Audi relies on RFID system from Dürr and Kathrein Solutions for demand-driven maintenance

All Dürr atomizers are equipped with a quick-change device. The big advantage: If a malfunction or problem occurs, production can be resumed after a quick exchange. This technology helps to reduce line downtimes to a minimum. However, with up to 80 atomizers, it also entails the risk of confusion for the worker when atomizers, bell disks, turbines, valves and air rings are located close together at maintenance stations and need to be quickly assigned, processed and reinstalled in the paint booth. Until now, it was very difficult to keep track of which part was installed in which robot and when, partly because, for example, production and maintenance are at different locations or the inspection does not take place on the same shift. This often made communication channels and the documentation of individual parts difficult. However, this information is valuable for operators.

To make the life history traceable, Dürr is now equipping every component of its latest EcoBell4 atomizer generation with RFID - the hardware comes from Kathrein Solutions. Just as a detective monitors people, the technology can identify objects and document their use. Each type of component has its own data record, from which the number of switching cycles can be read from valves, for example, or the number of revolutions or the amount of paint that has been processed from the bell cup. This is used to calculate the service life, which can be individually adjusted by the customer as required. In the new top coat line at the Ingolstadt plant, 28 painting robots are equipped with RFID technology.

RFID makes processes more efficient

RFID stands for "Radio-Frequency Identification", i.e. identification using radio waves. Many industries are already using the technology, which transmits information wirelessly, to make their processes more efficient. RFID is used to identify containers in port terminals, control ticketless entrances in parking garages and automate checkout processes in retail. In simple terms, the wireless data exchange of an RFID system works by something sending and something receiving. The transmitter is a RFID transponderwhich consists of a microchip and an antenna. The receiver is the RFID readerwhich reads the data from the chip and forwards it to a computer system. Dürr recognized the advantages that the technology offers in a paint shop, both for high system availability and for more efficient maintenance. As there was no RFID system available for this environment, Dürr developed a tailor-made solution based on the technology from Kathrein Solutions GmbH.

New geometry for interference-free data exchange

The metal often used in paint booths shields the radio signals. Conventional RFID chips, which achieve long ranges in many applications, do not work there. Accordingly, the engineers at Dürr and Kathrein Solutions jointly developed a transponder with individual antenna geometry for each component of the atomizer. The chips and ranges of the antennas are designed in such a way that the radio waves penetrate all materials. Inside the cabin Low-range antennas with the lowest possible susceptibility to interference, outside Wide-range antennas. They supply the passive transponders with energy.

Illustration: The new topcoat line at the Audi plant in Ingolstadt has 28 painting stations.
robots are equipped with RFID technology. This allows extensive
information chains, for example on the number of operating cycles or speeds, directly
on the components.

 

Read and write function on a transponder

The transponders can both read and write operating data. This allows extensive information chains, such as the number of operating cycles or speeds, to be recorded directly on the components. The memory capacity of the chips is sufficient for large amounts of data. The newly developed infrastructure also connects a PC to a central database that manages all RFID data from one or more painting lines. The maintenance station is also connected to this. As all information is stored both in the database and directly on the atomizers, a seamless system with data access at both levels is created. The operator can therefore view the current status of the atomizer and its components both at the maintenance station and at the line itself.

Avoid typical mistakes in the paint booth

After manual installation, it could always happen that a bell cup was installed in the wrong paint booth or for the wrong painting process. This worsened the painting result and, in practice, could possibly only become apparent after several incorrectly coated car bodies and cause considerable reworking. Such typical errors are avoided in the new line at Audi, as the RFID readers automatically identify each component using a unique identification number. In the event of incorrect replacement or missing parts, the system warns the operator via a pop-up window before the painting process is even started.

Demand-driven maintenance saves costs

The RFID maintenance station shows the technician all the specifications of a component and its maintenance history. The exact history enables needs-based maintenance that makes optimum use of the service life of components. This saves maintenance costs, as only parts that are actually worn out are replaced. System availability is also significantly increased as the operating personnel can plan all maintenance measures in advance. Detailed tutorials support high maintenance quality. Clearly prepared videos guide even semi-skilled personnel step-by-step through the processes, starting with the right tools and the required auxiliary materials through to the necessary steps for individual assembly elements or entire atomizers. The workstation contains all the necessary tools and a printer. This can be used to print labels with information such as operating hours and the date of the last repair, so that the worker in the production plant immediately recognizes that a component is a serviced, freshly reconditioned atomizer.

More sustainable and efficient painting

Audi has placed great emphasis on sustainable and at the same time highly productive equipment for the new top coat line. The redesign of one line, i.e. half of the top coat capacity, improves the environmental balance of the entire Ingolstadt plant. The application technology with the economical EcoBell4 with 4-main needle technology, which significantly reduces overall paint consumption, contributes to this. The amount of paint saved can be used to produce an additional 12,500 car bodies. The digitalization of the atomizer contributes to system availability. This is because it makes it possible to use the newly developed RFID system to optimize processes in the paint shop, reduce errors and increase efficiency.

 

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Case Study | Audi relies on RFID system for demand-driven maintenance