Cross-Layer Adaptive Feedback Scheduling

Wireless sensor-actuator networks (WSANs) are being adopted in process industries because of their advantages in lowering deployment and maintenance costs. While there has been significant theoretical advancement in networked control design, only limited empirical results that combine control design with realistic WSAN standards exist. This paper presents a cyber-physical case study on a wireless process control system that integrates state-of-the-art network control design and a WSAN based on the WirelessHART standard. The case study systematically explores the interactions between wireless routing and control design in the process control plant. The network supports alternative routing strategies, including single-path source routing and multi-path graph routing. To mitigate the effect of data loss in the WSAN, the control design integrates an observer based on an Extended Kalman Filter with a model predictive controller and an actuator buffer of recent control inputs. We observe that sensing and actuation can have different levels of resilience to packet loss under this network control design. We then propose a flexible routing approach where the routing strategy for sensing and actuation can be configured separately. Finally, we show that an asymmetric routing configuration with different routing strategies for sensing and actuation can effectively improve control performance under significant packet loss. Our results highlight the importance of co- joining the design of wireless network protocols and control in wireless control systems.

The integration of wireless communication and control systems revealed wireless networked control systems (WNCSs). One fundamental problem in WNCSs is to have a wide coverage area. For the first time in the literature, we address this problem and we obtain the maximum coverage area by solving an optimization problem. In this technical note, we consider a WNCS where the output sensor measurements are transmitted over separate heterogeneous multi-hop wireless ad-hoc subnetworks. The observation process is divided into N parts and the system state is estimated using the Kalman filter. We present the critical arrival probability for a sensor measurement packet such that if the packet arrival probability is larger than the critical value, it is guaranteed that the estimator of the WNCS converges. We derive the maximum total coverage area of the heterogeneous wireless subnetworks having maximum cost-efficiency under the constraint of the convergence of the WNCS estimator.

Introduction. In order to ensure the sustainable functioning of critical infrastructures (CI), in conditions of the growth of various types of threats, security systems (SB) for various purposes, for example, technical SB, should be created on them. As such systems, first of all, there are security alarm systems, access control and some others. These systems are usually integral parts of the overall physical protection of CI, so they play an important role in ensuring the security of CI. One of the most important SB on the CI is the identification and access control system. In recent years, specialists in these systems have paid closer attention to the issues of ensuring the security of checkpoints for vehicles. It is known that they can be one of the most vulnerable places in the system of physical protection of the CI. Based on this, the task of improving identification and access control systems, including the vehicle, is currently an urgent scientific and practical task, and therefore require further study. Aims and Purposes. The purpose of this study is to develop a simplified conceptual design of the wireless identification and access control system of the vehicle on the CI. Methods. To achieve this goal, the methods of system analysis, elements of the theory of radio engineering, as well as methods of analysis, description, generalization, results of research works on the subject of research were used. Results and discussion. The existing systems of wireless identification and access control on CI are considered on the example of wireless identification and access control systems of the vehicle. Some ways of improving the safety and reliability of the operation of these systems are outlined. The analysis of ways to improve the systems of wireless identification and access control on CI is carried out on the example of wireless identification and access control systems of the vehicle. A simplified conceptual design of the wireless identification and access control system of the vehicle on CI has been developed. The main primary provisions of the system under development related to the circuit engineering stage of conceptual design are formulated. Conclusions. As a result of the conducted research, a simplified conceptual design of the wireless identification and access control system of the vehicle on CI has been developed. According to the authors, the developed simplified conceptual project, with appropriate adaptation, can be applied in practice for the purposes of ensuring the physical protection of CI. Keywords: critical infrastructure; identification systems; access control; wireless data transmission systems; conceptual project.

The PIDPLUS algorithm is one of the candidates to be used in wireless automation systems. The control performance of this algorithm under packet losses is investigated in the paper. First, the performance of PIDPLUS is evaluated with respect to packet loss rates for a general first-order plus time-delay process, a model widely used for controller tuning. This simulation study reveals how the performance is affected by packet losses in a wireless control system. Secondly, we will elaborate on the implementation of PIDPLUS and discuss its design, tuning and performance in wireless control systems in light of an unstable case process. The results suggest that PIDPLUS can well be used for wireless control, but better performance could be attained by further development of the controller tuning methodology.

In order to overcome the power frequency electromagnetic interference existing in the wireless liquid level control system and realize the accurate control to the liquid level, a compound digital filter algorithm is proposed and implemented. This article discusses the topology of the wireless liquid level control system, the form and characteristics of the electromagnetic interference signal, the architecture of the digital filter and the algorithm flow chart, finally compares and analyzes actual operation results. The digital filtering algorithm runs effectively and can achieve the purpose of filtering the electromagnetic interference.

ZigBee-based Real-time Wireless Networked Motor Control System

Wireless is now a pervasive aspect of everyday life; from the Bluetooth module in a mobile handset to broadband wireless networks covering scores of square kilometres. No longer is wireless networking an experimental technology, it has become ubiquitous, and wireless closed-loop control is now being seriously considered for industrial applications. Wireless networking enables the vision of a security enterprise - ease of expansion with minimal implementation and maintenance costs. The bottom line is that wireless networking is cheaper. Computer-based simulation can help develop a thorough understanding of wireless control systems; the network and control system can be configured quickly and the results from modifications to either the protocol or the control strategy can be implemented and tested scientifically, without time-consuming and difficult hardware implementation.

