Localization by RFID ref LANDMARC Indoor Location Sensing

Localization by RFID ref: “LANDMARC: Indoor Location Sensing Using Active RFID”, Per. Com’ 03 by: L. Ni, Y. Liu, Y. C. Lau, and A. P. Patil

Some Thought ¢ Solution 1: deploying many readers ¢ Solution 2: deploying many tags 2 11/30/2020

Goal of This Work ¢ goal: l l ¢ ¢ to investigate whether the RFID technology is suitable for locating objects with accuracy and cost-effectiveness. LANDMARC: by Active RFID Calibration l l 3 few readers and many tags in the environment user only carries a tag for in-building use. utilizing the concept of reference tags. 11/30/2020

LANDMARC Architecture: 1. readers 2. fixed tags 3. tracking tag (carried by user) 4 11/30/2020

LANDMARC Approach (I) ¢ In the sensing field: l l l ¢ Readers are configured with continuous mode. Detection range = 1 ~ 8. l l 5 n readers m fixed tags u tracking tags (attached to a moving object) Signal Strength Vector of a tracking tag: S=(S 1, S 2, …, Sn) Signal Strength Vector of a fixed tag i: Fi=(θ 1, θ 2, …, θn) 11/30/2020

LANDMARC Approach (II) l Euclidian distance between a tracking tag and the i-th fixed tag: l Location of the tracking tag: • pick the k fixed tags with the smallest “Euclidean distances” • weighted location: 6 11/30/2020

Experiment Environment 7 11/30/2020

Environmental Factors: Daytime vs. Night ¢ 8 Do not see much difference in the overall accuracy. 11/30/2020

Effect of n (Number of Readers) ¢ 9 With more RF readers, a better decision can be made. 11/30/2020