This article was originally published by RFID Update.
July 16, 2008—An automaker used approximately 405,000 passive UHF RFID tags and active ultra wideband (UWB) real time locating system (RTLS) tags to make sure the right parts were installed in the right vehicles during a six-week test that was announced this week. Ubisense of Cambridge, UK provided the UWB technology and tracking software, and Alien Technology provided the UHF systems for the automaker, which will not disclose its identity, the manufacturing site location, or details of the results.
A UWB tag was applied to each chassis at the beginning of the final assembly process and encoded with the unique Vehicle Identification Number (VIN), Ubisense CEO Richard Green told RFID Update. Ubisense UWB readers tracked each vehicle as it progressed through 26 different assembly stations. Every component installed at the stations included a passive RFID tag from Alien. Fixed-position readers automatically recorded each component installed. System software matched the component to the specific vehicle using part data from the passive system and chassis location data from the UWB system. Alerts were issued if incorrect components were installed in the vehicle.
Passive UHF RFID technology commonly has a read range of 20 to 30 feet, but provides limited ability to determine the actual tag location within that range. Ubisense’s UWB technology was developed to provide precise location data, and is accurate to within about 15 centimeters, according to the company.
The RFID readings replaced bar code scanning to verify that vehicles were at the right production station and receiving the correct components. “In the automotive industry, the practice is known as ‘error proofing,'” said Green. “Most importantly, RFID can prevent errors. The automaker also believes it can reduce the labor required for verification by a significant amount.”
The manufacturer will not disclose its labor requirements or error rates. Green said the company is now evaluating whether to use the UHF-UWB system full time in production. During the test, the factory produced 500 vehicles per day, according to Green. Based on that production, the six-week trial would have required approximately 405,000 RFID tags, including 15,000 UWB tags for vehicles and 390,000 passive UHF tags for components.
“We thought this project was a really neat combination of the two types of technologies,” Green said. “Anywhere there are components you need to track and verify where they have been placed, the combination of technologies makes enormous sense.”
Green said most of Ubisense’s installations in industrial environments have been for tool tracking, and that the company has integrated with UHF systems before. There is increasing momentum for multiple-frequency RFID systems. In May, Cisco released a new platform to simplify the integration of RTLS and other RFID technologies (see New System Marries RFID Location Data With Item Info). Previously, RTLS provider AeroScout announced other RFID technologies could be integrated into its system (see New RTLS Solution Combines WiFi, UWB, and RFID), and several other vendors reported similar developments during an industry event in April (see RFID Journal LIVE a Signpost of RFID Market Maturity).