, such as the number of drives, the message size, the network topology, and the bandwidth.

We employ an external processor to distribute the master computing load in the EtherCAT networked control system and develop a method for time synchronization between the Linux on the external processor and EtherCAT network. The synchronization between the Linux on the external processor and EtherCAT master is performed by using general-purpose input/output and shared memory, and the synchronization accuracy is significantly improved by compensating for the system time setting latency and general-purpose input detection latency in the EtherCAT master. The developed method is implemented as part of the master application without modifying the EtherCAT protocol or requiring an excessive computational load. By performing extensive experiments and analyzing the results, we demonstrate that the developed method achieves the synchronization error means less than 1 $\mathrm {~ \mu s}$ with standard deviations less than 5 $\mathrm {~ \mu s}$ between the external processor and EtherCAT network. This synchronization accuracy can be acceptable for various networked control applications based on Linux.

This paper presents a novel real-time collision-free speed alteration strategy using a danger index and an elite real-coded genetic algorithm (ERGA) for environments in which humans and robots coexist or cooperate, in order to guarantee the safety of an operator who works with a collaborative robot. A danger index based on ellipsoid modeling of the operator and robot describes the degree of safety during human-robot interactions. The ERGA and a penalty function are used to solve the constrained nonlinear optimization problem to change the handling speed of the robot. Comparative simulation results show the superiority of the proposed method by comparing to two existing methods. The applicability of the proposed method is verified using two experiments involving a 6-DoF industrial manipulator with an EtherCAT network protocol, an RGB-D sensor and a real-time operation system.

In the study, we develop a method to improve the accuracy of master-slave synchronization in EtherCAT networks. The method involves two key compensations that are not considered in the EtherCAT protocol. First, the propagation delay between the master and reference slave is measured, and the system time of the reference slave is then compensated for the measured propagation delay. Second, the bias component of the synchronization error between the master and reference slave is periodically estimated, and system time of each slave is then compensated for the estimated bias component. The entire method is implemented as part of the master application without modifying the EtherCAT protocol or requiring excessive computation load or large memory space. Thus, the developed method is advantageous because it can be immediately applied at low cost to existing EtherCAT networks. By performing extensive experiments based on a Linux-based EtherCAT master, we demonstrate that the developed method significantly improves the accuracy of the master-slave synchronization in EtherCAT networks.

Piston prover has been widely used as a gas flow standard for its advantages of high accuracy in standard volume, flow stability and repeatability. It has also been employed as the primary gas flow standard in many countries to calibrate meters. However, it is difficult to ensure the uniformity of the inside dimension of the piston, thus the application of conventional piston provers are limited by the maximum calibration flow generated by the piston cylinder volume. In this paper, an improved piston gas prover that mainly consists of two uniform plungers was proposed. Their external diameter constitutes the flow standard. The plungers are driven by servo motor, and the high speed fieldbus EtherCAT has been introduced as the control unit. Hence the two pistons could work collaboratively and operate in three modes: single-piston mode, double-pistons parallel mode, and double-pistons reciprocating mode. Besides generating steady-flow rate, the double-plunger prover can even produce an unsteady-flow rate which could be used to research the dynamic characteristics of flow meters. The structure and working principle of the three modes were carefully introduced. Then experiments for calibrating critical nozzles were carried out, and the results show that the repeatability of the discharge coefficient could be better than 0.06%, and the pressure fluctuation during the process was less than 50 Pa.

This paper presents a robotic automatic drilling and riveting system for single-sided fasteners composed of a robot, an end effector including an intelligent camera and normal measurement cells, a rivet feeder, and some auxiliary system. The control system is designed with the functions of normal adjustment, drilling and riveting position adjustment, compaction, drilling, rivets feeding, glue spread, workstation conversion, and riveting. In order to meet the design needs, communication networks including EtherCAT bus, TCP/IP, serial communication, Automation Device Specification (ADS) communication, and digital IO communication are implemented. The laser sensors and intelligent camera assist to realize algorithms of the normal adjustment and the drilling and riveting positioning. The drilling and riveting system is verified by experiments of flat plate and curved surface. At last, a conclusion is made based on the experiment results which show drilling accuracy the maxi-mum aperture accuracy is 0.016 mm, the maximum deviation of dimple depth is 0.025 mm and the maximum deviation of normal is 0.151°. Aperture accuracy can reach H9 and the efficiency of drilling and riveting in this system can be 5/min.

