Wireless Actuator Research Articles

WSN Based Tariff and Electrical Loads Theft Identification

Energy storing has turned into a notable statement for the society of nowadays. This paper displays a Wireless Sensor and Actuator Network (WSN) intended to offer help to a programmed framework, based on the GSM, which empowers a mindful utilization of vitality. The proposed system plays out a proficient administration of devices, machines and procedures, upgrading their activity to accomplish a decrease in their general vitality use at some random time. For this reason, significant information is gathered from smart sensors, which are placed at the required areas, just as from the vitality showcase through the wireless communication. This data analysis is to give learning about load use, and to enhance proficiency.

Wireless Sensor and Actuator Networks (WSANs): Insights and Scope of Research

Recent years are witnessing the growth of different kinds of networks including Wireless Sensor and Actuator Networks (WSANs). WSANs are self-configured and ad-hoc natured networks without any permanent infrastructure that consists of numerous sensor nodes and few actuator nodes that can collaboratively monitor the characteristics of physical and environmental conditions like vibration, sound, temperature, pressure, motion or pollutants, and determine an appropriate action to take depending upon the sensed data, thereby changing the state of the field of interest by performing the suitable action in it. We can say it as an advancement of Wireless Sensor Networks (WSNs) with the inclusion of actuating component. Along with the existing research challenges of WSNs, the WSANs have many additional research challenges to be addressed. This paper gives an insight into the scope of ongoing and future research in the aspect of preserving temporal relationship among the events, restoring the connectivity in case of node failures, need for QoS parameters, along with several operational details of WSANs.

Industrial wireless sensor and actuator networks in industry 4.0: Exploring requirements, protocols, and challenges—A MAC survey

SummaryThe vision to connect everyday physical objects to the Internet promises to create the Internet of Things (IoT), which is expected to integrate the diverse technologies such as sensors, actuators, radio frequency identification, communication technologies, and Internet protocols. Thus, IoT promises to transfer traditional industry to advance digital industry known as the Industry 4.0.At the core of the Industry 4.0 are the wireless sensor networks (WSNs) and wireless sensor and actuator networks (WSANs) that led to the development of industrial wireless sensor networks (IWSNs) and industrial wireless sensor and actuator networks (IWSANs). These networks play a central role of connecting machines, parts, products, and humans and create a diverse set of new applications to support intelligent and autonomous decision making.The IWSAN is a promising technology for numerous industrial applications because of their several potential benefits such as simple deployment, low cost, less complexity, and mobility support. However, despite such benefits, they impose several unique challenges at different layers of the protocol stack when deploying them for various monitoring and control applications in the Industry 4.0. In this article, we explore IWSAN, its applications, requirements, challenges, and solutions in the context of industrial control applications. Our main focus is on the medium access control (MAC) layer that can be exploited to satisfy such requirements. Our discussion presents extensive background study of the MAC schemes and it reviews the MAC protocols of the existing wireless standards and technologies. A number of application‐specific MAC protocols developed to support industrial applications, which are not part of these standards, are also elaborated. We rationalize to what extent the existing standards and protocols help in solving such requirements as laid down by the Industry 4.0. In the end, we emphasize on existing challenges and present important future directions.

A Multiphase Resonance-Based Boosting Rectifier With Dual Outputs for Wireless Power Transmission

This paper proposes a multiphase resonance-based rectifier (MPRR), capable of delivering power to multiple loads with large difference in their output voltages. This behavior is particularly useful for wireless sensors and actuators, in which the micromachined transducer/actuator needs a high voltage to operate but the interface circuitry requires only a fraction of that voltage. This is achieved by shorting the receiver (Rx) L3C3-tank to increase its loaded quality factor, QRx , over several cycles to accumulate wirelessly transferred energy in the inductor during this period, and then first break the loop in-phase, by connecting the L3C3-tank to the in-phase load ( RL,I ), to transfer energy at low voltage in a half cycle (in-phase charging), and then transfer energy to the quadrature load ( RL,Q ) through a diode in a quarter cycle at high voltage (quadrature charging). By optimizing the number of cycles for in-phase charging, NI , and quadrature charging, NQ , through an iterative design procedure, the MPRR can achieve the highest power delivered to the load under a given set of design constraints. Governing equations in the MPRR operation are derived to identify the key specifications for the design procedure. Using an exemplar set of specifications, the optimized MPRR was able to generate 21.5 and 1.84 V across 100 kΩ and 200 Ω loads, respectively, from a class-D power amplifier operating at 15 V, 6.78 MHz sinusoid input in the industrial-scientific-medical band (ISM-band) at a Tx/Rx coil separation of 1.3 cm with NI = 3 cycles, NQ = 6 cycles, and IQ Ratio = 5.

