Energy per Operation Optimization for Energy-Harvesting Wearable IoT Devices

Abstract

Wearable internet of things (IoT) devices can enable a variety of biomedical applications, such as gesture recognition, health monitoring, and human activity tracking. Size and weight constraints limit the battery capacity, which leads to frequent charging requirements and user dissatisfaction. Minimizing the energy consumption not only alleviates this problem, but also paves the way for self-powered devices that operate on harvested energy. This paper considers an energy-optimal gesture recognition application that runs on energy-harvesting devices. We first formulate an optimization problem for maximizing the number of recognized gestures when energy budget and accuracy constraints are given. Next, we derive an analytical energy model from the power consumption measurements using a wearable IoT device prototype. Then, we prove that maximizing the number of recognized gestures is equivalent to minimizing the duration of gesture recognition. Finally, we utilize this result to construct an optimization technique that maximizes the number of gestures recognized under the energy budget constraints while satisfying the recognition accuracy requirements. Our extensive evaluations demonstrate that the proposed analytical model is valid for wearable IoT applications, and the optimization approach increases the number of recognized gestures by up to 2.4× compared to a manual optimization.

A Comprehensive Survey on Machine Learning-Based Big Data Analytics for IoT-Enabled Smart Healthcare System

“…Usually, wearable and sensors attached to the human body are energy-constrained. They are equipped with limited energy supplies [ 122 ]. The frequent changes of batteries in these sensors and devices is cumbersome and sometimes impossible.…”

ECO: Enabling Energy-Neutral IoT Devices through Runtime Allocation of Harvested Energy

“…Figure 10 shows 12 design points for a gesture recognition application from the literature [28]. A function with the form y = ax b + c fits much better to these data points than the logarithmic function in Section III (i.e.…”

“…For example, Figure 2 shows the utility of different applications according to the energy consumption along with the generalized utility function in Equation 4. Actual energy consumption and utility (measured by recognition accuracy) of real studies exhibit varying patterns [27], [28]. For example, the dashed lines in Figure 2 show data from two real applications, which significantly deviate from the logarithmic utility function.…”

Underwater Energy Harvesting to Extend Operation Time of Submersible Sensors

“…A capacitor of 1F/9 V and 3.7 V/2400 mA LiPo battery is used to store the energy to power the sensors, using energy management of the harvested energy to maximize its use and storage [ 33 , 34 , 35 ]. A full bridge rectifier is used to perform AC/DC conversion, as presented in Figure 2 , to connect the LEG to sensors and charge the storage device.…”