CN101858768A - Device and method for detecting liquid level after beverage filling - Google Patents

本发明公开了一种饮料灌装后液位检测装置及方法，通过处理工业相机获取的图像，检测饮料灌装后的液位信息。该发明中的算法包括液位扫描单元，液位获取单元，质量判别单元三个部分，通过液位所在区域的灰度变化来达到检测液位的目的，本算法检测液位测量精度高，实时性好，且对人体不会造成任何伤害。既可以采用本发明叙述的方法做成单独的产品，也可以方便的添加到现有的视觉检测装置内，扩展现有系统的功能，拥有广泛的应用价值。

The invention discloses a liquid level detection device and method after beverage filling, which detects liquid level information after beverage filling by processing images acquired by an industrial camera. The algorithm in this invention includes three parts: a liquid level scanning unit, a liquid level acquisition unit, and a quality discrimination unit. The purpose of detecting the liquid level is achieved through the gray scale change of the area where the liquid level is located. This algorithm has high precision in liquid level detection and real-time Good sex, and will not cause any harm to the human body. The method described in the present invention can be used to make a separate product, and can also be conveniently added to the existing visual inspection device to expand the functions of the existing system, and has wide application value.

一种饮料灌装后液位检测装置及方法 Device and method for detecting liquid level after beverage filling

技术领域technical field

本发明涉及一种饮料灌装后液位检测装置及方法。The invention relates to a liquid level detection device and method after beverage filling.

背景技术Background technique

在饮料灌装过程中，因灌装机无法保证每次灌装量相等，市场产生灌装量过大或过小的状况，灌装量较大会使企业利润减小，灌装量过少影响企业形象，所以在饮料灌装后进行灌装量检测很有必要，目前现场中常用的射线检测方法容易给现场工作人员带来健康的威胁，因此并不适合在非无人车间安装使用。In the beverage filling process, because the filling machine cannot guarantee the same filling volume each time, the market has a situation where the filling volume is too large or too small. A large filling volume will reduce the profit of the enterprise, and too little filling volume will affect Therefore, it is necessary to detect the filling volume after the beverage is filled. The ray detection method commonly used in the field is likely to bring health threats to the field workers, so it is not suitable for installation and use in non-manned workshops.

机器视觉技术不会对人体造成任何伤害，而且更直观准确，目前机器视觉检测技术已经成功应用于很多行业，例如啤酒瓶的空瓶检测，集成电路的检测等领域，机器视觉检测代替人工检测成为一种发展方向。Machine vision technology will not cause any harm to the human body, and is more intuitive and accurate. At present, machine vision inspection technology has been successfully applied in many industries, such as empty beer bottle inspection, integrated circuit inspection and other fields. Machine vision inspection has replaced manual inspection. a direction of development.

机器视觉系统在图像采集部分条件相同的时候，可以在保证实时性的情况下，用升级软件的方法来大大的增强机器视觉系统的功能，升级过程方便，成本低廉。When the image acquisition part of the machine vision system has the same conditions, the function of the machine vision system can be greatly enhanced by upgrading the software while ensuring real-time performance. The upgrade process is convenient and the cost is low.

为检测饮料灌装量，为灌装后饮料的质量判别提供依据，本发明利用工业相机采集现场生产线中灌装后饮料的实时图像，图像经数据线传给处理器，由处理器依据本发明提供的算法计算液位并判断灌装量是否合格，为达到该目的本发明采用的步骤是：首先，通过可设置条数和长度的液位扫描线采集液位待检点；其次，在液位待检点寻找能代表液位信息的液位点；再次，通过液位点信息计算液位在图像中的位置；最后根据液位在图像中的位置和图像与待检品的尺寸关系判断液位的实际尺寸，根据液位实际尺寸判定灌装量是否合格。In order to detect the amount of beverage filling and provide a basis for the quality judgment of the beverage after filling, the present invention uses an industrial camera to collect real-time images of beverages after filling in the on-site production line. The provided algorithm calculates the liquid level and judges whether the filling volume is qualified. The steps adopted by the present invention are as follows: firstly, collect the liquid level to-be-checked points through the liquid level scanning lines whose number and length can be set; secondly, at the liquid level Find the liquid level point that can represent the liquid level information at the point to be inspected; again, calculate the position of the liquid level in the image through the information of the liquid level point; finally judge the liquid level according to the position of the liquid level in the image and the size relationship between the image and the product to be inspected The actual size of the liquid level, according to the actual size of the liquid level to determine whether the filling volume is qualified.

