KR-20260062595-A - Electronic device for three-dimensional reconstruction of profiling sonar data and method thereof

KR20260062595AKR 20260062595 AKR20260062595 AKR 20260062595AKR-20260062595-A

Abstract

An electronic device for performing three-dimensional reconstruction of profiling sonar data according to an embodiment of the present invention may include a processor that acquires three-dimensional point cloud data for an object using data acquired from a profiling sonar sensor and a forward-looking sonar sensor mounted on an underwater robot in a first scan path, extracts a first plurality of points existing in a scan area of the underwater robot according to a second scan path from the three-dimensional point cloud data, estimates a second plurality of points based on two-dimensional profiling sonar data acquired in the second scan path, the distance from the first plurality of points to the underwater robot, and an azimuth angle, and generates three-dimensional profiling sonar data using the second plurality of points estimated in the plurality of second scan paths.

Inventors

유선철
노세환

Assignees

포항공과대학교 산학협력단

Dates

Publication Date: 20260507
Application Date: 20241029

Claims (10)

In an electronic device for performing three-dimensional reconstruction of profiling sonar data, 3D point cloud data for an object is obtained using data acquired from a profiling sonar sensor and a forward-looking sonar sensor mounted on an underwater robot in the first scan path, and Extracting a first plurality of points existing in the scan area of the underwater robot according to the second scan path from the above 3D point cloud data, and Estimating a second plurality of points based on 2D profiling sonar data acquired from the second scan path, the distance and azimuth angle from the first plurality of points to the underwater robot, and An electronic device comprising a processor that generates three-dimensional profiling sonar data using a second plurality of points estimated from a plurality of second scan paths.
In paragraph 1, The above processor is, Based on whether the above 3D point cloud data is acquired, the angle between the scan direction of the above forward-looking sonar sensor and the front edge line of the object is calculated, and An electronic device that sets the scan direction as the first scan path when the above angle is vertical.
In paragraph 2, The above processor is, An electronic device for controlling the underwater robot so that the angle becomes vertical when the angle is not vertical.
In paragraph 1, The above processor is, Depending on the azimuth resolution of the forward-looking sonar sensor, the azimuth of the profiling sonar sensor is divided into multiple sections, and An electronic device for extracting the first plurality of points to correspond to the above plurality of sections.
In paragraph 4, The above processor is, Generate at least one normal distribution based on the distance from at least one point included in each section among the first plurality of points to the underwater robot, and An electronic device that estimates a point having the maximum probability in each interval based on at least one normal distribution and two-dimensional profiling sonar data.
A method for performing three-dimensional reconstruction of profiling sonar data performed by an electronic device, A step of acquiring 3D point cloud data for an object using data acquired from a profiling sonar sensor and a forward-looking sonar sensor mounted on an underwater robot in a first scan path; A step of extracting a first plurality of points existing in the scan area of the underwater robot according to the second scan path in the above 3D point cloud data; A step of estimating a second plurality of points based on 2D profiling sonar data acquired from the second scan path, the distance and azimuth angle from the first plurality of points to the underwater robot; A method comprising the step of generating three-dimensional profiling sonar data using a second plurality of points estimated from a plurality of second scan paths.
In paragraph 6, The step of acquiring the above 3D point cloud data is, A step of calculating the angle between the scan direction of the forward-looking sonar sensor and the front edge line of the target object based on whether the above 3D point cloud data is acquired; A method comprising the step of setting the scan direction as the first scan path when the above angle is vertical.
In Paragraph 7, A method comprising the step of controlling the underwater robot so that, if the above angle is not vertical, the above angle becomes vertical.
In paragraph 8, The step of extracting the first plurality of points above is, A step of dividing the azimuth of the profiling sonar sensor into multiple sections according to the azimuth resolution of the forward-looking sonar sensor; A method comprising the step of extracting the first plurality of points to correspond to the plurality of segments.
In Paragraph 9, The step of estimating the second plurality of points above is, A step of generating at least one normal distribution based on the distance from at least one point included in each segment among the first plurality of points to the underwater robot; A method comprising the step of estimating a point having the maximum probability in each interval based on at least one normal distribution and the two-dimensional profiling sonar data.

