scholarly journals RF-Powered Low-Energy Sensor Nodes for Predictive Maintenance in Electromagnetically Harsh Industrial Environments

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 386
Author(s):  
Giacomo Paolini ◽  
Marco Guermandi ◽  
Diego Masotti ◽  
Mazen Shanawani ◽  
Francesca Benassi ◽  
...  
Keyword(s):  
Energy Requirement ◽  
Predictive Maintenance ◽  
Sensor Nodes ◽  
Sleep Mode ◽  
Accelerometer Data ◽  
Worst Case ◽  
Active Antennas ◽  
Duty Cycles ◽  
Current Consumption ◽  
Real Scenario

This work describes the design, implementation, and validation of a wireless sensor network for predictive maintenance and remote monitoring in metal-rich, electromagnetically harsh environments. Energy is provided wirelessly at 2.45 GHz employing a system of three co-located active antennas designed with a conformal shape such that it can power, on-demand, sensor nodes located in non-line-of-sight (NLOS) and difficult-to-reach positions. This allows for eliminating the periodic battery replacement of the customized sensor nodes, which are designed to be compact, low-power, and robust. A measurement campaign has been conducted in a real scenario, i.e., the engine compartment of a car, assuming the exploitation of the system in the automotive field. Our work demonstrates that a one radio-frequency (RF) source (illuminator) with a maximum effective isotropic radiated power (EIRP) of 27 dBm is capable of transferring the energy of 4.8 mJ required to fully charge the sensor node in less than 170 s, in the worst case of 112-cm distance between illuminator and node (NLOS). We also show how, in the worst case, the transferred power allows the node to operate every 60 s, where operation includes sampling accelerometer data for 1 s, extracting statistical information, transmitting a 20-byte payload, and receiving a 3-byte acknowledgment using the extremely robust Long Range (LoRa) communication technology. The energy requirement for an active cycle is between 1.45 and 1.65 mJ, while sleep mode current consumption is less than 150 nA, allowing for achieving the targeted battery-free operation with duty cycles as high as 1.7%.

scholarly journals Low-Power CMOS Integrated Hall Switch Sensor

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Rongshan Wei ◽  
Shizhong Guo ◽  
Shanzhi Yang
Keyword(s):  
Supply Voltage ◽  
Reducing Power ◽  
Cmos Technology ◽  
Sleep Mode ◽  
Test Results ◽  
Offset Voltage ◽  
Current Consumption ◽  
Low Power Cmos ◽  
Switch Circuit ◽  
Hall Element

This paper presents an integrated Hall switch sensor based on SMIC 0.18 µm CMOS technology. The system includes a front-end Hall element and a back-end signal processing circuit. By optimizing the structure of the Hall element and using the orthogonal coupling and spinning current technology, the offset voltage can be suppressed effectively. The simulation results showed that the Hall switch can eliminate offset voltage greater than 1 mV at 3.3 V supply voltage. Two modes of the Hall switch circuit, the awake mode and the sleep mode, were realized by using clock logic signals without compromising the performance of the Hall switch, thereby reducing power consumption. The test results showed that the operate point and the release point of the switch were within the range of 3–7 mT at 3.3 V supply voltage. Meanwhile, the current consumption is 7.89 µA.

Optimizing Power Consumption for the Wireless Sensor Node

2015 ◽  
Vol 738-739 ◽  
pp. 107-110
Author(s):  
Hui Lin
Keyword(s):  
Power Consumption ◽  
Radio Frequency ◽  
Power Saving ◽  
Sensor Nodes ◽  
Wireless Sensor ◽  
Wireless Sensor Node ◽  
Wireless Sensor Nodes ◽  
Cycle Times ◽  
Current Consumption ◽  
Saving Effect

A Wireless Sensor Network is composed of sensor nodes powered by batteries. Thus, power consumption is the major challenge. In spite of so many research works discussing this issue from the aspects of network optimization and system design, so far not so many focus on optimizing power consumption of the Radio Frequency device, which consumes most of the energy. This paper describes the digital features of the Radio Frequency device used to optimize current consumption, and presents a practical approach to measure current consumption in static and dynamic scenarios in details, by which we evaluates the power saving effect. The results demonstrated that according to cycle times and application characteristics choosing appropriate features can prolong the lifetime of wireless sensor nodes.

scholarly journals Wearable bioimpedance for continuous and context-aware clinical monitoring

2020 ◽  
Author(s):  
Walter Karlen ◽  
Abhilash Guru Dutt ◽  
Michaela Verling
Keyword(s):  
Clinical Decision Making ◽  
Clinical Decision ◽  
Accelerometer Data ◽  
Non Invasive ◽  
Standardized Protocol ◽  
Current Consumption ◽  
Wide Range ◽  
Measurement Operation ◽  
Total Body ◽  
Commercial Device

