A linear structured light camera calibration and posture adjustment system

Abstract

The present invention relates to the technical field of linear structured light camera calibration, and specifically to a linear structured light camera calibration posture adjustment system, comprising a sawtooth calibration plate and a split laser camera, wherein the sawtooth calibration plate is arranged on a sawtooth calibration plate base, and the split laser camera is arranged on one side of the sawtooth calibration plate. The present invention realizes precise positioning of the relative position of the split camera and the calibration viewing distance through a scale slide, a lateral fine-tuning top cylinder, a rotary indexing plate, a laser rangefinder, a load-bearing adjustable height support foot, a low-position pulley, and a high-position spiral height adjustment top cylinder.

Description

Technical Field

[0001] The present invention relates to the technical field of linear structured light camera calibration, and in particular to a linear structured light camera calibration posture adjustment system. Background Art

[0002] Line structured light cameras are widely used in the 3C and automotive industries for dimensional inspection, identification, positioning, and navigation. The inspection and measurement principle of line structured light cameras is based on laser triangulation. When a line laser beam strikes the workpiece surface from one side, its reflected light is imaged by a camera on the other side, resulting in a laser stripe image. The position of the laser stripe image on the camera varies depending on the height of the laser spot on the workpiece surface. System calibration and stripe centerline extraction can now determine the workpiece surface height. Calibration is performed to determine the correspondence between image pixels captured by the camera and three-dimensional points in space. Therefore, calibration accuracy determines the inspection and measurement accuracy of line structured light cameras.

[0003] Currently, line structured light cameras are primarily used in industrial inspection and recognition applications, such as mobile phone and other electronic device inspection, workpiece inspection, and tire inspection. These cameras have short inspection ranges and small fields of view. Therefore, camera calibration can be accomplished using small-scale calibration plates, such as checkerboards, scaled in millimeters or centimeters, supplemented by fixtures. However, for line structured light cameras with inspection ranges greater than 3 meters and fields of view greater than 1 meter, the use of sawtooth calibration methods to achieve satisfactory calibration accuracy requires adjusting the geometry of the calibration plate, which has a large number of teeth, large dimensions, and heavy weight, making it difficult to achieve autonomous stability during the calibration process. Furthermore, to improve calibration accuracy, the geometric position of the line structured light camera and the calibration plate must be adjusted to align the laser line parallel to both sides of the plate's thickness. For line structured light cameras with large fields of view and large viewing distances, the calibration scene is large, the device is heavy, and stability is difficult to control and adjust. Stabilizing the sawtooth calibration plate with handholds or clamps, as well as external factors such as uneven surfaces, can cause the plate to be offset from an absolutely vertical position, resulting in an angle with the line laser emission or a deviation in the camera's image orientation. This makes the calibration process of long-viewing-distance structured light cameras difficult, reduces calibration accuracy, and ultimately affects the shooting effect of structured light cameras. Therefore, it is particularly important to design a sawtooth calibration fixing and adjustment device that can stabilize large-sized and heavy equipment, and can be used flexibly and accurately adjusted for long-viewing-distance and large-field-of-view structured light cameras. Summary of the Invention

[0004] The purpose of the present invention is to provide a linear structured light camera calibration device that is stable, fine-tuned, and precisely controlled, so as to overcome the problems of existing devices in long-distance and large-field-of-view application scenarios.