Modeling, planning, and scheduling of shop-floor assembly process with dynamic cyber-physical interactions: a case study for CPS-based smart industrial robot production

In recent years, the applications of industrial robots are expanding rapidly due to Industry 4.0 oriented evolutions, ranging from automobile industry to almost all manufacturing domains. As demands with rapid product iterations become increasingly fluctuant and customized, the assembly process of industrial robots faces new challenges including dynamic reorganization and reconfiguration, ubiquitous sensing, and communication with time constraints, etc. This paper studies the industrial robot assembly process modeling, planning, and scheduling based on real-time data acquisition and fusion under the framework of advanced shop-floor communication and computing technologies such as wireless sensor, actuator network, and edge computing. Taking the assembly of industrial robots as the specific object, the multi-agent model of industrial robot assemble process is established. Then, the encapsulation, communication, and interaction of agents with real-time data acquisition and fusion are studied. Based on multi-agent reinforcement learning approach, an intelligent planning and scheduling algorithm for industrial robot assembly is proposed, and a simulation case is presented to demonstrate the proposed model and algorithm.

UHF RFID Prototyping Platform for ISO 29167 Decryption Based on an SDR.

Ultra high frequency radio frequency identification (UHF RFID) is becoming a key technology in the Internet of Things. It allows the implementation of batteryless and wireless nodes, including sensors and actuators. Due to its possible transmission range of >10 m and potential to carry critical information, security is a highly important topic. For this reason, the International Organization for Standardization has published several crypto suites for UHF RFID within the ISO-29167 standard in 2014. Recently, research has focused on implementing those encryption features on the transponder side. However, currently no crypto enabled UHF RFID readers are available. In order to cope with the rapid development in this field, ‘open’ and flexible readers based on software defined radios are needed. They make it possible to quickly adapt the protocol and to test new functionalities such as encryption. This paper deals with the first implementation of the ISO 29167-19 standardized RAMON decryption on a software defined radio. The programming of this hardware is done in LabVIEW which allows for controlling the built-in transceiver modules. However, first measurements show that the decryption takes 51 s. This is because LabVIEW is not suitable for handling very large numbers like they are utilized in cryptography. Because such a long processing time is not feasible in experiments nor in a real-life scenarios, this method is not suitable for a prototyping platform. Thus, a different approach is chosen to optimize the decryption processing time. LabVIEW still provides the framework for handling the protocol and controlling the transceivers, but the decryption is performed in a Java application. In that way, the entire decryption process takes only about 2.2 ms, which is 23,318 times faster than the implementation in LabVIEW. Thus, this new approach meets the necessary timing requirements and is suitable for realistic application scenarios. The shown method allows development and testing of new functionalities in UHF RFID systems but may also be employed in any application that require long processing times in LabVIEW. Furthermore, the implementation of decryption features is the first necessary step towards a fully compliant, crypto enabled interrogator for UHF RFID, featuring a high adaptability.

An enhanced distributed control-theoretic time synchronization protocol using sliding mode control for wireless sensor and actuator network

<span>Time synchronization is very important in a wireless sensor and actuator network (WSAN) as it provides a common time notation to the WSAN. To handle the time synchronization issue, this paper presented an enhanced distributed control-theoretic time synchronization protocol for wireless sensor and actuator networks, named Time Synchronization using Distributed Observer algorithm with Sliding mode control element (TSDOS). In this protocol, an augmented sliding mode control element is used for robustification purpose. From the theoretical convergence analysis and simulation results presented in this paper, it proved that the proposed TSDOS is the best if compared to another two algorithms from the literature in terms of cumulative integral absolute error.</span>

