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This article presents a novel stochastic event-triggered communication scheme (SETS) and a switching-like H∞ control method for networked control systems (NCSs) through an open bandwidth-limited network. To overcome the stochastic Denial of Service (DoS) attacks and save the limited network resource, a SETS is first proposed to decrease the number of packets transmitted while considering the malicious DoS attacks. Compared with the existing event-triggered schemes under a precondition that all triggered packets must be successfully transmitted, the proposed SETS has outstanding flexibility since it allows part event-triggered packets to be lost during the communication process. To fully use the dynamic features of communication in an open network, a switching-like control scheme is well designed, which can actively choose the different controller gains based on the current network Quality of Services (QoSs). Then, a networked closed-loop model is constructed, which considered both the effects of SETS and stochastic DoS attacks in a unified framework. Sufficient conditions for the existence of the switching-like controller are presented to ensure the stability of the networked control system while achieving the prescribed performance index. Gain matrices of the desired switching-like controller and the SETS parameters are reached in the light of the solutions to certain matrix inequalities. Compared with the existing time-invariant control strategy in a transmission interval, higher control performance can be expected since both the dynamic network information and the latest available state are well considered in the proposed communication and control framework. Finally, an illustrative example is given to verify the effectiveness of the proposed scheme.

In this paper, the resilient controller design and synthesis issues of networked control systems under denial-of-service (DoS) attacks are investigated via an adaptive event-triggered strategy. In a networked control system, DoS attacks have serious impacts on the security of communication, possibly causing degraded stability performance of the system. To remove threats from DoS attacks, an adaptive event-triggered communication mechanism is proposed, which also provides benefits in reducing the consumption of communication resources and relieving the pressure on network bandwidth. Since the system state information is usually not fully known, an observer-based controller is developed to stabilize the system and maintain a desired performance index despite the occurrence of stochastic attacks. Furthermore, a joint design method is proposed to obtain the controller gain, observer gain and event-triggered weight matrix. Finally, practical examples based on a four-tank system, an Internet-based three-tank system and an Internet-based test rig system are presented to illustrate the effectiveness of the proposed techniques to respond and eliminate the impact of DoS attacks.

The robustness of process control systems to cyberattacks has become an increasingly important topic, especially in light of the increased dependence of process operations on networked control system architectures wherein dedicated sensor-controller and controller-actuator links are replaced by real-time, wired or wireless, shared communication networks. To mitigate the risks of cyberattacks, we propose in this work an integrated model-based framework for the detection, estimation and mitigation of false data injection cyberattacks in nonlinear networked process systems. The framework leverages a classification-based neural network scheme for attack detection and estimation, coupled with a stability-based attack mitigation strategy based on a model-based controller design. An illustrative chemical process example is used to demonstrate the effectiveness of the proposed framework and assess its robustness with respect to possible attack detection and estimation errors.

The coupling of physical systems with information technologies infrastructure in a networked control system (NCS) has a number of advantages such as remote control, reduced system complexity, low maintenance cost and improved system efficiency. But these benefits come at the cost of making the NCS vulnerable to cyberphysical attacks on the communication layer. One such class of attacks is the zero-dynamics attack (ZDA) which targets the internal dynamics of an NCS with the potential to cause serious damage to the physical system while remaining stealthy. A better understanding of how ZDAs are constructed will enable more effective countermeasures. In this paper, we discuss two approaches for constructing a ZDA and demonstrate using three industrial processes studied in this context perhaps for the first time.

This paper investigates the networked control system (NCS) with faults and disturbances which affect both actuator and sensor. A fast high-order sliding mode (FHOSM) controller is proposed to compensate for actuator faults and sensor disturbances, which is constructed based on the estimated information of the NCS. Accordingly, an adaptive observer with multi-stage is designed to estimate the states and sensor disturbances and protect the NCS from actuator faults. Furthermore, a new sliding function is assembled to realize the finite-time convergence of system states. The stability of the system with the suggested procedure is illustrated by the stability analysis underneath the designed control law. Finally, the simulation results are implemented and confirm the effectiveness of the proposed method in defending the system against both issues and inhibiting system failures.

The large integrated industrial applications require unified communication to combine data from multiple domains forming a hybrid network. The scheduling of network access time to multi-domain data...

