TITLE:
Compound Hidden Markov Model for Activity Labelling
AUTHORS:
Jose Israel Figueroa-Angulo, Jesus Savage, Ernesto Bribiesca, Boris Escalante, Luis Enrique Sucar
KEYWORDS:
Hidden Markov Model, Compound Hidden Markov Model, Activity Recognition, Human Activity, Human Motion, Motion Capture, Skeleton, Computer Vision, Machine Learning, Motion Analysis
JOURNAL NAME:
International Journal of Intelligence Science,
Vol.5 No.5,
October
9,
2015
ABSTRACT: This research presents a novel way of
labelling human activities from the skeleton output computed from RGB-D data
from vision-based motion capture systems. The activities are labelled by means
of a Compound Hidden Markov Model. The linkage of several Linear Hidden Markov
Models to common states, makes a Compound Hidden Markov Model. Each separate
Linear Hidden Markov Model has motion information of a human activity. The
sequence of most likely states, from a sequence of observations, indicates
which activities are performed by a person in an interval of time. The purpose
of this research is to provide a service robot with the capability of human
activity awareness, which can be used for action planning with implicit and
indirect Human-Robot Interaction. The proposed Compound Hidden Markov Model,
made of Linear Hidden Markov Models per activity, labels activities from
unknown subjects with an average accuracy of 59.37%, which is higher than the
average labelling accuracy for activities of unknown subjects of an Ergodic
Hidden Markov Model (6.25%), and a Compound Hidden Markov Model with activities
modelled by a single state (18.75%).