Underwater Moving Object Detection Using Superficial Electromagnetic Flow Velometer Array-Based Artificial Lateral Line System

Inspired by the flow perception ability of underwater organisms' lateral line system (LLS), recently, the artificial lateral line system (ALLS) has shown highly competitive application prospects in AUVs. However, the existing ALLS contains lots of movable parts, which are easily damaged and entangled and will generate flow resistance to the AUV carrier. Moreover, existing ALLS mainly focus on vibration object detection, while the studies on the more common and valuable translational moving objects are relatively less. In this article, a novel and practical theory for underwater moving object detection is proposed to achieve no-contact object velocity estimation via the measured object wake flow signal. The object motion-induced flow field and sensor signals are well studied. The signal-processing method is established based on the array signals' time delay features. A fully solid-state ALLS is proposed using a permanent magnet-based superficial electromagnetic flow velometer array without any movable parts. The experimental results prove that the proposed ALLS and the object velocity estimation method are ultrarobust to the object shape and object distance changes. The object velocity estimation accuracy of the proposed ALLS reaches 96.64%-99.96% within the range of 0-0.875 [m/s] and the maximum detection range reaches 0.14 [m] of the test 0.02 [m] width cuboid object at 0.5 [m/s].