阅读说明：本技术 一种单目视觉系统成像参数标定装置及方法 (Monocular vision system imaging parameter calibration device and method ) 是由 夏晓华 秦绪芳 杨殿斌 田明锐 刘晓辉 王朋辉 董畅 陈仕旗 岳鹏举 孙宏斐 于 2020-04-13 设计创作，主要内容包括：本发明公开了一种单目视觉系统成像参数标定装置及方法,包括单目视觉系统、置于单目视觉系统前方的标定物以及图像采集与分析模块,单目视觉系统包括镜头和相机,镜头与相机之间的距离或镜头内的镜片组与相机之间的距离可调；标定物为表面具有纹理的一个或一组平面标定板；一个平面标定板可移动且移动距离可测；一组平面标定板相互平行且之间的距离可测；或标定物为表面具有纹理的三维标定块且该三维标定块的表面形貌信息已知；三维标定块是固定的或可移动的。该方法通过调整单目视觉系统对焦于不同远近的物体或区域记录系统状态信息和被聚焦点的位置信息,利用成像公式联立方程组求解成像参数。本发明易于实现单目视觉系统成像参数精确标定。(The invention discloses a monocular vision system imaging parameter calibration device and a method, comprising a monocular vision system, a calibration object arranged in front of the monocular vision system and an image acquisition and analysis module, wherein the monocular vision system comprises a lens and a camera, and the distance between the lens and the camera or the distance between a lens group in the lens and the camera is adjustable; the calibration object is one or a group of plane calibration plates with textures on the surfaces; a plane calibration plate can move and the moving distance can be measured; the plane calibration plates are parallel to each other and the distance between the plane calibration plates can be measured; or the calibration object is a three-dimensional calibration block with texture on the surface, and the surface appearance information of the three-dimensional calibration block is known; the three-dimensional calibration block is fixed or movable. The method records system state information and focused point position information by adjusting the monocular vision system to focus on different distant objects or areas, and solves imaging parameters by using an imaging formula simultaneous equation set. The method is easy to realize the accurate calibration of the imaging parameters of the monocular vision system.)

1. The monocular vision system imaging parameter calibration device is characterized by comprising a monocular vision system (1), a calibration object (2) arranged in front of the monocular vision system (1) and an image acquisition and analysis module (3) connected with the monocular vision system (1) for acquiring an image of the calibration object (2) shot by the monocular vision system (1) and analyzing whether the whole image or a partial area of the image is focused accurately or not;

the monocular vision system (1) comprises a lens (11) and a camera (12), and the lens (11) is positioned between the camera (12) and the calibration object (2); the distance between the lens (11) and the camera (12) or the distance between a lens group in the lens (11) and the camera (12) is adjustable, and a first displacement sensor or a first distance measuring sensor is arranged on the monocular vision system (1) so that the moving distances of the lens (11), the lens group in the lens (11) and the camera (12) can be measured;

the calibration object (2) is one or a group of plane calibration plates (21) with textures on the surface; if the calibration object (2) is a plane calibration plate (21), the plane calibration plate (21) can move and the moving distance can be measured; if the calibration object (2) is a group of plane calibration plates (21), the plane calibration plates (21) are parallel and the distance between the plane calibration plates (21) can be measured;

or the calibration object (2) is a three-dimensional calibration block (22) with texture on the surface, and the surface topography information of the three-dimensional calibration block (22) is known; the three-dimensional calibration block (22) is fixed or movable, and the moving distance can be measured or not measured;

the texture includes a texture formed by surface treatment, pasting, or projection.

2. Monocular vision system imaging parameter calibration device according to claim 1, characterized in that, a second displacement sensor or a second distance measuring sensor is provided beside the planar calibration plate (21) to measure the moving distance of the planar calibration plate (21).

3. The monocular vision system imaging parameter calibration method using the monocular vision system imaging parameter calibration device of claim 1 or 2, characterized by comprising the steps of:

the method comprises the following steps: placing the calibration object in front of the monocular vision system;

step two: adjusting the distance between a lens and a camera in the monocular vision system or the distance between a lens group in the lens and the camera to focus the monocular vision system on a calibration object or a certain area of the calibration object, and recording the state information of the monocular vision system and the position information of a focused point;

step three: changing the position of the focused point, adjusting the distance between a lens and a camera in the monocular vision system or the distance between a lens group in the lens and the camera, enabling the monocular vision system to focus again, and recording the state information of the monocular vision system and the position information of the focused point;

step four: judging whether the third step needs to be repeated, if so, jumping to the third step, and if not, executing the fifth step;

step five: and calculating imaging parameters according to the recorded monocular vision system state information and the position information of the focused point and the imaging formula column equation set of the monocular vision system.

4. The monocular vision system imaging parameter calibration method of claim 3, wherein the state information of the monocular vision system is obtained by a first distance measurement sensor or a first displacement sensor, and the position information of the focused point is known in advance or obtained by a second distance measurement sensor or a second displacement sensor.

5. The method for calibrating imaging parameters of a monocular vision system according to claim 3, wherein the step four for determining whether the step three needs to be repeated is a step for determining whether the focusing frequency of the monocular vision system in the calibration process is smaller than a certain value, if so, the step three needs to be repeated, otherwise, the step three does not need to be repeated;

the determined number is greater than or equal to the number of the imaging parameters to be calibrated.

