A device for indoor calibration with binocular camera

Abstract

This utility model patent discloses a device for indoor calibration of a binocular camera, mainly comprising: a camera guide rail, a support, an adjustment turntable, and a mounting turntable. It can be used for indoor calibration of a binocular camera, a collimator, an electronic theodolite, and a computer. This utility model allows the binocular camera to translate along its horizontal axis on the camera guide rail. The design of the support and adjustment turntable provides the mounting turntable, which houses the collimator and electronic theodolite, with three degrees of rotational freedom. Furthermore, the design of the mounting turntable allows for adjustment of the mounting height of the collimator and electronic theodolite. This device can assist in building a binocular vision system and is compatible with binocular cameras or optical instruments of different specifications for indoor calibration within a certain distance, exhibiting good versatility.

Description

Technical Field

[0001] This utility model relates to a device for indoor calibration in conjunction with a binocular camera, belonging to the field of binocular calibration. Technical Background

[0002] Binocular vision systems are widely used in many fields due to their ability to perform three-dimensional spatial coordinate measurements, their rapid measurement capabilities, and their non-contact nature. The core of setting up a binocular vision system lies in calibrating the binocular cameras used in the system to obtain the necessary system parameters. Existing calibration methods can be divided into indoor calibration, which aims to set up the binocular cameras, calibrate and acquire the internal parameters of the system, and outdoor calibration, which aims to obtain unknown parameters in the transfer matrix.

[0003] Existing indoor calibration methods for binocular cameras mainly rely on optical instruments such as electronic theodolites and collimators, and use a reticle to simulate targets at infinity to obtain and calculate the intrinsic and extrinsic parameters of the binocular camera, thereby calibrating the camera (refer to Jiang Haijun. Research on Camera Calibration Methods under Large Field of View Conditions [D]. National University of Defense Technology, 2017.). This method mainly calibrates the camera's intrinsic and extrinsic parameters and needs to be performed in both indoor and outdoor environments. Indoor calibration alone yields fewer parameters, while outdoor calibration requires the assistance of a total station. Furthermore, existing baseline distance measurement methods rely on the simultaneous measurement of a prefabricated calibration plate using two electronic theodolites (refer to Li Qingan, Wang Xia, Sun Zhiyuan, Qiao Yanfeng, Zhu Wei. Calibration Research of Binocular CCD Measurement System Based on Electronic Theodolite [J]. Journal of Instrumentation, 2006(S1):188-190.DOI:10.19650 / j.cnki.cjsi.2006.s1.072.). This method requires the simultaneous use of two electronic theodolites and a prefabricated high-flatness glass plate, which places high demands on the equipment and imposes significant limitations on the specifications of the calibrated binocular camera. Moreover, the final baseline distance is obtained through indirect measurement and calculation, lacking intuitiveness.

[0004] Existing methods lack specific working devices to assist in indoor calibration of binocular cameras. Calibration requires precise movement of multiple targets, which can easily lead to accumulated errors in optical instruments due to repeated movements. In addition, the calibration workload is large, and different binocular camera specifications also require their own corresponding calibration systems. Therefore, there is a need for a device that can reduce calibration movement errors and assist in indoor calibration of binocular cameras to address the shortcomings of existing methods. Summary of the Invention

[0005] This invention aims to provide a device for indoor calibration of binocular cameras, solving the problems of existing methods that involve a large workload, easy accumulation of errors, and weak universality for camera specifications. It has reference value for practical engineering.

[0006] To achieve the above objectives, the present invention adopts the following solution:

[0007] This utility model provides a device for indoor calibration of a binocular camera. The device includes a camera guide rail, a support, an adjustment turntable, and a mounting turntable. It can be used with a binocular camera, a collimator, an electronic theodolite, and a computer for indoor calibration of the binocular camera.

[0008] The binocular camera is mounted at both ends of the mounting crossbar, which is mounted in the center of the slider. The slider is placed on the guide rail and can slide along the guide rail.

[0009] The camera rail is placed on the support;

[0010] The adjustable turntable is mounted on an adjustable support;

[0011] The mounting turntable is placed on the adjusting turntable;

[0012] The collimator and electronic theodolite are mounted on an adjustable bracket;

[0013] The computer connects to and controls camera 1 and camera 2 to acquire their imaging information.

