Preliminary investigation on activity recognition for packaging tasks using motif-guided attention networks

This study presents a method for recognizing packaging tasks using wrist-worn accelerometer sensors under real conditions. As the lead times and actions of packaging activities depend on the number of objects to pack along with the size and shape of each object, it is difficult to recognize operations during every period. We propose a segmentation neural network augmented with a multi-head attention mechanism to capture actions found in a specific operation, which can be useful to identify individual operations. To efficiently detect useful actions with limited training data, we propose an attention guiding approach based on existing motif detection algorithms, which find actions (motifs) that frequently appear in a specific operation. We then use the occurrence of these motifs as a target for each attention head, enabling it to increase its ability to recognize similar operations during the packaging process. We evaluate our framework using data obtained in an actual logistics center.