<div>Bioimpedance monitoring provides a non-invasive,</div><div>safe and affordable opportunity to monitor total body water for a wide range of clinical applications. However, the measurement is susceptible to variations in posture and movement. Existing devices do not account for the variations and are therefore unsuitable to perform continuous measurements to depict trend changes. We developed a wearable bioimpedance monitoring system with embedded real-time posture detection using a distributed accelerometer network. We tested the device on 14 healthy volunteers following a standardized protocol of posture change and compared the obtained measurements with an existing commercial device. The impedance measured with both systems had a high correlation (r>0.98) and a Bland-Altman analysis revealed a bias of -4.5 and limits of agreement of -30 and 21. Context-awareness was achieved with processing accelerometer data placed at the upper and lower leg with an accuracy >95%. The calculated current consumption is as low as 10 mA during continuous measurement operation, suggesting that without recharge the system can be used for multiple days. The proposed motion-aware design will enable the measurement of relevant bioimpedance parameters continuously over long periods and aid in informed clinical decision making.</div>

scholarly journals Mutual Aid Among Sensors: An Emergency Function for Sensor Networks

2020 ◽  
Author(s):  
Costas Michaelides ◽  
Foteini-Niovi Pavlidou
Keyword(s):  
Sensor Networks ◽  
Ieee 802.15.4 ◽  
Sensor Nodes ◽  
Wireless Sensor ◽  
Sleep Mode ◽  
Mutual Aid ◽  
Neighboring Node ◽  
Data Packets ◽  
Critical Data ◽  
Timely Delivery

A large number of wireless sensor nodes in a certain area results in high contention. Inevitably, the transmissions of any possible critical data packets may fail due to collisions. In this article, we introduce an aspect of human intelligence in wireless sensor networks, influenced by cooperative networking, which enhances the timely delivery of critical data. Mutual aid among sensors (MAAS), is an emergency out-of-the-box medium access control (MAC) function for IEEE 802.15.4-2020. Specifically, the network coordinator detects critical data packets and sets an emergency flag to its next beacon, to inform the nodes that they may overhear data packets. When a node overhears a critical data packet from a neighboring node it switches to sleep mode and stays idle until the end of the superframe. Thus, interference is mitigated locally and temporarily. Simulation results, using the CC2650 radio parameters in OMNeT++, show that interference is reduced significantly, in favor of the timely delivery of critical data packets.

scholarly journals A new hybrid architecture with an intersection-based coverage algorithm in wireless sensor networks

2014 ◽  
Vol 11 (3) ◽  
pp. 1017-1035 ◽  
Author(s):  
Young-Long Chen ◽  
Mu-Yen Chen ◽  
Fu-Kai Cheung ◽  
Yung-Chi Chang
Keyword(s):  
Wireless Sensor Networks ◽  
Energy Consumption ◽  
Sensor Networks ◽  
Sensor Nodes ◽  
Wireless Sensor ◽  
Sleep Mode ◽  
Hybrid Architecture ◽  
Power Efficient ◽  
Adaptive Clustering ◽  
Average Distribution

Energy is limited in wireless sensor networks (WSNs) so that energy consumption is very important. In this paper, we propose a hybrid architecture based on power-efficient gathering in sensor information system (PEGASIS) and low-energy adaptive clustering hierarchy (LEACH). This architecture can achieve an average distribution of energy loads, and reduced energy consumption in transmission. To further extend the system lifetime, we combine the intersection-based coverage algorithm (IBCA) with LEACH architecture and the hybrid architecture to prolong the system lifetime that introducing sensor nodes to enter sleep mode when inactive. This step can save more energy consumption. Simulation results show that the performance of our proposed LEACH architecture with IBCA and the hybrid architecture with IBCA perform better than LEACH architecture with PBCA in terms of energy efficiency, surviving nodes and sensing areas.

AN EFFICIENT NEIGHBOR-AWARE PROTOCOL FOR SNET FORMATION

2008 ◽  
Vol 09 (04) ◽  
pp. 439-454
Author(s):  
TAREK R. SHELTAMI
Keyword(s):  
Mac Protocols ◽  
Sensor Nodes ◽  
Sleep Mode ◽  
Sleep Scheduling ◽  
Mobile Hosts ◽  
Fairness Concerns ◽  
Good Potential ◽  
Scheduling Protocols ◽  
Standard Support ◽  
Wireless Mobile

A wireless mobile sensor network is a collection of wireless mobile hosts forming nodes that are communicating without the aid of any centralized administration or standard support services. Nodes are classified as sensor nodes and router. Some nodes act both as sensors and routers. While traditional MAC protocols must balance between throughput, delay, and fairness concerns, WSN MAC protocols place an emphasis on energy efficiency as well. Schedule-based MAC protocols have been proposed for WSN. A common theme through all these protocols is putting radios to a low-power "sleep mode" either periodically or whenever possible when a node is neither receiving nor transmitting. In this paper, we propose a novel cluster-based infrastructure creation protocol, namely: the Neighbor-Aware Clusterhead (NAC). We investigate the performance of the NAC protocol under different sleep scheduling protocols and compare it against another cluster-based protocol. In NAC protocol nodes are synchronized with their clusterheads and are allowed to go sleep mode in order to conserve their energy without degrading the performance of the network. The network is divided into clusters managed by a clusterhead. The simulation results show that NAC protocol has a good potential to be a good candidate protocol for SNET.

scholarly journals Performance of Non-Uniform Duty-Cycled ContikiMAC in Wireless Sensor Networks