[0014] Furthermore, a universal level is installed in the center of the camera guide rail mounting crossbar to control the relative levelness of the two cameras.

[0015] Furthermore, a vernier is connected to the slider, and a scale is connected to the guide rail. The vernier and the scale work together to measure the translation distance.

[0016] Furthermore, the camera guide rail is placed on four mounting posts in the support via four adjusting studs and corresponding nuts at the bottom.

[0017] Furthermore, the adjustable support has two pairs of grooves that engage with two pairs of ridges on the fixed support, and the fixed support has two locking screws for locking the adjustable support.

[0018] Furthermore, the adjustable support has a ball head, and the bottom of the adjusting turntable has a ball joint and a locking screw. The ball head and the ball joint are assembled together and locked by the locking screw.

[0019] Furthermore, the upper part of the adjustment turntable has 3 positioning pins and 1 rotating shaft. The axis of the rotating shaft coincides with the vertical axis of the ball head. The positioning pins are arranged at 90° intervals around the rotating shaft, and the distance from each positioning pin to the rotating shaft is equal.

[0020] Furthermore, the mounting turntable base plate of the mounting turntable has one rotating shaft hole, the position and diameter of which correspond to the rotating shaft, and two positioning holes, the position and diameter of which correspond to two adjacent positioning pins.

[0021] Furthermore, there are two pairs of adjustable brackets, which are fixed on the mounting turntable base plate. The center line between the two brackets of each pair of adjustable brackets coincides with the line connecting the positioning hole below it to the rotating shaft hole.

[0022] Each side of the bracket has a stepped elongated hole with a locking bolt. The locking bolt is used to connect and fix the base of the collimator and electronic theodolite, and can adjust the height of the base on the adjustable bracket.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. This utility model allows for the rapid adjustment of binocular cameras to the same horizontal position by rotating the nut on the adjusting stud, in conjunction with the mounting crossbar and the universal level bubble, which is beneficial for assisting in the construction of a binocular vision system.

[0025] 2. This utility model can intuitively obtain the position degree of the slider before and after movement by combining the vernier and the scale, and then quickly obtain the baseline distance of the binocular camera. The operation is intuitive and simple.

[0026] 3. This invention, through the cooperation of the ball joint and the ball joint, grants the mounting turntable carrying the optical instrument three degrees of rotational freedom; furthermore, through the cooperation of the fixed support and the adjustable support, and the design of the adjustable bracket, it grants the collimator and electronic theodolite degrees of freedom for translation along the horizontal and vertical axes. This invention is compatible with binocular cameras or optical instruments of different specifications, enabling indoor calibration within a certain distance, and has strong versatility.

[0027] 4. This utility model, through the cooperation of positioning pins and positioning holes, allows the electronic theodolite to be rotated to the other side when using a collimator. When the electronic theodolite is needed, it can be rotated back to its original position, reducing the number of times the optical instrument needs to be adjusted and calibrated, improving the error caused by frequent movement and recalibration of the optical instrument, and significantly reducing the related workload. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the device of this utility model.

[0029] Figure 2 This is a schematic diagram of a camera guide rail.

[0030] Figure 3 This is a schematic diagram of the support.

[0031] Figure 4This is a schematic diagram of the adjustable turntable.

[0032] Figure 5 This is a diagram showing the installation of the turntable.

[0033] In the diagram: binocular camera (1), camera 1 (11), camera 2 (12), camera guide rail (2), slider (21), guide rail (22), vernier (23), scale (24), adjusting stud (25), mounting crossbar (26), universal level (27), support (3), fixed support (31), adjustable support (32), ball head (33), locking screw (34), mounting column (35), adjusting turntable (4), positioning pin (41), rotating shaft (42), ball joint (43), locking screw (44), adjusting turntable base plate (45), mounting turntable (5), mounting turntable base plate (51), adjustable bracket (52), locking bolt (53), rotating shaft hole (54), positioning hole (55), collimator (6), electronic theodolite (7), computer (8). Detailed Implementation

[0034] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments:

