More RFID Journal Sites: RFID Journal Espanol RFID Journal Brasil RFID Journal Events RFID Journal Awards
Manufacturing NEWS
Text size:
T
T
T
BMW Finds the Right Tool
The system, which was fully deployed in January 2009, enables BMW to identify each vehicle as it moves through the assembly line, and to recognize not only its location to within inches, but all of the tools being used on that car as well. Extreme precision was necessary for pinpointing location, since each vehicle on the line is situated approximately 1 foot behind the one before it, and as many as five tools are often used on a single vehicle at the same time.
When the empty shell of a BMW car enters the assembly process, an employee encodes its VIN onto a Ubisense UWB RFID tag and places that tag—which has a magnetic backing—onto the vehicle's hood. The tag then transmits the car's VIN number via a series of short signals (between 6 and 8 GHz). Approximately 380 Ubisense interrogators were installed above the assembly line, capturing the VIN numbers being transmitted by any UWB active tags in their vicinity. This helps the system identify each tag's location. In addition, the system measures a signal's angle, in order to better pinpoint a tag's location. A similar UWB tag is attached to each tool, with a unique ID number that beacons at different rates, depending on whether a particular tool is moving. If the tool remains motionless, it ceases transmitting entirely until someone picks it up.
Once readers capture a tool's tag ID number, they transmit that data to the back-end system via a cabled connection. The TAS software then integrates the tags' location with the existing IBS tool-control system, which sends the appropriate instructions to the tools being used on that specific tagged car.
Now that the infrastructure is in place, Green says, the company can use the data for additional purposes as well, such as tracking the location of a vehicle sent back for servicing or adjustments after assembly has been completed. Once the factory's quality-control department approves a vehicle, the tag is removed and the BMW emblem is placed on the hood. The tag can then be reused on another car.
According to Green, the greatest challenge for the system was ensuring that the tags could be interrogated accurately in a highly metallic environment, as metal can potentially make it harder to read tags. The ability to pinpoint the location of tools and vehicles was critical, he notes, and the large network of UWB readers was able to provide that level of precision. "We've learned quite a lot through this installation," Green states, though Ubisense already had experience deploying a similar tool-tracking application for Caterpillar (see RFID Tightens Up Caterpillar's Assembly Process). One key lesson, he says, has been the importance of having tagged tools, and Ubisense is now in discussions with several tool manufacturers to embed RFID tags in the tools before they ever reach a customer like BMW.
more Manufacturing articles
When the empty shell of a BMW car enters the assembly process, an employee encodes its VIN onto a Ubisense UWB RFID tag and places that tag—which has a magnetic backing—onto the vehicle's hood. The tag then transmits the car's VIN number via a series of short signals (between 6 and 8 GHz). Approximately 380 Ubisense interrogators were installed above the assembly line, capturing the VIN numbers being transmitted by any UWB active tags in their vicinity. This helps the system identify each tag's location. In addition, the system measures a signal's angle, in order to better pinpoint a tag's location. A similar UWB tag is attached to each tool, with a unique ID number that beacons at different rates, depending on whether a particular tool is moving. If the tool remains motionless, it ceases transmitting entirely until someone picks it up.
Once readers capture a tool's tag ID number, they transmit that data to the back-end system via a cabled connection. The TAS software then integrates the tags' location with the existing IBS tool-control system, which sends the appropriate instructions to the tools being used on that specific tagged car.
According to Green, the greatest challenge for the system was ensuring that the tags could be interrogated accurately in a highly metallic environment, as metal can potentially make it harder to read tags. The ability to pinpoint the location of tools and vehicles was critical, he notes, and the large network of UWB readers was able to provide that level of precision. "We've learned quite a lot through this installation," Green states, though Ubisense already had experience deploying a similar tool-tracking application for Caterpillar (see RFID Tightens Up Caterpillar's Assembly Process). One key lesson, he says, has been the importance of having tagged tools, and Ubisense is now in discussions with several tool manufacturers to embed RFID tags in the tools before they ever reach a customer like BMW.
