Research Article
CapSense: Capacitor-based Activity Sensing for Kinetic Energy Harvesting Powered Wearable Devices
@INPROCEEDINGS{10.4108/eai.7-11-2017.2273509, author={Guohao Lan and Dong Ma and Weitao Xu and Mahbub Hassan and Wen Hu}, title={CapSense: Capacitor-based Activity Sensing for Kinetic Energy Harvesting Powered Wearable Devices}, proceedings={14th EAI International Conference on Mobile and Ubiquitous Systems: Computing, Networking and Services}, publisher={ACM}, proceedings_a={MOBIQUITOUS}, year={2018}, month={4}, keywords={energy-efficiency activity recognition wearable devices}, doi={10.4108/eai.7-11-2017.2273509} }- Guohao Lan
Dong Ma
Weitao Xu
Mahbub Hassan
Wen Hu
Year: 2018
CapSense: Capacitor-based Activity Sensing for Kinetic Energy Harvesting Powered Wearable Devices
MOBIQUITOUS
ACM
DOI: 10.4108/eai.7-11-2017.2273509
Abstract
We propose a new activity sensing method, CapSense, which detects activities of daily living (ADL) by sampling the voltage of the kinetic energy harvesting (KEH) capacitor at an ultra low sampling rate. Unlike conventional sensors that generate only instantaneous motion information of the subject, KEH capacitors accumulate and store human generated energy over time. Given that humans produce kinetic energy at distinct rates for different ADL, the KEH capacitor can be sampled only once in a while to observe the energy generation rate and identify the current activity.Thus, with CapSense, it is possible to avoid collecting time series motion data at high frequency, which promises significant power saving for the sensing device. We prototype a shoe-mounted KEH-powered wearable device and conduct experiments with 10 subjects for detecting 5 different activities. Our results show that compared to the existing time-series-based activity recognition, CapSense reduces sampling induced power consumption by 99% and the overall system power, after considering wireless transmissions by 75%. CapSense recognizes activities with up to 90%.