Fall recognition system to determine the point of no return in real‐time

Abstract

In this study, we collected data on human falls, occurring in four directions while walking or standing, and developed a fall recognition system based on the center of mass (COM). Fall data were collected from a lower‐body motion data acquisition device comprising five inertial measurement unit sensors driven at 100 Hz and labeled based on the COM‐norm. The data were learned to classify which stage of the fall a particular instance belongs to. It was confirmed that both the rep-resentative convolutional neural network learning model and the long short‐term memory learning model were performed within a time of 10 ms on the embedded platform (Jetson TX2) and the recognition rate exceeded 94%. Accordingly, it is possible to verify the progress of the fall during the unbalanced and falling steps, which are classified by subdividing the critical step in which the real‐time fall proceeds with the output of the fall recognition model every 10 ms. In addition, it was confirmed that a real‐time fall can be judged by specifying the point of no return (PONR) near the point of entry of the falling down stage.