Automatic checkerboard calibration mechanism
By designing an automatic calibration mechanism including a base, a turret, a swing frame and a rotating disk, and using a drive motor to control the movement of these components, the problems of position adjustment error and incomplete coverage of the field of view of the calibration plate in the existing technology are solved, achieving High-precision and efficient automatic calibration.
Patent Information
- Application Number
- CN202421042517.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-14
- Publication Date
- 2025-01-24
- Estimated Expiration
- 2034-05-14
AI Technical Summary
In the prior art, in the checkerboard calibration timing, there is an error in the calibration plate position adjustment, which affects the calibration accuracy, and manual adjustment of the bracket angle is time-consuming and cannot fully cover the field of view angle.
Design an automatic calibration mechanism that includes a base, rotating frame, swinging rack, and rotating disc. The movement of these components can be controlled by driving the motor to form a mechanical arm support with a degree of free, and the position of the calibration board is automatically adjusted.
The stable movement of the calibration board is achieved, avoiding the error caused by manual adjustment, which can completely cover the shooting perspective, and improve the calibration accuracy and efficiency.
Smart Images
Figure CN222394375U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of chessboard automatic calibration, in particular to a chessboard automatic calibration mechanism. Background Art
[0002] When shooting some high-precision scenes, holding the calibration plate will cause shaking, which reduces the accuracy of the shooting and increases the error manually. When shooting with a fixed bracket, the bracket angle must be adjusted every time the shot is taken. Frequent adjustment of the bracket angle increases the shooting time and fails to cover the FOV at multiple angles. There are errors when holding the calibration plate manually or using a fixed bracket to fix the calibration plate.
[0003] Introduction to proper nouns:
[0004] Checkerboard: The black and white rectangular grid pattern on the chessboard is a commonly used graphic pattern.
[0005] Calibration: Since each camera lens has errors during the production and assembly process, the degree of distortion of each lens varies. Camera calibration can correct this lens distortion and generate a corrected image - corrected lens distortion. Another method is to establish a camera imaging geometry model based on the camera parameters obtained after calibration, and reconstruct the three-dimensional scene from the obtained image.
[0006] FOV (Field of view): The field of view of the camera.
[0007] In summary, the applicant has found that the prior art has at least the following technical problems:
[0008] When performing chessboard calibration, the calibration plate position is adjusted manually in the prior art, and there is an error in the fixed position of the calibration plate. Utility Model Content
[0009] The utility model aims to provide a chessboard automatic calibration mechanism to solve the problem of error in position adjustment of the calibration plate in the prior art.
[0010] The various technical effects that can be produced by the preferred technical solution among the various technical solutions provided by the utility model are described in detail below.
[0011] In order to solve the above technical problems, the utility model provides the following technical solutions:
[0012] The utility model provides an automatic chessboard calibration mechanism, comprising a base, a rotating frame, a swing frame and a rotating disk which are sequentially connected from bottom to top; the base is rotatably connected to the rotating frame; the swing frame is rotatably connected to the rotating frame, and the position where the swing frame is connected to the rotating frame is perpendicular to the position where the base is connected to the rotating frame; the rotating disk is rotatably connected to the swing frame, and the position where the rotating disk is connected to the swing frame is perpendicular to the position where the rotating frame is connected to the swing frame; driving motors are respectively installed on the rotating frame, the swing frame and the rotating disk, and the rotation of the rotating frame, the swing frame and the rotating disk are all controlled and driven by the driving motor; a calibration installation surface is provided on the rotating disk, and a calibration plate is installed on the calibration installation surface.
[0013] In one embodiment, the base rotates relative to the rotating frame, and the rotating frame rotates left and right in the horizontal direction; the rotating frame rotates relative to the swing frame, and the swing frame swings up and down in the vertical direction; the rotating disk rotates relative to the swing frame with its own center as the rotation axis.
[0014] In one embodiment, the base is provided with a fixed side and a connecting side, and the fixed side is connected to the plane to be fixed; the rotating frame is provided with a rotating surface and a swinging surface; the rotating surface is rotatably connected to the connecting side; the swinging frame is provided with a swinging side and a rotating side; the swinging side is rotatably connected to the swinging surface; the rotating disk is provided with a rotating surface and the calibration mounting surface which are arranged opposite to each other; the rotating surface is rotatably connected to the rotating side.
