Light-emitting calibration plate for deformation monitoring camera calibration

Abstract

The utility model discloses a luminous calibration plate for deformation monitoring camera calibration, which comprises a rectangular frame, a calibration pattern layer, an illumination layer and a back plate, the periphery of the front surface of the rectangular frame extends inwards to be provided with a baffle, and the calibration pattern layer, the illumination layer and the back plate are sequentially stacked in the frame from front to back. The back face of the frame framework is provided with a back plate fixing buckle used for fixing the back plate. Calibration patterns are uniformly illuminated through LED backlight, so that a camera can obtain clear calibration images in a dark light environment, high-precision calibration work is facilitated, and the problem that an existing calibration plate depends on external light source illumination and cannot work in the dark light environment is solved.

Description

Technical Field

[0001] The utility model belongs to the field of deformation observation of close-range photogrammetry means, and in particular relates to a luminous calibration plate used for calibration of a deformation monitoring camera. Background Art

[0002] Camera calibration is an important part of non-contact optical measurement, and the accuracy of camera calibration is closely related to the measurement accuracy of the measurement system. Existing camera calibration targets generally rely on external light sources such as sunlight and lamplight for passive illumination. When the surrounding light is poor, the quality of the calibration image will be reduced, which in turn affects the calibration accuracy of the camera, making it difficult to adapt to the high-precision and all-weather operation requirements of deformation observation projects. Utility Model Content

[0003] In order to solve the above technical problems, the utility model proposes a luminous calibration plate for calibration of a deformation monitoring camera.

[0004] The technical solution adopted by the utility model is a luminous calibration plate for calibration of a deformation monitoring camera, comprising a rectangular frame, a calibration pattern layer, a lighting layer and a back plate, wherein baffles are provided on the front and sides of the rectangular frame extending inward, the calibration pattern layer, the lighting layer and the back plate are stacked in sequence from front to back in the frame, and a back plate fixing buckle is provided on the back of the frame frame for fixing the back plate.

[0005] Preferably, the lighting layer is made of white EPP foam board, on which a number of LED lamp beads are arranged, and the number of LED lamp beads are respectively connected to the circuit board and the power switch through lines.

[0006] Preferably, there are at least five LED lamp beads, one LED lamp bead is installed in the center of the foam board, and the remaining four LED lamp beads are arranged on the diagonals of the foam board, and the distance from the four LED lamp beads to the center of the foam board is twice the distance from the LED lamp bead to the nearest vertex of the foam board.

[0007] Preferably, the calibration pattern layer is 3 mm thick optical glass with a diffuse reflection coating, and a calibration pattern consisting of black and white squares is printed on the front of the glass. The square side length is 25 mm, the number of rows and columns is 6×9, and the overall pattern size is 150×225 mm.

[0008] Preferably, the backboard is made of cardboard or wood and has a thickness of 3 mm.

[0009] Preferably, there are four back panel fixing buckles, which are respectively installed on the back side of the frame near the four corners. The back panel fixing buckle includes a strip metal limit plate, a fixing pin and a magnet. The fixing pin and the magnet are respectively arranged on two adjacent sides of the frame and close to the right angle of the frame. One end of the limit plate is rotated to connect to the fixing pin, and the other end is rotated and connected to the magnet by magnetic attraction.

[0010] Preferably, the top and bottom ends of the frame frame are respectively provided with fixing plates, hanging holes are provided on the fixing plates, and the fixing plates are rotatably connected to the back of the frame frame. After the fixing plates are rotated inwardly, the fixing plates overlap on the back plate.

[0011] Compared with the prior art, the beneficial effect of the present invention is that the calibration pattern is evenly illuminated by the LED backlight, so that the camera can obtain a clear calibration image even in a dark light environment, which facilitates high-precision calibration work and overcomes the problem that the existing calibration plate relies on external light source illumination and cannot operate in a dark light environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is the overall structure diagram of the calibration board;

[0013] Figure 2 It is a schematic diagram of the front and back sides of the border frame;

[0014] Figure 3 It is a schematic diagram of the calibration pattern layer structure;

[0015] Figure 4 Schematic diagram of the front and back structures of the lighting layer. DETAILED DESCRIPTION

[0016] The present invention will be further explained below in conjunction with the accompanying drawings to facilitate better understanding by those skilled in the art.

[0017] Example 1

[0018] like Figure 1-4 As shown, a luminous calibration plate for calibration of a deformation monitoring camera includes a rectangular frame 1, a calibration pattern layer 2, a lighting layer 3 and a back plate 4. The rectangular frame 1 is made of metal and has a thickness of 1 cm. Baffles 5 are provided on the front and sides of the frame 1 to extend inward. The calibration pattern layer 2, the lighting layer 3 and the back plate 4 are stacked in sequence from front to back in the frame 1. The baffle 5 is abutted against the calibration pattern layer 2. A back plate fixing buckle 6 is provided on the back of the frame 1 to fix the back plate, so that the calibration pattern layer 2, the lighting layer 3 and the back plate 4 are firmly stacked in the frame 1.

[0019] The lighting layer 3 is made of white EPP foam board, on which a number of LED lamp beads 7 are arranged. The LED lamp beads 7 are respectively connected to the circuit board and the power switch through lines, and the power switch is connected to the power battery.

[0020] Furthermore, there are at least five LED lamp beads 7, one LED lamp bead 7 is installed in the center of the foam board, and the remaining four LED lamp beads 7 are arranged on the diagonals of the foam board, and the distance between the four LED lamp beads 7 and the center of the foam board is twice the distance between the LED lamp bead 7 and the nearest vertex of the foam board, which is beneficial for the lighting layer 3 to provide a uniform and stable light source, ensure that the pattern light at various locations on the calibration pattern layer 2 is uniform, and improve the calibration accuracy.

