阅读说明：本技术 车身外观缺陷检测方法及检测系统 (Vehicle body appearance defect detection method and detection system ) 是由 严婉 张俊 刘益 于 2019-08-16 设计创作，主要内容包括：本发明提供一种车身外观缺陷检测方法及检测系统,包括：使用激光器照射车身表面；通过图像采集装置采集实时光斑形状,对实时光斑图像进行检测；判断光斑形状是否出现异常,对所述实时光斑图像与激光照射在标准车身表面的参照光斑图像进行差分处理,得到差分图像,若差分图像的灰度值大于预设值,则确定所述车身表面存在缺陷,否则,则确定所述车身表面不存在缺陷。本发明的车身外观缺陷检测方法,采用激光照射凸显车身,通过差分算法,获得差分图像,检测差分图像的灰度值判断车身是否存在缺陷。采用本发明检测方法的检测系统,自动化程度高,不需要人工参与,自动记录存储,检测速度快,准确率高,设备安装方便。(The invention provides a method and a system for detecting appearance defects of a vehicle body, comprising the following steps: irradiating the surface of the vehicle body with a laser; acquiring the shape of a real-time light spot through an image acquisition device, and detecting the real-time light spot image; judging whether the shape of the light spot is abnormal or not, carrying out difference processing on the real-time light spot image and a reference light spot image irradiated on the surface of a standard vehicle body by laser to obtain a difference image, if the gray value of the difference image is larger than a preset value, determining that the surface of the vehicle body has defects, otherwise, determining that the surface of the vehicle body has no defects. The method for detecting the appearance defects of the vehicle body adopts laser to irradiate the vehicle body to be highlighted, obtains a difference image through a difference algorithm, and detects the gray value of the difference image to judge whether the vehicle body has defects. The detection system adopting the detection method has the advantages of high automation degree, no need of manual participation, automatic record and storage, high detection speed, high accuracy and convenient equipment installation.)

1. A method for detecting appearance defects of a vehicle body is characterized by comprising the following steps:

irradiating the surface of the vehicle body with a laser;

acquiring the shape of a real-time light spot through an image acquisition device, and detecting the real-time light spot image;

judging whether the shape of the light spot is abnormal or not, carrying out difference processing on the real-time light spot image and a reference light spot image irradiated on the surface of a standard vehicle body by laser to obtain a difference image, if the gray value of the difference image is larger than a preset value, determining that the surface of the vehicle body has defects, otherwise, determining that the surface of the vehicle body has no defects.

2. A vehicle body appearance defect detection system, comprising:

a laser for emitting laser light to irradiate a vehicle body surface;

the image acquisition device shoots a real-time light spot image formed on the surface of the vehicle body by the laser;

the difference processing module is used for carrying out difference processing on the real-time light spot image and the standard light spot image and outputting a difference image with readable gray value;

and the defect judgment module analyzes the gray value of the difference image, if the gray value is larger than a preset value, the defect exists on the surface of the output vehicle body, otherwise, the defect does not exist on the surface of the output vehicle body.

3. The system of claim 2, further comprising a display device for displaying the difference image.

4. The system for detecting the defects of the external appearance of the vehicle body according to claim 2, further comprising a storage unit for storing the real-time spot image, the standard spot image and the difference image.

5. The vehicle body appearance defect detection device of claim 2, wherein the laser is a line laser, and laser radiation emitted by the laser forms a line-shaped light spot.

6. The vehicle body appearance defect detection device of claim 2, wherein at least one laser is arranged at the top of the vehicle body, at least one laser is arranged at the left side part of the vehicle body along the vehicle head direction, and at least one laser is arranged at the right side part of the vehicle body along the vehicle head direction.

7. The apparatus according to claim 6, wherein the image capturing device comprises a plurality of industrial cameras, each of the industrial cameras corresponds to a laser, and the image capturing device is responsible for capturing the spot image of the laser.

8. The apparatus for detecting the apparent defect of the car body according to any one of claims 2 to 7, wherein the system further comprises a gantry, the gantry is arranged on a car body production line, and the laser and the image acquisition device are mounted on the gantry.

Technical Field

The invention belongs to the field of automobile manufacturing, and particularly relates to a method and a system for detecting appearance defects of an automobile body.

