Industrial Process Control Systems Research Articles

An Operating Nanoscale Data Segmentation Method Based on Curve Entropy for Close-Loop Identification of Industrial Process Control System

An Operating Nanoscale Data Segmentation Method Based on Curve Entropy for Close-Loop Identification of Industrial Process Control System

Effects of wireless packet loss in industrial process control systems

Timely and reliable sensing and actuation control are essential in networked control. This depends on not only the precision/quality of the sensors and actuators used but also on how well the communications links between the field instruments and the controller have been designed. Wireless networking offers simple deployment, reconfigurability, scalability, and reduced operational expenditure, and is easier to upgrade than wired solutions. However, the adoption of wireless networking has been slow in industrial process control due to the stochastic and less than 100% reliable nature of wireless communications and lack of a model to evaluate the effects of such communications imperfections on the overall control performance. In this paper, we study how control performance is affected by wireless link quality, which in turn is adversely affected by severe propagation loss in harsh industrial environments, co-channel interference, and unintended interference from other devices. We select the Tennessee Eastman Challenge Model (TE) for our study. A decentralized process control system, first proposed by N. Ricker, is adopted that employs 41 sensors and 12 actuators to manage the production process in the TE plant. We consider the scenario where wireless links are used to periodically transmit essential sensor measurement data, such as pressure, temperature and chemical composition to the controller as well as control commands to manipulate the actuators according to predetermined setpoints. We consider two models for packet loss in the wireless links, namely, an independent and identically distributed (IID) packet loss model and the two-state Gilbert-Elliot (GE) channel model. While the former is a random loss model, the latter can model bursty losses. With each channel model, the performance of the simulated decentralized controller using wireless links is compared with the one using wired links providing instant and 100% reliable communications. The sensitivity of the controller to the burstiness of packet loss is also characterized in different process stages. The performance results indicate that wireless links with redundant bandwidth reservation can meet the requirements of the TE process model under normal operational conditions. When disturbances are introduced in the TE plant model, wireless packet loss during transitions between process stages need further protection in severely impaired links. Techniques such as retransmission scheduling, multipath routing and enhanced physical layer design are discussed and the latest industrial wireless protocols are compared.

The system of technical diagnostics of the industrial safety information network

This research is devoted to problems of safety of the industrial information network. Basic sub-networks, ensuring reliable operation of the elements of the industrial Automatic Process Control System, were identified. The core tasks of technical diagnostics of industrial information safety were presented. The structure of the technical diagnostics system of the information safety was proposed. It includes two parts: a generator of cyber-attacks and the virtual model of the enterprise information network. The virtual model was obtained by scanning a real enterprise network. A new classification of cyber-attacks was proposed. This classification enables one to design an efficient generator of cyber-attacks sets for testing the virtual modes of the industrial information network. The numerical method of the Monte Carlo (with LPτ - sequences of Sobol), and Markov chain was considered as the design method for the cyber-attacks generation algorithm. The proposed system also includes a diagnostic analyzer, performing expert functions. As an integrative quantitative indicator of the network reliability the stability factor (Kstab) was selected. This factor is determined by the weight of sets of cyber-attacks, identifying the vulnerability of the network. The weight depends on the frequency and complexity of cyber-attacks, the degree of damage, complexity of remediation. The proposed Kstab is an effective integral quantitative measure of the information network reliability.

New algorithm for controlling electric arc furnaces using their vibrational and acoustic characteristics

The processes occurring in arc discharges are analyzed as the sources of acoustic radiation in an electric arc furnace (EAF). Acoustic vibrations are shown to transform into mechanical vibrations in the furnace laboratory. The shielding of the acoustic energy fluxes onto water-cooled wall panels by a charge is experimentally studied. It is shown that the rate of charge melting and the depth of submergence of arc discharges in the slag and metal melt can be monitored by measuring the vibrational characteristics of furnaces and using them in a universal industrial process-control system, which was developed for EAFs.

Industrial process control systems: research status and \\development direction

Industrial process control systems: research status and \\development direction

Modeling techniques as applied to generating tool-independent automation projects

Abstract The Industrie 4.0 initiative emphasizes the consistent digitalization and linking of all productive units, including the definition of industrial control systems. This work proposes a model-based approach to develop Industrial Process Measurement and Control Systems. It uses modern software technologies but software complexity is wrapped using the notation, syntax and semantics of the field. It is UML modeling tool independent, due to the definition of domain profiles. It is also PLC programming tool independent, as the software architecture is generated following the PLCopen XML standard.

Hybrid distributed acoustic and temperature sensor using a commercial off-the-shelf DFB laser and direct detection.