Mapping imprecise computation tasks on cyber-physical systems

By allocating a set of tasks onto a set of nodes and adjusting the execution time of tasks, task mapping is an efficient approach to realize distributed computing. Cyber-Physical Systems (CPS), as a particular case of distributed systems, raise new challenges in task mapping, because of the heterogeneity and other properties traditionally associated with Wireless Sensor and Actuator Networks (WSAN), including shared sensing, acting and real-time computing. In addition, many of the real-time tasks of CPS can be executed in an imprecise way. Such systems accept an approximate result as long as the baseline Quality-of-Service (QoS) is satisfied and they can execute more computations to yield better results, if more system resources is available. These systems are typically considered under the Imprecise Computation (IC) model, achieving a better tradeoff between QoS and limited system resources. However, determining a QoS-aware mapping of these real-time IC-tasks onto the nodes of a CPS creates a set of interesting problems. In this paper, we firstly propose a mathematical model to capture the dependency, energy and real-time constraints of IC-tasks, as well as the sensing, acting, and routing in the CPS. The problem is formulated as a Mixed-Integer Non-Linear Programming (MINLP) due to the complex nature of the problem. Secondly, to efficiently solve this problem, we provide a linearization method that results in a Mixed-Integer Linear Programming (MILP) formulation of our original problem. Finally, we decompose the transformed problem into a task allocation subproblem and a task adjustment subproblem, and, then, we find the optimal solution based on subproblem iteration. Through the simulations, we demonstrate the effectiveness of the proposed method.

Robust Wireless Sensor and Actuator Networks for Networked Control Systems.

The stability guarantee of wireless networked control systems is still challenging due to the complex interaction among the layers and the vulnerability to network faults, such as link and node failures. In this paper, we propose a robust wireless sensor and actuator network (R-WSAN) to maintain the control stability of multiple plants over the spatial-temporal changes of wireless networks. The proposed joint design protocol combines the distributed controller of control systems and the clustering, resource scheduling, and control task sharing scheme of wireless networks over a hierarchical cluster-based network. In particular, R-WSAN decouples the tasks from the inherently unreliable nodes and allows control tasks to share between nodes of wireless networks. Our simulations demonstrate that R-WSAN provides the enhanced resilience to the network faults for sensing and actuation without significantly disrupting the control performance.

Multiprocessor Scheduling meets the Industrial Wireless

This survey covers schedulability analysis approaches that have been recently proposed for multi-hop and multi-channel wireless sensor and actuator networks in the industrial control process domain. It reviews results with a focus on WirelessHART-like networks. The paper address the mapping of multi-channel transmission scheduling to multiprocessor scheduling theory, and recognize it as the key aspect of the research direction covered by this survey. It also provides a taxonomy of the existing approaches concerning this direction, and discuss its main features and evolution. The survey identifies open issues, key research challenges, and future directions.

SANSync: An Accurate Time Synchronization Protocol for Wireless Sensor and Actuator Networks

Wireless sensor and actuator networks (WSANs) consists of a large number of sensors and a relatively small number of actuators connected through wireless links. In the WSANs applications, sensors detect the events in their environment and inform actuators. The actuators cooperate together and respond quickly to events. To coordinate their operations, a common time reference to all nodes in the network is a critical need. In this paper, we propose an accurate time synchronization protocol for WSANs, namely Sensor and Actuator Networks Synchronization Protocol (SANSync), which allows the clocks of all sensors and actuators in the network to be synchronized with a reference clock. SANSync is based on clustering; it takes advantage of the large transmission capacity of actuators to increase the accuracy of time synchronization. The simulation results show that the proposed protocol increases significantly the accuracy of time synchronization compared to FTSP and FCSA protocols.

EATDDS: Energy-aware middleware for wireless sensor and actuator networks

According to Object Management Group organization, Data Distribution Service (DDS) middleware is the leading technology for Industrial Internet of Things (IIoT). Therefore, using DDS-based middleware for Wireless Sensor/Actuator Networks (WSAN) will extremely ease the development and integration of WSAN applications into IIoT, which has an effective impact on improving the productivity and saving the cost. However, applying such technology over WSAN significantly affects the energy consumption. In this work, an energy-aware middleware for WSAN is developed based on DDS standard, which is called EATDDS. Furthermore, developing this middleware leads to a major enhancement into TOSSIM simulator; in which an Online Energy Model (OEM) is developed to make TOSSIM capable of developing and testing energy-aware protocols. The model is validated by comparing it against POWERTOSSIM. Our results show that EATDDS is efficient and can be accommodated with limited system resources.