The optimization in the configuration of network communication with time delays among field devices is a major challenging task of a networked control system (NCS). In view with the network-based model of literature, the present paper introduces the dynamic network scheduler to customize the aperiodic time delay for optimal bandwidth allocation of the network. This is achieved with the following three objectives: (a) classification of data packets among periodic and aperiodic communication using support vectors; (b) deciding the bandwidth associated with the priority weightage for aperiodic data packets; (c) simulation for fairness of NCS with dynamic network scheduler switching integrated the weighted fair queuing algorithm. The outcome of proposed dynamic network scheduler is compared with the network model of literature for reduced and bounded delays of aperiodic communication in NCS.

This paper addresses the hybrid-triggered security control design for the networked control system (NCS) under multiple cyber attacks. A hybrid-triggered scheme (HTS) is introduced to mitigate the burden of the network transmission. Besides, a new model of multiple cyber attacks is built by simultaneously considering deception attacks and DoS attacks. In addition, A novel NCS model based on multiple cyber attacks is established with the hybrid-triggered scheme. Then, based on Lyapunov stability theory, criteria for guaranteeing the closed-loop system stability and achieving hybrid-triggered security controller design are derived. Finally, an illustrative example is given to validate the usefulness of the theoretical results.

Networked control systems can help build cost-effective and flexible industrial systems. A system that can function while being immune to cyberattacks is necessary. A method called fixed redundant path selection (FRPS) has been proposed to detect and mitigate data tampering attacks in a networked motion control system. This system contains redundant forward network paths from the controller to the motor sides to detect the attacked path by comparing the values that are received through respective paths. Then, a path selector on the motor side chooses a value on the path that is not attacked based on the majority decision. Increasing the number of redundant paths improves the detection performance of simultaneous attacks against multiple paths. However, it also increases the amount of traffic because the same data are transmitted to all of the redundant paths. This study proposes a dynamic redundant path selection (DRPS) method to balance the detection performance and the amount of traffic. The proposed method initially applies three redundant paths and changes the number of redundant paths to five only when the path selector detects a difference among the received values for the three paths. The experiments confirm that the proposed DRPS outperforms the conventional FRPS. The former can detect and mitigate the data tampering attacks while reducing the number of network paths during tampering detection when the system is exposed to simultaneous attacks against up to two of the redundant paths.

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.

Event-triggered control (ETC) is becoming increasingly popular in load frequency control (LFC) operation in power systems. So far, the existing literature has primarily focused on load disturbance rejection in face of communication delay without considering much on networked-induced measurement disturbances and messages sent. In this paper, we study the LFC operation as a problem of networked control system and propose, for the first time, an ETC based switching approach for frequency regulation. We derive delay-dependent conditions to obtain the lower bound on inter-event time during event-trigger mechanism which assures the robust stability under networked induced time-varying delays and measurement disturbance and reduction in the amount of sent measurements. The effectiveness of the proposed approach is verified via numerical examples based on single-, two-area power systems and single-area with electric vehicle (EV) participation.

This paper is concerned with the security problem for a networked control system subject to deception attacks. An adversary is present to corrupt both the sensor-to-controller channel and the controller-to-actuator channel with deception signals when sensor and control data are transmitted via the network medium. We model the malicious deception signals as unknown-but-bounded signals in such a way that no priori knowledge of the attack signals is required. First, a delicate set-membership performance index is proposed for meeting the system security requirement. Second, a novel set-membership estimation method is developed to obtain the desired ellipsoidal estimation set which guarantees the enclosing of true state of the system at every instant of time. Such an ellipsoidal estimation set is then used for deriving the sufficient conditions such that the resulting closed-loop system is set-membership input-to-state-stable and achieves the prescribed security requirement. Finally, a target tracking system is given to demonstrate the effectiveness of the proposed method.

Cyber-physical Systems can be defined as a complex networked control system, which normally develop by combining several physical components with the cyber space. Cyber Physical System are already a part of our daily life. As its already being a part of everyone life, CPS also have great potential security threats and can be vulnerable to various cyber-attacks without showing any sign directly to component failure. To protect user security and privacy is a fundamental concern of any kind of system; either it's a simple web application or supplicated professional system. Digital Multifactor authentication is one of the best ways to make secure authentication. It covers many different areas of a Cyber-connected world, including online payments, communications, access right management, etc. Most of the time, Multifactor authentication is little complex as it requires extra step from users. This paper will discuss the evolution from single authentication to Multi-Factor Authentication (MFA) starting from Single-Factor Authentication (SFA) and through Two-Factor Authentication (2FA). This paper seeks to analyze and evaluate the most prominent authentication techniques based on accuracy, cost, and feasibility of implementation. We also suggest several authentication schemes which incorporate with Multifactor authentication for CPS.