[0015] In one embodiment, the driving motor includes a rotary motor, a swing motor and a rotating motor; the rotary motor is mounted on the rotating frame, and the output shaft of the rotary motor passes through the rotating surface and is fixedly connected to the connecting side; the swing motor is mounted on the swing frame, and the output shaft of the swing motor is coaxially arranged with the position where the swing surface and the swing side are rotationally connected, and the output shaft of the swing motor is fixedly connected to the swing surface; the rotating motor is mounted on the swing frame, and the output shaft of the rotating motor is fixedly connected to the rotating surface.
[0016] In one embodiment, the rotary motor, the swing motor and the rotating motor are all servo motors.
[0017] In one embodiment, the swing frame includes a mounting plate and a fixed swing arm; one side of the mounting plate is the rotating side, and the other side of the mounting plate is the arm-mounted side, and the arm-mounted side is connected and fixed to the fixed swing arm; there are two fixed swing arms, and the two fixed swing arms are arranged opposite to each other, and the swing side is provided on the inner sides of the two fixed swing arms, and the rotating frame is rotatably mounted between the two fixed swing arms; the swing motor is mounted on the arm-mounted side, and the rotating motor is mounted on the rotating side.
[0018] In one of the embodiments, a limit plate is provided on the arm-mounted side, the limit plate protrudes outward from the arm-mounted side, and the side surface of the limit plate in the thickness direction is arranged adjacent to the swing motor, and the limit plate is used to limit the rotation of the body of the swing motor.
[0019] The beneficial effects of the utility model are as follows:
[0020] When the calibration plate is held in the hand, the calibration plate shakes due to the shaking of the human body, which affects the calibration accuracy. The present invention sets a base, a rotating frame, a swing frame and a rotating disk which are connected in sequence from bottom to top. The rotating frame, the swing frame and the rotating disk are respectively equipped with driving motors, and the rotation of the rotating frame, the swing frame and the rotating disk are all controlled and driven by the driving motors. A stable mechanical arm bracket with three degrees of freedom is formed, and the movement of the calibration plate installed on the rotating disk is driven by the driving motor. The calibration plate is stably moved by mechanical control without manual intervention, so that the calibration plate is prevented from shaking during the movement. At the same time, the field of view (FOV) of the shooting is fully covered, and an automatic calibration method is realized. The movement of the driving motor is set by the control program, and the movement trajectory of the rotating frame, the swing frame and the rotating disk is controlled to automatically adjust the position of the calibration plate. This solves the problem of shaking caused by handheld shooting, and also solves the problem that manual shooting may not fully cover the shooting field of view (FOV). BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the implementation mode will be briefly introduced below. Obviously, the drawings described below are only some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0022] Figure 1 It is a schematic diagram of the overall pitch axonometric structure of the utility model;
[0023] Figure 2 It is a schematic diagram of the overall structure of the utility model;
[0024] Figure 3It is the overall axonometric drawing of the utility model;
[0025] Figure 4 It is a front view schematic diagram of the calibration plate of the utility model.
[0026] The reference numerals are as follows:
[0027] 1. Base; 11. Fixed side; 12. Connection side;
[0028] 2. rotating frame; 21. rotating surface; 22. swinging surface;
[0029] 3. Swing frame; 31. Mounting plate; 311. Arm mounting side; 312. Rotation side; 32. Fixed swing arm; 321. Swing side; 33. Limit plate; 34. Motor guard plate;
[0030] 4. Rotating disk; 41. Calibration mounting surface; 42. Rotating surface;
[0031] 5. Calibration plate;
[0032] 6. Drive motor; 61. Rotary motor; 62. Swing motor; 63. Rotary motor. DETAILED DESCRIPTION
[0033] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.
[0034] The existing checkerboard calibration technology, when performing calibration, uses a hand-held calibration plate 5 or mounts the calibration plate 5 on a fixed bracket, but there are certain disadvantages; when holding the calibration plate 5, the calibration plate 5 will shake due to human body shaking, which affects the calibration accuracy; when the calibration plate 5 is mounted on a fixed bracket, the position of the bracket needs to be adjusted frequently and multiple times, which is inconvenient to use, and there is also a problem that the camera field of view (FOV) may not be fully covered.