We demonstrate a hybrid distributed acoustic and temperature sensor (DATS) using a commercial off-the-shelf (COTS) distributed feedback (DFB) laser, a single-mode optical fiber, and a common receiver block. We show that the spectral and frequency noise characteristics of the laser, combined with a suitable modulation scheme, ensure the inter-pulse incoherence and intra-pulse coherence conditions required for exploiting the fast denoising benefits of cyclic Simplex pulse coding in the hybrid measurement. The proposed technique enables simultaneous, distributed measurement of vibrations and temperature, with key industrial applications in structural health monitoring and industrial process control systems. The sensor is able to clearly identify a 500 Hz vibration at 5 km distance along a standard single-mode fiber and simultaneously measure the temperature profile along the same fiber with a temperature resolution of less than 0.5°C with 5 m spatial resolution.

Industrial Automation and Process Control System Using Can Bus

Industrial Automation and Process Control System Using Can Bus

Designing and Implementation of Industrial Process Control and Monitoring System Using Fuzzy PID and WSN

The paper addresses the nonlinear control design problem for a two tank system. Three crucial industrial parameters i.e. temperature, level and flow are used in this work. Mathematical modeling of the proposed two tank system is presented in this work and the proposed system is also implemented using Lab View. Industrial parameters are controlled by Fuzzy PID controller which greatly improves the performance of the system. This system can be adopted by industries to improve their processes and it can also be used by academia for teaching purposes. This system provides real time simulation and hardware implementation which provide aid in learning for the graduate and undergraduate control students.

Intrinsic Safety Explosion-Proof System

The paper introduces the structure and basic theory of the intrinsic safety explosion-proof, the parameters of each part and the principles of selection. Emphasizes the features、work theory and earthing of the isolated barrier, which is used in intrinsic safety explosion-proof industry process control system .

Annular Heating Furnace Temperature Control Based on the Fuzzy-PID Algorithm and Cascade Double-Cross Limiting Control

Annular heating furnace temperature control is a typical and complex industrial process control system,with the characteristics of multivariable,time-varying parameters,nonlinear,coupling, large inertia and pure delay,so it is difficult to obtain satisfactory control effect when using conventional PID control. In view of the above problems, adopting fuzzy PID algorithm and cascade double-cross limiting control, combustion control effect is greatly improved, self-tuning of PID parameters is realized, and control quality is enhanced. The experimental results show that, fuzzy PID control shows good dynamic and steady performance, its control effect is significantly improved when compared with conventional PID control, and it has better overall performance.

Fractional Order Models of Industrial Pneumatic Controllers

This paper addresses a new approach for modeling of versatile controllers in industrial automation and process control systems such as pneumatic controllers. Some fractional order dynamical models are developed for pressure and pneumatic systems with bellows-nozzle-flapper configuration. In the light of fractional calculus, a fractional order derivative-derivative (FrDD) controller and integral-derivative (FrID) are remodeled. Numerical simulations illustrate the application of the obtained theoretical results in simple examples.

Self-adaptive PID controller of microwave drying rotary device tuning on-line by genetic algorithms

The control design, based on self-adaptive PID with genetic algorithms (GA) tuning on-line was investigated, for the temperature control of industrial microwave drying rotary device with the multi-layer (IMDRDWM) and with multivariable nonlinear interaction of microwave and materials. The conventional PID control strategy incorporated with optimization GA was put forward to maintain the optimum drying temperature in order to keep the moisture content below 1%, whose adaptation ability included the cost function of optimization GA according to the output change. Simulations on five different industrial process models and practical temperature process control system for selenium-enriched slag drying intensively by using IMDRDWM were carried out systematically, indicating the reliability and effectiveness of control design. The parameters of proposed control design are all on-line implemented without iterative predictive calculations, and the closed-loop system stability is guaranteed, which makes the developed scheme simpler in its synthesis and application, providing the practical guidelines for the control implementation and the parameter design.

A disturbance observer enhanced composite cascade control with experimental studies

The presence of strong disturbances usually causes great performance degradation of industrial process control systems. A disturbance observer (DOB) enhanced composite cascade control consisting of model predictive control (MPC), proportional-integral-derivative (PID) control, and DOB is proposed in this paper. DOB is employed here to estimate the severe disturbances and the estimated values are applied for feed-forward compensation, forming a composite control together with MPC. To evaluate the efficiency and validity of the proposed control structure, the simulation as well as experimental studies have been carried out for a level tank process which represents a typical first-order plus dead-time (FODT) industry process. Both the simulation and experimental results show that the proposed composite control method significantly improves the disturbance attenuation property of the MPC scheme in controlling such a typical industrial process.

