RFID Paves the Way for Road Construction

An RFID read of the tag documents when the truck leaves the plant. As the vehicle approaches the paving machine, a fixed interrogator on the paver culls the tag's ID number and, via GPS positioning and GPRS communications on the paver (also provided by Minds), that data is transmitted back to Minds' servers.

For each load, the PaveTag system can collect or calculate the time the truck arrives at the plant, receives its load of hot-mix asphalt, leaves the factory, arrives at the paver, dumps its load into the machine and leaves the site (the system is not currently designed to track the load-weighing process). At any given time, Vidaillac says, customers can access reports on the data via the Web, and also by using SMS messaging.

Ultimately, Vidaillac notes, the data can help customers—typically asphalt manufacturers—to optimize delivery schedules so that the dump trucks never need to wait at a paver to dump their loads of hot-mix asphalt, or that the paver never has to stop and wait for a delivery. The software is designed to compute transportation and waiting time by tracking all RFID reads and the time in between them, and by correlating that information with the tonnages each hauler can carry. "This tool helps you schedule better so the paving machine doesn't stop, and the truck doesn't wait," Vidaillac says. "It helps you get your operation as smooth as possible."

PaveTag was used in a pilot in the summer of 2007, and Vidaillac says many of Minds' customers are interested. At least two companies have ordered the PaveTag system thus far, he says—one in the Netherlands, another in Belgium—though he is not at liberty to name them at this time.

The tags operate in the 902-921 MHz frequency band and comply with EPCglobal's proposed Class 3 standard. Specifically, PaveTag leverages the Intelleflex SMT-7100, which has an antenna configured to perform well around liquids, metals and other RF-unfriendly conditions that can interfere with RF waves.

The tag incorporates Intelleflex's patent-pending "inverted F-plane" antenna design, which the tag maker says helps improve the tag's readability around metal by exploiting the tendency of RF signals to bounce off nearby metal objects. It features a durable casing designed to protect it against physical impact and damage, and also has an IP67 rating, signifying its protection against impairment due to moisture, dust and vibration. The tag can be mounted via adhesives, screws or plastic cable ties, and offers a read range of up to 50 meters.