Description

Electronic device for three-dimensional reconstruction of profiling sonar data and method thereof The present invention relates to an electronic device and method for performing three-dimensional reconstruction of profiling sonar data. The detection and mapping of objects or landmarks on the seabed using underwater robots has been studied as an important technology in various underwater missions, such as marine resource exploration and shipwreck detection. In such robot mapping, it is important to obtain precise information through 3D reconstruction, and since this must be done based on data acquired from sensors, performing 3D reconstruction of the seabed or objects using poor sensor data obtained in the extreme underwater environment has been one of the important research elements. In particular, among the sensors available for underwater use, sonar sensors have the advantage of not being affected by water turbidity, lack of light, or color distortion compared to cameras or optical-based sensors, so they are used in the missions of various underwater robots, and similarly, 3D reconstruction research using sonar data is also being conducted. However, in the case of 3D reconstruction research using sonar sensors, accuracy is reduced due to a lot of noise in the sonar data, so research on various methods is being conducted to address this. One such method involves fusion between heterogeneous sonar sensors using profiling sonar and forward-looking sonar. However, since profiling sonar data is fundamentally limited to 2D mapping, a problem arises where the accuracy of 3D reconstruction results is reduced in some situations. Additionally, while fusion between heterogeneous sonar reduces information uncertainty, there are limitations, such as accuracy being affected when applied to objects with complex structures and the assumption that the underwater robot encounters the object vertically. FIG. 1 is a schematic diagram illustrating a three-dimensional reconstruction system according to one embodiment of the present invention. FIG. 2 is a block diagram illustrating the configuration of an electronic device according to one embodiment of the present invention. FIG. 3 is a diagram illustrating the operation flowchart of an electronic device according to one embodiment of the present invention. FIG. 4 is a diagram illustrating a forward-looking sonar sensor according to one embodiment of the present invention. FIG. 5 is a diagram illustrating a forward-looking sonar sensor and a profiling sonar sensor according to an embodiment of the present invention. FIG. 6 is a drawing illustrating a three-dimensional point cloud according to an embodiment of the present invention. FIG. 7 is a diagram illustrating the setting of a scan path according to one embodiment of the present invention. FIG. 8 is a diagram illustrating the operation flowchart of a three-dimensional restoration system according to one embodiment of the present invention. FIG. 9 is a diagram illustrating profiling sonar data according to one embodiment of the present invention. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. The detailed description disclosed below, together with the accompanying drawings, is intended to describe exemplary embodiments of the present invention and is not intended to represent the only embodiment in which the present invention can be practiced. In order to clearly explain the present invention in the drawings, parts unrelated to the description may be omitted, and the same reference numerals may be used for identical or similar components throughout the specification. FIG. 1 is a schematic diagram illustrating a three-dimensional reconstruction system according to one embodiment of the present invention. The three-dimensional restoration system (1) of FIG. 1 may include an underwater robot (10), a forward looking sonar (FLS) sensor (20), a profiling sonar (PS) sensor (30), and an electronic device (100). The forward-looking sonar sensor (20) refers to a multi-beam imaging sonar sensor that emits multiple beams having a field of view (FoV) in the vertical and horizontal directions and outputs the reflected signals as an image. At this time, each beam has a narrow field of view in the horizontal direction and a wide field of view in the vertical direction, and the angle from the center of each beam in the horizontal direction is called the azimuth angle (φ). An example of the forward-looking sonar sensor (20) is shown in FIG. 4. The profiling sonar sensor (30) is a sensor that scans an area within a specific range through mechanical rotation of a single beam sonar. In this case, the single beam has a narrow horizontal field of view and a wide vertical field of view. An example of the profiling sonar sensor (30) is shown in FIG. 5. The forward-looking sonar sensor (20) and the profiling sonar sensor (30) are mounted on the underwater