Innovations to Locate Stacked or Deep Utilities (2014)

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62 Technical Support Information for Long-Range Smart Tags Abstract Visible Assets Incorporated (VAI) is developing long-range radio frequency identification (RFID) devices suitable for direct burial use. These devices conform to the IEEE 1902.1, or RuBee, communication protocol. These smart tags can be located from a distance and queried for a unique serial num- ber and other user data. The tags developed by VAI incorpo- rate low-power microprocessors and batteries with 20-year life expectancies. Future versions of these tags could incorpo- rate sensors. Smart tags have the potential to solve a number of issues with the locating of underground utilities. Once installed, smart tags greatly ease the problems associated with back-navigating to a particular feature and positively identifying it. Smart tag tech- nology is complementary to that of GPS. The accuracy of GPS can be degraded by interference from buildings, weather, and other issues. Even under the best conditions, the z-axis accuracy of GPS is lower than the x-y accuracy. A smart tag can be located to a relatively high degree of x, y, and z precision once the tag and its associated reader are within range of one another. One scenario might be to use an inexpensive GPS or physical landmarks to get within read range of a smart tag and then use the tag reader to get a pre- cise location. The expected range of the RuBee tags from VAI is on the order of 30 ft. This is in contrast to a range of 5–10 ft from other direct burial tags. The extended range opens up under- ground applications not previously possible. Smart tags can be attached to the exterior of deep utilities and so provide fixed reference points that are not disturbed by most excava- tion. The current practice is to locate short-range tags above deep utilities rather than at true depth. Over time, these tags may become dissociated from the features they were intended to identify. Conformance with an IEEE standard allows tags to interact with readers from various manufacturers. This is in contrast to the proprietary data formats that are currently used for buried smart tags. In such cases, the end user is locked into tags and readers from a single manufacturer. Technology Synopsis and Key Performance Indicators Title: Smart Tags and Sensors for Deep Facilities Provider: Visible Assets Incorporated Targets: All pipe materials, as well as valves and mission crit- ical assets. Depth range: At least 20–50 ft. Depth accuracy: The expected accuracy is ±10% of the pipe depth (to be determined). Location accuracy: The expected accuracy is ±12 in. or ±5% of the pipe depth. Application: Smart tags are placed internally or externally on buried facilities. Once in place, the active tags can be used to identify and locate these facilities. Specialized tags can also return sensor data about the facility. Some tags may be used on valves and other mission-critical aboveground assets. Basic principle: RuBee IEEE 1902.1 is a peer-to-peer low- frequency standard that has been optimized for harsh envi- ronments. The tags can have a CPU, and memory, as well as sensors. Tags with a lithium coin-size battery (CR2525) have a proven life of up to 25 years. Projected life is 15 years of normal use. Limitations: Data rates are about six to eight reads per sec- ond. Detection range may be enhanced, but this will reduce battery life. Additional notes: RuBee is not blocked by water, and steel can actually enhance range. A P P e n d I x G