We propose an autonomous operation system for hydraulic excavators that fully automatizes the sequence of excavation and loading in indoor environments at actual shield-tunneling construction sites. This system possesses all the components and functions necessary for excavation and loading. It also consists of an architecture composed of a networked control system. This architecture enables the system to mitigate the physical limitations of sensors and computers such as installation locations and computing power. We also devised practical engineering solutions that make our system highly accurate and efficient for actual construction sites, such as prediction control concerning hydraulic and mechanical delays and an external actuator that requires no special modifications to construction machinery.

Feedback control systems consist of components such as sensory systems, state estimators, controllers, and actuators. By transmitting signals between these components across insecure transmission channels, feedback control systems become vulnerable to cyber-physical attacks. For example, passive eavesdropping attacks may result in a leak of confidential system and control parameters. Active deception attacks may manipulate the behavior of the state estimators, controllers, and actuators through the injection of spoofed data. To prevent such attacks, we must ensure that the transmitted signals remain confidential across the transmission channels, and that spoofed data is not allowed to enter the feedback control system. We can achieve both these goals by using cryptographic tools. By encrypting the signals, we achieve confidential signal transmission. By applying message authentication codes (MACs), we assert the authenticity of the data before allowing it to enter the components of the feedback control system. In this paper, a toolbox containing implementations of state-of-the-art high-performance algorithms such as the Advanced Encryption Standard (AES), the AEGIS stream cipher, the Keyed-Hash Message Authentication Code (HMAC), and the stream ciphers from the eSTREAM portfolio, is introduced. It is shown how the algorithm implementations can be used to ensure secure signal transmission between the components of the feedback control system, and general guidelines that the users must adhere to for safe operation are provided. © 2020 Norwegian Society of Automatic Control. All articles in MIC are published with the Creative Commons Attribution 3.0 Unported (CC BY 3.0) license. See: http://creativecommons.org/licenses/by/3.0/.

Time delay in a networked control system can negatively impact the performance of the system. Dynamic networks with unknown and varying latency such as the Internet are studied. Also, experiments with teleoperation of drones and communication loops through the Internet are conducted. Smith Predictors are well known for their ability to handle time delay. Smith Predictor controllers perform well when modeled accurately and when the delay is known. The proposed method combines a delay estimation technique based on characteristic roots of delay differential equations to measure the delay with an Adaptive Smith Predictor. When the delay parameter is adjusted correctly, the negative effects caused by delay are significantly reduced. The proposed method performs satisfactory for networked systems with unknown delay and the results are validated through simulations and experimentation.

With the rapid developments in communication technology, the bidirectional wireless communication channel is widely used to exchange information between the train and wayside control center. As an emerging technology, the communication based heavy haul train control (CBHHTC) system is becoming a better alternative for administrative department to provide the greater transport capacity. In order to put the latest automatic control methods into the practice, this paper investigates the robust optimal control problem of heavy haul train under CBHHTC. By formulating the CBHHTC based real-time control procedure as a networked control system (NCS) model, the possible data loss phenomenon in the wireless communications is considered, and its impact on the stability and performances of the controller design is elaborated. On the basis of Lyapunov stability theory and model predictive control (MPC) approach, a set of linear matrix inequalities (LMIs) is given as sufficient conditions to ensure the velocity tracking ability, energy-efficiency and operational safety with a prescribed H∞ disturbance attenuation level under the control constraints. Case studies are conducted to illustrate the effectiveness of the proposed controller.

Industrial processes are multi input multi output, non-linear, and constrained in nature. The sensors, data acquisition systems, controller and the actuators of the above said processes are all networked to form as networked control system with various network constraints. Other issues in the smart measurement sensor non-linearity, uncertainty and noises. The PID and MPC are the famous industrial controller for controlling the above processes. PID controller is popular due to its simplicity in tuning parameter and the MPC is preferred for its superior control performance. However, in process industries, the MPC based controller is used in the supervisory level which gives the command signal to the regulatory level PID controller. This PID controller is used for controlling the industrial process which makes limited MPC performance. It makes challenges to the researcher to develop next generation controller which can able to address the above stated problems. This enhances the research scope in the domain of SMART process measurement and automation. There arises a necessity to come up with a solution for the above problems which has industrial acceptability, simplicity, flexibility and scalability. This research paper is aimed to bring into sight the various research challenges involved in smart process measurement and automation and solution to some of the same.