发明内容Contents of the invention

为了达到上述目的，本发明所实施的技术方案是：In order to achieve the above object, the technical scheme implemented in the present invention is:

一种饮料灌装后液位检测装置，该装置包括光源和相机，所述光源和相机与待检品相配合；所述相机与算法处理装置的液位扫描单元连接；所述算法处理装置还包括液位获取单元和质量判别单元，所述液位扫描单元、液位获取单元和质量判别单元依次连接；质量判别单元还与算法处理装置外的控制设备连接。A liquid level detection device after beverage filling, the device includes a light source and a camera, the light source and camera are matched with the product to be inspected; the camera is connected to the liquid level scanning unit of the algorithm processing device; the algorithm processing device also It includes a liquid level acquiring unit and a quality judging unit, the liquid level scanning unit, the liquid level acquiring unit and the quality judging unit are sequentially connected; the quality judging unit is also connected with the control equipment outside the algorithm processing device.

所述光源选择LED光源，光源颜色与待检品颜色相匹配，暖色用红色光源，冷色用绿色光源，无色用白色光源。The light source is an LED light source, and the color of the light source matches the color of the product to be inspected. A red light source is used for warm colors, a green light source is used for cool colors, and a white light source is used for colorless colors.

所述相机采用工业黑白相机。The camera is an industrial black and white camera.

一种饮料灌装后液位检测方法，该检测方法步骤如下：A liquid level detection method after beverage filling, the detection method steps are as follows:

Step1：首先对采集的待检品图像进行液位扫描工作，根据现场液位的变动区域，设定液位扫描线的信息；Step1: First, perform liquid level scanning on the collected image of the product to be inspected, and set the information of the liquid level scanning line according to the change area of the liquid level on site;

Step2：液位扫描单元沿与液位线垂直的方向在液位检测区域内寻找液位扫描线上的液位待检点；Step2: The liquid level scanning unit looks for the liquid level waiting point on the liquid level scanning line in the liquid level detection area along the direction perpendicular to the liquid level line;

Step3：液位获取单元找到液位待检点数值分布满足条件的区域，记录该区域内所有液位待检点为液位点；Step3: The liquid level acquisition unit finds the area where the value distribution of the liquid level to-be-inspected points meets the conditions, and records all the liquid-level to-be-inspected points in this area as liquid level points;

Step4：液位获取单元获取到所有液位点之后，计算出液位在待检品中的实际高度；Step4: After the liquid level acquisition unit acquires all the liquid level points, calculate the actual height of the liquid level in the product to be inspected;

Step5：质量判别单元接受液位获取单元给出的液位值与预先设定的液位上限值和下限值比较，如液位值在上限值和下限值之间则认为液位合格，否则认为液位不合格；Step5: The quality discrimination unit accepts the liquid level value given by the liquid level acquisition unit and compares it with the preset upper limit value and lower limit value of the liquid level. If the liquid level value is between the upper limit value and the lower limit value, the liquid level is considered Qualified, otherwise the liquid level is considered unqualified;

Step6：控制设备将灌装不合格的产品剔除。Step6: The control equipment will remove the unqualified products.

所述的step1中，所述的图像是从工业相机中获取的包含液位信息的灰度图像。In said step1, said image is a grayscale image including liquid level information obtained from an industrial camera.

