Self-Powered 6LoWPAN Sensor Node for Green IoT Edge Devices

Copyright © 2020 The Authors. In this paper, a simulation model and practical testbed for green Internet of Things (IoT) edge devices are proposed based on solar harvester with constant voltage-maximum power point tracking (CV-MPPT) technique. Billions of connected edge devices represent the essential part of the IoT through the IP-enabled sensor networks based on IPv6 over Low power Wireless Personal Area Network (6LoWPAN). In traditional IoT edge devices, the stored energy in the non-rechargeable battery determines the node lifetime while it is being depleted with time. Therefore, purchasing billions of such batteries is costly and must be disposed of efficiently. This paper is aimed at simulating and implementing a new class of green IoT edge devices that can report data wirelessly and powered perpetually using clean energy. The developed edge device utilizes solar energy harvesting mechanism through photovoltaic (PV) module, this approach will avoid periodical battery replacement and hence, the energy supplied to the sensor mode is not limited anymore. The implemented testbed is based on open-source hardware and software platforms while the simulation environment is based on MATLAB/SIMULINK 2019a. The effects of temperature and solar irradiance on the performance of the developed approach are examined in order to confirm the leverage of the proposed methodology scheme. The lifetime of the developed green IoT device is predicted based on the device's activities, current consumption, and energy storage capacity. The obtained results showed that the battery lifetime is extended by 38-49% when the edge device runs on an independent power source

Circuits and Systems for Energy Harvesting and Internet of Things Applications

The Internet of Things (IoT) continues its growing trend, while new “smart” objects are con-stantly being developed and commercialized in the market. Under this paradigm, every common object will be soon connected to the Internet: mobile and wearable devices, electric appliances, home electronics and even cars will have Internet connectivity. Not only that, but a variety of wireless sensors are being proposed for different consumer and industrial applications. With the possibility of having hundreds of billions of IoT objects deployed all around us in the coming years, the social implications and the economic impact of IoT technology needs to be seriously considered. There are still many challenges, however, awaiting a solution in order to realize this future vision of a connected world. A very important bottleneck is the limited lifetime of battery powered wireless devices. Fully depleted batteries need to be replaced, which in perspective would generate costly maintenance requirements and environmental pollution. However, a very plausible solution to this dilemma can be found in harvesting energy from the ambient. This dissertation focuses in the design of circuits and system for energy harvesting and Internet of Things applications. The first part of this dissertation introduces the research motivation and fundamentals of energy harvesting and power management units (PMUs). The architecture of IoT sensor nodes and PMUs is examined to observe the limitations of modern energy harvesting systems. Moreover, several architectures for multisource harvesting are reviewed, providing a background for the research presented here. Then, a new fully integrated system architecture for multisource energy harvesting is presented. The design methodology, implementation, trade-offs and measurement results of the proposed system are described. The second part of this dissertation focus on the design and implementation of low-power wireless sensor nodes for precision agriculture. First, a sensor node incorporating solar energy harvesting and a dynamic power management strategy is presented. The operation of a wireless sensor network for soil parameter estimation, consisting of four nodes is demonstrated. After that, a solar thermoelectric generator (STEG) prototype for powering a wireless sensor node is proposed. The implemented solar thermoelectric generator demonstrates to be an alternative way to harvest ambient energy, opening the possibility for its use in agricultural and environmental applications. The open problems in energy harvesting for IoT devices are discussed at the end, to delineate the possible future work to improve the performance of EH systems. For all the presented works, proof-of-concept prototypes were fabricated and tested. The measured results are used to verify their correct operation and performance

Recent start-up techniques intended for TEG energy harvesting: a review

ABSTRACT: The growing number of energy-autonomous applications raises the need for reliable DC energy harvesting techniques such as Thermoelectric Generators (TEGs). One key issue, however, is the minimum voltage (40–60 mV) required for start-up in small TEG energy harvesting sources. We review in this paper recent start-up solutions for TEG energy harvesting technologies. Different solutions have been categorized into 5 main approaches: external battery, extra-fabrication-process-based, transformers, multisource energy harvesting, and DC-AC-DC conversion using oscillators. The “DC-AC-DC conversion ring oscillators” approach is then shown to be the most promising solution in line with DC energy harvesting applications because it offers several advantages over other approaches, such as allowing full integration with good performance, compatibility with regular CMOS technology, and lower cost. Then, its different implementations are discussed and a detailed analysis is provided to identify their respective advantages and limitations

treNch: Ultra-Low Power Wireless Communication Protocol for IoT and Energy Harvesting

Although the number of Internet of Things devices increases every year, efforts to decrease hardware energy demands and to improve efficiencies of the energy-harvesting stages have reached an ultra-low power level. However, no current standard of wireless communication protocol (WCP) can fully address those scenarios. Our focus in this paper is to introduce treNch, a novel WCP implementing the cross-layer principle to use the power input for adapting its operation in a dynamic manner that goes from pure best-effort to nearly real time. Together with the energy-management algorithm, it operates with asynchronous transmissions, synchronous and optional receptions, short frame sizes and a light architecture that gives control to the nodes. These features make treNch an optimal option for wireless sensor networks with ultra-low power demands and severe energy fluctuations. We demonstrate through a comparison with different modes of Bluetooth Low Energy (BLE) a decrease of the power consumption in 1 to 2 orders of magnitude for different scenarios at equal quality of service. Moreover, we propose some security optimizations, such as shorter over-the-air counters, to reduce the packet overhead without decreasing the security level. Finally, we discuss other features aside of the energy needs, such as latency, reliability or topology, brought again against BLE.ECSEL Joint Undertaking through CONNECT project 737434Federal Ministry of Education & Research (BMBF)European Union's Horizon 2020 research and innovation programSpanish Ministry of Education, Culture and Sport (MECD)/FEDER-EU FPU18/01376BBVA FoundationUniversity of Granad

