Cognex smart cameras are widely used in meter character detection

 The Power Grid Company (hereinafter referred to as State Grid) is the largest power grid enterprise in China. Since digital meters in various places must be uniformly distributed and installed after testing by State Grid, due to the huge number, automated testing equipment is urgently needed to improve production efficiency.
"In the previous electricity meter testing process, specialized personnel were required to manually switch screens to observe whether the characters displayed on each screen were correct." A technical engineer from the State Grid said, "Because of the large number of characters, complex shapes, and small character areas, Because of the fast detection speed and easy fatigue of personnel, the detection efficiency is low, and problems of missed detection and false detection are easy to occur."
Chengdu Xinxiwang Automation Technology Co., Ltd. has strong technical capabilities to complete various application challenges. The market has accumulated a good reputation. State Grid learned through website inquiries that Xinxiwang Technology had extensive experience in LCD screen testing, so it approached them for cooperation.
After on-site investigation, Xinxiwang Technology found that the testing equipment needs to be installed before the electric meter is transferred to Zhengding for testing. After passing the test, it will be sent to the Zhengding testing platform. After the electric meter enters the appearance inspection machine, the software loads the corresponding inspection template from the database according to the type of electric meter. Then, after the device is inserted into the ejection pin and powered on, it switches to different wheel display screens according to commands. During the process of switching pictures, the camera takes pictures and detects each picture. After the test is completed, the test screen and test results must be uploaded to the server database to achieve traceability of the test data.
"The biggest challenge in this application is that the types of electricity meters on each production line are different, requiring frequent switching of models. Moreover, the camera installation methods on each production line are also different, which results in an increase in the number of templates." Technical engineer of Xinxiwang Technology Company Pointed out, "In addition, this application involves database storage templates and data, as well as various communication protocols, which all need to be re-learned." "
Because the customer has configured a central database, we envisage storing all model detection tools in In the database, what needs to be pointed out here is that VisionPro's tools can be perfectly stored in the database. Every time you change a product, you need to extract the required detection template from the database first, and then start detection." Technology from Xinxiwang Technology Company The engineer said, "After the test is completed, the data and images are compressed and uploaded to the database. In this way, we do not need to configure a complex database system locally and can reduce the amount of terminal design." In addition, because the surface reflectivity of the meter is inconsistent
, When choosing a light source, you need to consider the lighting method. Xinxiwang Technology Company chose a strip light source. Lighting from the side can reduce direct reflection from the front and prevent the pattern from being unclear.
"In addition, customers have shorter requirements for CT time, and the detection content is large and complex, which takes a long time." said a technical engineer from Xinxiwang Technology Company. "In order not to affect the CT time, we adopted a dual-station mode. , reducing the time by half."
The optimized operation process is as follows:
1) When a new model arrives, use the template creation function to create a corresponding template for each character, and then store the template in the database. In the main program, just reload the template sequence of the corresponding batch. In the next inspection, a new template will be called to inspect each instrument.
2) When replacing an existing model, first use the template search function to fuzzy search for the template of the corresponding batch, and then load it. Just reload the corresponding template sequence in the main program. In the next inspection, a new template will be called to inspect each instrument.
3) The equipment only requires personnel intervention when changing models, and will run by itself at other times.
"After using Cognex's smart cameras, the detection efficiency of electric meters has been greatly improved, the production speed has increased by 200%, and the missed detection rate and false detection rate have been effectively reduced, saving a lot of labor costs. It meets the requirements of the new production line's 24-hour continuous operation According to the production requirements, no personnel is required to attend the whole process, and the meter model can be switched at will, realizing the traceability of the test data." The excellent performance and reliable quality of Cognex products have been highly praised and recognized by the technical engineers of the State Grid. "At present, The system has been running stably for half a year, and we will give priority to Cognex products in subsequent new production lines."

1: Appearance of on-site equipment

2: Appearance of testing equipment and software

3: Software interface