This paper is concerned about detection and estimation of malicious attacks on the network and the linear physical system of a networked control system (NCS) by using linear matrix inequality (LMI)...

With the wide application of networked control systems, how to deal with data injection attacks and maintain the stability of control systems including wireless multi-hop networks is a prob...

[EN] In this paper, periodic event-triggered sampling and dual-rate control techniques are integrated in a wireless networked control system (WNCS), where time-varying network-induced delays and packet disorder are present. Compared to the conventional time-triggered sampling paradigm, the control solution is able to considerably reduce network utilization (number of transmissions), while retaining a satisfactory control performance. Stability for the proposed WNCS is ensured using linear matrix inequalities. Simulation results show the main benefits of the control approach, which are experimentally validated by means of an unmanned-aerial-vehicle-based test-bed platform., This work was supported in part by the European Commission as part of Project H2020-SEC-2016-2017-Topic: SEC-20-BES-2016 (Id: 740736)-"C2 Advanced Multi-domain Environment and Live Observation Technologies," in part by the European Regional Development Fund as part of OPZuid 2014-2020 under the Drone Safety Cluster project, in part by the Innovational Research Incentives Scheme under the VICI Grant "Wireless control systems: A new frontier in automation" (No. 11382) awarded by The Netherlands Organization for Scientific Research Applied and Engineering Sciences, and in part by the Ministerio de Economia y Competitividad, Spain, under Project FPU15/02008.

A multiagent system based distributed cooperative control is proposed for a dc microgrid. First, the multiagent system based control scheme is built, where each distributed energy resource unit is associated with a first-level unit control agent to deal with primary control and a secondary-level distributed cooperative control agents to implement secondary control. For the secondary control purposes of global voltage regulation and proportional current sharing, both voltage and current regulators are installed in each secondary-level agent. Their consensus secondary control protocols are designed by using the state information exchanged among only adjacent secondary-level control agents based on a switching topology communication network with time-vary delays. Then these protocols are applied into the associated first-level agent to structure an improved outer-loop droop controller. According to the reference set points corrected by the improved droop controller, an inner-loop voltage/current robust controller is designed in place of the conventional PI control to regulate the voltage and current of distributed energy resource unit. Finally, the validity of the proposed control is testified by means of simulation results.

Network-induced imperfections such as transmission delays, time-varying sampling intervals and clock asynchronization among nodes make it complicated to analysis and design a networked control system (NCS). Further, constructing such an NCS becomes tedious and difficult when there are a number of nodes needed to be integrated together through the imperfect network. In this paper, to solve these problems, we design and develop a network interface device termed as information pipeline CAN (IPCAN) that can facilitate rapid integration of network nodes and provide well-designed transmission properties. The IPCAN adopts information pipeline technology (IPT) to construct an endpoint-based data interface, which makes nodes modular and reusable. A time-triggered information-exchange mechanism is proposed for the IPCAN to achieve fixed and predictable transmission delays and temporal-spatial consistency of received data. These properties contribute to realizing synchronous time-driven mode among nodes and simplifying the analysis of the system. In addition, several novel technical methods are proposed to implement the IPCAN with controller area network (CAN) and serial peripheral interface (SPI) as the physical connections of network and user interface, respectively. The IPCAN is applied to a distributed temperature control system and its utility and performance are well demonstrated.

This paper introduces a highly integrated educational instrument designed for control engineering education. Based on the plug-and-play design principle, the instrument can be compatible and deployed massively. To reduce the power consumption and bandwidth usage when the test rig is not occupied, the electrical converter is introduced to control the power supply status. The controller design based on the root locus principle is taken as an example for the fan speed control. Both simulation and physical test rig experiment are conducted in Networked Control System Laboratory to verify the practicality of the proposed educational instrument. The results show that the instrument can be applied into remote laboratory seamlessly, which enriches the available physical test rigs resources in remote laboratories largely.