Modern robots are mainly controlled by monolithic black-box controllers provided by the individual manufacturers. In research institutions the first version of the Robot Operating System (ROS1) is widely used for different applications. However, ROS1 lacks real-time capable communication. The ongoing development of ROS2 promises to break this paradigm. By employing Data Distribution Service (DDS) as a middleware the modular architecture aims at providing realtime capabilities. This study assesses the current prospects and limitations of ROS2. It gains novel insights towards improved and, in particular, reliable results regarding latencies and jitter. To this end, the allocation and transmission of ROS2 messages is evaluated in an example application for robotic control. An oscilloscope is applied for external validation of the measurements in such a time-synchronized distributed network. The complete application is set up from non-real-time object detection towards real-time control via ROS2 and EtherCAT. An in-depth evaluation of the ROS2 communication stack on a single host and in distributed setups is included. With real-time safe memory allocation and highly privileged ROS2 processes real-time capabilities are ensured.

Ethernet Control Automation Technology (EtherCAT) applies distributed clock (DC) to realize synchronization among different slaves. Due to the influence of the crystal oscillator manufacturing process and environment, there is still synchronization error between reference clock and non-reference clock. To solve the clock synchronization problem, this paper proposes a clock drift compensation algorithm based on the idea of closed-loop control. By designing integer-order proportional integral (IOPI) and fractional-order proportional integral (FOPI) controllers, the synchronization error between slaves can be minimized. The IOPI and FOPI controllers designed in this paper are used to eliminate the drift error. This method improves the synchronization accuracy without bringing too much computational load. The results show that the proposed FOPI controller can effectively reduce the synchronization error with even better performance over the IOPI controller.

Objectives/Method: SCADA networks are crucial for industrial organizations, and play an important role in real time industrial communication. Today, with the fourth industrial revolution, infrastructures are increasingly connected to the corporate network and to Internet, which makes them more dependent on networks and communication protocols used. This connectivity can help optimize manufacturing and distribution processes while reducing costs, but it also exposes the industrial network to security issues. The purpose of this article is to describe the architecture of SCADA networks and present the most used SCADA communication protocols such as Modbus TCP, IEC 60870-5-104, DNP3, ETHERCAT, SERCOS III, OPC AU, MQTT and SNMP, to provide a comparative study that allows us to choose the most appropriate protocol for industrial communication, especially in the context of Industry 4.0. Applications/Improvements: We have presented a comparative study to describe the most used SCADA communication protocols. We therefore present the archetecture of each protocol, the quality of service, the context of use, the security, the frame and other information that allow us to choose the most appropriate protocol to apply in the Industry 4.0. Findings: OPC UA is often considered as the next reference for industrial communications, it is a multi-level protocol that includes a security layer to indicate whether future communications will be signed, encrypted or in plain text.

EtherCAT has become one of the leading real-time Ethernet solutions for networked industrial systems, where a reliable communication infrastructure is needed due to highly error-prone environments. However, existing work on EtherCAT mainly focuses on clock synchronization and timeliness improvement. The reliability of EtherCAT-based networked systems has largely been ignored. In this paper, we present a proportional integral derivative (PID)-based feedback control scheme that aims at enhancing reliability of networked systems under timing and system resource constraints. Instead of retransmitting data upon error detection, we use forward error control technique based on inequality of arithmetic and geometric means to achieve the required system reliability at a low deadline miss rate of messages. We further optimize the forward error control technique and design a fast and fair error resilient mechanism by using a cooperative game. In addition to reliability enhancement, our PID-based error control scheme can also improve the stability of a system in terms of deadline miss rate in the presence of burst errors. Simulation results show that the proposed scheme can achieve reliability enhancement of up to 91% compared to benchmarking methods.

Boosted by trends such as Industrial IoT and Industry 4.0, industrial Ethernet networks (EtherNet/IP, EtherCAT and PROFINET IRT as top-3 players) have been commonly deployed in industrial automation. The aim of this paper is to provide a practical guideline for selecting the right protocol in industrial networked control systems (NCSs) by comparing the performance of these protocols. Communication delays are discussed, formulated and evaluated with a study of a typical NCS. Simulation results demonstrate that with different frame packing, media access scheme, etc., EtherNet/IP, EtherCAT and PROFINET IRT offer different levels of real-time capabilities which lead to different control performance. Economic Development Board (EDB) The authors would like to thank the editor and anonymous reviewers for their valuable comments on the manuscript. This work was supported by Singapore Economic Development Board (EDB) [grant number S11-1669-IPP].

Fuzzing (Fuzz testing) can effectively identify security vulnerabilities in software by providing a large amount of unexpected input to the target program. An important part of fuzzing test is the fuzzing data generation. Numerous traditional methods to generate fuzzing data have been developed, such as model-based fuzzing data generation and random fuzzing data generation. These techniques require the specification of the input data format or analyze the input data format by manual reverse engineering. In this paper, we introduce an approach using Wasserstein generative adversarial networks (WGANs), a deep adversarial learning method, to generate fuzzing data. This method does not require defining the input data format. To the best of our knowledge, this study is the first to use a WGAN-based method to generate fuzzing data. Industrial security has been an important and pressing issue globally. Network protocol fuzzing plays a significant role in ensuring the safety and reliability of industrial control systems (ICSs). Thus, the proposed method is significant for ICS testing. In the experiment, we use an industrial control protocol such as the Modbus-TCP protocol and EtherCAT protocol as our test target. Results indicate that this approach is more intelligent and capable than the methods used in previous studies. In addition, owing to its design, this model can be trained within a short time, which is computationally light and practical.