Spectrum handoff strategy for cognitive radio-based MAC for real-time industrial wireless sensor and actuator networks

A spectrum handoff or channel switching mechanism for Industrial Wireless Sensor and Actuator Networks (IWSAN) which is capable of detecting interference and hopping to another channel (in the same or other band) in a deterministic time is proposed. This is possible because the spectrum handoff strategy detects interference in the MAC layer, and can ensure the high requirements in terms of time and reliability demanded by real-time IWSAN applications. An existing cognitive radio-based MAC is used as the basis. It has been evaluated with and without the proposed spectrum handoff mechanism to assess its performance. Using Network Calculus, a theoretical analysis has been provided to determine bounds on the delay, and simulations in OPNET have been carried out in order to validate the theoretical results. Several environments have been considered in the simulation (lognormal shadowing, Rice and Rayleigh fading and interference) so as to characterize the performance of the algorithm under the most common conditions of industrial channels. The results prove the benefits of using the proposed spectrum handoff, which provides robustness and guarantees delay bounds in industrial environments with interference.

Energy-efficient smart home systems: Infrastructure and decision-making process

One of the main global challenges in the last few years has been to improve energy efficiency. In this area, the residential sector is responsible for a considerable proportion of energy consumption and a possible way to address this problem is to adopt a HAS (Home Automation System). This work reports the results of our investigation in smart home systems that combine WSANs (Wireless Sensor and Actuator Networks) and Computational Intelligence techniques with a focus on energy efficiency. We discuss several valuable ideas from this systematic review, including guidelines for new research projects in the area of home automation. As result of this survey, the main contributions of this work are: (i) identification and discussion of studies that combine WSANs and computation intelligence in HAS that particularly target energy-saving; (ii) finding gaps in the selected works, and offering solutions that can guide new areas of research, as well as new projects in HAS and (iii) demonstrating that solutions based on WSANs that are integrated with computational intelligence have emerged as an attractive alternative that can be deployed in a HAS.

Fault Tolerance Events Ordering with Coverage and Connectivity Aware Clustering in Wireless Sensor and Actuator Networks

ABSTRACT A network delay or a fail link is prone to be occurred in wireless sensor and actuator networks (WSAN). Since the events captured by sensors are related to others, events ordering is an vital issue in WSAN. However, it is hard to guarantee that no prior event is transmitted while the latter events arrive at actuator in network. While a fail link is occurred, it could be assumed as a special case that the delay is set to infinity. Event ordering by double confirmation (OBDC) was a typical events ordering while a network delay was occurred. Fault tolerance events ordering by aging learning (FTEOAL) was a typical events ordering mechanism while a fail link existed. However, both of them assumed that sensors were all covered by one actuator and none of them was the orphan sensor. Once a sensor was non-covered by an actuator or an orphan sensor existed, the rate of correct events ordering will decrease. Therefore, in this paper, we proposed a fault tolerance events ordering with coverage and connectivity aware clustering, FTEOCCAC. The simulation results demonstrated that events were treated in correct order even if the sensors are deployed randomly or an orphan sensor existed while a network delay or a fail link existed in network. The rate of correct events ordering could be closed to the expect value.

MBPSKA: Multi-Biometric and Physiological Signal-Based Key Agreement for Body Area Networks

A body area network (BAN) consists of wireless sensors and actuators deployed on a patient's body for real-time health monitoring and personalized medical care. It is essential and challenging to secure wireless communications in a BAN to protect the patient's privacy while also allowing the authorized healthcare practitioners (e.g., emergency room doctors and nurses) to easily communicate with and configure the BAN devices transparent to the patient or even when the patient loses consciousness. With the existing schemes, the devices are based on a pre-installed secret password or a physiological signal feature to authenticate each other and to agree upon a cryptographic key for secure communications. The former requires a patient's input to access and configure the BAN, and the latter is not sufficiently reliable or secure due to signal dynamics. This motivates us to design a new key agreement scheme in this paper, called multi-biometric and physiological signal-based key agreement (MBPSKA), to achieve more secure and reliable authentication and communication session establishment between the BAN devices while providing flexibility to authorized personnel to access, control, and adjust the BAN without patient involvement. The proposed scheme exploits both the reliable biometric traits and the time-variant physiological signal features of a patient along with the efficient fuzzy crypto-algorithms and key distribution protocols. The devices use multiple biometric and physiological features for mutual authentication and cryptographic key protection. We analyze the security characteristics of MBPSKA, including its capabilities against various attacks. Our evaluation results using the real-world datasets demonstrate that MBPSKA outperforms the existing physiological signal-based key agreement schemes in terms of security, authentication reliability, and accuracy.

