  With the advancement of deep neural networks and computer vision-based Human
Activity Recognition, employment of Point-Cloud Data technologies (LiDAR,
mmWave) has seen a lot interests due to its privacy preserving nature. Given
the high promise of accurate PCD technologies, we develop, PALMAR, a
multiple-inhabitant activity recognition system by employing efficient signal
processing and novel machine learning techniques to track individual person
towards developing an adaptive multi-inhabitant tracking and HAR system. More
specifically, we propose (i) a voxelized feature representation-based real-time
PCD fine-tuning method, (ii) efficient clustering (DBSCAN and BIRCH), Adaptive
Order Hidden Markov Model based multi-person tracking and crossover ambiguity
reduction techniques and (iii) novel adaptive deep learning-based domain
adaptation technique to improve the accuracy of HAR in presence of data
scarcity and diversity (device, location and population diversity). We
experimentally evaluate our framework and systems using (i) a real-time PCD
collected by three devices (3D LiDAR and 79 GHz mmWave) from 6 participants,
(ii) one publicly available 3D LiDAR activity data (28 participants) and (iii)
an embedded hardware prototype system which provided promising HAR performances
in multi-inhabitants (96%) scenario with a 63% improvement of multi-person
tracking than state-of-art framework without losing significant system
performances in the edge computing device.