[0005] In order to achieve the above purpose, a linear structured light camera calibration posture adjustment system is designed, which includes a split laser camera, a camera and a laser. The camera is set on a rotating indexing plate, and the rotating indexing plate is set on a horizontal slide plate through a fixed chassis. The laser is set on a horizontal slide plate through a laser fixing plate. The horizontal slide plate is provided with a scale slide, so that the camera and the laser can move along the scale slide. The camera deflection angle and the distance between the two can be accurately adjusted according to the requirements of the field of view to be calibrated; the sawtooth calibration plate is set on the split laser camera On one side, a plurality of tooth-shaped structures are provided on one side of the sawtooth calibration plate, and the sawtooth calibration plate stands vertically on the sawtooth calibration plate base. The two diagonals of the sawtooth calibration plate base are respectively provided with groove structures, and the sawtooth calibration plate base is provided with a calibration plate guide rail, and the sawtooth calibration plate is connected to the sawtooth calibration plate base through the calibration plate guide rail. A side limit slot is provided on the other side of the sawtooth calibration plate. The top of the sawtooth calibration plate fixing bracket is connected to the sawtooth calibration plate through the side limit slot, and the bottom is connected to the sawtooth calibration plate base, so that the sawtooth calibration plate fixing bracket can stabilize the sawtooth calibration plate.

[0006] The present invention also has the following preferred technical solutions:

[0007] 1. The side limit slot is a U-shaped positioning plate, which is connected to the serrated calibration plate by screws.

[0008] 2. Laser rangefinders are installed on the side of the laser fixing plate facing the camera and the side of the serrated plate.

[0009] 3. The bottom of the sawtooth calibration plate is connected to the sawtooth calibration plate base through a calibration plate guide rail, and a wedge-shaped pad is provided at the bottom of the side of the sawtooth calibration plate where the saw teeth are provided.

[0010] 4. The bottom of the sawtooth calibration plate fixing bracket is equipped with adjustable height feet.

[0011] 5. The horizontal slide plate is set on the split laser camera adjustment bracket, and the bottom of the bracket is provided with an adjustable height foot.

[0012] 6. The adjustable height support leg includes a low-position pulley and a high-position spiral height adjustment cylinder.

[0013] 7. A level and a scale are provided on the horizontal slide plate.

[0014] 8. A side limit slot is provided on one side of the horizontal slide plate, and a lateral fine-tuning top cylinder is provided on the other side of the horizontal slide plate.

[0015] 9. The split laser camera adjustment bracket includes a vertical pole and a base, and the base is provided with a groove structure connected to the vertical pole.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] 1. Split laser cameras suitable for different viewing distance and field of view requirements;

[0018] 2. Through the scale slide, lateral fine-tuning cylinder, rotary indexing plate, and laser rangefinder, the relative position of the split camera and the calibration of the viewing distance are accurately positioned to reduce system errors;

[0019] 3. The sawtooth calibration plate is locked by the calibration plate guide rail and the wedge-shaped pad to achieve the relative position of the sawtooth calibration plate fixed, preventing the sawtooth calibration plate from shaking due to environmental interference during the calibration process;

[0020] 4. The low pulley of the height-adjustable support leg and the high spiral height-adjusting top cylinder can respectively realize meter-level and centimeter-level position movement, as well as fine-tuning of the horizontality. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is an assembly diagram of the linear structured light camera calibration and posture adjustment system of the present invention;

[0022] Figure 2 This invention Figure 1 Enlarged view of the middle camera section;

[0023] Figure 3 1 is a schematic diagram of the operation of the laser of the present invention;

[0024] Figure 4 This is the main view of the working state of the system of the present invention;

[0025] Figure 5 This is a schematic top view of the system of the present invention in working state;

[0026] Figure 6 This is a top view of the system of the present invention in working state;

[0027] In the figure: 1. Camera 2. Laser 3. Rotating indexing plate 4. Fixed chassis 5. Horizontal slide plate 6. Laser fixing plate 7. Scale slide 8. Sawtooth calibration plate 9. Sawtooth calibration plate fixing bracket 10. Side limit slot 11. Laser rangefinder 12. Calibration plate guide rail 13. Wedge-shaped spacer 14. Adjustable height support foot 15. Level. DETAILED DESCRIPTION

[0028] The present invention will be further described below with reference to the accompanying drawings. The structure and principle of the present invention will be very clear to those skilled in the art. It should be understood that the specific embodiments described herein are only intended to explain the present invention and are not intended to limit the present invention.

