Action Detection and Recognition in Continuous Action Streams by Deep Learning-Based Sensing Fusion

This paper presents a deep learning-based sensing fusion system to detect and recognize actions of interest from continuous action streams, which contain actions of interest occurring continuously and randomly among arbitrary actions of non-interest. The sensors used in the fusion system consist of a depth camera and a wearable inertial sensor. A convolutional neural network is utilized for depth images obtained from the depth sensor, and a combination of convolutional neural network and long short-term memory network is utilized for inertial signals obtained from the inertial sensor. Each sensing modality first performs segmentation of all actions and then detection of actions of interest for a particular application. A decision-level fusion of the two sensing modalities is carried out to achieve the recognition of the detected actions of interest. The developed fusion system is examined for two applications: one involving transition movements for home healthcare monitoring and the other involving smart TV hand gestures. The results obtained show the effectiveness of the developed fusion system in dealing with realistic continuous action streams.