Due to Industrial Control System (ICS)’s critical location, any compromise in their security can have serious consequences. The resilience of ICSs has become a crucial concern to administrators and governments following widely publicized cybersecurity incidents. The inability to apply traditional Information Technology (IT) security practice to ICSs further compounds challenges in adequately securing critical systems. Therefore, there is a need to have a SCADA testbed for checking vulnerabilities and validating security solutions. This paper presents a secure testbed infrastructure for waste and potable water management. The testbed is established under the critical infrastructures national testbed center (CENTER) for training, security research, and attack/defense analysis/tests. Waste and potable water processes support multiple ICS protocols such as DNP3, S7, EtherCAT, Modbus. Each station in the processes is autonomously controlled by local RTUs/PLCs and secured by firewalls with a segregated network. Alternative applications can be made by selecting scenarios with the developed SCADA applications. Also, it provides a robust experimental environment due to its features such as monitoring of both systems, logging, cyber-attack detection.

Industrial control systems (ICSs) are complex systems due to the technology and protocol diversity they contain. Operational Technology (OT), an ICS operating structure, has different performance and security requirements than the standard IT infrastructure. ICS systems consist of field devices where operational processes take place and control systems that provide management of these devices. Attackers are involved in the whole process after gaining access from the control layer. As a result, critical infrastructure systems are threatened by cyber-attacks. Therefore, continuous monitoring and security audits are also necessary processes for critical infrastructures. In this study, studies on the cyberattack and detection system were carried out on the critical infrastructures of the water management process. On the EtherCAT-based water management process, six different attack vectors for field devices were developed by the techniques in the MITRE ICS ATT&CK matrix, and these attacks were separated by data obtained from network traffic and determined by the SVM algorithm. Attack scenarios were created by selecting seven different MITRE ICS ATT&CK matrix techniques for attacks on the SCADA system in the control center via the engineering computer on the same process. Wazuh HIDS was used for the intrusion detection system for the SCADA system. Visualization of both attacks was done on ELK.

Proprietary field buses such as PROFINET IRT, EtherNet/IP, and EtherCAT are currently used to ensure realtime communication in industrial automation appliances. Despite the fact that they are mostly Ethernet-based, interoperability between them is limited or not feasible at all. In the Industry 4.0 context, the goal is to enable real-time communication with ultralow latencies, while also permitting non-critical traffic and ensuring interoperability between devices from different manufacturers. Time-Sensitive Networking (TSN) is a promising candidate to meet these requirements on layer 2 of the OSI reference model in conjunction with a suitable higher-level protocol. The IEEE 802.1 TSN Task Group has been developing extensions to the Ethernet technology to make it more deterministic and reliable since 2012. In this paper, we have evaluated the TSN mechanisms (1) Time-Aware Shaper (TAS) and (2) frame preemption (FP) and compared them to the existing strict priority scheduling (ST) mechanism in exemplary setups. The chosen comparison criteria are latency guarantee, jitter, and the influence on non-critical traffic. Since the support of TSN devices on the market is low, we have carried out the evaluation using the simulation framework OMNeT++ and the NeSTiNg library. Our evaluation shows that, all in all, TAS performs the best, but it introduces a great configuration overhead. FP and ST can keep up in certain scenarios and their performance can even be improved.

EtherCAT is a real-time industrial Ethernet technology suitable for hard and soft real-time requirements. It is based on new technology, “on-the-fly processing”, which significantly reduces cycle times and jitter to further expand the capabilities of IIoT. IEEE 802.1 TSN in recent years gained more attention in IIoT because it offers real-time communication over a shared Ethernet medium with predictable end-to-end delay and jitter. However, there is no work presented to showcase the benefits of EtherCAT and TSN integration apart from theoretical information. Therefore, to expedite the analysis of EtherCAT over a TSN network, we used OMNeT++. Here, we will compare the cycle time and jitter by evaluating different scenarios of EtherCAT communications over a NeSTiNg TSN network.