[0035] like Figure 1 As shown, this utility model provides a device for indoor calibration of a binocular camera. The device includes a camera guide rail (2), a support (3), an adjustment turntable (4), and a mounting turntable (5). It can be used with a binocular camera (1), a collimator (6), an electronic theodolite (7), and a computer (8) for indoor calibration of the binocular camera. Specifically: the binocular camera (1) is the object to be set up and calibrated; the camera guide rail (2) supports the binocular camera (1), allowing it to move along the guide rail, and can also assist in measuring the baseline distance. The binocular camera (1) is adjusted to a horizontal state using a universal level bubble (27); the support (3) connects all parts of the device, providing support for the device, and simultaneously... The adjustment turntable (4) can provide conditions for longitudinal movement; the adjustment turntable (4) is responsible for supporting the installation turntable (5) and connecting itself to the support (3), while providing three rotational degrees of freedom for the installation turntable (5); the installation turntable (5) is responsible for installing optical instruments and providing conditions for them to move along the vertical axis, while the installation turntable (5) can rotate around the axis (42); the collimator (6) is responsible for providing a parallel light source to assist in the construction of the binocular vision system; the electronic theodolite (7) is responsible for leveling the camera and assisting in the calibration of the binocular camera; the computer (8) connects to and controls camera 1 (11) and camera 2 (12) to obtain the imaging information of the above two cameras and assist in the calibration of the binocular camera.

[0036] like Figure 2As shown, a gimbal level (27) is installed in the center of the mounting bar (26) to ensure that the binocular camera (1) is in a horizontal position. Camera 1 (11) and camera 2 (12) are installed at both ends of the mounting bar (26). The upper and lower end faces of the cameras, the upper end face of the mounting bar (26), and the bottom face of the gimbal level (27) are parallel to each other.

[0037] The binocular camera (1) is fixed in the center of the slider (21) by means of a mounting bar (26).

[0038] like Figure 3 As shown, a vernier (23) is connected to the slider (21), and a ruler (24) is connected to the guide rail (22). The zero mark of the vernier (23) and the center line of the binocular camera (1) are in the same vertical plane. The vernier (23) and the ruler (24) work together to measure distance with an accuracy of 0.02 mm.

[0039] The camera rail (2) is placed on the four mounting posts (35) in the support (3) by four adjusting studs (25) at the bottom and corresponding nuts. The height of the camera rail can be adjusted or it can be adjusted to a horizontal position by rotating the nuts.

[0040] like Figure 4 As shown, the adjustable support (32) has two pairs of grooves that engage with the two pairs of ridges on the fixed support (31). The fixed support (31) has two locking screws (34) for locking the adjustable support (32). When it is necessary to change the extension length of the adjustable support (32), first loosen the locking screws (34), then pull out or retract the adjustable support (32), and finally tighten the locking screws (34) to fix it.

[0041] The adjustable support (32) has a ball head (33) at its end, which is engaged with the ball joint (43) at the bottom of the adjustable turntable (4) and fixed by a locking screw (44); this method gives the adjustable turntable (4) and the mounting turntable (5) on which the optical instrument is mounted three degrees of rotational freedom while connecting the adjustable turntable (4) to the adjustable support (32).

[0042] like Figure 5 As shown, the upper part of the adjustment turntable (4) has 3 positioning pins (41) and 1 rotating shaft (42). The axis of the rotating shaft (42) coincides with the vertical axis of the ball head (33). The positioning pins (41) are arranged at 90° intervals with the rotating shaft (42) as the center, and the distance from each positioning pin (41) to the rotating shaft (42) is equal. The mounting turntable base plate (51) of the mounting turntable (5) has 1 rotating shaft hole (54) with the position and diameter corresponding to the rotating shaft (42). The mounting turntable base plate (51) has 2 positioning holes (55) with the position and diameter corresponding to the 2 adjacent positioning pins (41).

[0043] In actual use, the pivot hole (54) coincides with the pivot (42), and the two positioning holes (55) coincide with the two adjacent positioning pins (41) (e.g. Figure 5 First, align the right and middle positioning pins with the positioning holes to fix the mounting turntable (5) on the adjusting turntable (4); when conversion is needed, lift the mounting turntable (5) and rotate it 90° so that the positioning holes coincide with other positioning pins (e.g., Figure 5 At this point, the positioning pins on the left and in the middle coincide with the positioning holes, thus completing the conversion of the optical instrument.