Cyber-physical systems (CPSs) and the Internet of Things (IoT) are converging towards a hybrid platform that is becoming ubiquitous in all modern infrastructures. The massive deployment of CPS requires comprehensive, secure, and reliable communication. The integration of complex and heterogeneous systems makes enormous space for the adversaries to get into the network and inject malicious data. To obfuscate and mislead the attackers, we propose DDAF, a deception defense-based data acquisition framework for a hierarchical communication network of CPSs. Each switch in the hierarchical network generates a random pattern of addresses/IDs by shuffling the original sensor IDs reported through it. Later, while sending the measurement data from remotely located sensors to the central controller, the switches craft the network packets by replacing the sensors’ original IDs with pre-generated deceptive IDs. Due to the deception, any stealthy attack turns into a random data injection and ends up as an outlier during the bad data detection process. By analyzing the outlier data, DDAF detects and localizes the attack points and the targeted sensors. DDAF is generic and highly scalable to be implemented in any size of networked control systems. Experimental results on the standard IEEE 14, 57, and 300 bus power systems show that DDAF can detect, mitigate, and localize almost 100% of the stealthy cyber-attacks. To the best of our knowledge, this is the first framework that implements complete randomization in the data acquisition of a networked control system.

This paper considers a co-design problem for industrial networked control systems to ensure both system stability and resources efficiency. Solving such a co-design problem is challenging because wireless communications in industrial environments are subject to shadow fading, and are stochastically correlated with their surrounding environments. To address such challenges, this paper first introduces a novel state-dependent Markov channel model that explicitly captures the state-dependent features of the wireless communications by correlating model's transition probabilities with environment states. Under the proposed channel model, sufficient conditions on maximum allowable transmission interval are presented to ensure almost sure asymptotic stability for a nonlinear networked control system. With the stability constraints, the co-design problem is then formulated as constrained optimization problems, which can be efficiently solved by Semidefinite programs for a two-state Markov channel. Simulation results are provided to demonstrate the efficacy of the proposed co-design scheme.

This chapter addresses the problem of detecting stealthy data injection attacks on sensor measurements in a networked control system. A multiplicative watermarking scheme is proposed, where the data from each sensor is post-processed by a time-varying filter called watermark generator. At the controller’s side, the watermark is removed from each channel by another filter, called the watermark remover, thus reconstructing the original signal. The parameters of each remover are matched to those of the corresponding generator, and are supposed to be a shared secret not known by the attacker. The rationale for time-varying watermarks is to allow model-based schemes to detect otherwise stealthy attacks by constantly introducing mismatches between the actual and the nominal dynamics used by the detector. A specific model-based diagnosis algorithm is designed to this end. Under the proposed watermarking scheme, the robustness and the detectability properties of the model-based detector are analyzed and guidelines for designing the watermarking filters are derived. Distinctive features of the proposed approach, with respect to other solutions like end-to-end encryption, are that the scheme is lightweight enough to be applied also to legacy control systems, the absence of side-effects such as delays, and the possibility of utilizing a robust controller to operate the closed-loop system in the event of the transmitter and receiver losing synchronization of their watermarking filters. The results are illustrated through numerical examples.

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.

State-dependent attack and defense mechanisms in a wireless networked control system are investigated. The controller in this system attempts to transmit control commands to a remotely located plant by using a wireless channel that is subject to jamming attacks from an adversary. The probability of a failure on this channel depends on the powers of both the transmission signal emitted from the controller and the jamming interference signal emitted from the attacker. We show that if the power levels of transmissions from the controller are consistently above a threshold and the average power level of the jamming interference is sufficiently small, then the networked control system is guaranteed to be almost surely asymptotically stable. However, it is hard to analytically derive optimal attack and defense policies due to the complexity of the wireless channel model. To find out potentially dangerous attacks and high-performance defense policies, we propose a search-based approach and utilize genetic algorithms. Specifically, by considering Voronoi partitions of the state space, we find attack policies that achieve large quadratic costs. We use the search-based approach also for designing defense policies, where the controller adjusts the power of the transmission signal based on the plant’s state information. The efficacy of the proposed approach is demonstrated through a number of simulation-based experiments.

In recent years, there has been a rapid expansion in the development of Cyber-Physical Systems (CPS), which allows the physical components and the cyber components of a system to be fully integrated and interacted with each other and with the physical world. The commercial aviation industry is shifting towards Aviation Cyber-Physical Systems (ACPS) framework because it allows real-time monitoring and diagnostics, real-time data analytics, and the use of Artificial Intelligent technologies in decision making. Inevitably, ACPS is not immune to cyber-attacks due to integrating a network system, which introduces serious security threats. False Data Injection (FDI) attack is widely used against CPS. It is a serious threat to the integrity of the connected physical components. In this paper, we propose a novel security algorithm for detecting FDI attacks in the communication network of ACPS using Artificial Immune System (AIS). The algorithm was developed based on the negative selection approach. The negative selection algorithm is used to detect malicious network packets and drop them. Then, a Nonlinear Autoregressive Exogenous (NARX) network is used to predict packets that dropped by the negative selection algorithm. The developed algorithm was implemented and tested on a networked control system of commercial aircraft as an Aviation Cyber-physical system.