Background

When the automobile body is welded, the defects of concave-convex marks and the like of the automobile body caused by various factors can be caused, and if the automobile body is not monitored, the state of the automobile body flowing out of a welding workshop can not be known. Once the vehicle body with the larger appearance defect flows into the subsequent production process, the greater economic loss is caused. At present, the appearance defect detection of the automobile body is to confirm whether the automobile body has defects through hands of advanced engineers, and the automobile body appearance defect detection method is high in cost, low in efficiency and high in false detection rate.

The technology for detecting the appearance defects of the vehicle body meeting the requirement of automatic production is urgently needed.

Disclosure of Invention

Therefore, the invention provides a method and a system for detecting the appearance defects of the vehicle body, which aims to solve the technical problem of lacking a means for detecting the appearance defects of the vehicle body.

In order to solve the above problems, the present invention provides a method for detecting an appearance defect of a vehicle body, including:

irradiating the surface of the vehicle body with a laser;

acquiring the shape of a real-time light spot through an image acquisition device, and detecting the real-time light spot image;

judging whether the shape of the light spot is abnormal or not, carrying out difference processing on the real-time light spot image and a reference light spot image irradiated on the surface of the standard vehicle body by the laser to obtain a difference image, if the gray value of the difference image is larger than a preset value, determining that the surface of the vehicle body has defects, otherwise, determining that the surface of the vehicle body does not have defects.

A vehicle body appearance defect detection system comprising:

the laser is used for emitting laser to irradiate the surface of the vehicle body;

the image acquisition device shoots a real-time light spot image formed on the surface of the vehicle body by the laser;

the difference processing module is used for carrying out difference processing on the real-time light spot image and the standard light spot image and outputting a difference image with readable gray value;

and the defect judging module analyzes the gray value of the differential image, if the gray value is larger than a preset value, the defect exists on the surface of the output vehicle body, otherwise, the defect does not exist on the surface of the output vehicle body.

Preferably, the system further comprises display means for displaying the difference image.

Preferably, the system further comprises a storage unit, and the storage unit is used for storing the real-time light spot image, the standard light spot image and the difference image.

Preferably, the laser is a line laser, and laser irradiation emitted by the laser forms a linear light spot.

Preferably, the top of the vehicle body is at least provided with one laser, the left side part of the vehicle body along the vehicle head direction is at least provided with one laser, and the right side part of the vehicle body along the vehicle head direction is at least provided with one laser.

Preferably, the image acquisition device comprises a plurality of industrial cameras, each industrial camera corresponds to one laser and is responsible for shooting the spot images of the lasers.

Preferably, the system further comprises a portal frame, the portal frame is arranged on the vehicle body production line, and the laser and the image acquisition device are installed on the portal frame.

The method and the system for detecting the appearance defects of the vehicle body have the following beneficial effects:

1. the invention discloses a vehicle body appearance defect detection method, which adopts laser to irradiate the surface of a vehicle body to obtain a facula image, obtains a difference image through a facula image difference algorithm with the surface of a standard vehicle body, and detects the gray value of the difference image to judge whether the vehicle body has defects.

2. The detection system adopting the detection method of the invention has the advantages of high automation degree, no need of manual participation, automatic record and storage, high detection speed, high accuracy and convenient equipment installation

Drawings

FIG. 1 is a flow chart of a method for detecting defects in the appearance of a vehicle body according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a vehicle body appearance defect detection system according to an embodiment of the invention;

fig. 3 is a schematic view of the installation of a laser, an industrial camera and a gantry of the vehicle body appearance defect detection system according to the embodiment of the invention.

The reference numerals are represented as:

1. a laser; 2. a vehicle body; 5. an image acquisition device; 6. a defect judgment module; 8. a display device; 9. a storage unit; 10. an industrial camera; 11. a gantry; 12. and a difference processing module.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the specific embodiments of the present invention and the accompanying drawings. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-3 in combination, the embodiment of the invention discloses a method for detecting appearance defects of a vehicle body, which comprises the following steps:

step A, irradiating the surface of a vehicle body by using a laser 1; the laser 1 is a line laser, and laser emitted by the laser 1 irradiates the surface of the vehicle body 2 to form a linear light spot.