[0035] In order to solve the above problems, an implementation of the automatic checkerboard calibration mechanism is as follows: Figures 1 to 4 As shown, it includes a base 1, a rotating frame 2, a swing frame 3 and a rotating disk 4 which are connected in sequence from bottom to top; the base 1 is rotatably connected to the rotating frame 2; the swing frame 3 is rotatably connected to the rotating frame 2, and the position where the swing frame 3 is connected to the rotating frame 2 is perpendicular to the position where the base 1 is connected to the rotating frame 2; the rotating disk 4 is rotatably connected to the swing frame 3, and the position where the rotating disk 4 is connected to the swing frame 3 is perpendicular to the position where the rotating frame 2 is connected to the swing frame 3; the rotating frame 2, the swing frame 3 and the rotating disk 4 are respectively installed with a driving motor 6, and the rotation of the rotating frame 2, the rotation of the swing frame 3 and the rotation of the rotating disk 4 are all controlled and driven by the driving motor 6; the rotating disk 4 is provided with a calibration mounting surface 41, and the calibration plate 5 is installed on the calibration mounting surface 41.
[0036] Among them, the checkerboard pattern of the calibration plate 5 is as follows: Figure 4 As shown, the installation of the calibration plate 5 is as follows Figure 3 As shown, by photographing the checkerboard pattern of the calibration plate 5, using the single-plane checkerboard camera calibration method of "Zhang Zhengyou Calibration", multiple photos of the calibration plate 5 located at different positions are taken, and the taken photos are recognized by the set program algorithm to complete the calibration.
[0037] The present invention sets a base 1, a rotating frame 2, a swing frame 3 and a rotating disk 4 which are connected in sequence from bottom to top; and a driving motor 6 is respectively installed on the rotating frame 2, the swing frame 3 and the rotating disk 4, and the rotation of the rotating frame 2, the swing frame 3 and the rotating disk 4 are all controlled and driven by the driving motor 6; a stable mechanical arm bracket with three degrees of freedom is formed, and the movement of the calibration plate 5 installed on the rotating disk 4 is controlled and driven by the driving motor 6, and the calibration plate 5 is stably moved by mechanical control without manual intervention, so as to avoid the calibration plate 5 from shaking during the movement, and at the same time, the shooting angle of view (FOV) is fully covered, and an automatic calibration method is realized. The movement of the driving motor 6 is set by the control program, and the movement trajectory of the rotating frame 2, the swing frame 3 and the rotating disk 4 is controlled, and the position of the calibration plate 5 is automatically adjusted, so as to solve the problem of shaking caused by handheld shooting, and at the same time, it also solves the problem that manual shooting may not fully cover the shooting angle of view (FOV).
[0038] As an optional implementation,
[0039] Regarding the movement modes of the base 1, the rotating frame 2, the swing frame 3 and the rotating disk 4, this embodiment is as follows: Figures 1 to 4 As shown, as indicated by the direction of the arrow in the figure, the base 1 and the rotating frame 2 rotate relative to each other, and the rotating frame 2 rotates left and right in the horizontal direction; the rotating frame 2 and the swing frame 3 rotate relative to each other, and the swing frame 3 swings up and down in the vertical direction; the rotating disk 4 rotates relative to the swing frame 3 with its own center as the rotation axis.
[0040] Regarding the specific connection positions of the base 1, the rotating frame 2, the swing frame 3 and the rotating disk 4, this embodiment is as follows: Figure 1 and Figure 2 As shown, the base 1 is provided with a fixed side 11 and a connecting side 12, and the fixed side 11 is connected to the plane to be fixed; the rotating frame 2 is provided with a rotating surface 21 and a swinging surface 22; the rotating surface 21 is rotatably connected to the connecting side 12; the swinging frame 3 is provided with a swinging side 321 and a rotating side 312; the swinging side 321 is rotatably connected to the swinging surface 22; the rotating disk 4 is provided with a rotating surface 42 and a calibrated mounting surface 41 which are arranged opposite to each other; the rotating surface 42 is rotatably connected to the rotating side 312.