Industrial protocols are used to control medical destrinuted and virtual systems, to control refining and other processes in critical infrastructure. Such infrastacture must be protected and any vulnurabilities must be found and fixed. The fuzzing of industrial control protocols is the most efficient way to discover their most common vulnerabilities. We have chosen the widely used EtherCAT industrial protocol for fuzzing. Its structure has been analyzed and specificity for testing purpose has been determined. We have chosen fields that may effect the tested program. This fields have helped us to create initial test-cases by modifying them. In this paper, we have proposed to use feedback-based greybox fuzzing due to its high efficiency. The virtual stand has been designed and realized by authors to emulate EtherCAT Master using opensource library SOEM. A coverage guided fuzzer AFL has been adapted by authors for EtherCAT protocol testings. Three different experiments have been conducted. The modification within experiments differs to gain maximum efficiency from the used fuzzer. The data obtained as a result of the selected fuzzing method has been processed in order to determine the reasons for the program's crash and interpret them. In conclusion, the future work for EtherCAT fuzzing are proposed. Keywords-fuzzing, ICS protocols, EtherCAT, greybox, SOEM, vulnerability detection, AFL

An open real-time control system based on the EtherCAT fieldbus communication technology is proposed to fulfill the high real-time requirement of the human-robot cooperation controller in this paper. An open source real-time kernel of Xenomai is employed as the real-time software platform of the robot control system. Based on this, four-layer interfaces architecture are accomplished, which are human-machine cooperation control layer, motion control layer, robot axis control layer and hardware abstraction layer, through the corresponding four real-time tasks to meet the demand of human-robot cooperation operations. In addition, the scheduling task is developed to manage the 4 real-time tasks. The dual buffer communication mechanisms and priority-based scheduling strategy between layers was exploited to synchronize these real-time tasks. The underlying hardware abstract interface and the human-robot collaborative control algorithm interface are opened in the control system as the quadric exploitation interfaces to meet the need of developing application tasks in real-time space. Experiment results which are conducted on a self-developed 6-DOF collaborative robot show that the proposed control system is effective in real-time control applications of human-robot cooperative control at the control cycle of 5 milliseconds.

Through nonlinear effects, airborne ultrasound phased arrays enable mid-air tactile presentations, as well as auditory presentation and acoustic levitation. To create workplaces flexibly, we have developed a scalable phased array system in which multiple modules can be connected via Ethernet cables and controlled from a PC or other host device. Each module has 249 transducers and the software used can individually specify the phase and amplitude of each of the connected transducers. Using EtherCAT for communication, the system achieves high accuracy synchronization among the connected modules. In this article, we describe the details of the hardware and software architecture of the developed system and evaluate it. We experimentally confirmed the synchronization of 20 modules within an accuracy of 0.1 μs and the phase and amplitude can be specified at 8 bits resolution. In addition, using nine modules, we confirmed that we could make a focal point of the size consistent with the theory at 500 mm above the array surface.

Robotic testbeds used for flight and research technology development are highly complicated electromechanical systems demanding large engineering effort to configure and manage safety-critical hardware. The software that interoperates with robotic testbeds needs to be robust yet flexible to accommodate rapidly changing testbed needs and other operational demands in a cost-efficient manner. The Jet Propulsion Laboratory (JPL) presents a new open-source C++ library called Fastcat for powerful and flexible EtherCAT device configuration for testbed and robotic applications. Fastcat implements a set of C drivers called ‘Just SOEM Drivers’ built on the popular Simple Open EtherCAT Master library for a small, but highly tested set of supported EtherCAT devices. Fastcat offers a rich set of capabilities such as supporting an arbitrary number of EtherCAT Masters, a YAML input configuration file, and a visualization tool ‘Fcviz’ to graph the bus topology using the open-source Graphiz library. Furthermore, a novel feature called ‘Fastcat Signals’ can efficiently route data and commands between devices to compose self-contained closed loop control systems such as heaters or joint-torque controllers with zero added latency. Abstract device types like signal generators, functions, and PID controllers and offline versions of device hardware drivers allow for powerful composability, offline-only testing, and flexible hybrid partial online – offline bus topologies. The Fastcat core library is middleware agnostic, but ROS2 wrappers are developed for ease-of-use. This paper will describe design tradeoffs, an overview of the implementation of these capabilities, and early results from the first JPL Robotic testbed use.

The design of the collaborative robot control system is restricted by the following key factors: real-time system, field bus, robot frame and human-computer interaction module. Academia and industry have an urgent need for high-quality, high-stability, distributed and easy-to-operate control systems with the development of the robotics industry. Robot systems architecture based on ROS and ROS2 have attracted more and more attention due to the flexibility, openness, modularity, scalability and friendliness. The main contribution of this article is to partially construct the real-time architecture of the collaborative robot control system. In addition, the timing jitter of the system, EtherCAT master station and ROS under different frequencies and loads is analyzed. First, a Linux kernel based on PREEMPT_RT patch is constructed, the basic architecture is described, and the timing performance of the robot system is improved through the application of high-precision timers, priority assignment, scheduling mode, and energy consumption management. Furthermore, the timing jitter performance of the operating system is analyzed. The maximum jitter of the system and the EtherCAT master station is about 10 us, and the average jitter is 1 us. Finally, the timing jitter of the built-in timing callbacks in ROS and ROS2 is evaluated. The design of the real-time system and performance analysis provide critical support for the design of the robot controller.