[0029] The present invention provides a linear structured light camera calibration and posture adjustment system, comprising a split laser camera, a horizontal slide plate, a split laser camera adjustment bracket, a sawtooth calibration plate, and a sawtooth calibration plate fixing bracket. The split laser camera comprises a camera and a laser. The camera is mounted on a rotating indexing plate, which is mounted on the horizontal slide plate via a fixed chassis. The laser is mounted on the horizontal slide plate via a laser fixing plate. The horizontal slide plate is provided with a graduated slide, allowing the camera and laser to move along the graduated slide to adjust the distance between them. The sawtooth calibration plate is mounted on one side of the split laser camera, perpendicular to the sawtooth calibration plate fixing bracket. The sawtooth calibration plate is provided with side limit slots, which stabilize the sawtooth calibration plate fixing bracket. A laser rangefinder is provided on the side of the laser fixing plate facing the camera. The bottom of the sawtooth calibration plate is connected to the sawtooth calibration plate fixing bracket via a calibration plate guide rail. A wedge-shaped pad is provided at the bottom of the sawtooth calibration plate on the side where the sawteeth are provided. The bottom of the sawtooth calibration plate mounting bracket is equipped with an adjustable height foot. The horizontal slide plate is mounted on the split laser camera adjustment bracket and has an adjustable height foot at its bottom. The adjustable height foot includes a low-position pulley and a high-position spiral height adjustment cylinder. A level ruler is attached to the horizontal slide plate. A side limit slot is provided on one side of the horizontal slide plate, and a lateral fine-tuning cylinder is provided on the other side.

[0030] To achieve the distance from the laser to the camera in the split laser camera (such as Figure 6 In the middle, the adaptability and precise positioning of the distance AA1) are achieved, and a scale and a lateral fine-tuning top cylinder are used to ensure the precise positioning of the distance between the laser and the camera of the split laser camera, with a distance error of 0.05mm.

[0031] To achieve the laser deflection angle (such as Figure 6 In the process, the angle α is precisely positioned, and a rotating indexing plate is used to ensure the precise deflection of the laser angle, with an angle deflection error of 2".

[0032] In order to realize the sawtooth calibration plate in the X direction and Z direction (the direction is defined as Figure 1 ) and the serrated calibration plate fixing bracket remain relatively stable, and the serrated calibration plate is locked through the side limit slots and the calibration plate guide rails.

[0033] After keeping the split laser camera and the sawtooth calibration plate stable, further adjust the relative position of the split laser camera and the sawtooth calibration plate in the X direction through the low-position pulley of the adjustable height foot so that the laser line falls on the sawtooth surface;

[0034] Furthermore, according to the visual range measurement result of the laser rangefinder, the split laser camera adjustment bracket is dragged along the Z direction until the preset visual range position (such as Figure 6 , distance AD);

[0035] Furthermore, the top cylinder is raised by the high-position screw adjustment of the load-bearing adjustable height support, and the split laser camera adjustment bracket and the sawtooth plate fixing bracket are adjusted respectively until the level ruler shows their respective positions. At the same time, the laser is facing the height center line of the sawtooth calibration plate (i.e. AD┴BC and AB=AC);

[0036] Furthermore, by fine-tuning the top post laterally, the laser line is adjusted to the center of the serrated surface and parallel to the side lines of the tooth surface.

[0037] The operating principle of the linear structured light camera calibration and posture adjustment system of the present invention is as follows:

[0038] During calibration, place both brackets on the same level ground. Clip the sawtooth calibration plate into the sawtooth plate mounting bracket, with the bottom resting against the wedge-shaped spacer. Tighten the sawtooth calibration plate by turning the side limit slots to ensure a stable, upright position. Mount the camera and laser on the horizontal slide plate at the top of the laser camera adjustment bracket. Slide the camera and laser to the desired distance and secure them with bolts. The horizontal slide plate is equipped with a scale and fine-tuning cylinder, and the camera mounting base is equipped with a rotating indexing plate for precise adjustment of distance and camera angle.

