MiNet: Efficient Deep Learning Automatic Target Recognition for Small Autonomous Vehicles

Abstract

On-the-fly automatic target recognition (ATR) is a challenge for small autonomous vehicles performing remote sensing. Advances in deep learning have made object detection practicable on data from a variety of sensor types, and neural network-based object detector models trained on big data sets of natural images are commonly adapted to the remote sensor (RS) domain via transfer learning. However, constraints of small vehicle hardware, such as computational performance and battery power, limit capacity for running deep learning models onboard. Standard pretrained object detection models, such as YOLO and R-CNN, contain large convolutional neural networks requiring tens to hundreds of billions of floating-point operations to distinguish between many natural image object classes. Such large models may be overly complex for ATR tasks in RS data. This letter describes an efficient deep learning model, MiNet, developed to detect mine-like objects in sonar data. It was built in Keras and TensorFlow and trained entirely on real and synthetically generated sonar data using an incremental training procedure. MiNet was successfully deployed onboard small OceanServer Iver3 autonomous underwater vehicles during the REBOOT sea trial and predicted the latitude, longitude, and class of objects detected in sonar images within minutes of the completion of each mission leg.