阅读说明：本技术 一种圆弧状模拟传送带纵撕的视觉检测试验台 (Visual inspection test bed that circular-arc simulation conveyer belt was indulged and is torn ) 是由 程刚 徐世昌 康彬 顾伟 崔振国 金祖进 于 2020-06-12 设计创作，主要内容包括：本发明公开了一种圆弧状模拟传送带纵撕的视觉检测试验台,包括输送机模型、平面镜模块和图像采集模块；输送机模型包括传送带和托辊；传送带的上输送面为圆弧状；上输送面的圆弧圆心位于传送带的上方；平面镜模块包括平面镜和旋转轴；旋转轴穿过上输送面的圆弧圆心,且平行于传送带的托辊；平面镜同平面固定在旋转轴上,以旋转轴为轴心旋转；图像采集模块包括摄像机；摄像机的光轴为水平设置,垂直于旋转轴且与旋转轴相交。本发明高还原度地模拟煤矿现场带式输送机高速运行、频繁振动情况下传送带撕裂的图像,且试验台结构简单,提供海量的输送带纵撕图像用以测试、调试,显著缩短开发周期、降低开发成本,适用于基于视觉的纵撕监测的多种方法。(The invention discloses a visual detection test bed for simulating longitudinal tearing of a conveyor belt in a circular arc shape, which comprises a conveyor model, a plane mirror module and an image acquisition module; the conveyor model comprises a conveyor belt and a carrier roller; the upper conveying surface of the conveying belt is arc-shaped; the circle center of the arc of the upper conveying surface is positioned above the conveying belt; the plane mirror module comprises a plane mirror and a rotating shaft; the rotating shaft penetrates through the circular arc center of the upper conveying surface and is parallel to the carrier roller of the conveying belt; the plane mirror is fixed on the rotating shaft in the same plane and rotates by taking the rotating shaft as an axis; the image acquisition module comprises a camera; the optical axis of the camera is horizontally arranged, perpendicular to the rotating shaft and intersected with the rotating shaft. The invention simulates the images of the torn conveyer belt of the belt conveyer in the coal mine field under the conditions of high-speed operation and frequent vibration with high reduction degree, has simple structure, provides massive vertical torn images of the conveyer belt for testing and debugging, obviously shortens the development period, reduces the development cost, and is suitable for various methods of vertical torn monitoring based on vision.)

1. The utility model provides a visual detection test bench that circular-arc simulation conveyer belt was indulged and is torn which characterized in that: comprises that

A conveyor model; the conveyor model comprises a conveyor belt (101) and carrier rollers (102); the upper conveying surface of the conveying belt (101) is arc-shaped; the circle center of the arc of the upper conveying surface is positioned above the conveyor belt (101); the carrier roller (102) is used for supporting the upper conveying surface of the guide conveyor belt (101) to form an arc shape;

a plane mirror module; the plane mirror module comprises a plane mirror (201) and a rotating shaft (202); the rotating shaft (202) penetrates through the circle center of the arc of the upper conveying surface and is parallel to the carrier roller (102) of the conveying belt (101); the plane mirror (201) is fixed on the rotating shaft (202), the plane mirror (201) and the rotating shaft (202) are positioned on the same plane and rotate by taking the rotating shaft (202) as an axis;

an image acquisition module; the image acquisition module comprises a camera (301); the optical axis of the camera (301) is horizontally arranged, is perpendicular to the rotating shaft (202) and intersects with the rotating shaft (202).

2. The arc-shaped simulation conveyor belt longitudinal tearing visual detection test bed according to claim 1, characterized in that: the plane mirror (201) is axisymmetric along the rotation axis (202).

3. The arc-shaped simulation conveyor belt longitudinal tearing visual detection test bed according to claim 2, characterized in that: the image acquisition module further comprises a guide rail (302); the guide rail (302) is parallel to the optical axis of the camera (301); the camera (301) is slidably connected to the guide rail (302).

4. The arc-shaped simulation conveyor belt longitudinal tearing visual detection test bed according to claim 3, characterized in that: the image acquisition module further comprises a vertical telescopic rod (303); the fixed end of the telescopic rod (303) is connected to the guide rail (302) in a sliding way through a sliding block (304); the telescopic end of the telescopic rod (303) is connected with the camera (301).

5. The arc-shaped simulation conveyor belt longitudinal tearing visual detection test bed according to claim 4, characterized in that: the image acquisition module further comprises an illumination device (305) for specularly reflecting illumination of the conveyor belt (101) by means of the plane mirror (201); the lighting device (305) is rotatably arranged at the telescopic end of the telescopic rod (303).