Most robotic manufacturers use domain-specific programming languages (DSL), in contrast with general-purpose languages such as C++. By using DSL, it enables the optimization of solutions since the common attribute can be taken off from the language hence a more detailed and focus program can be created. However, these languages restrict the flexibility of creative programming. By using a broader and less restrictive programming language, a more innovative interface protocol can be created. This research paper will present a methodology of handshaking communication protocol with high flexibility and modular design of a LabVIEW based interface protocol. It will approach firstly to configure safety circuit by using Protective extra low-voltage (PELV) to provide mandatory safety, and secondly to configure Beckhoff EtherCAT and KUKA WorkVisual to translate signals and data to PLC for defined tasks. Electronic signals would mostly be controlled by in-house LabVIEW interface program and cDAQ. Machine accuracy before and after using the protocol was unaltered since the robot was controlled directly by its controller.

A new material testing reactor Jules Horowitz Reactor is under construction at CEA Cadarache. The materials to be irradiated will be placed into experimental devices around the reactor. Process and measurements of experimental devices will be carried out by command control. A data acquisition system having processing performances will be associated to the programmable logic controller. The challenge is to design and realize for twenty experiment devices a high availability data acquisition system architecture for 50 years of sustainability. The real time target will achieve 24/7 data acquisition and real time processing. This scalable architecture could be use as well for JHR experimental devices with high availability as for testbed. This architecture could be run on a standalone station for a measuring bench or deployed on cluster for high availability. CAREDAS’s design is modular and use proven widely used open source solutions. All parts are independent from each other and can be replaced with another technology with the same functionalities. This ensures sustainability and control of software sources.

In recent years, Factory Automation is evolving towards the so-called Industry 4.0, and the creation of a smart factory ecosystem comprising of ubiquitously interconnected objects, namely the Industrial Internet of Things (IIoT), is gaining much research interest. This paradigm aims at developing new smart technological equipment and protocols, thus providing interconnection among "factory objects" anywhere and at any time. In this context, people and machines have to safely cooperate and a high level of protection needs to be guaranteed for both operators and the surrounding environment. For this reason, safety systems, aiming at decreasing risks and failure probabilities, are nowadays of uttermost importance. Several Functional Safety communication protocols have been developed during these years pointing to increase data integrity and guarantee protection in a safety system. Popular examples are Fail Safe over EtherCAT (FSoE), ProfiSAFE, and OPC-UA Safety. These protocols, al-though conceived for wired networks, can be in principle adopted also by wireless communication, as they are developed by using a black channel approach. Nevertheless, the implementation of these protocols over different wireless networks is challenging as they might not ensure the required Safety Integrated Level (SIL). This paper, moving from the aforementioned observations and the need for wireless solutions in the IIoT context, focuses on proposing a possible implementation of FSOE over Wi-Fi, running UDP at the transport layer. In particular, by using suitable experimental outcomes, an OMNeT++ simulator has been calibrated, thus enabling the possibility to analyze the proposed protocol in wide industrial systems.

Here we present the design for a compliant actuator than makes use of agonistic-antagonistic tendons. Its novelty lies in its use of worm-gear motor drive and industrial EtherCAT control. We first describe a test rig to investigate variable-stiffness tendon drive for a single link and the construction of a corresponding EtherCAT controller. The tendon drive was based on the shoulder joint in the GummiArm and made use of tendons that exhibit a non-linear extension characteristic, so co-contraction increases joint stiffness. To ensures power was only needed when the arm is moving, low-cost worm-drive DC motors were used. An LQR observed-based controller was designed to realize angular position control of the link. The link controller was implemented using the custom-build EtherCAT panel. We present preliminary results of moving the joint link between angular target positions.

In this paper. We use FPGA to achieve high-performance cycle times for EtherCAT Slave Controller (ESC) internal data switch between ports. Commonly, ESC is implemented by a dedicated chip. Using FPGA to implement ESC can improve its scalability as much as possible while ensuring the basic functions of ESC. For the FPGA, XILINX ZYNQ was selected to take full advantage of the heterogeneous characteristics of its processor. The mature IP was used to implement the MAC and switching logic on the programmable logic (PL) side, while the EtherCAT software protocol stack and driver can be implemented on the programming system (PS) side. Our first objective is to introduce the implementation of the EtherCAT slave controller’s rapid switch module. The switch logic is created as IP core, and can be easily ported on any of the FPGA devices. The second objective is to provide the FPGA developers with some useful guidelines during the EtherCAT slave design. Furthermore, it measure the proposed FPGA based ESC switch module performance in the lab.

