Method for setting scan paths for underwater objects using an ultrasonic camera and an underwater robot

Underwater Object Scan Path Planning Technology Using Polygon Overlapping Analysis for Ultrasonic Cameras

This technology converts 3D point clouds acquired by an underwater robot's ultrasonic camera into 2D polygons and dynamically sets scan paths based on the line vectors and normal vectors of the maximum overlapping polygon extracted by comparing them with pre-stored polygons.

Due to the nature of underwater ultrasonic cameras, which only perform unidirectional scanning, it has been difficult to grasp the full shape of objects, and technical limitations often led to blind spots because the underwater robot's movement path could not be optimized.

This technology proposes a method that determines the next scan direction through 2D projection of 3D data and maximum overlapping polygon analysis, and automatically terminates the scan based on scan coverage angles and area change thresholds. It can be applied to seafloor surveys and shipwreck exploration, reducing survey time and energy by scanning along optimal paths without blind spots.

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Key Features:

• Acquiring multiple 3D point cloud data of an object through scans performed by an ultrasonic camera
• Converting the multiple 3D point cloud data into a first polygon with 2D coordinates
• Extracting a maximum overlapping polygon by overlapping the first polygon with a pre-stored second polygon
• Setting the scan path of the ultrasonic camera based on the line vectors and normal vectors of the maximum overlapping polygon

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This invention was developed with the support of the Smart Underwater Tunnel System Research Center under the Ministry of Science and ICT.