The use of Internet-connected devices at homes has increased to monitor energy consumption. Furthermore, renewable energy sources have also increased, reducing electricity bills. However, the high cost of the equipment limits the use of these technologies. This paper presents a low-cost secured-distributed Internet of Things (IoT) system to monitor and control devices connected in a polygeneration microgrid, as a combined power system for local loads with renewable sources. The proposed mechanism includes a Wireless Sensor Actuator Networked Control System that links network nodes using the IEEE 802.15.4 standard. The Internet communication enables the monitor and control of devices using a mobile application to increase the efficiency. In addition, security mechanisms are implemented at several levels including the authentication, encryption, and decryption of the transmitted data. Furthermore, a firewall and a network intrusion detection-and-prevention program are implemented to increase the system protection against cyber-attack. The feasibility of the proposed solution was demonstrated using a DC microgrid test bench consisting of a diverse range of renewable energy sources and loads.

Real-time is a challenge facing the industrial communications technology. For this purpose, a large number of protocols have been promoted to enable the goal of real-time control. In the first time, many network types are developed based on CAN. In this time, Ethernet is a trend in modern industrial network. A chosen the best one plays an importance role in engineering. In this paper, the authors present an evaluation on the performance of two networking protocols: Mechatrolink III and SSCNET III. In each network type, the commonly theories are presented. We also consider how each protocol be used on the networked control system. Moreover, each protocol is developed on STM32F207 to evaluate the time communication individually. The cycle time is measured to demonstrate the performance of each network type.

This paper discusses a new concept of control systems, characterized as the Internet of Things Control Systems (IoTCS), which is based on the control techniques of networked control systems and the concept of the Internet of Things. To obtain IoTCS, the Internet of Things hardware, which belongs to embedded systems and boards hardware class, is used. The example of temperature control shows how the concept of IoTCS can be practically realized with the selected Internet of Things hardware. The operation of the implemented IoTCS is based on the principle of a networked control system in which the Arduino Uno board is equivalent to a communication network. Temperature control is enabled by a PID controller designed in Simulink, which shows that software packages traditionally used for the synthesis and analysis of control systems can be effectively used for the synthesis and analysis of control systems based on the Internet of Things hardware.

Privacy and security have become the most important aspects in any sphere of technology today from embedded systems to VLS I circuits. One such an attack compromising the privacy, security and trust of a networked control system by making them vulnerable to unauthorized access is the Hardware Trojan Horses. Even cryptographic algorithms whose purpose is to safeguard information are susceptible to these Trojan attacks. This paper discusses hybrid supervised machine learning models that predict with great accuracy whether the RSA asymmetric cryptosystem implemented in Atmel XMega microcontroller is Trojan-free (Golden) or Trojan-infected by analyzing the power profiles of the golden algorithm and trojan-infected algorithm. The power profiles are obtained using the ChipWhisperer Lite Board. The features selected from the power profiles are used to create datasets for the proposed hybrid models and train the proposed models using the 70/30 rule. The proposed hybrid models can be concluded that it has an accuracy of more than 88% irrespective of the Trojan types and size of the datasets.

In this paper, we study stabilizing problems for networked control systems in the presence of Denial-of-Service (DoS) attacks. DoS attacks may prevent signal transmissions over the network communication channels. The control objective is to save communication resources as many as possible while closed-loop stability is not destroyed under DoS attacks. By constructing a predictor-based periodic event-triggered control framework, we provide a stabilizing condition. The condition is up to the maximum unstable eigenvalue of the dynamic matrix of the plant and the parameters of DoS attacks. Through the event-triggered scheme, the transmission interval is extended, and the communication resources are saved. Simulations are done to confirm the bit rate under event-triggered control is lower than that under periodic sampling control.