所述的step1中，所述的液位扫描线的信息包括液位扫描线的条数和间隔。In the step 1, the information of the liquid level scanning lines includes the number and interval of the liquid level scanning lines.

所述step3中，所述液位点寻找步骤如下：In the step3, the steps of finding the liquid level point are as follows:

1)设置区域内液位待检点最大值mnum的初始值为0，区域中心位置c初始值为液位扫描线起始a坐标值f，f为现场出现的最低液位所在位置a坐标值，终止值为液位扫描线终止a坐标值t，t值设定为瓶口所在位置a坐标值，区域半径为r；1) The initial value of the maximum value mnum of the liquid level to be checked in the area is set to 0, the initial value of the center position c of the area is the initial value of the a coordinate value f of the liquid level scanning line, and f is the a coordinate value of the position where the lowest liquid level appears on the scene, The end value is the end a coordinate value t of the liquid level scanning line, the t value is set as the a coordinate value of the position of the bottle mouth, and the area radius is r;

2)计算所有液位待检点中数值在c-r与c+r之间的液位待检点个数num，如果num大于mnum，则mnum=num，修改液位区域中心点levelcenter=c；2) Calculate the number num of liquid level points to be checked with values between c-r and c+r among all liquid level points to be checked. If num is greater than mnum, then mnum=num, and levelcenter=c is modified as the center point of the liquid level area;

3)将c值加1，如c>t，转到步骤4），否则转到步骤2）；3) Add 1 to the value of c, if c>t, go to step 4), otherwise go to step 2);

4)记录所有液位待检点中数值在levelcenter-r与levelcenter+r之间的液位待检点为液位点。4) Record all liquid level checkpoints whose values are between levelcenter-r and levelcenter+r as liquid level points.

所述的step4中，所述液位在待检品中的实际高度的计算步骤为：In said step4, the calculation steps of the actual height of the liquid level in the product to be inspected are:

（1）计算所有液位点的数值和sum；(1) Calculate the value and sum of all liquid level points;

（2）计算液位点的平均值得到液位线a轴坐标lev=sum/mnum；(2) Calculate the average value of the liquid level points to obtain the a-axis coordinates of the liquid level line lev=sum/mnum;

（3）根据工业相机获取的图像和待检品匹配关系计算液位，设拍摄视野内待检品最低处对应的a坐标值为low，对应的待检品实际高度为h，所述最低处是相对液位；每像素对应的待检品实际高度为pixh，则液位实际高度level为：(3) Calculate the liquid level according to the matching relationship between the image acquired by the industrial camera and the product to be inspected. Let the a coordinate value corresponding to the lowest point of the product to be inspected in the shooting field of view be low, and the corresponding actual height of the product to be inspected be h. is the relative liquid level; the actual height of the product to be inspected corresponding to each pixel is pixh, then the actual height level of the liquid level is:

level=h+（lev-low）*pixh。level=h+(lev-low)*pixh.

本发明的有益效果：本发明检测液位测量精度高，实时性好，且对人体不会造成任何伤害。既可以采用本发明叙述的方法做成单独的产品，也可以方便的添加到现有的视觉检测装置内，扩展现有系统的功能，可完全代替人工检测，拥有广泛的应用价值。Beneficial effects of the present invention: the present invention has high detection accuracy of liquid level measurement, good real-time performance, and does not cause any harm to the human body. The method described in the present invention can be used to make a separate product, and can also be conveniently added to the existing visual inspection device to expand the functions of the existing system, can completely replace manual inspection, and has wide application value.

附图说明Description of drawings

图1为实现本发明的一个较佳系统结构图；Fig. 1 is a preferred system structure diagram for realizing the present invention;

图2为实现本发明的算法说明示意图；Fig. 2 is a schematic diagram illustrating an algorithm for realizing the present invention;

其中，1光源，2待检品，3相机，4算法处理装置，5液位扫描单元，6液位获取单元，7质量判别单元，8控制设备，9液位扫描线，10液位线。Among them, 1 light source, 2 items to be inspected, 3 cameras, 4 algorithm processing devices, 5 liquid level scanning unit, 6 liquid level acquisition unit, 7 quality discrimination unit, 8 control equipment, 9 liquid level scanning line, 10 liquid level line.