[0041] Regarding the specific configuration of the driving motor 6, this embodiment Figure 1 and Figure 2 As shown, the driving motor 6 includes a rotary motor 61, a swing motor 62 and a rotating motor 63; the rotary motor 61 is mounted on the rotating frame 2, and the output shaft of the rotary motor 61 passes through the rotating surface 21 and is fixedly connected to the connecting side 12; the swing motor 62 is mounted on the swing frame 3, and the output shaft of the swing motor 62 is coaxially arranged with the position where the swing surface 22 and the swing side 321 are rotationally connected, and the output shaft of the swing motor 62 is fixedly connected to the swing surface 22; the rotating motor 63 is mounted on the swing frame 3, and the output shaft of the rotating motor 63 is fixedly connected to the rotating surface 42.
[0042] Regarding the specific types of the above-mentioned rotary motor 61, swing motor 62 and rotating motor 63, the rotary motor 61, swing motor 62 and rotating motor 63 are all servo motors.
[0043] Furthermore, the servo motor adopts a steering gear. Specifically, the steering gear includes an electric steering gear and an electric hydraulic steering gear; in order to facilitate control and reduce the use cost, the steering gear adopts an electric steering gear, which is electrically connected to the electric steering gear through a servo controller, and the servo realizes high-precision angle rotation control.
[0044] Regarding the specific structure of the swing frame 3, this embodiment Figure 1 and Figure 2 As shown, the swing frame 3 includes a mounting plate 31 and a fixed swing arm 32; one side of the mounting plate 31 is a rotating side 312, and the other side of the mounting plate 31 is an arm-mounted side 311, and the arm-mounted side 311 is connected and fixed to the fixed swing arm 32; there are two fixed swing arms 32, and the two fixed swing arms 32 are arranged opposite to each other, and the inner sides of the two fixed swing arms 32 are provided with a swing side 321, and a rotating frame 2 is rotatably installed between the two fixed swing arms 32; the swing motor 62 is installed on the arm-mounted side 311, and the rotating motor 63 is installed on the rotating side 312.
[0045] Because the output shaft of the swing motor 62 is coaxially arranged with the position where the swing surface 22 and the swing side 321 are rotatably connected, the swing frame 3 is used as the action end. In order to make the torque borne by the swing frame 3 more uniform, this embodiment is as follows. Figure 1 and Figure 2 As shown, a limit plate 33 is provided on the arm mounting side 311, the limit plate 33 protrudes outward from the arm mounting side 311, and the side surface of the limit plate 33 in the thickness direction is arranged adjacent to the swing motor 62, and the limit plate 33 is used to limit the rotation of the body of the swing motor 62. The limit plate 33 is in contact with the body of the swing motor 62, and when the output shaft of the swing motor 62 is relatively fixed, the body of the swing motor 62 drives the swing frame 3 to swing, so that one end of the fixed swing arm 32 rotates around the swing surface 22 of the rotating frame 2, thereby realizing the pitch swing of the swing frame 3.
[0046] Preferably, in order to better fix the body of the rotating motor 63, the rotation of the rotating disk 4 is more stable; Figure 2 As shown, motor guard plates 34 are provided on both sides of the rotating side 312 of the mounting plate 31 , and the motor guard plates 34 are connected and fixed to the rotating side 312 .
[0047] In addition, the servo motor (servo) is composed of a standard DC system and an internal feedback control device (a reduction gear and potentiometer). The main function of the servo motor (servo) is to rotate the gear shaft to a predefined direction. The servo motor (servo) has 3 input pins, GND, VCC and Signal.
[0048] When the application is carried out, after the control rotary motor 61, the swing motor 62 and the rotating motor 63 are installed, Figure 1 As shown, the calibration plate 5 can rotate along three axes, namely, X (simulating rotation along the longitudinal axis of the calibration plate 5), Y (simulating rotation along the transverse axis of the calibration plate 5), and Z (rotation along the center of the calibration plate 5); and then the single-chip microcomputer equipped with the motor control program is electrically connected to the rotary motor 61, the swing motor 62, and the rotating motor 63.
