Elderly People Activity Recognition in Smart Grid Monitoring Environment

Abstract

Elderly people activity recognition has become a vital necessity in many countries, because most of the elderly people live alone and are vulnerable. Thus, more research to advance in the monitoring systems used to recognize the activities of elderly people is required. Many researchers have proposed different monitoring systems for activity recognition using wired and wireless wearable sensing devices. However, the activity classification accuracy achieved so far should be improved to meet the challenges of more precise activity monitoring. Our study proposes a smart Human Activity Recognition system architecture utilizing an open source dataset generated by wireless, batteryless sensors used by 14 healthy aged persons and unsupervised and supervised machine learning algorithms. In this paper, we also propose using a smart grid for checking regularly the wearable sensing device operational status to address the well-known reliability challenges of these devices, such as wireless charging and data trustworthiness. As the data from the sensing device is very noisy, we employ the K-means++ clustering to identify outliers and use advanced ensemble classification techniques, such as the stacking classifier for which a meta model built using the random forest algorithm gave better results than all other base models considered. We also employ a bagging classifier, which is an ensemble meta-estimator fitting the prediction outputs of the base classifiers and aggregating them to produce the ensemble output. The best classification accuracy of 99.81 was achieved by the stacking classifier in training and 99.78% in testing, respectively. Comparisons for finding the best model were conducted using the recall, F1 score, and precision values.