具体实施方式Detailed ways

下面结合附图，对本发明做进一步的详细介绍：Below in conjunction with accompanying drawing, the present invention is described in further detail:

如图1所示，一种饮料灌装后液位检测装置，该装置包括光源1和相机3，所述光源1和相机3与待检品2相配合；所述相机3与算法处理装置4的液位扫描单元5连接；所述算法处理装置4还包括液位获取单元6和质量判别单元7，所述液位扫描单元5、液位获取单元6和质量判别单元7依次连接；质量判别单元7还与算法处理装置4外的控制设备8连接。As shown in Figure 1, a liquid level detection device after beverage filling, the device includes a light source 1 and a camera 3, the light source 1 and the camera 3 cooperate with the product 2 to be inspected; the camera 3 and the algorithm processing device 4 The liquid level scanning unit 5 is connected; the algorithm processing device 4 also includes a liquid level acquisition unit 6 and a quality discrimination unit 7, and the liquid level scanning unit 5, the liquid level acquisition unit 6 and the quality discrimination unit 7 are connected in sequence; the quality discrimination The unit 7 is also connected to a control device 8 outside the algorithm processing device 4 .

本发明所处理的图像来自采用工业相机采集的现场生产线上的灌装后饮料，图像采集部分（相机和光源）可以是为单独检测液位安装的背光照明和工业相机（如果是彩色工业相机需要对图像进行灰度化），也可以是现场具有类似图像采集结构的现有系统，如果是对现场现有的图像采集系统，则该发明作为现有系统的功能扩展添加到现有系统之中。The images processed by the present invention come from the beverages after filling on the on-site production line collected by industrial cameras. The image acquisition part (camera and light source) can be a backlight and an industrial camera installed for separate detection of liquid level (if it is a color industrial camera, it needs grayscale image), or an existing system with a similar image acquisition structure on site, if it is an existing image acquisition system on site, the invention will be added to the existing system as a functional extension of the existing system .

图1所表示的是能够实现本发明的一套较佳系统，系统中待检品2经过有背光照明的区域，待检品2的图像在照明区域被工业相机准时捕捉并发送给现场的算法处理装置4，经算法处理装置4处理后，检测结果被发送给控制设备8，当待检品2检测结果不合格时，由控制设备8将不合格待检品2剔出包装线。其中背光光源建议选择启动速度快，能耗低，寿命长的LED光源，光源颜色最好与待检品颜色相近，暖色用红色光源，冷色用绿色光源，无色用白色光源。Figure 1 shows a set of better systems that can realize the present invention. In the system, the product 2 to be inspected passes through an area with backlighting, and the image of the product to be inspected 2 is captured by an industrial camera in the illuminated area on time and sent to the scene. The processing device 4 is processed by the algorithm processing device 4, and the test result is sent to the control device 8. When the test result of the product 2 to be inspected is unqualified, the control device 8 will remove the unqualified product 2 to be inspected from the packaging line. Among them, the backlight light source is recommended to choose the LED light source with fast start-up speed, low energy consumption and long life.

附图2中a轴，b轴均是为表达算法方便而设定的坐标线，算法中设定的液位扫描线与a轴平行与b轴垂直，液位扫描线范围要包括整个检测区域。The a-axis and b-axis in Figure 2 are coordinate lines set for the convenience of expressing the algorithm. The liquid level scanning line set in the algorithm is parallel to the a-axis and perpendicular to the b-axis. The range of the liquid level scanning line should include the entire detection area .

相机3建议采用工业黑白相机，黑白相机采集数据量小，而且对图像灰度的表示更精确。Camera 3 is recommended to use an industrial black-and-white camera. The black-and-white camera collects a small amount of data and has a more accurate representation of the grayscale of the image.