[0039] Switch the adjustable height legs to the low pulley mode, move the laser camera bracket to the set distance, twist the four legs to retract the pulley, switch to the high-position spiral height adjustment cylinder, fix the bracket at the preset viewing distance, turn on the power, and the laser emitted by the laser shines on the sawtooth surface of the serrated plate.

[0040] Use a spirit level to measure the vertical placement of the serrated plate and the horizontal placement of the horizontal slide plate. According to the measurement results and the deflection direction of the laser line, adjust the high-position screw to raise the top cylinder, so as to achieve the purpose of fine-tuning the bracket position, so that the laser line is parallel to the side lines of the serrated plate, and a clear and horizontal laser line appears on the screen of the camera control end - the computer.

Claims

1. A linear structured light camera calibration and orientation adjustment system, characterized in that include: A split laser camera includes a camera and a laser. The camera is mounted on a rotating indexing plate, which is mounted on a horizontal slide plate via a fixed chassis. The laser is mounted on a horizontal slide plate via a laser fixing plate. The horizontal slide plate is provided with a graduated slide, allowing the camera and laser to move along the graduated slide to adjust the distance between them. A sawtooth calibration plate is provided on one side of the split laser camera. A plurality of tooth-shaped structures are provided on one side of the sawtooth calibration plate. The sawtooth calibration plate stands vertically on the sawtooth calibration plate base. The two diagonal lines of the sawtooth calibration plate base are respectively provided with groove structures. A calibration plate guide rail is provided at the bottom of the sawtooth calibration plate. The sawtooth calibration plate is connected to the sawtooth calibration plate base through the calibration plate guide rail. A side limit slot is provided on the other side of the sawtooth calibration plate. The top of the sawtooth calibration plate fixing bracket is connected to the sawtooth calibration plate through the side limit slot, and the bottom is connected to the sawtooth calibration plate base, so that the sawtooth calibration plate fixing bracket can stabilize the sawtooth calibration plate. The side limit slot is a U-shaped positioning plate, which is connected to the sawtooth calibration plate by screws; A laser rangefinder is provided on the side of the laser fixing plate facing the camera.

2. The linear structured light camera calibration and orientation adjustment system according to claim 1, characterized in that: The bottom of the sawtooth calibration plate is connected to the sawtooth calibration plate base through a calibration plate guide rail, and a wedge-shaped pad is provided at the bottom of one side of the sawtooth calibration plate where the saw teeth are provided.

3. The linear structured light camera calibration and orientation adjustment system according to claim 2, characterized in that: The bottom of the sawtooth calibration plate fixing bracket is provided with adjustable height support feet.

4. The linear structured light camera calibration and orientation adjustment system according to claim 3, characterized in that: The horizontal slide plate is arranged on the split laser camera adjustment bracket, and an adjustable height support foot is provided at the bottom of the bracket.

5. The linear structured light camera calibration and orientation adjustment system according to claim 4, characterized in that: The height-adjustable supporting foot comprises a low-position pulley and a high-position spiral height-adjustable top cylinder.

6. The linear structured light camera calibration and orientation adjustment system according to claim 5, characterized in that: The horizontal slide plate is provided with a level ruler and a graduated ruler.

7. The linear structured light camera calibration and orientation adjustment system according to claim 6, characterized in that: One side of the horizontal chute plate is provided with a side limit groove, and the other side of the horizontal chute plate is provided with a lateral fine-tuning top cylinder.

8. The linear structured light camera calibration and orientation adjustment system according to claim 4, characterized in that: The split laser camera adjustment bracket includes a vertical pole and a base, and the base is provided with a groove structure connected to the vertical pole.

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