Underwater small-space rotary laser scanning equipment

Abstract

The utility model relates to the technical field of laser scanning equipment, and particularly discloses underwater small-space rotary laser scanning equipment, which is characterized in that an industrial camera and a servo motor which extend along the axial direction are respectively arranged on two sides of the central axis of the front part of an inner cavity of an outer shell; a blue line laser and a green line laser which are parallel to the industrial camera are fixed at the front end of a power output shaft of the servo motor, and a transparent window I and a transparent window II are respectively nested in positions, opposite to the servo motor and the industrial camera, of the front wall of the outer shell; a power module and an FPGA module are arranged at the rear end of the outer shell, the power module is used for supplying power to the FPGA module, the industrial camera, the servo motor, the blue line laser and the green line laser, and the industrial camera, the blue line laser and the green line laser are electrically connected with the FPGA module; the problem that a laser scanning device is difficult to carry out high-precision scanning safely in a small underwater space is well solved.

Description

Technical Field

[0001] The utility model relates to the technical field of laser scanning, in particular to an underwater small space rotating laser scanning device. Background Art

[0002] Currently, when performing laser scanning on targets in confined underwater spaces, both domestic and international approaches mostly use traditional laser line scanners and pulsed laser line scanners. These two types of underwater laser scanning equipment can perform precise three-dimensional laser scanning of targets in unrestricted underwater areas. However, when the underwater operating area is restricted, or when the target is located in a very confined space, such as a narrow pipe, these devices are ineffective. This is because their scanning of the target relies on the rotation of the scanning device driven by an underwater motor. Therefore, when the space is limited, the scanning device will collide with surrounding non-target objects during rotation, making it impossible to complete high-precision scanning and very easy to damage the device.

[0003] Therefore, there is an urgent need for an underwater small space rotating laser scanning device to achieve laser three-dimensional scanning of targets in small underwater spaces. Utility Model Content

[0004] The purpose of the utility model is to provide a small underwater space rotating laser scanning device, which is used to solve the problem that the current laser scanning device is difficult to perform high-precision scanning safely in a small underwater space.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: an underwater small space rotating laser scanning device, comprising an outer shell, an industrial camera and a servo motor extending axially are respectively provided on both sides of the central axis of the front part of the inner cavity of the outer shell, a blue line laser and a green line laser parallel to the industrial camera are fixed to the front end of the servo motor power output shaft, and a transparent window 1 and a transparent window 2 are respectively nested in the front wall of the outer shell opposite to the servo motor and the industrial camera; a power module and an FPGA module are respectively provided at the rear end of the outer shell, the power module is used to supply power to the FPGA module, the industrial camera, the servo motor, the blue line laser and the green line laser, and the industrial camera, the blue line laser and the green line laser are respectively electrically connected to the FPGA module.

[0006] Preferably, a support plate is fixed to the inner peripheral wall of the outer shell, and the servo motor is fixed on the support plate.

[0007] Preferably, the power output shaft of the servo motor is fixedly mounted with a support plate, and the rear ends of the blue line laser and the green line laser are respectively and vertically mounted on both sides of the center of the front wall of the support plate.

[0008] Preferably, the transparent window 1 and the transparent window 2 are respectively made of high-transmittance tempered glass.

[0009] The reason for setting two different colored line lasers is that if a single line laser is used, the servo motor needs to rotate 180° after scanning the target. If two cross-line lasers are used, it only needs to rotate 90° to complete the laser line coverage of the target. In addition, the use of line lasers of different colors is to facilitate the distinction based on the color of the laser line in subsequent data processing.

[0010] Compared with the prior art, the beneficial effects of the present invention are:

[0011] The utility model relates to an underwater small space rotating laser scanning device which realizes laser three-dimensional scanning imaging of a target under the condition that the underwater space is very limited, and provides a new solution based on laser line scanning. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the overall three-dimensional structure of the utility model;

[0013] Figure 2 This is a data processing flow chart of the scanned image of the present invention.

[0014] In the figure: 1-outer shell; 1.1-transparent window 1; 1.2-transparent window 2; 1.3-support plate;

[0015] 2-Power module;

[0016] 3-FPGA module;

[0017] 4-Industrial cameras;

[0018] 5-Servo motor;

[0019] 6- support plate;

[0020] 7-blue line laser;

[0021] 8-Green line laser. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] See also Figure 1-2The present invention provides a technical solution: an underwater small-space rotary laser scanning device, comprising an outer shell 1. An industrial camera 4 and a servo motor 5 are axially extending on either side of the central axis of the front inner cavity of the outer shell 1. A blue line laser 7 and a green line laser 8 are fixed to the front end of the servo motor 5's power output shaft, parallel to the industrial camera 4. Transparent windows 1.1 and 1.2 are nested in the front wall of the outer shell 1, facing the servo motor 5 and the industrial camera 4, respectively. A power module 2 and an FPGA module 3 are provided at the rear end of the outer shell 1. The power module 2 is used to supply power to the FPGA module 3, the industrial camera 4, the servo motor 5, the blue line laser 7, and the green line laser 8. The industrial camera 4, the blue line laser 7, and the green line laser 8 are electrically connected to the FPGA module 3. A support plate 1.3 is fixed to the inner circumferential wall of the outer shell 1, to which the servo motor 5 is fixed. A support plate 6 is fixedly mounted on the power output shaft of the servo motor 5. The rear ends of the blue line laser 7 and the green line laser 8 are respectively mounted perpendicularly on either side of the center of the front wall of the support plate 6. Transparent window 1 1.1 and transparent window 2 1.2 are both made of high-transmittance tempered glass.

