This work was supported by the National Research Fund of Luxembourg (grant number C14/IS/8311593 – INDOORS project)
Activity tracking and indoor positioning
with a wearable magnet
Andrei Popleteev, University of Luxembourg
Magnetic sensing
Wearable: permanent magnet • Carried by the user (in a ring,
bracelet, jewelry, clothes) • No batteries required
• Water- and shock-proof
Sensors: 3D digital compass
• Installed in monitored places
• Can be hidden in furniture/walls • Low power consumption
Advantages
• Power- and cost-efficient • Respects user’s privacy
• Works in humid areas • Readily available
Challenges
• No identity
• Limited range
• Precision is hard
• Magnets are sticky
Applications and proof-of-the-concept experiments
• Ambient assisted living • Indoor localization • Activity tracking • Sleep monitoring • Touch-free interaction 42 43 44 45 46 47 48 0.2 0.4 0.6 0.8 1 M ag n e tic fi e ld str e n gth , u T Distance, m Test magnet Earth's field 0 0.1 0.2 0.3 0.4 13:00 14:00 15:00 16:00 17:00 Time of day
Office desk - work day
Coffee break 0 0.1 0.2 0.3 0.4 0:00 1:00 2:00 3:00 4:00 5:00 6:00 7:00 8:00 Stan d ar d d e vi ation Time of day
Office desk - night
0.0 0.1 0.2 0.3 0.4 0:00 1:00 2:00 3:00 4:00 5:00 6:00 7:00 8:00 St an d ar d d e vi at io n Time of day Sleep monitoring
going to bed waking up standing up
reading in bed
andrei.popleteev@uni.lu
Image courtesy of S. Afshari, A.Popleteev, R.McCall, T. Engel.
