tobacco Industry

Application of machine vision in tobacco industry

2019-11-13

Tobacco industry is a big industry in China, which can create a lot of tax and employment opportunities for the government every year. The management of these enterprises attaches great importance to the quality of products, and they are willing to choose good automation equipment to improve the quality of their products.

Cigarette machine is one of the complex machines in the field of automation, and the production speed of cigarette is very fast. For example, the production speed of flexible packaging line is 360 packages / min. because of the fast production speed and the very soft packaging of products, there are many unqualified products in the production process. It is very important to find and remove the unqualified products in time, otherwise the unqualified products will flow to the next process and be packed and boxed. For the unqualified products, although it does not affect the use, it will reduce the satisfaction of users, and the time will also weaken the brand value and product reputation, which is absolutely not what the management is willing to see.

There are three types of packages: soft package, hard package and strip box. Because the outer package of the soft bag is soft and easy to deform, it is difficult to detect the soft bag. For soft bags, a major problem is surface damage, as shown in the figure:

2. Test content:

Trademark printing (whether it is missing, whether the direction is correct, and whether the position is correct);

Small flower on the top, (whether it is missing, whether the direction is correct, and whether the position is correct);

Top and bottom internal packaging quality;

Detection of relevant positions of inner and outer packaging, etc.

Because the speed of the production line is very fast (6 packets / second) and the detection task is very complex and urgent, it is impossible to find and remove the unqualified products on the production line manually.

The current detection method is manual sampling. In other words, it can't be detected online. As a result, there are many unqualified products entering the market, but the management cannot control or know the specific quantity.

2. Test content:

Trademark printing (whether it is missing, whether the direction is correct, and whether the position is correct);

Small flower on the top, (whether it is missing, whether the direction is correct, and whether the position is correct);

Top and bottom internal packaging quality;

Detection of relevant positions of inner and outer packaging, etc.

The current detection method is manual sampling. In other words, in fact, it is impossible to check online. For high-speed applications, machine vision is the only solution. Specifically for the tobacco industry, intelligent camera can be used. The system uses intelligent visual sensor to replace human eye to complete the detection task and logic operation. The visual sensor captures the image and sends it to the internal processor within 0.4ms. After being digitized by the processor, the machine vision system can evaluate its color, surface and size. According to the calculation results, we can realize the automatic detection and elimination of cigarette box by the external interface signal.

3. Advantages of selecting machine vision system:

• reduce product turnover costs

• reduce machine downtime

• improve product quality

4. Speed of production line:

It's 360 packets per minute, or 6 packets per second.

5. Detection principle:

The two vision sensors capture the image of the front, rear, left, right and top five sides of the cigarette packet respectively, and then determine the edge of the soft packet with the positioning analysis "spectrum function", and carry out the detection task according to the actual position after the edge is determined. For example, for the top image, we use "soft sensor" such as density, eigenvalue counting, template matching, measurement to achieve the detection task. The test results are output to S7 300 PLC, the controller is programmed to complete the control of the rejection device, and the output signal is sent to the executive system - air valve to reject the unqualified products.

After on-line debugging, we get satisfactory results. Almost all the marked unqualified products are removed. The application of the system can ensure that the non-conforming products do not enter the market, which can improve the product level, user satisfaction and potential brand value, of course, can also reduce the cost of recycling. Measurement. As a result, there are many unqualified products entering the market, but the management cannot control or know the specific quantity.