6. The longitudinal tearing visual detection test bed of the arc-shaped simulation conveyor belt according to any one of claims 1 to 5, characterized in that: the plane mirror module further comprises a mounting frame (203) and a plane mirror driving motor (204); the plane mirror driving motor is fixed on the mounting frame (203) and is used for driving the rotating shaft (202) to rotate.

7. The longitudinal tearing visual detection test bed of the arc-shaped simulation conveyor belt according to claim 6, characterized in that: the conveyor model further comprises a conveyor motor (103) and a drum (104); the conveying motor (103) drives the conveying belt (101) to move through the roller (104).

8. The longitudinal tearing visual detection test bed of the arc-shaped simulation conveyor belt according to claim 6, characterized in that: the conveyor model is mounted on an electric vibratory table (105).

Technical Field

The invention belongs to the field of coal mine monitoring equipment, and particularly relates to a visual detection test bed for simulating longitudinal tearing of a conveyor belt in an arc shape.

Background

The belt conveyor is transportation equipment which is widely used in coal mines in China and has an important function, most faults of the belt conveyor are faults of a conveyor belt, wherein longitudinal tearing of the conveyor belt is one of the faults with higher frequency and serious consequences, and the failure to detect the longitudinal tearing fault in time aggravates the damage of the conveyor belt and destroys other components of the belt conveyor, thereby seriously affecting production and bringing about huge economic loss.

With the gradual maturity of machine vision technology, compared with the traditional contact type conveyor belt longitudinal tearing detection method and other non-contact type detection methods such as electromagnetic and ultrasonic, the conveyor belt longitudinal tearing detection method based on vision is gradually developed and adopted more with the advantages of reliability, accuracy, no need of modifying field equipment and the like.

Development and correction of a visual-based conveyor belt longitudinal tearing monitoring method require a large amount of conveyor belt longitudinal tearing image data as support, and it is unrealistic to obtain longitudinal tearing images on a coal mine site. The main reasons are: longitudinal tearing of the coal mine conveyor belt occurs randomly, and if a large number of longitudinally torn images are acquired on site for algorithm development, the acquisition period is extremely long, and acquisition overhead is huge. Meanwhile, hidden dangers are brought to a production site by the installation and debugging of the acquisition equipment on the coal mine site, and the normal production of the coal mine is seriously influenced by the shutdown of the acquisition equipment for the installation and debugging.

Therefore, image data acquisition for visual inspection of the development of the conveyor belt longitudinal tearing method can only be realized by setting up a test bed and simulating a longitudinal tearing image by artificially manufacturing cracks on the conveyor belt. However, the whole belt conveyor is expensive, the damaged conveyor belt accounts for about 50% of the total cost of the conveyor, and the conveyor belt needs to be replaced repeatedly in order to obtain a large amount of image data.

Disclosure of Invention

In order to solve the problems, the invention provides the arc-shaped visual detection test bed for simulating the longitudinal tearing of the conveyor belt, which can simulate the tearing image of the conveyor belt under the conditions of high-speed operation and frequent vibration of a belt conveyor in a coal mine field with high reduction degree, has a simple structure, is cheap and convenient to replace the conveyor belt for test destruction, provides a large number of longitudinal tearing images of the conveyor belt for testing and debugging for a monitoring method based on the visual longitudinal tearing, obviously shortens the development period, reduces the development cost, and is suitable for various methods for monitoring based on the visual longitudinal tearing.

The technical scheme is as follows: the invention provides a visual detection test bed for simulating longitudinal tearing of a conveyor belt, which comprises

A conveyor model; the conveyor model comprises a conveyor belt and a carrier roller; the upper conveying surface of the conveying belt is arc-shaped; the circle center of the arc of the upper conveying surface is positioned above the conveying belt; the carrier roller is used for supporting the upper conveying surface of the guide conveying belt to form an arc shape;

a plane mirror module; the plane mirror module comprises a plane mirror and a rotating shaft; the rotating shaft penetrates through the circular arc center of the upper conveying surface and is parallel to the carrier roller of the conveying belt; the plane mirror is fixed on the rotating shaft, is positioned on the same plane with the rotating shaft and rotates by taking the rotating shaft as an axis;

an image acquisition module; the image acquisition module comprises a camera; the optical axis of the camera is horizontally arranged, is perpendicular to the rotating shaft and is intersected with the rotating shaft.

