Practical Monitoring of Undergrown Pigs for IoT-Based Large-Scale Smart Farm

Taking care of individual pigs is important in the management of a group-housed pig farm. However, this is nearly impossible in a large-scale pig farm owing to the shortage of farm workers. Therefore, we propose an automatic monitoring method in this study to solve the management problem of a large-scale pig farm. Particularly, we aim to detect undergrown pigs in group-housed pig rooms by using deep-learning-based computer vision techniques. Because the typical deep learning techniques require a large computational overhead (i.e., Mask-R-CNN), fast and accurate detection of undergrown pigs on an IoT-based embedded device is very challenging. We first obtain the video monitoring data of group-housed pigs by using a top-view camera that is installed in the pig room, and then detect each moving pig by combining image processing and deep learning techniques. Gaussian Mixture Model is used to detect moving frames and moving objects. In embedded device implementations, by applying deep learning (i.e., TinyYOLO3) to a few frames only with a large number of pixel changes, embedded GPUs can be used efficiently, satisfying the real-time requirement. As a subsequent step, we check the acceptable conditions of the posture and separability from each video frame of the continuous video stream. Finally, to compute the relative size of each pig quickly and accurately, we develop image processing steps to complement the result of deep learning with minimum computational overhead. Furthermore, by pipelining the CPU and GPU steps of a continuous video stream, we can hide the additional image processing time. Based on the experimental results obtained from an embedded device, we confirm that the proposed method can automatically detect undergrown pigs in real-time, by working as an early warning system without any human inspection or measurement of actual weight by a farm worker.