[0021] The calibration pattern layer 2 is a 3mm thick optical glass with a diffuse reflection coating, with a size of 200×275mm. The front of the glass is printed with a calibration pattern consisting of black and white squares in a checkerboard pattern, with a square side length of 25mm, 6×9 rows and columns, and an overall pattern size of 150×225mm. The calibration pattern layer 2 of this structure is conducive to uniform transmission of light sources under the action of the lighting layer 3, so that the camera can obtain clear calibration images even in a dark environment, facilitating high-precision calibration work.

[0022] The back plate 4 is made of cardboard or wood, has a thickness of 3 mm, is lightweight, and has a shielding and protective effect on the lighting layer 3 .

[0023] Furthermore, the back panel fixing buckle 6 is provided with four, which are respectively installed on the back of the frame frame 1 near the four corners. The back panel fixing buckle 6 includes a strip metal limit plate 61, a fixing pin 62 and a magnet 63. The fixing pin 62 and the magnet 63 are respectively arranged on two adjacent sides of the frame frame 1 and at a right angle close to the frame frame 1. One end of the limit plate 61 is rotated to connect the fixing pin 62, and the other end is rotated and magnetically connected to the magnet 63. When in use, the back panel 4, the lighting layer 3 and the calibration pattern layer 2 can be loaded and unloaded by rotating the limit plate 61, which is simple to maintain and easy to use. In addition, the magnet 63 can also enhance the connection stability between the calibration plate and the metal calibration surface.

[0024] A fixing plate 8 is provided at the top and bottom of the border frame 1, respectively. A hanging hole is provided on the fixing plate 8, and the calibration plate is fixed at a set position through the hanging hole. The fixing plate 8 is rotatably connected to the back of the border frame 1. After the fixing plate 8 is rotated inward, the fixing plate 8 overlaps on the back plate 4 to prevent the fixing plate 8 from extending out and scratching the staff, and is convenient for storage.

[0025] Instructions for use: When working, rotate the limit plate 61 and the fixing plate 8 outward, open the back plate 4, install the power battery of the lighting layer 3, close the back plate 4 and gently press it, rotate the limit plate 61 inward until the movable end of the limit plate 61 is adsorbed by the magnet 63, limit and fix the back plate 4, use ropes or screws to fix the calibration plate at the set position through the hanging hole of the fixing plate 8, turn on the lighting power switch, and then you can calibrate the camera. After the end, turn off the power switch.

[0026] The above-mentioned embodiments are only for describing the preferred implementation of the utility model, and are not intended to limit the scope of the utility model. Without departing from the design spirit and principle of the utility model, various modifications and improvements made by those skilled in the art to the technical solution of the utility model shall fall within the protection scope determined by the claims of the utility model.

Claims

1. A luminous calibration plate for calibration of a deformation monitoring camera, characterized in that: The invention comprises a rectangular frame (1), a marking pattern layer (2), an illumination layer (3) and a back plate (4); the front of the rectangular frame (1) is provided with baffles (5) extending inwardly around the front, the marking pattern layer (2), the illumination layer (3) and the back plate (4) are stacked in sequence from front to back in the frame (1); and the back of the frame (1) is provided with a back plate fixing buckle (6) for fixing the back plate (4).

2. The luminous calibration plate for calibration of a deformation monitoring camera according to claim 1, characterized in that: The lighting layer (3) is made of a white EPP foam board, on which a plurality of LED lamp beads (7) are arranged, and the plurality of LED lamp beads (7) are respectively connected to the circuit board and the power switch via lines.

3. The luminous calibration plate for calibration of a deformation monitoring camera according to claim 2, characterized in that: At least five LED lamp beads (7) are provided, one LED lamp bead (7) is installed in the center of the foam board, and the remaining four LED lamp beads (7) are arranged on the diagonals of the foam board respectively, and the distance between the four LED lamp beads (7) and the center of the foam board is twice the distance between the LED lamp bead (7) and the nearest vertex of the foam board.

4. The luminous calibration plate for calibration of a deformation monitoring camera according to claim 1, characterized in that: The calibration pattern layer (2) is an optical glass with a thickness of 3 mm and a diffuse reflection coating. A calibration pattern in the form of a checkerboard composed of black and white squares is printed on the front of the glass. The side length of the square is 25 mm, the number of rows and columns is 6×9, and the overall pattern size is 150×225 mm.

5. The luminous calibration plate for calibration of a deformation monitoring camera according to claim 1, characterized in that: The backboard (4) is made of cardboard or wood and has a thickness of 3 mm.

6. The luminous calibration plate for calibration of a deformation monitoring camera according to claim 1, characterized in that: There are four back panel fixing buckles (6) which are respectively mounted on the back side of the frame frame (1) near the four corners. The back panel fixing buckles (6) comprise a strip-shaped metal limiting plate (61), a fixing pin (62) and a magnet (63). The fixing pin (62) and the magnet (63) are respectively arranged on two adjacent sides of the frame frame (1) and at right angles close to the frame frame (1). One end of the limiting plate (61) is rotatably connected to the fixing pin (62), and the other end is magnetically connected to the magnet (63) after rotation.

7. The luminous calibration plate for calibration of a deformation monitoring camera according to claim 1, characterized in that: The top and bottom ends of the frame frame (1) are respectively provided with fixing plates (8), and the fixing plates (8) are provided with hanging holes. The fixing plates (8) are rotatably connected to the back of the frame frame (1). After the fixing plates (8) are rotated inwards, the fixing plates (8) overlap on the back plate (4).

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