[0044] like Figure 5 As shown, there are two pairs of adjustable brackets (52), which are fixed on the mounting turntable base plate (51). The center line between the two brackets of each pair of adjustable brackets (52) coincides with the line connecting the positioning hole (55) below it to the pivot hole (54). This design ensures that even if the mounting turntable (5) is rotated, the axis of the optical instrument mounted on the adjustable bracket (52) can still point towards the binocular camera (1) along the longitudinal axis.

[0045] Each side of the bracket has a stepped elongated hole and a locking bolt (53). The locking bolt is used to connect and fix the base of the collimator (6) and the electronic theodolite (7), and can adjust the height of the base on the adjustable bracket (52). When the locking bolt (53) is tightened, the base of the collimator or the electronic theodolite can be locked at any position within the length limit of the elongated hole. When the locking bolt (53) is loosened, the base can move within the length limit of the elongated hole, thereby adjusting the height of the base on the adjustable bracket (52).

[0046] The general steps for setting up and calibrating a binocular vision system using this device are as follows:

[0047] S1) Arrange this device indoors, and install the mounting crossbar (26), camera rail (2), support (3), adjustment turntable (4), and mounting turntable (5) according to... Figure 1 Install according to the diagram, rotate the corresponding nut on the adjusting stud (25), adjust the bubble of the universal level bubble (27) to be in the center, so that the installation crossbar (26) is in a horizontal state;

[0048] S2) Install camera 1 (11) on the mounting bar (26), and move the slider (21) to roughly move the camera to the center of the camera guide rail (2). Install the electronic theodolite (7) on the adjustable bracket (52) facing the camera guide rail (2), and adjust the height of the base so that the lens of camera 1 (11) and the lens of the electronic theodolite (7) are at the same height;

[0049] S3) Using the outer end face of the mounting bar (26) as a reference, adjust the position of camera 1 (11) with an electronic theodolite to ensure that the lens mounting end face of camera 1 (11) is parallel to the outer end face of the mounting bar (26) and fix the mounting position of camera 1 (11) relative to the mounting bar (26).

[0050] S4) Rotate the mounting turntable (5) 90° so that another pair of adjustable brackets (52) face the camera guide rail (2) and install the collimator (6) on the bracket so that the lens of the collimator (6) is at approximately the same height as the lens of camera 1 (11).

[0051] S5) Connect camera 1 (11) to computer (8). The computer generates a bright spot at the center of the field of view of camera 1 (11). Turn on the collimator (6). By adjusting the height of the base of the collimator (6) on the adjustable bracket (52) and simultaneously adjusting the rotation of the turntable (4) around the ball head (33), the star image of the collimator (6) is imaged at the center of the field of view of camera 1 (11). That is, the bright spot and the star image are made to coincide in the image displayed on the computer.

[0052] S6) Keeping the position and orientation of the collimator (6) determined in S5) unchanged, mount camera 2 (12) on the mounting crossbar (26) and connect it to the computer (8). Move the slider (21) so that the star image of the collimator (6) enters the field of view of camera 2 (12), and adjust the mounting orientation of camera 2 (12) so that the star image of the collimator (6) coincides with the bright spot at the center of the field of view of camera 2 (12);

[0053] S7) Rotate the mounting turntable (5) 90° back and move the slider (21) so that the electronic theodolite (7) is facing the camera (11) again. Remove the lenses of the two cameras, adjust the electronic theodolite (7) so that the crosshair it emits is centered in the field of view of the camera (11), and record the degree of the vernier (23) on the scale (24) at this time. Move the slider (21) until the crosshair is centered in the field of view of camera 2 (12), and record the degree of the vernier (23) on the scale (24) at this time. ;

[0054] The baseline distance of the binocular camera as specified in S8) Represented as: ;

[0055] As can be seen from the above, this utility model can assist in the construction of a binocular vision system and perform indoor calibration of binocular cameras, which can provide a certain reference for engineering practice.

[0056] The above description is only a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or modifications made by those skilled in the art within the spirit and principles of this utility model should be covered within the patent scope of this utility model.