Further, the plane mirror is axisymmetric along the rotation axis.

Further, the image acquisition module also comprises a guide rail; the guide rail is parallel to the optical axis of the camera; the camera is slidably connected to the guide rail.

Furthermore, the image acquisition module also comprises a vertical telescopic rod; the fixed end of the telescopic rod is connected to the guide rail in a sliding manner through a sliding block; the telescopic end of the telescopic rod is connected with the camera.

Further, the image acquisition module further comprises an illumination device for illuminating the conveyor belt by mirror reflection of the plane mirror; the lighting equipment can be rotatably arranged at the telescopic end of the telescopic rod.

Further, the plane mirror module also comprises a mounting frame and a plane mirror driving motor; the plane mirror driving motor is fixed on the mounting frame and used for driving the rotating shaft to rotate.

Further, the conveyor model further comprises a transmission motor and a roller; the conveying motor drives the conveying belt to move through the roller.

Has the advantages that: the invention designs a unique arrangement scheme of a circular arc conveyor belt surface-mirror surface-camera by applying a mirror reflection principle in a longitudinal tearing image acquisition design, obtains a rapidly-changed conveyor belt change image by mirror surface rotation, ensures that the size of a view field range of the image acquired by the camera is not changed in the process, and is used for simulating image capture during high-speed motion of a horizontal conveyor belt in actual use; the rotating speed of the plane mirror driving motor is adjusted, so that the conveying belt change images under different equivalent conveying belt moving speeds can be obtained; the conveyor belt of the conveyor model does not need to simulate the rapid movement in actual use, and only needs to slowly move to adjust the position of the longitudinal tearing seam, so that the structure of the conveyor model is reduced and simplified, the size of the conveyor belt is exponentially reduced, and the installation convenience and the economical efficiency of the conveyor model are greatly improved;

the method is characterized in that a solution scheme for facilitating the adjustment of visual field visual range of a camera, replacement and extension of a laser and other visual methods is designed; an electric vibration table is introduced to simulate the situation of field vibration.

Compared with the existing method for acquiring the image data of the computer vision conveyor belt longitudinal tearing detection test, the introduction of the visual detection belt conveyor longitudinal tearing test bed provided by the invention enables the image acquisition process to be more controllable, convenient and rapid on the premise of maximally simulating the acquisition of the on-site conveyor belt longitudinal tearing image, and greatly reduces the test cost.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic view of the principle of the present invention in a first state;

FIG. 3 is a schematic diagram illustrating the operation of the present invention in a second state;

FIG. 4 is a front view of an image acquisition module of the present invention;

fig. 5 is a back view of an image capture module of the present invention.

Detailed Description

Referring to fig. 1, the invention provides a visual inspection test bed for simulating longitudinal tearing of a conveyor belt, which comprises a conveyor model, a plane mirror module and an image acquisition module.

The conveyor model comprises a conveyor belt 101 and carrier rollers 102; the carrier rollers 102 are used for supporting and guiding the upper conveying surface of the conveyor belt 101, and the height difference guidance of the carrier rollers 102 enables the upper conveying surface of the conveyor belt 101 to form a circular arc, namely a circular arc PQ in fig. 2 and 3; the circle center of the arc of the upper conveying surface is located above the conveyor belt 101, i.e., point O in fig. 2 and 3;

the conveyor model further comprises a conveyor motor 103 and a roller 104; the conveyor motor 103 drives the conveyor belt 101 to move via the rollers 104.

As shown in fig. 1, the conveyor belt 101 does not bear material conveying and is only used for longitudinal tear seam detection, and can be replaced by an inexpensive product which has strength and short service life compared with a conventional conveyor belt; the length of the conveyor belt 101 is less than 1/10 of the conveyor belt of the conventional mining conveyor, and the width of the conveyor belt is about half of the width of the conveyor belt of the conventional mining conveyor, so that the conveyor belt is more convenient and quicker to install and replace than the conventional conveyor belt, and the cost is saved; the longitudinal tear seam was simulated on the conveyor belt 101 by artificially piercing the tear with sharp objects in combination with the characteristic of the crack created by the different mechanisms of belt tearing.

The conveyor model in this embodiment has four legs, all mounted on an electric oscillating table 105. To simulate a vibrating environment in the field.

The plane mirror module includes a plane mirror 201, a rotation shaft 202, a mounting bracket 203, and a plane mirror driving motor 204.

The plane mirror driving motor 204 is fixed to the mounting frame 203, and is used for driving the rotation shaft 202 to rotate.