[0024] In summary, when the device is operating, the front wall of the outer housing 1, with its first and second transparent windows 1.1 and 1.2, faces the object being scanned. After scanning begins, the industrial camera 4 begins continuously capturing images and transmits them to the FPGA module 3. The high-precision servo motor 5 rotates in a single direction from its starting position, synchronously transmitting the motor's position information to the FPGA module 3 until it completes a 90-degree rotation and stops. Simultaneously, the industrial camera 4 stops capturing images. During this process, the blue and green line lasers 7 and 8, when powered on, each emit a monochromatic line laser. The two line lasers form a cross pattern, and the intersecting blue and green laser lines are projected onto the object being scanned, completely scanning the side of the object facing the lens. The FPGA module 3 synchronously processes the image data captured by the industrial camera 4 and outputs point cloud data of the scanned target.

[0025] Among them, the high-definition industrial camera 4 is used to collect photos of the scanned object and transmit them to the FPGA module 3 for data processing. The high-precision servo motor 5 is used to control the synchronous rotation of the blue line laser 7 and the green line laser 8, and feed back the position information to the FPGA module 3 in real time for image data fusion. The core board of the FPGA module 3 is used to control the power of the laser, output the synchronous pulse signal to control the rotation of the industrial camera 4 and the servo motor 5, process the collected image information and fuse it with the motor rotation position information, and finally output the point cloud data of the scanned anchor target. The specific data processing flow of a single scanned image is as follows: Figure 2 shown.

[0026] To better extract the green and blue laser lines in the camera image, we use the HSV color space to determine the color of the laser lines. This is because HSV is closer to human perception of color than RGB. It intuitively expresses the hue, vividness, and brightness of a color, making it easier to compare colors.

[0027] The above process converts the image from RGB color space to HSV color space and extracts the laser line, which can be expressed as:

[0028] 1.HSV=fRGB to HSV(I).

[0029] Where: I is the image; fRGB to HSV is the conversion function from RGB to HSV in the image.

[0030] 2. Color range filtering formula:

[0031]

[0032] 3. Mask creation formula:

[0033]

[0034]

[0035] 4. Extract the pixel coordinates of the blue and green laser lines through the mask:

[0036] Blue coordinate set Cb = {(x,y) | Mb(x,y) = 1};

[0037] Green coordinate set Cg = {(x,y)|Mg(x,y) = 1};

[0038] Given the light plane equation, we can use it to convert pixel coordinates on the image plane into actual 3D coordinates in the camera coordinate system. The calculation process from pixel coordinates to output laser point cloud data is as follows, where fx and fy are the focal lengths, and cx and cy are the principal point coordinates (image center), which are the camera intrinsic parameters after camera calibration.

[0039] The light plane equation is usually expressed as: aX + bY + cZ + d = 0, where a, b, c, and d are the known parameters of the light plane, (X, Y, Z) are the three-dimensional coordinates in the camera coordinate system, and pixel coordinates are converted to the normalized plane. First, convert the pixel coordinates (u, v) to the normalized plane coordinates (xn, yn):

[0040]

[0041] The calibration of the industrial camera 4 has been completed in advance, and the light plane equations of the servo motor 5 at different rotational positions have also been calibrated. A corresponding relationship dataset D between the light plane equations and the motor rotational positions has been created.

[0042] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0043] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An underwater small space rotating laser scanning device, comprising an outer shell (1), characterized in that: An industrial camera (4) and a servo motor (5) extending in the axial direction are respectively provided on both sides of the central axis of the front inner cavity of the outer shell (1); a blue line laser (7) and a green line laser (8) parallel to the industrial camera (4) are fixed to the front end of the power output shaft of the servo motor (5); and a transparent window 1 (1.1) and a transparent window 2 (1.2) are respectively embedded in the front wall of the outer shell (1) at positions corresponding to the servo motor (5) and the industrial camera (4); A power module (2) and an FPGA module (3) are provided at the rear end of the outer shell (1); the power module (2) is used to supply power to the FPGA module (3), the industrial camera (4), the servo motor (5), the blue line laser (7), and the green line laser (8); and the industrial camera (4), the blue line laser (7), and the green line laser (8) are electrically connected to the FPGA module (3), respectively.

2. The underwater small space rotating laser scanning device according to claim 1, characterized in that: A support plate (1.3) is fixed to the inner peripheral wall of the outer shell (1), and the servo motor (5) is fixed on the support plate (1.3).

3. The underwater small space rotating laser scanning device according to claim 1, characterized in that: The power output shaft of the servo motor (5) is fixedly mounted on a support disk (6), and the rear ends of the blue line laser (7) and the green line laser (8) are respectively and vertically mounted on both sides of the center of the front wall of the support disk (6).

4. The underwater small space rotating laser scanning device according to claim 3, characterized in that: The transparent window 1 (1.1) and the transparent window 2 (1.2) are respectively made of high-transmittance tempered glass.

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