算法处理装置4可选用DSP或工控机等可编程处理器。Algorithm processing device 4 can choose programmable processors such as DSP or industrial computer.

算法处理装置4中实现一种饮料灌装后液位检测方法主要包括三部分，即液位扫描单元5、液位获取单元6和质量判别单元7。A method for detecting the liquid level of beverages after filling in the algorithm processing device 4 mainly includes three parts, namely, the liquid level scanning unit 5 , the liquid level acquisition unit 6 and the quality judgment unit 7 .

图片进入算法处理装置4之后液位扫描单元5首先进行液位扫描的工作，根据现场液位的变动区域，设定液位扫描线的起始a轴坐标和结束a轴坐标，液位扫描线的条数和间隔，液位扫描线条数越多越密则液位求取精度越高，不过实时性却随着液位扫描线条数的增多而降低。After the picture enters the algorithm processing device 4, the liquid level scanning unit 5 first performs the work of liquid level scanning. According to the fluctuation area of the liquid level on site, the initial a-axis coordinate and the end a-axis coordinate of the liquid level scanning line are set, and the liquid level scanning line The more and denser the number of liquid level scanning lines, the higher the accuracy of liquid level calculation, but the real-time performance decreases with the increase of the number of liquid level scanning lines.

液位扫描线是多条与液位所在的坐标轴（b轴）垂直的平行直线。The liquid level scanning line is a plurality of parallel straight lines perpendicular to the coordinate axis (b axis) where the liquid level is located.

液位扫描采用自定义条数的扫描线沿与液位线10垂直的方向在液位检测区域内寻找扫描线上灰度变化最强烈的点，像素灰度变化强度用该像素灰度值和沿扫描线反方向的相邻像素灰度值的差的绝对值表示，如像素p1灰度变化强度intensity的计算公式为Liquid level scanning adopts a custom number of scanning lines to find the point with the strongest gray scale change on the scanning line in the liquid level detection area along the direction perpendicular to the liquid level line 10, and the pixel gray scale change intensity is determined by the pixel gray value and The absolute value of the difference between the gray value of adjacent pixels along the opposite direction of the scan line, for example, the calculation formula of the gray change intensity intensity of pixel p1 is:

intensity=|gp1-gp2|；intensity=|gp1-gp2|;

其中gp1表示像素p1灰度值，gp2表示像素p1沿扫描线反方向的相邻像素p2的灰度值。Where gp1 represents the gray value of the pixel p1, and gp2 represents the gray value of the adjacent pixel p2 of the pixel p1 along the opposite direction of the scanning line.

液位扫描单元5计算所有扫描线上的像素的灰度变化强度并记录所有扫描线上灰度变化强度最高的点的a轴坐标，将这些坐标数值保存为液位待检点。The liquid level scanning unit 5 calculates the gray scale change intensity of pixels on all scanning lines and records the a-axis coordinates of the points with the highest gray scale change intensity on all scanning lines, and saves these coordinate values as liquid level waiting points.

液位获取单元6接收液位扫描单元5提供的液位待检点，并寻找液位待检点数值分布最集中的区域（区域大小可设定），记录区域内所有待检点数值为液位点。The liquid level acquisition unit 6 receives the liquid level to-be-checked points provided by the liquid-level scanning unit 5, and finds the area where the values of the liquid-level to-be-checked points are most concentrated (the size of the area can be set), and records all the values of the to-be-checked points in the area as liquid level points.