Claims

1. An apparatus for indoor calibration with a binocular camera, characterized in that, The device includes a camera guide rail (2), a support (3), an adjustment turntable (4), and a mounting turntable (5), and can be used with a binocular camera (1), a collimator (6), an electronic theodolite (7), and a computer (8) for indoor binocular aiming, wherein: The binocular camera (1) includes camera 1 (11) and camera 2 (12). The camera guide rail (2) includes a slider (21), a guide rail (22), a vernier (23), a scale (24), an adjusting stud (25), a mounting crossbar (26), and a universal level (27). The support (3) includes a fixed support (31), an adjustable support (32), a ball joint (33), a locking screw (34), and a mounting post (35). The adjusting turntable (4) includes a positioning pin (41), a rotating shaft (42), a ball joint (43), a locking screw (44), and an adjusting turntable base plate (45). The mounting turntable (5) includes a mounting turntable base plate (51), an adjustable bracket (52), a locking bolt (53), a rotating shaft hole (54), and a positioning hole (55). The binocular camera (1) is installed at both ends of the mounting crossbar (26), the mounting crossbar (26) is installed in the center of the slider (21), and the slider (21) is placed on the guide rail (22) and can slide along the guide rail (22); The camera guide rail (2) is placed on the support (3); The adjustable turntable (4) is mounted on the adjustable support (32); The mounting turntable (5) is placed on the adjusting turntable (4); The collimator (6) and the electronic theodolite (7) are mounted on an adjustable bracket (52); The computer (8) connects to and controls camera 1 (11) and camera 2 (12) to acquire their imaging information.

2. The device for indoor calibration in conjunction with a binocular camera according to claim 1, characterized in that, The camera guide rail (2) has a universal level bubble (27) in the center of the mounting crossbar (26).

3. The device for indoor calibration in conjunction with a binocular camera according to claim 1, characterized in that, A vernier (23) is connected to the slider (21); a ruler (24) is connected to the guide rail (22); the vernier (23) and the ruler (24) cooperate to measure the translation distance.

4. The device for indoor calibration in conjunction with a binocular camera according to claim 1, characterized in that, The camera guide rail (2) is mounted on the four mounting posts (35) in the support (3) by four adjusting studs (25) at the bottom and corresponding nuts.

5. The apparatus for indoor calibration in conjunction with a binocular camera according to claim 1, characterized in that, The adjustable support (32) has two pairs of grooves that engage with the two pairs of ridges on the fixed support (31); the fixed support (31) has two locking screws (34) for locking the adjustable support (32).

6. The apparatus for indoor calibration in conjunction with a binocular camera according to claim 1, characterized in that, The adjustable support (32) has a ball head (33); the bottom of the adjustable turntable (4) has a ball joint (43) and a locking screw (44). The ball head (33) is assembled with the ball joint (43) and locked by the locking screw (44).

7. The apparatus for indoor calibration in conjunction with a binocular camera according to claim 1, characterized in that, The upper part of the adjustment turntable (4) has 3 positioning pins (41) and 1 rotating shaft (42). The axis of the rotating shaft (42) coincides with the axis of the ball head (33) in the vertical direction. The positioning pins (41) are arranged at 90° intervals with the rotating shaft (42) as the center, and the distance from each positioning pin (41) to the rotating shaft (42) is equal.

8. The apparatus for indoor calibration in conjunction with a binocular camera according to claim 1, characterized in that, The mounting turntable (5) has a rotating shaft hole (54) on its mounting turntable base plate (51), the position and diameter of which correspond to the rotating shaft (42); the mounting turntable base plate (51) has two positioning holes (55), the position and diameter of which correspond to the two adjacent positioning pins (41).

9. The apparatus for indoor calibration in conjunction with a binocular camera according to claim 1, characterized in that, There are two pairs of adjustable brackets (52), which are fixed on the mounting turntable base plate (51). The center line between the two brackets of each pair of adjustable brackets (52) coincides with the line connecting the positioning hole (55) below it to the rotating shaft hole (54). Each side of the bracket has a stepped elongated hole and a locking bolt (53); the locking bolt (53) is used to connect and fix the base of the parallel light tube (6) and the electronic theodolite (7), and can adjust the height of the base on the adjustable bracket (52).

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