2017 ◽  
Vol 7 (2) ◽  
pp. 942
Author(s):  
Nur Rabiul Liyana Mohamed ◽  
Ansar Jamil ◽  
Lukman Hanif Audah Audah ◽  
Jiwa Abdullah ◽  
Rozlan Alias
Keyword(s):  
Duty Cycle ◽  
Dynamic Network ◽  
Poor Performance ◽  
Sensor Nodes ◽  
Wireless Sensor ◽  
Sleep Mode ◽  
Bursty Traffic ◽  
Delivery Ratio ◽  
Clear Channel Assessment ◽  
Clear Channel

<span lang="EN-GB">Wireless Sensor Network (WSN) is a promising technology in Internet of Things (IoTs) because it can be implemented in many applications. However, a main drawback of WSN is it has limited energy because each sensor node is powered using batteries. Therefore, duty-cycle mechanisms are introduced to reduce power consumption of the sensor nodes by ensuring the sensor nodes in the sleep mode almost of the time in order to prolong the network lifetime. One of the de-facto standard of duty-cycle mechanism in WSN is ContikiMAC, which is the default duty-cycle mechanism in Contiki OS. ContikiMAC ensures nodes can participate in network communication yet keep it in sleep mode for roughly 99\% of the time. However, it is found that the ContikiMAC does not perform well in dynamic network conditions. In a bursty network, ContikiMAC provides a poor performance in term of packet delivery ratio, which is caused by congestion. One possible solution is ContikiMAC should increase its duty-cycle rate in order to support the bursty traffic. This solution creates a non-uniform duty-cycle rates among the sensor nodes in the network. This work aims to investigate the effect of non-uniform duty-cycle rates on the performance on ContikiMAC. Cooja simulator is selected as the simulation tool. Three different simulation scenarios are considered depending on the Clear Channel Assessment Rate (CCR) configurations: a low uniform CCR value (Low-CCR), a high uniform CCR value (High-CCR) and non-uniform CCR values (Non-uniform-CCR). The simulation results show that the Low-CCR scenario provides the worst performance of PDR. On the other hand, the High-CCR scenario provides the best performance of PDR. The Non-uniform-CCR provides PDR in between of Low-CCR and High-CCR.</span>

scholarly journals Wearable bioimpedance for continuous and context-aware clinical monitoring

2020 ◽  
Author(s):  
Walter Karlen ◽  
Abhilash Guru Dutt ◽  
Michaela Verling
Keyword(s):  
Clinical Decision Making ◽  
Clinical Decision ◽  
Accelerometer Data ◽  
Non Invasive ◽  
Standardized Protocol ◽  
Current Consumption ◽  
Wide Range ◽  
Measurement Operation ◽  
Total Body ◽  
Commercial Device

<div>Bioimpedance monitoring provides a non-invasive,</div><div>safe and affordable opportunity to monitor total body water for a wide range of clinical applications. However, the measurement is susceptible to variations in posture and movement. Existing devices do not account for the variations and are therefore unsuitable to perform continuous measurements to depict trend changes. We developed a wearable bioimpedance monitoring system with embedded real-time posture detection using a distributed accelerometer network. We tested the device on 14 healthy volunteers following a standardized protocol of posture change and compared the obtained measurements with an existing commercial device. The impedance measured with both systems had a high correlation (r>0.98) and a Bland-Altman analysis revealed a bias of -4.5 and limits of agreement of -30 and 21. Context-awareness was achieved with processing accelerometer data placed at the upper and lower leg with an accuracy >95%. The calculated current consumption is as low as 10 mA during continuous measurement operation, suggesting that without recharge the system can be used for multiple days. The proposed motion-aware design will enable the measurement of relevant bioimpedance parameters continuously over long periods and aid in informed clinical decision making.</div>

scholarly journals A Novel Hybrid HNN and Firefly Algorithm to Overcome Denial of Sleep Attack on Wireless Sensor Nodes

2021 ◽  
Vol 2 (4) ◽  
pp. 223-227
Author(s):  
Vivekanadam B
Keyword(s):  
Energy Consumption ◽  
Firefly Algorithm ◽  
Data Transfer ◽  
Hopfield Neural Network ◽  
Sensor Nodes ◽  
Wireless Sensor ◽  
Sleep Mode ◽  
Wireless Sensor Nodes ◽  
Sleep Attack ◽  
Energy Consumption Patterns

A typical Wireless Sensor Network (WSN) comprises of multiple nodes that are used to control as well as monitor the environment and perform pre-described actions. Based on the network, the sensor nodes are distributed and their energy consumption proves to be challenging. When the nodes are located near the sink, they serve as the interface for data transfer between the sink and the node. Because of this, there is a decrease in the networks lifetime and further the energy consumption of the nodes increases significantly. Denial-of-sleep attack is a threat that sensor nodes face in WSNs. DoSA is the condition when there is much loss of energy at the nodes by preventing them from entering into sleep mode and power save mode. We propose a hybrid methodology of Hopfield neural network and firefly algorithm using leach to tackle this issue such that there is a significant increase in network lifetime and energy consumption patterns.

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