In-Floor RFID Tags to Navigate Robots

By Rhea Wessel

Mar. 17, 2006—Vorwerk Teppichwerke, a manufacturer of vacuum cleaners and carpets located in Hamlin, Germany, has launched the market debut of its "smart-floor" system, a flooring underlayment with embedded passive 13.56 MHz RFID tags.

Just like an ordinary underlayment—padding or other material placed over a subfloor to provide a smooth, stable surface for the finish material—Vorwerk's RFID-enabled version serves as an insulator and noise reducer, and can be installed under a variety of flooring, including tile, hardwood, carpet and laminates. The smart-floor underlayment, however, also has embedded RFID tags, four per square meter, which can be programmed to navigate automated transport systems, such as robotic systems that deliver mail or clean floors.

Matthias Hanelt, Vorwerk Teppichwerke

After three years of research, Vorwerk has developed its underlayment to the point where it can be mass-produced, and the company hopes to begin selling it this year. InMach Intelligente Maschinen, headquartered in Ulm, which creates robots for such everyday tasks as cleaning or transporting goods or people, will design and manufacture robots with built-in RFID interrogators. Future Shape is writing the software for the system, according to Matthias Hanelt, Vorwerk Teppichwerke's project manager for the smart floor. Vorwerk and InMach will sell the robots, underlayment and system software together as a smart-floor solution. As a result of the information stored on the underlayment's embedded RFID tags, the robots will be able to orient themselves in a room and move toward precise targets on the floor.

The smart-floor underlayment is made of woven polyester, into which the specially designed RFID tags have been sewn. The tags consist of a tiny silicon ISO 15693-compliant microchip joined to an antenna coil and attached to an ultra-thin substrate made of polyethylene terephthalate (PET) plastic. The underlayment can be installed in all sizes and shapes and is cut with a standard carpet knife. If a tag is damaged when the underlayment is cut, the functionality of the other tags remains intact.

Each tag has its own ID number and holds 256 bits of read-write memory; in the future, the company plans to offer underlayment with tags holding as much as 10 kilobytes. A robot's RFID interrogator can read a tag up to 10 centimeters away.

The robot's built-in RFID interrogator can use the tag's memory to store quality-control information about whether a target area or a room has been cleaned, and when it is to be cleaned again. By conducting an analysis of the tag data read by the robot, software can be programmed to send a robot back to places where obstacles have been removed. This allows it to achieve full coverage of the surface. System administrators can manage a fleet of robots from a central point, sending information to the robots via a control PC using Wi-Fi or Bluetooth.