In order to meet the requirements of the space environment for the lightweight and load capacity of the manipulator, this paper designs a lightweight space manipulator with a weight of 9.23 kg and a load of 2 kg. It adopts the EtherCAT communication protocol and has the characteristics of high load-to-weight ratio. In order to achieve constant force tracking under the condition of unknown environmental parameters, an integral adaptive admittance control method is proposed. The control law is expressed as a third-order linear system equation, the operating environment is equivalent to a spring model, and the control error transfer function is derived. The control performance under the step response is further analyzed. The simulation results show that the proposed integral adaptive admittance control method has better performance than the traditional method. It has no steady-state error, overcomes the problems caused by nonlinear discrete compensation, and can facilitate analysis in the frequency domain, realize parameter optimization, and improve calculation accuracy.

Continuous operation and monitoring of critical infrastructure networks are crucial to ensure their sustainability and security. To achieve these, industrial control system (ICS) networks and supervisory control and data acquisition (SCADA) systems are deployed in critical infrastructure assets. Many events in ICS networks present strong periodical patterns because of process repetition or cyclic communication. From the security viewpoint, inferring the periodicity primarily in the device-level communications where the actuator/sensor, field, and the cell-level transmissions are performed is important for detecting anomalies. The synchronization period and traffic pattern need to be known for anomaly detection. This article presents a novel periodicity detection approach specifically for Ethernet for control automation technology (EtherCAT) networks. It uses protocol-specific operations and fields for detecting device-level periodicity. Using the period, an anomaly detection method that uncovers traffic pattern statistics is also proposed. The periodicity can be detected with different precision, significance levels, and lag sizes. Four programmable logic controller (PLC) programs were developed to demonstrate the feasibility of the periodicity detection approach, and the periodicity was automatically obtained with high accuracy. As any malicious activity on the system causes variances in the periodic pattern, the approach was also tested on synthetic traffic traces that contain denial of service (DoS) and code-injection attacks. The traffic patterns were uncovered by an anomaly detection module, which was developed on a Snort intrusion detection/prevention system (IDS/IPS) and used the captured period. The tests demonstrated that intrusions that exploit communication patterns are fully flagged.

Each of the seven primary mirror cell in the GMT contains over 225 EtherCAT slaves in the cell, leading to a nightmare of cabling. Optimization of the initial construction and ongoing maintenance of the cells requires reduced complexity of wiring in the cell. Employing the concept of Power over EtherCAT and a star configuration, the resulting the EtherCAT Power and Communications Hub design reduces the wiring in the cell by 2/3, while additionally providing centralized power management and diagnosis of each actuator communications link. The design consists of an EtherCAT slave to allow the central control system to monitor and control the slaves attached to the hub, and power control circuits to provide and monitor power to each slave. In addition to providing a significant reduction in wiring complexity, the hub serves as an additional control point for power to each support actuator, enhancing mirror safety through redundant control of the actuators. This paper describes the motivation driving the requirements, the resulting requirements and design, and test results of the prototype EtherCAT and Power Hubs.

This paper provides a description of the Instrument Control Hardware design for MAORY (Multi-conjugate Adaptive Optics RelaY), a first light instrument for ESO ELT. The MAORY Instrument Control Hardware is in charge of the control electronics of the entire system. It comprises all the implemented electronic devices (power supplies, PLC CPUs and terminals, motor drivers, control panel, network switches, sensors) and the harness used to connect them. The instrument control system architecture is based on the use of PLC and EtherCAT fieldbus protocol, which allows for a distribution of PLC terminals controlled by the same CPU that do not have to be physically located in the same place to communicate among each other.

In the ESO ELT control electronics guidelines, the hardware devices are located in standard COTS cabinets, each equipped with an air-liquid heat exchanger. In this paper a different architecture is explored, with the purpose of further exploiting the possibility of these devices to communicate remotely via EtherCAT. Advantages and drawbacks of this architecture are analyzed in terms of harness complexity, cabinets volume and mass, type of installation. Particular focus is given to the thermal requirement, with an analysis of the distributed architecture compliance with said requirement.

The Primary Mirror Device Control System (M1 DCS) is one of the many Device Control Systems (DCS) included in the Giant Magellan Telescope (GMT) control system and is responsible for the overall control and operation of the GMT primary mirror segments. The primary mirror is composed of seven 8.4m diameter segments, six off-axis and one in the center. The active support system of each segment comprises 170 support actuators for the off-axis segments and 154 actuators for the center segment to control the mirror figure, and 6 hardpoints to control the six degrees of freedom of rigid body motion. The software design follows a component model-based architecture, implemented using the GMT core software frameworks. Software components of the M1 DCS are specified using a custom Domain Specific Language (DSL) and inherit all key features of the core components such as communication ports, default behaviors, telemetry, logs, alarms, faults, state machines and engineering user-interface without the need of a separate implementation. The communication between the real time software and the controlled devices is implemented by an EtherCAT Fieldbus in a ring topology. This master-slave standard protocol enables the control system to reach 100 Hz closed loop rate for active support control. This paper describes the software of the M1 DCS, the tests performed with different software and hardware simulators, and the strategy to ensure software readiness with the final optical mirror.