液位点寻找步骤如下（假设液位扫描线起始a坐标值为f，终止a坐标值为t，可变大小区域半径为r）The steps to find the liquid level point are as follows (assuming that the starting a coordinate value of the liquid level scanning line is f, the ending a coordinate value is t, and the radius of the variable size area is r)

a)设置区域内液位待检点最大值mnum的初始值为0，区域中心位置c初始值为液位扫描线起始a坐标值f（f值设定为现场可能出现的最低液位所在位置a坐标值），终止值为液位扫描线终止a坐标值t（t值设定为瓶口所在位置a坐标值），区域半径为r；a) Set the initial value of the maximum value mnum of the liquid level to be checked in the area to 0, and the initial value of the center position c of the area to be the coordinate value f of the initial a of the liquid level scanning line (the value of f is set to the position of the lowest liquid level that may appear on the site a coordinate value), the termination value is the liquid level scanning line termination a coordinate value t (the t value is set as the a coordinate value of the position of the bottle mouth), and the area radius is r;

b)计算所有液位待检点中数值在c-r与c+r之间的液位待检点个数num，如果num大于mnum，则mnum=num，修改液位区域中心点levelcenter=c；b) Calculate the number num of the liquid level to-be-checked points whose value is between c-r and c+r in all the liquid-level to-be-checked points, if num is greater than mnum, then mnum=num, and modify the levelcenter=c of the center point of the liquid level area;

c)将c值加1，如c>t，转到步骤（4），否则转到步骤（2）；c) Add 1 to the value of c, if c>t, go to step (4), otherwise go to step (2);

d)记录所有液位待检点中数值在levelcenter-r与levelcenter+r之间的液位待检点为液位点。d) Record all liquid level checkpoints whose values are between levelcenter-r and levelcenter+r as liquid level points.

液位获取单元6获取到所有液位点之后，根据液位点数值和图像与待检品匹配关系计算液位的实际值，具体步骤为：After the liquid level acquisition unit 6 obtains all the liquid level points, it calculates the actual value of the liquid level according to the value of the liquid level points and the matching relationship between the image and the product to be inspected. The specific steps are:

（1）计算所有液位点的数值和sum；(1) Calculate the value and sum of all liquid level points;

（2）计算液位点的平均值得到液位线10的a轴坐标lev=sum/mnum；(2) Calculate the average value of the liquid level points to obtain the a-axis coordinate lev=sum/mnum of the liquid level line 10;

（3）根据工业相机获取的图像和待检品匹配关系计算液位，设拍摄视野内待检品最低处（相对液位）对应的a坐标值为low，对应的待检品实际高度为h，每像素对应的待检品高度为pixh，则液位实际高度level为(3) Calculate the liquid level according to the matching relationship between the image acquired by the industrial camera and the product to be inspected. Let the a coordinate value corresponding to the lowest point (relative liquid level) of the product to be inspected in the shooting field of view be low, and the corresponding actual height of the product to be inspected be h , the height of the product to be inspected corresponding to each pixel is pixh, then the actual height level of the liquid level is

level=h+（lev-low）*pixh；level=h+(lev-low)*pixh;

质量判别单元7接受液位获取单元6给出的液位值与预先设定的液位上限值和下限值比较，如液位值在上限值和下限值之间则认为液位合格，否则认为液位不合格，液位上限值和下限值根据企业所能容忍的最大最小灌装量和灌装设备的精度设定，如上限值可设定为距离瓶口3厘米，下限值可设定为距离瓶口5厘米。The quality discrimination unit 7 accepts the liquid level value given by the liquid level acquisition unit 6 and compares it with the preset liquid level upper limit value and lower limit value. If the liquid level value is between the upper limit value and the lower limit value, it is considered that the liquid level Qualified, otherwise the liquid level is considered unqualified. The upper limit and lower limit of the liquid level are set according to the maximum and minimum filling volume that the company can tolerate and the accuracy of the filling equipment. For example, the upper limit can be set at 3 cm from the bottle mouth , the lower limit can be set at 5 cm from the bottle mouth.

图片处理结束后质量判别单元7将处理结果发送给控制设备8，由控制设备8控制将灌装不合格的产品剔除。After the picture processing is finished, the quality judging unit 7 sends the processing result to the control device 8, and the control device 8 controls to reject the unqualified filling products.