The networked control system includes controllers, actuators and sensors, information is exchanged among every part via the network. To solve the problem that the information monitoring must depend on PC, a mobile terminal supervisory system based on Networked Control systems is introduced in this paper. It is a real-time platform to monitor the realistic performance of the networked control systems. The system adopts a more universal hardware platform: mobile phone, which is compact, low-cost and resourceful. In this paper, client/server architecture of this system is described. The stability and richly functional controls are integrated into the system, which meet the requirement of customize supervisory interface and improve the reliability of systems. The system also supports tuning parameters online to achieve consecutive observation through the duplex channel based on TCP/IP protocol. In this paper we illustrate the overall framework and details and its potential applications. Finally, for the air-bearing simulation system, the networked control based experiment demonstrate the feasibility and practicability of the designed system.

We consider a leader-follower formation control setup as an example for a multi-agent networked control system (NCS). This paper proposes an event-based wireless communication scheme with a MIMO precoder, that dynamically adapts to both the channel and the current control state. We apply a Lyapunov drift approach for optimizing the precoder and for defining an event-triggering policy. To evaluate the performance of the proposed scheme, we simulate a formation control of two unmanned aerial vehicles (UAVs) connected via a point-to-point MIMO fading channel. Compared to a benchmark scheme with periodic transmissions and a basic water-filling algorithm, we demonstrate that our proposed event-based scheme is more efficient by consuming less energy and requiring less frequent transmissions on average.

Cooperative control for multi-agent systems usually requires some communication between the various subsystems. In the resulting networked control system, sensitive data is transmitted and shared between the agents. We propose a novel encrypted control scheme that ensures privacy of the individual agents’ data not only during transmission but also during controller evaluations at neighboring agents. Our control scheme efficiently combines the design of structured feedback laws for multi-agent systems with encrypted controllers for conventional linear systems. The underlying key technology is partial homomorphic encryption, which allows simple computations to be carried out on encrypted data.

This study addresses the sliding mode controller design for a networked control system with quantisation and random packet loss. A logarithmic quantiser is adopted in order to guarantee the coarsest density and decrease the possibility of unsuccessful transmission. The quantisation process is designed as an event driven to reduce the amount of data to be transmitted over the channel. A sliding mode controller is adopted to suppress the measurement noise and error caused by the features of a wireless communication channel. The existence of quasi-sliding mode in the sense of mean-square and closed loop stability in the sense of mean square are claimed. Simulations are carried out to support the algorithms proposed.

This paper provides a survey on modeling and theories of networked control systems &#x0028 NCS &#x0029. In the first part, modeling of the different types of imperfections that affect NCS is discussed. These imperfections are quantization errors, packet dropouts, variable sampling &#x002F transmission intervals, variable transmission delays, and communication constraints. Then follows in the second part a presentation of several theories that have been applied for controlling networked systems. These theories include: input delay system approach, Markovian system approach, switched system approach, stochastic system approach, impulsive system approach, and predictive control approach. In the last part, some advanced issues in NCS including decentralized and distributed NCS, cloud control system, and co-design of NCS are reviewed.

Wireless networked control systems (WNCSs) with control loops closed over a wireless network are prevailing these days. However, due to uncertainties such as random accessing delays and possible packet drops, the stability analysis for a WNCS is a challenging task. Most previous studies on the communication network analysis either relied on Monte Carlo simulation or followed the multistate Markov chain framework. In this paper, our main contribution is to propose a formal method-based stability analysis in which the communication system is modeled as a probabilistic timed automaton. The underlying communication protocol is analyzed through probabilistic model checking. In particular, the stability condition of the WNCS is expressed in the probabilistic temporal logic formula as the quality of service requirement, which can be checked, and the satisfaction of the specification is equivalent to the stability guarantee of the WNCS. We then study the impact of different media access control (MAC) parameters on the satisfaction of the specification. Furthermore, if the specification is not satisfied initially, we propose a systematic way to tune the MAC parameters or redesign the controller so that the specification can be met. This paper presents an attempt and a new angle to the communication and control system codesign problem.

Microgrid has emerged as an answer to growing demand for distributed generation &#x0028 DG &#x0029 in power systems. It contains several DG units including microalternator, photovoltaic system and wind generation. It turns out that sustained operation relies on the stability of these constituent systems. In this paper, a microgrid consisting of microalternator and photovoltaic system is modeled as a networked control system of systems &#x0028 SoS &#x0029 subjected to packet dropouts and delays. Next, an observer-based controller is designed to stabilize the system in presence of the aforementioned communication constraints and simulation results are provided to support the control design methodology.