EtherCAT is one of the most popular industrial Ethernet protocols used in multi-axis motion control. Its unique Distributed Clocks mechanism can ensure high-precision clock synchronization among multiple devices. In the study, we first improve the clock drift compensation algorithm used in Distributed Clocks. This algorithm not only shows excellent compatibility with existing standard protocol but also tracks the reference clock faster and more accurately. Similarly, we also propose a method for synchronization between the network clock and the local motor control task. The modified timing after synchronization eliminates the time uncertainty that up to one PWM period and reduces the necessary interrupts for network control. The proposed methods pave the way for better motion control performance and are verified by both simulations and experiments.

As an important supporting technology for Industrial Internet, Industrial Ethernet has attracted extensive attention in recent years. EtherCAT is a typical Industrial Ethernet specification and widely used in field networks. With the development of Internet Protocol version 6 (IPv6), it is a challenge for connecting EtherCAT filed network to IPv6-based industrial backbone network in the factory. This paper proposes a protocol translation scheme between EtherCAT network and IPv6 network. The methods for packet identification, frame format translation, priority translation, and address translation are presented. The translation scheme is implemented in the testbed. Test results verify the effectiveness of the proposed translation scheme.

This paper proposes a gateway based on EtherCAT and DeviceNet for a smart factory. EtherCAT is chosen as the primary protocol and DeviceNet is used as secondary protocol. Due to its outstanding features, the gateway can support many devices and increase the quality of service (QoS) of the network. With proposal gateway, an embedded programmable logic controller (ePLC) can replace the hardware programmable logic controller. The gateway was implemented with an ARM-Cortex M3 and TwinCAT3 was used as the ePLC. Experiments show that this gateway provides a high QoS and also satisfies the real-time requirements of a factory system.

IoT is often associated with low-power wireless, where best-effort communication is sufficient for many of its applications. Yet, in particular in Industrial IoT, strict quality of service (QoS) guarantees are required to enable deterministic real-time applications. Hence, wired communications are still predominant here, with Ethernet having become the main media for the industrial fieldbuses such as PROFINET, EtherCAT, or the emerging Field-Level Communications (FLC) of OPC UA. With the addition of Time-Sensitive Networking (TSN), an IEEE standards family for deterministic networking over Ethernet, Information Technology (IT) and Operational Technology (OT) can converge even at the shopfloor, as TSN-enabled Ethernet allows for several traffic types to co-exist in the same network. This paper proposes an extension to the W3C Web of Things (WoT) for semantics-enabled connectivity, which allows to cover application QoS requirements and network configuration within the W3C WoT abstractions. We contribute a QoS vocabulary for the W3C WoT Thing Description as well as design and open-source implementation of protocol bindings for OPC UA and NETCONF. Moreover, we discuss the challenges and pitfalls when designing new protocol bindings for W3C WoT.

Cyber attacks on Industrial Control Systems (ICS) are considered to be an extremely dangerous threat as they lead material losses or undermine a process. These attacks are mostly targeted to the field level of the critical systems. EtherCAT, one of the most preferred hard real-time protocol in Europe is also open to both known and zero-day attacks. In this work, EtherCAT based anomaly detection is studied applying machine learning methods. To do this, first, a water level control testbed is developed in laboratory scale. Attack vectors are created, and a dataset is formed considering EtherCAT communication principles. Secondly, attributes related to the running-process are selected and reduced. Finally, anomalies are detected both for supervised and unsupervised methods and an evaluation of the methods are done. Results showed that, SVM and Random Forest can be used for EtherCAT anomaly detection as supervised methods. It is also observed that each algorithm applied in unsupervised learning is successful in detecting a specific attack trace.

Moving towards new technologies, such as Time Sensitive Networking (TSN), in industries should be gradual with a proper integration process instead of replacing the existing ones to make it beneficial in terms of cost and performance. Within this context, this paper identifies the challenges of integrating a legacy EtherCAT network, as a commonly used technology in the automation domain, into a TSN network. We show that clock synchronization plays an essential role when it comes to EtherCAT-TSN network integration with important requirements. We propose a clock synchronization mechanism based on the TSN standards to obtain a precise synchronization among EtherCAT nodes, resulting to an efficient data transmission. Based on a formal verification framework using UPPAAL tool we show that the integrated EtherCAT-TSN network with the proposed clock synchronization mechanism achieves at least 3 times higher synchronization precision compared to not using any synchronization.

