Energy-Aware Approaches for Energy Harvesting Powered Wireless Sensor Nodes

Abstract

Abstract-Intensive research on energy harvesting powered wireless sensor nodes (WSNs) has been driven by the needs of reducing the power consumption by the WSNs and the increasing the power generated by energy harvesters. The mismatch between the energy generated by the harvesters and the energy demanded by the WSNs is always a bottleneck as the ambient environmental energy is limited and time-varying. This paper introduces a combined energy-aware interface (EAI) with an energy-aware program to deal with the mismatch through managing the energy flow from the energy storage capacitor to the WSNs. These two energy-aware approaches were implemented in a custom developed vibration energy harvesting powered WSN. The experimental results show that, with the 3.2 mW power generated by a piezoelectric energy harvester (PEH) under an emulated aircraft wing strain loading of 600 με at 10 Hz, the combined energy-aware approaches enable the WSN to have a significantly reduced sleep current from 28.3 µA of a commercial WSN to 0.95 µA and enable the WSN operations for a long active time of about 1.15 s in every 7.79 s to sample and transmit a large number of data (388 bytes), rather than a few ten milliseconds and a few bytes, as demanded by vibration measurement. When the approach was not used, the same amount of energy harvested was not able to power the WSN to start, not mentioning to enabling the WSN operation, which highlighted the importance and the value of the energy-aware approaches in enabling energy harvesting powered WSN operation successfully.Index Terms-energy harvesting, energy-aware interface, energy-aware program, wireless sensor nodes

Strain Energy Harvesting Powered Wireless Sensor System Using Adaptive and Energy-Aware Interface for Enhanced Performance

“…As the energy stored in C S can be related to the voltage V CS of C S, the EAI is realized using a voltage supervisor (LTC2935-1) to monitor V CS and toggle the NMOS > REPLACE THIS LINE WITH YOUR PAPER IDENTIFICATION NUMBER (DOUBLE-CLICK HERE TO EDIT) < 4 switch. The voltage supervisor has a selection of turn-on and turn-off threshold voltages but it can be instructed by the WSS to turn off the NMOS without having to wait for V CS to reach the turn-off threshold voltage by using a software control which will be explained later in Section D [18]. Fig.…”

“…1(a) and (b). The MCU (Jennic JN5148) used is low power, compliant to IEEE 802.15.4 standard for communication using ZigBee protocol [4], [18] and has 128 kB of random access memory (RAM). The sensors used are a humidity sensor (HIH-5030), a temperature sensor (MCP9700), and a 3-axis accelerometer (ADXL335).…”

“…It should be noted that the energy required E required by the WSS to stay active has to be available within the turn-on and turn off threshold voltages set by the EAI, as shown in (10) The power consumed P W by the WSS for a particular task can be determined experimentally by setting the WSS to perform the task and measuring its power consumption [18]. The power consumption can be assumed to be constant for a specific implemented system.…”

Single Piezoelectric Transducer as Strain Sensor and Energy Harvester Using Time-Multiplexing Operation

“…The MCU used in the WSS is Jennic JN5148, which has a 2.4 GHz IEEE 802.15.4 compliant transceiver to communicate wirelessly using ZigBee protocol with transmission current of around 13 mA [18]. The transmit power was set to 2.5 dBm to ensure successful transmission over a long distance.…”

Both Worst Case and Outage Constrained Robust Design for Mimo Wiretap Wireless Sensor Networks

“…Wireless sensor networks (WSNs) are considered as a promising technique with numerous applications such as data acquisition, location monitoring, and node control [1,2]. However, secure transmission has been seen as an important problem for WSN due to the openness of wireless channel [3,4].…”