This paper investigates the co-design problem of communication parameters and controller for a linear networked control system (NCS). The distributed sensors of the NCS communicate with the controller via a single wireless channel where a slotted ALOHA protocol with binary exponential backoff algorithm is used for media access control. The main contributions are two-fold: the lower bound of network throughput satisfying the mean square stability of the NCS is derived based on a designed feedback control gain; the other is that the key parameters of the slotted ALOHA protocol are designed so as to provide a viable media access control protocol for the sensors. Numerical examples are given to illustrate the effectiveness of the proposed design method and to further show the relationship between the communication part and the control part.

Recently, the incorporation of telecommunication technology with control systems provides the usability of remote measurement signals for the designing of networked controllers for geographically distributed large-scale systems. However, communication network introduces new difficulties such as time delays and packet dropouts to the design of networked controllers. This paper presents a new Distributed Networked Control Scheme (DNCS) and its stability analysis for stabilizing of large-scale systems with interconnected subsystems featuring both random delays and random packet dropouts in their communication links. Firstly, a general model for large scale distributed networked system consisting of subsystems is used in which the state of each subsystem has its own time varying delay and there are also delays and packet dropouts in their interconnection communication links. To compensate the influence of subsystems on each other and enhance performance and stability margin of the closed-loop system, a suitable distributed control scheme is proposed. The stability criteria are provided based on Lyapunov-Krasovskii and Linear Matrix Inequality (LMI) techniques. For this, a new type of Lyapunov-Krasovskii functional and certain slack matrices are developed to conclude some LMI-based delay-dependent theorems for designing the control law, as well as the stabilizing of the DNCS. To evaluate the proposed method, three illustrative examples are provided. To indicate the efficiency of the suggested approach, a small-gain-based approach and an observer-based consensus method are applied for comparison. Simulation results show the effectiveness of the proposed approach to enhance the performance of large-scale networked systems among a non-ideal communication network.

Packet data flow control from internet nodes to wireless transmission nodes will become increasingly important in 5G wireless systems. One reason is the new requirement to maintain and guarantee a maximum round-trip loop delay for high-bandwidth feedback control applications. Another driver is the emerging multipoint mobile broadband internet access, where data starvation needs to be avoided in the transmit queue buffers of the wireless transmission nodes. Moreover, robust global stability is a requirement, since an only locally stable data flow controller would have a nonzero likelihood to malfunction algorithmically. The resulting networked control problem is further complicated by an uncertain internet backhaul loop delay, in combination with a one-directional data flow that introduces saturation in the feedback loop. The paper therefore contributes with a proof of global robust stability for a nonlinear networked window-based packet flow control algorithm. The performance and stability of the controller are assessed with simulation, which shows that the algorithm performs as required.

Networked control systems have recently experienced a surge in fundamental theoretical results ignited by numerous advantages of introducing shared multipurpose communication networks in control systems. Regarding developments on the practical side, however, a networked control system is still wanting when it comes to experimental platforms suitable for research and educational purposes, which contributes to most of networked control system theory being validated by means of numerical examples and simulations. This paper addresses this issue by presenting a low-cost real-time networked control system platform, based on custom hardware and software solutions that can be readily explored with the sole use of a web browser connected to the Internet. The technical decisions made during development represent a fundamentally novel take on networked control system experimental platforms that can potentially be reproduced by several universities. The platform provides the user with multiple controller and input reference options, network configurations, delay statistics, and even a downloadable file containing advanced experiment data. A survey conducted with students located over 1200 km away from the platform who used it during laboratory assignments highlight the system’s usability and interactivity, and supports the platform is suitable for educational purposes.

In this paper, the potential improvement in performance of an NCS (Networked Control System) subject to variable delays controlled by means of an adaptive system is analyzed. An adaptive Smith Predictor has been used to compensate the effects of varying delays measured on the network. The NCS, closed over the Internet, has been implemented using a platform called NCS-CMUF, composed of local and remote stations. The plant used to carry out the experimental tests is consisted of an optical oven in which the luminosity loop is the main controlled variable whose time constant lies in the range of milliseconds. This paper highlights the importance of synchronization between the clocks of the local and remote stations to perform consistent measurements of network delays, in order to provide an active compensation of the effects of delays. The results show the effectiveness of adaptive Smith Predictor in coping with different delays and the performance improvements achieved with the proposed scheme.