Today, automotive part manufacturers and their suppliers need technology that allows them to catch major errors before they ship products to their customers. This technology needs to deliver absolute accuracy in part inspection, often with permitted deviations of only a few micrometers. That is why Bosch Diesel s.r.o. in Jihlava, Czechoslovakia, a manufacturer of automotive components for the Diesel Systems division, decided to install machine vision systems to check product quality as well as code readers to be able to track the components they produce.
“When I came to Bosch Diesel in 2008, Cognex was already being used quite a bit here; we were using about 30 barcode readers and four vision systems. These Cognex vision and ID systems proved useful for us since we produce bodies first in the soft state and then finish them in the solid state. We did not want to use vision and ID systems from several producers so as to avoid compatibility issues. This is why we acquired additional systems from Cognex as our needs grew. Today, just in our department for CP 3 body production alone, we employ about 80 barcode readers and more than 25 vision systems. In the whole of the Bosch production facility in Jihlava there are many more installed,” explains Petr Koten, Diesel Systems division working technologist of the Bosch Company.
“At the beginning of our cooperation, some selected workers were trained by Cognex. Subsequent training for the Bosch workers was arranged internally. With respect to the device management, the setting of the ID readers is done with the easy-to-use DataMan® ID reader Setup Tool. The vision system and program installation is more complex and requires specific experience. To meet this challenge at Bosch Jihlava we use the Spreadsheet programming interface found in the In-Sight® Explorer software which provides a robust, flexible and efficient way to configure the vision tools and handle the data created from our application” explains Koten.
It is not difficult to train users how to use the ID readers . They each receive a card with three configuration Data Matrix codes (DMCs) printed that are used for restarting the ID reader. This makes it easy to move an ID reader to another docking station and set up a reader for a given operation such as lighting, confirmation symbols, sound settings, etc. The machine operators themselves do not set up the vision systems; they only wipe the lens cover if needed.
In the CP 3 department, Cognex ID readers and vision systems are used to control the work and finishing on the production lines in twelve sections. Their main job is to eliminate production errors on pump bodies and other products, and if an error is detected, to identify the source. This allows Bosch Jihlava to eliminate the distribution of defective products to the next station and at the same time learn from these errors. DataMan ID readers are used to control the legibility of the imprinted 6mm DMCs. The success rate of the caught errors (readings) has increased from the original 85 percent before using Cognex vision systems and ID readers to a current rate of 99 to 100 percent.
The demanding operations at Bosch Jihlava also required the installation of other technologies that supported the functionality of the machine vision systems. “Ambient lighting is a factor that may have an impact on the functionality of the machine vision system. Therefore, it is necessary in some cases to use special external lights, such as infrared lighting. This can be built into the system without any problem. The whole system, made up of a camera, additional lighting and perhaps a blower, is controlled by an external control unit (PLC),” explains Koten.
The main advantage offered by the ID readers and vision systems is the availability of the tracked course of pump bodies through the production from all key operations. According to the production requirements, different properties are recorded using DMC: operation time, name of the worker, machine, spindle, code quality of the DMC and body status. One of the most striking effects on production is the possibility of back search by using the recorded images from production operations.
Another advantage provided by the Cognex ID readers at Jihlava Bosch is the ability to use them without the need for a fixed connection, which was not available earlier. Out of about 80 ID readers currently being used, approximately 75 are wireless. Sometimes it is necessary to use the readers two or three meters from the table where they are normally placed, and handling a wired reader would not only be more time consuming but also more dangerous as slippery floors in the production environment create hazards for line operators.
In the process of automotive components production, a high volume of dirt is created that also gets onto the vision systems. The Cognex ID readers and vision systems can cope with dust and smears easily. Workers only need to wipe the cover of thecamera lens twice or three times per shift and no other maintenance is needed. That is why an additional blower is used for the products to clean the dirt from the DMC so that it can be checked by the readers.
Even though the automotive industry and its suppliers are expending efforts to minimize how much they spend on new technologies, the Diesel Systems division at Jihlava Bosch plans to purchase three more vision systems because of the ease of use and robustness of Cognex products. Saving labor costs is very important in this area and ID and vision systems from Cognex contribute to driving down these costs.