This paper describes a flexible testbed of a hybrid AC/DC microgrid developed for research purposes. The experimental setup is composed of 3 AC and 6 DC distributed generator units which are emulated by using three-legs inverters and settable output filters. The microgrid architecture allows to validate control schemes upstream of the modulation stage of each inverter, by using real-time targets and Mat-lab/Simulink interface. Two independent real-time communication networks can be used. The first one is based on optical fibre technology, whereas the second one is an Ethercat communication network. Both of them are used for instrumentation purposes and to implement the primary control level of the microgrid. To implement secondary control schemes into the microgrid (or higher control levels), an additional optical fibre-based network is used, allowing to emulate scenarios with or without communication issues such as latency, data-losses and topology changes. The built microgrid can be splitted into AC-side (3 and/or 4 wires), DC-side and interlinking-side, where both the AC and the DC side can be operated independently, according to the required electrical topology. In this testbed, several control schemes, such as proportional-integral, proportional-resonant or predictive controllers, have been investigated. Realised experimental tests include load changes, plug-and-play and communication issues scenarios.

Based on the leg-mode kinematics of multi-locomotion mobile robot, this paper designs a control system with high real-time performance based on EtherCAT bus, and studies the problem of foot trajectory planning. The hardware of the system consists of PC + soft controller, EtherCAT network, driver, servo motor and multi-locomotion mobile robot. The software uses LabWindows to develop master computer in PC and CODESYS to develop slave computer control program in soft controller. The timing interpolation method and sinusoidal acceleration and deceleration control algorithm are used to study the half-sinusoidal trajectory of the foot. From the experimental results, this trajectory planning method is effective on multi-locomotion mobile robot based on EtherCAT bus, which provides the basis for the gait planning research of multi-locomotion mobile robot.

With the innovation and integration of technology, inkjet printing has been successfully applied in the field of microelectronics production. However, it poses a great challenge to the motion control ability of inkjet printer. The traditional inkjet printing adopts semi-closed loop control, which ensures print accuracy by controlling the printing head to move at a uniform speed. This is not applicable in the field of microelectronics production, especially some flexible electronic products. In addition, the traditional inkjet printing is to print line by line or column by column, which is not suitable for some occasions where continuous inkjet oblique lines or curves are required in the field of microelectronics production. Based on the above problems, the design scheme of applying the EtherCAT protocol to the motion control system of inkjet printer is proposed. Nowadays, in the field of microelectronics production, it is generally cooperate with image processing technology to perform closed-loop control of servo motors. In order to reduce the time-consuming image processing, it is necessary to transfer the image recognition work to a high-performance computer outside the servo motor controller. The EtherCAT protocol has a high real-time performance, which ensures that the controller can quickly receive commands from the host computer, which is helpful to improve the working efficiency of the inkjet printer. Drawing the slashes and curves requires controlling the two axes of the inkjet printer synchronously; just right the specific function of the EtherCAT can help multiple controllers achieve time synchronization. Obviously, the ink-jet printer using the motion control system based on the EtherCAT protocol has a great application prospect.

With the rapid development of industrial control industry, the requirements for fieldbus are getting higher and higher. Fieldbus is required to have the characteristics of long transmission distance, fast transmission speed, and high real-time performance. The traditional fieldbus cannot meet the development needs of the modern industry, so it is a trend to apply real-time industrial Ethernet technology to the step servo industry. Among many real-time industrial Ethernet networks, the EtherCAT (Ethernet control automation technology) from BECKHOFF of Germany is highly praised for its real-time performance, high synchronization accuracy, support for multiple topologies, and wide applicability. The slave station system designed in this paper is based on the scheme of STM32 + AX58100. The main station uses BECKHOFF configuration software TwinCAT, through which the basic functions of the slave station system are tested. The test results show that the slave station system can meet the design requirements and achieve the purpose of accurate, fast, and stable control of the motor.

A gyrowheel is a new type of equipment that integrates spacecraft attitude control and measurement functions. The upper and lower computers of the existing gyrowheel prototype system communicate with each other through Advantech PCL boards. The cost is high and the structure is complicated. This article designs and implements EtherCAT master of gyrowheel under RTX system with lower cost and simpler structure. First, the operation principle and data frame structure of the EtherCAT communication protocol are analyzed. Then, the EtherCAT master under the RTX system was designed, including the network card driver module, configuration module, and data communication module. Among them, the network card driver module is implemented by modifying the official open source network card driver provided by IntervalZero, which can configure the network card to send and receive data; the configuration module configures the registers of the slave by constructingˈsending and receiving data frames, and switches the slave from the Init state to the Op state; the data communication module periodically collects gyrowheel data information through the timer and outputs control amount. Finally, a system experiment platform was established to verify that EtherCAT communication can be performed between the master and slave.