Deadline-Aware Scheduling Perspectives in Industrial Wireless Networks: A Comparison between IEEE 802.15.4 and Bluetooth

In industrial contexts, most of process control applications use wired communication networks. The reliability of wired networks is indisputable and extensively demonstrated by several studies in the literature. However, it is important to consider several disadvantages provided by the use of wired technologies, like high deployment and maintenance costs and low network scalability. Although it is difficult to fully replace wired networks, wireless communication protocols have features which could undeniably affect in positive way the production mechanisms in factories. The wireless networks (WNs) are effectively used to detect and exchange information. The main communication protocols, currently available for WNs, however, do not support real-time periodic traffic flows which, as known, mainly characterize industrial networks. In this paper, we will analyze a real-time scheduling algorithm for both periodic and aperiodic traffic management, applied to networks based on IEEE 802.15.4 and Bluetooth, respectively. The main purpose of this research is to reduce, as much as possible, the packet loss on the channel, increasing at the same time the reliability of the wireless technology. Furthermore, the comparison between IEEE 802.15.4 and Bluetooth will allow to identify the more suitable communication protocol for industrial process control systems.

The design and simulation of networked control systems with online extreme learning machine PID

Network-based control systems (NCSs) for industrial processes recently have been paid much more attention. However, the control engineers must face to an unavoidable problem of whether or not the traditional proportional-integral-derivative (PID) controller for the network case is available. More specifically, how to design PID controller in the presence of the network-induced time-varying delay? In this paper, an online extreme learning machine-based PID controller is proposed, where the Jacobian information relating to online extreme learning machine is identified, and then is used to adjust the PID parameters. Lastly, a simulation using TrueTime blocks in a Simulink/MATLAB box is given, and it is observed that the closed loop system has good dynamic and adaptive performance.

Implementing constrained cyber-physical systems with IEC 61499

Cyber-physical systems (CPS) are integrations of computation and control with sensing and actuation of the physical environment. Typically, such systems consist of embedded computers that monitor and control physical processes in a feedback loop. While modern electronic systems are increasingly characterized as CPS, their design and synthesis still rely on traditional methods, which lack systematic and automated techniques for accomplishment. Recently, IEC 61499 has been proposed as a standard for designing industrial process-control and measurement systems. It prescribes a component-based approach for developing industrial automation software using function blocks. Executable code can then be automatically generated and simulated from these function blocks. This bodes well for designers of CPS, who are more likely to be experts in specific industrial domains, rather than in computer science. The intuitive graphical nature and automatic code synthesis of IEC 61499 programs will alleviate the programming burden of industrial engineers, while ensuring more reliable software. While software synthesis from IEC 61499 programs is not new, the generation of efficient code from them has been wanting. This has made it difficult for function blocks to be used in software development for resource-constrained embedded controllers commonly employed in CPS. To address this, we present an approach that can generate very efficient code from function block descriptions. Experimental results from a benchmark suite shows that our approach produces substantially faster and smaller code compared to existing techniques.

Automation of calibration of tanks in industrial production process control systems

A method of establishing a dependence of the volume of horizontal and vertical tanks on filling level by means of an automatic production process control system is considered. With the use of the system, it is possible to calibrate a tank in the course of operation without the use of additional production operations. An example illustrating the use of the automatic control system at an enterprise that stores and distributes petroleum products is given.

Autonomous Application Recovery in Distributed Intelligent Automation and Control Systems

Over the past decade, a clear trend toward distributed automation in industrial systems was observable. This means that applications are executed at heterogeneous control devices and communication networks. One of the main drivers of this development was the availability of cheap computing and communication resources. Moreover, a strong market demand for operation and adaptation of automation and control services with no downtime is also often requested. As a result, appropriate approaches recovering and (re)configuring automation and control devices as well as even their services and functions during full operation are needed. The relatively new standard IEC 61499 “Function Blocks” provides a reference model for the development and implementation of distributed industrial process measurement and control systems (IPMCSs). It provides a scalable and open architecture to model distributed automation and control applications. The high-level goals of IEC 61499 can be summarized as interoperability, (re)configurability, and portability of distributed applications for IPMCS. Therefore, it provides a very good basis for dynamic (re)configuration and recovery of applications and status information in heterogeneous IPMCS and may master some of the shortcomings of present-day systems. The main purpose of this paper is to present and discuss a general concept for autonomous recovery of applications within the context of distributed automation and control systems which has been implemented using the IEC 61499 reference model.

LCA of biomethane

As a renewable substitute for natural gas in the pipeline system, biomethane is a key option on the way to sustainable, renewable energy supplies. This paper evaluates biomethane production from energy crops with respect to its environmental impact and energy efficiency, taking into consideration own measurements and experience data from a modern, commercial plant as well as current studies. According to this study the specific GHG emissions associated with the production of biomethane amount to as little as 44.6 g CO 2eq/kWh, corresponding to an overall GHG emission reduction of 82% compared with natural gas. The specific non-renewable energy demand of the entire process is very low at only 12%. These two indicators are due either to environmentally friendly plant cultivation (fermenter residues used as fertilizer) or to optimized plant design and operation (amine upgrading, renewable process heat, gas-tight equipment, industrial process control system).