The design of a wireless water level control system is introduced and discussed in detail. In this system, the wireless Proportional Integral (PI) controller is developed using the LabVIEW graphical user programming language. Zigbee wireless technology is chosen for the wireless data transfer system. The experimental testbed was built and the system software and hardware were implemented. In order to compare the performance of the wired and wireless system, a corresponding wired water level control system was built. Experimental results show that under the same PI parameters, the settling time of the wired system is 3.3 times faster than the wireless system. However, the percent overshoot using the wireless controller is 4% smaller.

Wireless control has advantages in the case of synchronous cooperative motion control. We consider a wireless feedback control system with multiple plants. In such situation, not only the control performance of individual plants but also the synchronization among the plants is important. However, synchronization errors occur because of packet losses in the wireless channel. In this paper, we propose a relay transmission scheme with predictive control information to reduce the influence of packet losses in the synchronization performance. Numerical examples clarify the reduction of synchronization errors by the proposed scheme.

Wireless networked control system (WNCS) is given profound attention because of dynamic, flexibility and inexpensiveness. However, it is difficult to use a single simulator to simulate a WNCS which is a hybrid system. A co-simulation framework based on OPNET, Matlab and C++ is presented to capture both the system dynamics and communication events and depict the real WNCS accurately. MATLAB is good for simulating the mathematical modeling and feedback control, while OPNET is apt at simulating the WLAN communication behavior. The co-simulation framework can help WNCS designer understand and improve the performance of the WNCS.

This paper designs and makes up a wireless monitoring and control system based on the wireless communication with several single chips and the nRF905 modules. Transferring data and instructions via wireless interface, the system can control the opening and closing operation of a high voltage circuit breaker and measure the characteristic parameters. The reliability tests on the system under a series of typical interferes in vacuum switch cabinets are carried out. Parallel experiments on the data communication demonstrators without EMI are also conducted for comparison. Furthermore, signal intensity experiments is designed to review the wireless communication effect with different distances. By the tests designed and conducted, it is confirmed that the wireless measure and control system designed to monitor and control the high voltage circuit breaker is feasible

The wireless channel can influence the design of industrial applications. A majority of existing scheduling models of industry control network are designed without considering the characteristic of wireless technology. They face serious degradations in wireless industrial applications. This paper uses a secondary architecture of dual-band and presents a scheduling mechanism based on communication task deadline for wireless industrial control system. Thus the adverse effect on real-time and reliability, caused by transmission errors and other problems of the wireless channel, can be (partially) compensated.

Monitoring and control of critical parameters is of paramount importance for most of the industrial processes. But laying cables from various sensors and actuators to monitoring stations increases cost and complexity. This problem calls for wireless implementations for monitoring and control applications. This paper presents a low cost wireless temperature monitoring and control system based on ZigBee wireless communication protocol. The system uses Microchip's PIC18F458 microcontroller as the field unit and NI LabVIEW interface as the monitoring unit. It utilizes a precision temperature sensor IC, which being a low cost sensor provides a reliable output within its operating range. The system follows a request-response methodology, where the field unit responds to the requests made by the monitoring unit.

An industrial wireless monitoring and control system, capable of supporting energy-harvesting devices through smart sensing and network management, designed for improving electro-refinery performance by applying predictive maintenance, is presented. The system is self-powered from bus bars, and features wireless communication and easy-to-access information and alarms. With cell voltage and electrolyte temperature measurements, the system enables real-time cell performance discovery and early reaction to critical production or quality disturbances such as short-circuiting, flow blockages, or electrolyte temperature excursions. Field validation shows an increase in operational performance of 30% (reaching 97%) in the detection of short circuits, which, thanks to a neural network deployed, are detected, on average, 10.5 h earlier compared to the traditional methodology. The developed system is a sustainable IoT solution, being easy to maintain after its deployment, and providing benefits of improved control and operation, increased current efficiency, and decreased maintenance costs.

This study addresses the critical health challenges faced by premature infants by developing an innovative, wirelessly controlled incubator using Arduino technology. By maintaining optimal environmental conditions (37°C and 50% humidity), similar to a mother's womb, and utilizing photodynamic therapy with a 400nm wavelength light to treat jaundice, our system reduces the risks associated with traditional wired setups and operational costs. The results demonstrate effective regulation of temperature and humidity, as well as a reduction in bilirubin levels, suggesting that this technology has significant potential to enhance neonatal care for premature infants. Highlights: Wireless control systems in incubators improve safety and reduce the complexity and cost associated with traditional wired setups. Photodynamic therapy effectively reduces bilirubin levels, addressing jaundice in premature babies. Maintaining optimal incubator conditions of 37°C temperature and 50% humidity mirrors the environment of a mother’s womb, enhancing survival rates. Keywords: Premature Infants, Wireless Technology, Incubator, Photodynamic Therapy, Neonatal Care