Design of Wireless Sensors for IoT with Energy Storage and Communication Channel Heterogeneity

Autonomous Wireless Sensors (AWSs) are at the core of every Wireless Sensor Network (WSN). Current AWS technology allows the development of many IoT-based applications, ranging from military to bioengineering and from industry to education. The energy optimization of AWSs depends mainly on: Structural, functional, and application specifications. The holistic design methodology addresses all the factors mentioned above. In this sense, we propose an original solution based on a novel architecture that duplicates the transceivers and also the power source using a hybrid storage system. By identifying the consumption needs of the transceivers, an appropriate methodology for sizing and controlling the power flow for the power source is proposed. The paper emphasizes the fusion between information, communication, and energy consumption of the AWS in terms of spectrum information through a set of transceiver testing scenarios, identifying the main factors that influence the sensor node design and their inter-dependencies. Optimization of the system considers all these factors obtaining an energy efficient AWS, paving the way towards autonomous sensors by adding an energy harvesting element to them

Double smart energy harvesting system for self-powered industrial IoT

312 p. 335 p. (confidencial)Future factories would be based on the Industry 4.0 paradigm. IndustrialInternet of Things (IIoT) represent a part of the solution in this field. Asautonomous systems, powering challenges could be solved using energy harvestingtechnology. The present thesis work combines two alternatives of energy input andmanagement on a single architecture. A mini-reactor and an indoor photovoltaiccell as energy harvesters and a double power manager with AC/DC and DC/DCconverters controlled by a low power single controller. Furthermore, theaforementioned energy management is improved with artificial intelligencetechniques, which allows a smart and optimal energy management. Besides, theharvested energy is going to be stored in a low power supercapacitor. The workconcludes with the integration of these solutions making IIoT self-powered devices.IK4 Teknike

Design of Wireless Sensors for IoT with Energy Storage and Communication Channel Heterogeneity

Autonomous Wireless Sensors (AWSs) are at the core of every Wireless Sensor Network (WSN). Current AWS technology allows the development of many IoT-based applications, ranging from military to bioengineering and from industry to education. The energy optimization of AWSs depends mainly on: Structural, functional, and application specifications. The holistic design methodology addresses all the factors mentioned above. In this sense, we propose an original solution based on a novel architecture that duplicates the transceivers and also the power source using a hybrid storage system. By identifying the consumption needs of the transceivers, an appropriate methodology for sizing and controlling the power flow for the power source is proposed. The paper emphasizes the fusion between information, communication, and energy consumption of the AWS in terms of spectrum information through a set of transceiver testing scenarios, identifying the main factors that influence the sensor node design and their inter-dependencies. Optimization of the system considers all these factors obtaining an energy efficient AWS, paving the way towards autonomous sensors by adding an energy harvesting element to them

Design and Modeling of a Soil-Based Energy Harvester for Underground Wireless Sensor Nodes

Wireless Sensor Networks (WSN) have emerged as a reliable and viable solution for monitoring complex large-scale strategic assets that are placed in harsh and hostile environments. Some of the major application areas include environmental monitoring, disaster management, infrastructure monitoring, and security. A large number of such infrastructures are buried underground and have a limited service life. It is important to assess their condition throughout their life cycle to avoid possible catastrophic failures due to their deterioration. Monitoring such infrastructures creates a complex wireless sensor network with thousands of sensor nodes that are required to be functional with zero maintenance for 10∼20 years once deployed. Powering such Wireless Sensors (WS) for decades is a key challenge in the design and operation of WSN. Sacrificial Anode Cathodic Protection (SACP) technique is a well-known technique for corrosion protection. In this technique, steel structures are protected from natural corrosion by enabling an externally connected anode material to deplete over time. To model the depletion rate of the anode for replacement purposes, human readers visit each Sacrificial Anode (SA) site to take voltage and current measurements once a month. This approach is expensive and prone to human errors. Moreover, there is a large number of such sites in a city. The main challenge in using WSN in such scenarios is providing a reliable source of energy to power the sensor nodes. As the majority part of the structure is buried underground, traditional renewable energy sources, such as solar, wind, and thermal do not offer any lucrative solution due to their requirements for additional setup, space, and periodic maintenance. Thus, an underground soil-based energy harvester using the existing setup has been carefully researched, designed, developed, and implemented as part of this research. The technique exploits the electric current flowing from the cathode to the anode to energize the sensor nodes. The prototype developed in the lab uses the harvested energy from soil to power sensor nodes to communicate the data to the cloud. To develop and implement the prototype two test benches were set up, one indoor and the other outdoor. The outdoor setup facilitated the experiments under varying weather conditions and with the indoor one, experiments were conducted under a controlled environment. The prototype developed in the lab will be buried underground for security purposes, as a result, data needs to be transmitted through the soil between nodes. Radio Frequency (RF) transmission through the soil is one of the main challenges for this project. Various parameters affect RF signal attenuation in soil (i.e. transmission frequency, burial depth, soil dielectric properties, etc.). In this research, we have investigated, tested and implemented several wireless technology modules such as Global System for Mobile Communications (GSM), Wireless Fidelity (Wi-Fi), Zigbee, Narrow Band-Internet of Things (NB-IoT) to meet the desired requirements. The research also outlines the complete operation of the developed module. In addition to that, to estimate the energy harvesting rate, energy harvesting efficiency and to analyze the charging behavior several experiments were conducted to obtain the Current-Voltage (I-V) and the Power-Voltage (P-V) characteristics of the energy source. This study is later used to develop a model for the energy source. The model is validated with measurement data from the field trials. This developed model is helpful to easily realize a system and can be useful to solve numerical problems, find information about operating point or to analyze a circuit