The rotating shaft 202 passes through the arc center point O of the upper conveying surface and is parallel to the carrier roller 102 of the conveyor belt 101; the plane mirror 201 is fixed to the rotation shaft 202, and the plane mirror 201 is located on the same plane as the rotation shaft 202, rotates around the rotation shaft 202 as an axis, and is axisymmetric along the rotation shaft 202.

The image acquisition module comprises a camera 301; the optical axis of the camera 301 is arranged horizontally, perpendicular to the rotation axis 202 and intersecting the rotation axis 202.

According to the principle of mirror reflection, the mirror surface in the pose M of FIG. 2₀-M₀In FIG. 4, the mirror is rotated α around the center of rotation O by the rotating shaft 202, with the mirror pose at M₀-M₀' become M₁-M₁' then, the camera 301 acquires an image of the surface of the conveyor belt within the field of view centered on point B, again according to the principle of specular reflection. Since the curvature center of the arc PQ of the upper portion of the belt 101 is the mirror rotation center O, the imaging distance of the camera 301 is always kept constant during the rotation of the mirror, that is, the imaging distance is always kept constant

CO+OA＝CO+OK₁＝CO+OK₂The size of the field of view of the camera 301 is always constant and is directed toward the upper surface of the conveyor belt 101.

Assuming that the belt 101 does not move, the rotational angular velocity ω of the belt motor 103 is 1080 °/s, and the distance from the mirror surface rotation center to the upper arc surface of the belt 101, i.e., OA is 1m, the offset distance of the center of the field of view of the camera 301, i.e., the equivalent belt movement velocity, is 1s

Namely, the plane mirror 201 only needs to rotate at 3r/s, so that the conveying belt change image moving at 9.42m/s can be obtained, and according to the corresponding relation between the rotating speed angular velocity and the equivalent conveying belt moving speed, the rotating speed of the plane mirror driving motor 204 can be adjusted to obtain the conveying belt 101 change image at different equivalent conveying belt moving speeds for detecting the real-time performance and the effectiveness of the visual detection longitudinal tearing system at different speeds.

Therefore, the conveyor belt 101 of the conveyor model does not need to simulate the rapid movement in practical use, the power of the conveyor motor 103 can be smaller than that of a conventional mining motor, and the conveyor motor 103 can drive the conveyor belt 101 to move slowly and select types after being controlled by a frequency converter so as to adjust the position of the longitudinal tear seam without reaching a high belt speed; because of the low speed and torque requirements of the transfer motor 103, the conveyor model may also be provided without a gearbox, with the transfer motor 103 coupled directly to the drum 104 by a coupling.

As shown in fig. 4 and 5, the image acquisition module further comprises a guide rail 302, a vertical telescopic rod 303 and an illumination device 305; the guide rails 302 are parallel to the optical axis of the camera 301; the fixed end of the telescopic rod 303 is slidably connected to the guide rail 302 through a sliding block 304; the telescopic end of the telescopic rod 303 is connected with the camera 301.

The illumination device 305 is rotatably mounted at the telescoping end of the telescoping rod 303 for specularly reflecting illumination of the conveyor belt 101 by the flat mirror 201. The illumination device 305 is rotated to ensure that light is projected horizontally and perpendicular to the axis of rotation 202.

The height of the camera 301 and the lighting device 305 can be adjusted through the telescopic rod 303, and it is ensured that the optical axis of the camera 301 and the normal of the lighting center of the lighting device 305 can horizontally pass through the axis of the rotating shaft 202, that is, the optical axis of the camera 301 horizontally passes through the point O.

By moving the telescopic rod 303 along the guide rail 302, the distance from the camera 301 to the mirror surface can be adjusted, and accordingly, the size of the field of view of the camera 301 can be adjusted. As shown in fig. 3, when the point C of the video camera 301 is moved to the point C ', the imaging distance of the video camera 301 is increased from CO + OB to C' C + CO + OB, and the size of the field range is increased accordingly, so that the method can be conveniently used for camera debugging, such as focusing, determining the optimal field range, and the like.

For the situation that laser lines/planes need to be introduced in the active light source type visual detection method that requires laser-assisted positioning or structured light, the illumination device 305 may be replaced by a laser emitter, and in the rotation process of the plane mirror 201, the laser lines or laser planes emitted by the laser emitter irradiate the rotation center of the plane mirror and are reflected by the plane mirror, and then the relative position of the laser lines, which are printed on the conveyor belt 101, in the reflected image view field captured by the camera 301 does not change.