6. The method for calibrating imaging parameters of a monocular vision system of claim 3, wherein the imaging formula of the monocular vision system is a lens imaging formula, and when the number of the equation sets is greater than the number of the imaging parameters to be calibrated, the solution method of the equation sets is a least square method.

Technical Field

The invention belongs to the field of machine vision, and particularly relates to a monocular vision system imaging parameter calibration device and method.

Background

Monocular multi-focus stereo vision is a vision technology for realizing scene three-dimensional perception by acquiring scene multi-focus images, the precondition for realizing scene three-dimensional perception is that imaging parameters of a monocular vision system are accurately acquired, the existing camera calibration method mostly assumes that the image distance is equal to the focal length, and the accurate calibration of the imaging parameters of the monocular vision system cannot be realized, so the three-dimensional perception precision of the monocular multi-focus stereo vision technology is restricted.

Disclosure of Invention

Aiming at the defects and shortcomings in the prior art, the invention provides a monocular vision system imaging parameter calibration device and method, which can realize accurate calibration of monocular vision system imaging parameters and provide technical conditions for guaranteeing three-dimensional perception accuracy of monocular multi-focus stereo vision technology.

In order to achieve the purpose, the invention adopts the following technical scheme:

a monocular vision system imaging parameter calibration device comprises a monocular vision system, a calibration object arranged in front of the monocular vision system and an image acquisition and analysis module connected with the monocular vision system, wherein the image acquisition and analysis module is used for acquiring an image of the calibration object shot by the monocular vision system and analyzing whether the whole image or a partial area of the image is focused accurately;

the monocular vision system comprises a lens and a camera, and the lens is positioned between the camera and the calibration object; the distance between the lens and the camera or the distance between a lens group in the lens and the camera is adjustable, and a first displacement sensor or a first distance measuring sensor is arranged on the monocular vision system so that the moving distances of the lens, the lens group in the lens and the camera can be measured;

the calibration object is one or a group of plane calibration plates with textures on the surface; if the calibration object is a plane calibration plate, the plane calibration plate can move and the moving distance can be measured; if the calibration object is a group of plane calibration plates, the plane calibration plates are parallel and the distance between the plane calibration plates can be measured;

or the calibration object is a three-dimensional calibration block with texture on the surface, and the surface appearance information of the three-dimensional calibration block is known; the three-dimensional calibration block is fixed or movable, and the moving distance can be measured or not;

the texture includes a texture formed by surface treatment, pasting, or projection.

The invention also comprises the following technical characteristics:

specifically, a second displacement sensor or a second distance measuring sensor is arranged beside the plane calibration plate to measure the moving distance of the plane calibration plate.

The invention also provides a monocular vision system imaging parameter calibration method adopting the monocular vision system imaging parameter calibration device, which comprises the following steps:

the method comprises the following steps: placing the calibration object in front of the monocular vision system;

step two: adjusting the distance between a lens and a camera in the monocular vision system or the distance between a lens group in the lens and the camera to focus the monocular vision system on a calibration object or a certain area of the calibration object, and recording the state information of the monocular vision system and the position information of a focused point;

step three: changing the position of the focused point, adjusting the distance between a lens and a camera in the monocular vision system or the distance between a lens group in the lens and the camera, enabling the monocular vision system to focus again, and recording the state information of the monocular vision system and the position information of the focused point;

step four: judging whether the third step needs to be repeated, if so, jumping to the third step, and if not, executing the fifth step;

step five: according to the recorded monocular vision system state information and the position information of the focused point, calculating imaging parameters according to an imaging formula column equation set of the monocular vision system;

specifically, the state information of the monocular vision system is obtained by a first distance measuring sensor or a first displacement sensor, and the position information of the focused point is known in advance or obtained by a second distance measuring sensor or a second displacement sensor.

Specifically, the fourth step of determining whether the third step needs to be repeated is to determine whether the focusing frequency of the monocular vision system in the calibration process is smaller than a certain value, if so, the third step needs to be repeated, otherwise, the third step does not need to be repeated;

the determined number is greater than or equal to the number of the imaging parameters to be calibrated.

Specifically, the imaging formula of the monocular vision system is a lens imaging formula, and when the number of the equation sets is more than the number of the imaging parameters to be calibrated, the solving method of the equation sets is a least square method.

Compared with the prior art, the invention has the beneficial technical effects that:

the invention provides a monocular vision system imaging parameter calibration device, which has a simple structure, only needs to measure distance or displacement and is easy to realize monocular vision system imaging parameter calibration; the monocular vision system is adjusted to focus on objects or areas with different distances, imaging parameters are solved by using an imaging formula simultaneous equation set through monocular vision system state information and focused point position information, and accurate calibration of the imaging parameters of the monocular vision system is easy to realize.

Drawings

FIG. 1 is a schematic view of an imaging parameter calibration apparatus for a monocular vision system of the present invention, FIG. 1;

FIG. 2 is a schematic view of an imaging parameter calibration apparatus of the monocular vision system of the present invention 2;

FIG. 3 is a schematic view of an imaging parameter calibration apparatus for monocular vision systems according to the present invention, FIG. 3;

FIG. 4 is a flowchart of a monocular vision system imaging parameter calibration method of the present invention.

The number in the figure represents 1-monocular vision system, 2-calibration object, 3-image acquisition and analysis module;

11-lens, 12-camera;

21-plane calibration plate, 22-three-dimensional calibration block.

The following describes in detail specific embodiments of the present invention. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

Detailed Description