[0049] The driving motor 6 performs a cyclic action as follows: the rotary motor 61 rotates 5 times, from left to right, with a signal interval of 2 and each rotation degree; the swing motor 62 rotates 3 times, from front to back, with a signal interval of 4 and each rotation degree; the rotating motor 63 rotates 3 times, from top to bottom, with a signal interval of 3 and each rotation degree; the rotation sequence is that after the rotary motor 61 rotates once from left to right, the swing motor 62 rotates once from pitch, and the rotating motor 63 rotates 3 times from the center of the rotating disk as one cycle; the photographing calibration is performed in sequence until the rotary motor 61 rotates five times, a total of 45 photos are taken, and the calibrated photographing steps are completed.
[0050] The above is a preferred embodiment of the utility model. It should be noted that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the utility model, and these improvements and modifications are also considered to be within the protection scope of the utility model. Therefore, the protection scope of the utility model shall be based on the protection scope of the claims.
Claims
1. A chessboard automatic calibration mechanism, characterized in that: It includes a base, a rotating frame, a swing frame and a rotating disk which are sequentially connected from bottom to top; The base is rotatably connected to the rotating frame; The swing frame is rotatably connected to the rotating frame, and the position where the swing frame is connected to the rotating frame is perpendicular to the position where the base is connected to the rotating frame; The rotating disk is rotatably connected to the swing frame, and the position where the rotating disk is connected to the swing frame is perpendicular to the position where the rotating frame is connected to the swing frame; The rotating frame, the swing frame and the rotating disk are respectively equipped with driving motors, and the rotation of the rotating frame, the swing frame and the rotating disk are all controlled and driven by the driving motors; The rotating disk is provided with a calibration installation surface, and a calibration plate is installed on the calibration installation surface.
2. The automatic checkerboard calibration mechanism according to claim 1, characterized in that: The base and the rotating frame rotate relative to each other, and the rotating frame rotates left and right in the horizontal direction; The rotating frame and the swing frame rotate relative to each other, and the swing frame swings up and down in the vertical direction; The rotating disk rotates relative to the swing frame with its own center as the rotation axis.
3. The automatic checkerboard calibration mechanism according to claim 2, characterized in that: The base is provided with a fixing side and a connecting side, and the fixing side is connected to the plane to be fixed; The rotating frame is provided with a rotating surface and a swinging surface; the rotating surface is rotatably connected to the connecting side; The swing frame is provided with a swing side and a rotation side; the swing side is rotationally connected to the swing surface; The rotating disk is provided with a rotating surface and the calibration installation surface which are arranged opposite to each other; the rotating surface is rotatably connected to the rotating side.
4. The automatic checkerboard calibration mechanism according to claim 3, characterized in that: The driving motor includes a rotary motor, a swing motor and a rotating motor; The rotary motor is mounted on the rotating frame, and the output shaft of the rotary motor passes through the rotating surface and is connected and fixed to the connecting side; The swing motor is mounted on the swing frame, the output shaft of the swing motor is coaxially arranged with the position where the swing surface and the swing side are rotatably connected, and the output shaft of the swing motor is fixedly connected with the swing surface; The rotating motor is mounted on the swing frame, and the output shaft of the rotating motor is connected and fixed to the rotating surface.
5. The automatic checkerboard calibration mechanism according to claim 4, characterized in that: The rotary motor, the swing motor and the rotating motor are all servo motors.
6. The automatic checkerboard calibration mechanism according to claim 4, characterized in that: The swing frame includes a mounting plate and a fixed swing arm; One side of the mounting plate is the rotating side, and the other side of the mounting plate is the arm-mounted side, and the arm-mounted side is connected and fixed to the fixed swing arm; There are two fixed swing arms, which are arranged opposite to each other, the inner sides of the two fixed swing arms are provided with the swing side, and the rotating frame is rotatably installed between the two fixed swing arms; The swing motor is mounted on the arm-mounted side, and the rotation motor is mounted on the rotating side.
7. The automatic checkerboard calibration mechanism according to claim 6, characterized in that: A limit plate is provided on the arm-mounted side, the limit plate protrudes outward from the arm-mounted side, and a side surface of the limit plate in a thickness direction is arranged adjacent to the swing motor, and the limit plate is used to limit the rotation of the body of the swing motor.