Minimization of Energy Consumption Per Bit Using an Average Dwell-Time Approach for Wireless Networked Control Systems

We study the energy consumption of the communication links in a wireless networked control system, where sensors and actuators exchange information using a wireless channel. Our purpose is to minimize the energy consumption, assuming that the sensors and actuators may be battery-powered devices, without affecting the control system stability, which may be impacted by communication errors. As a consequence, the stability of the control system can be related to the switching time between stable and unstable subsystems. By resorting to a communication-control co-design approach, we obtain a closed-form expression for the optimal outage probability related to the system stability, which is then employed as a constraint to adapt the transmit power and the bit rate in order to minimize the energy consumption. Our results show a decreased energy consumption when compared to the traditional optimization approach in wireless communications, which is to treat communication and control systems independently, fixing the outage probability according to a reliability constraint, not necessarily linked to the stability.

Efficient Actuator Failure Avoidance Mobile Charging for Wireless Sensor and Actuator Networks

Actuators and sensors are two types of important nodes in wireless sensor and actuator networks (WSANs). Actuators consume a large amount of energy for driving themselves move, handling events, communicating with each other, and computation. Hence, the sensors and actuators all suffer from a serious energy-constrained problem in WSANs. Recently, many excellent energy recharging works are proposed for wireless sensor networks (WSNs). However, the wireless energy delivery issue for WSANs is rarely addressed. In this paper, by deeply analyzing the characteristics of WSANs, we discuss the wireless mobile recharging issue for WSANs and present a novel actuator failure avoidance online charging scheme (AFAC). To prevent as many sensors failure as possible while ensuring no actuator failure, AFAC always tries to select the node that not only makes no actuator failure but also brings about the least number of nonfunctional sensors as the next target. Furthermore, since charging the actuators takes a long time, maximum charging threshold is set for actuators to prevent sensor nodes failure in the network. The simulation results demonstrate that our scheme gets the lowest sensor failure ratio with low charging cost and charging delay in comparison with other wireless charging schemes for WSANs.

Learning desk fan usage preferences for personalised thermal comfort in shared offices using tree-based methods

Recent studies in the built environment lead a paradigm shift from conventional, one-fit-for-all thermal comfort models to more localised and personalised comfort models that cater to personal preferences as well as open up significant energy savings potential. In this project, desk fan usage preferences are collected using a wireless sensor and actuator network (WSAN) in two shared offices along with indoor and outdoor environmental conditions as well as user presence information. To predict the personal preferences of desk fans usage, the fan state is modelled as a classification problem and the fan speed as a regression problem considering only the instances when the fan state is ON. Tree-based methods such as decision tree, random forests and boosted trees are investigated and random forests method is found to achieve the best performance with an average test set accuracy of 97.73% in predicting the fan state among six users on a dataset of total size (192021, 10). It also achieved 95.42% average test accuracy for instances where user is present and the fan speed is estimated with average root-mean-squared error (RMSE) of 15.83 of the fan setting. The most important variables are also identified and it is noted that these variables vary among the users indicating diversity in preferences. Finally, the real-world deployment of the methods are discussed along with insights for future data collection.

THE INTERNET OF THINGS: A SURVEY

This paper addresses the Internet of Things. Main enabling factor of this promising paradigm is the integration of several technologies and communications solutions. Identification and tracking technologies, wired and wireless sensor and actuator networks, enhanced communication protocols (shared with the Next Generation Internet), and distributed intelligence for smart objects are just the most relevant. As one can easily imagine, any serious contribution to the advance of the Internet of Things must necessarily be the result of synergetic activities conducted in different fields of knowledge, such as telecommunications, informatics, electronics and social science. In such a complex scenario, this survey is directed to those who want to approach this complex discipline and contribute to its development. Different visions of this Internet of Things paradigm are reported and enabling technologies reviewed. What emerges is that still major issues shall be faced by the research community. The most relevant among them are addressed in details.