Chilean Copper Mine Tracks Vehicles and Workers

"The technology of today is RFID—it is proven and works well. These are the main reasons that convinced us to perform a proof of concept," Castro says. "The anticollision system will help us minimize accidents between big front loaders, which have always been a source of accidents with fatal consequences."

With the system, the front loader is equipped with a 433 MHz reader connected to an onboard anticollision alarm system. If the vehicle interrogator detects the active 433 MHz RFID tag of another vehicle or person ahead, it triggers a flashing light and buzzer on the front loader to attract the operator's attention.

Max von Dessauer

In addition, the mine has four RFID readers at the entrance of its two tunnels, which extend several miles underground. The first of two sets of interrogators is located about 900 feet before arriving at the entrance, while the second pair is about 300 feet from the entrance—that way, the order in which reads are received indicates the direction in which the miners are moving. Vuance's 433 MHz tags comply with the ISO 18000-7 standard, and transmit their unique ID number at a range of up to 900 feet. There are typically between two and five people in a particular vehicle, and each individual has his own tag-bearing ID card.

When interrogators capture the ID number, they send that data via an Ethernet connection to the mine's back-end system SQL database using a Web-based server, designed by RFID Chile. Software from RFID Chile links the RFID reads with the individual miners and vehicles, and makes that data available to the mine's office staff so they can know who is in the tunnel, when they entered and the company they represent.

A 42-inch LCD screen, located in an indoor common area, displays activity within the mine. In the event that the tunnels need to be cleared—for instance, when a detonation is planned—the screen shows the identity of contractors and employees in the mine. At any given time, hundreds of miners could be inside the tunnels, most of whom are contractors. When a supervisor needs to summon all of his people out of the mine, he can view the LCD screen to determine who is inside. That same supervisor can also log into Anglo American's Web site and, with a password, determine the name and time of entry of all his men in the tunnels.

RFID Chile began installing the new RFID-based system in the spring of 2007, after several months of proof-of-concept studies. Based on the proof of concept, Castro says, the company made only a few changes to the system. "We did find out, during the proof-of-concept testing, that in order to have a 100 percent detection rate, the tag should be used at chest level."

The mine is providing two types of training for personnel—one for system administrators and another for technical support. "If the problem can't be resolved by us, we will request support from the company [RFID Chile] that provided the solution," Castro says. Thus far, the mine is utilizing 600 tags for employees, front loaders and small vehicles (such as pickup trucks) entering the tunnels.