In this embodiment, the detection positions of the vehicle body are respectively located at the top, the left side portion and the right side portion along the vehicle head direction, so that at least one laser 1 is arranged at the top of the vehicle body, at least one laser 1 is arranged at the left side portion of the vehicle body along the vehicle head direction, and at least one laser 1 is arranged at the right side portion of the vehicle body along the vehicle head direction.

And B, detecting the shape of the laser spot on the surface of the vehicle body.

In this embodiment, after the laser device irradiates the vehicle body, the image acquisition device acquires the real-time light spot shape formed on the surface of the vehicle body, and then detects the real-time light spot image. The image acquisition device 5 comprises a plurality of industrial cameras, each industrial camera corresponds to one laser and is responsible for shooting spot images of the lasers.

And C, judging whether the shape of the light spot is abnormal or not.

In this embodiment, the real-time spot image and the reference spot image irradiated on the surface of the standard vehicle body by the laser are subjected to difference processing to obtain a difference image.

The difference processing in the present embodiment is a background difference method. The background subtraction method is a method for detecting an object by comparing a current frame in an image sequence with a background reference model, and the object can be detected as long as the current frame has an object different from the background reference model. In the embodiment, the real-time spot image is taken as the current frame, the spot image irradiated on the surface of the standard vehicle body by the laser is taken as the background reference model, and the real-time spot image and the spot image of the standard vehicle body are subjected to difference processing, so that different parts of the real-time spot image and the spot image of the standard vehicle body can be detected.

And D, judging the defects, if the gray value of the difference image is greater than the preset value, determining that the defects exist on the surface of the vehicle body, and if the gray value of the difference image is less than or equal to the preset value, determining that the defects do not exist on the surface of the vehicle body.

According to the method for detecting the appearance defects of the vehicle body, the images of the shapes of the light spots irradiated on the vehicle body by the laser are processed through the difference algorithm, whether the vehicle body has the defects can be judged according to whether the gray scale of the difference images reaches the preset value, the judgment standard is simple and efficient, the method is easy to convert into machine language, and the manufacturing equipment can be used for automatic control.

The embodiment of the invention also discloses a system for detecting the appearance defects of the car body, which comprises the following components:

the laser device 1 is used for emitting laser to irradiate the surface of the vehicle body 2;

the image acquisition device 5 is used for shooting a real-time light spot image formed on the surface of the vehicle body 2 by the laser;

the difference processing module 12 is used for carrying out difference processing on the real-time light spot image and the standard light spot image by the difference processing module 12 and outputting a difference image with readable gray value;

and the defect judging module 6 analyzes the gray value of the differential image, if the gray value is larger than a preset value, the defect exists on the surface of the output vehicle body 2, otherwise, the defect does not exist on the surface of the output vehicle body 2.

In the system for detecting the appearance defects of the vehicle body according to the embodiment, the laser 1 is adopted to irradiate the vehicle body, the image acquisition device 5 is used to shoot the shape of the light spot on the surface of the vehicle body, the difference processing module 12 is used to output the difference image, and the gray value of the difference image is detected, so that whether the appearance defects exist in the vehicle body can be judged.

The system further comprises a display device 8, and the display device 8 is used for displaying the difference image and the defect judgment result. The system further comprises a storage unit 9, and the storage unit 9 is used for storing the real-time light spot image, the standard light spot image and the difference image, so that the tracing is convenient.

In this embodiment, the system further includes a gantry 11, the gantry 11 is disposed on the vehicle body production line, and the laser 1 and the industrial camera 10 are mounted on the gantry 11. The industrial camera 10 and the laser 1 are directly arranged on a production line of the vehicle body under the support of the portal frame 11, the vehicle body is detected on line, and the detection efficiency is high.

The automobile body appearance defect detection system of this embodiment can realize the online defect detection of automobile body, and degree of automation is high, does not need artifical participation to judge the testing result, and the automatic recording is saved, and detection speed is fast, and the rate of accuracy is high, equipment fixing is convenient.

It is readily understood by a person skilled in the art that the advantageous ways described above can be freely combined, superimposed without conflict.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention. The above is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the technical principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.