Oct 12, 2012On large construction sites, such as those for oil refineries, tracking the locations of equipment and assemblies can involve many telephone calls, paper manifests and delays, especially when missing components and pieces of equipment are not where there are expected to be. To install a real-time location system (RTLS), on the other hand, is not always feasible, since the large quantity of readers required—often in remote locations—might interfere with the construction work underway, simply because construction crews will need to work and, in some cases, steer around them. Moreover, RTLS technology can be expensive, since the tags cost more than passive tags do. Australian solutions provider Industrial Automation Group has begun the early work to provide an RFID solution for a global oil company preparing a major construction project in a remote region of Western Australia. That company has asked to remain unnamed.
The refinery will be built on the west coast of Australia, north of Karratha. Though actual construction is not expected to commence until 2014, the RFID team has begun testing tags and readers. At the site where the new refinery will be erected, tags are already being affixed to some of the hundreds of thousands of tools, materials and components that will be used during construction.
To build the refinery, the company will fly in workers from other metropolitan areas, while equipment, as needed, will travel many hundreds of miles. The company, says Henk de Graaf, Industrial Automation Group's managing director, seeks a method for monitoring the project once it is underway—to see actual products moving, view where they were located and receive alerts if anything is not onsite when expected, or is located in the wrong place. "Keeping control of the construction costs is a major desire," de Graaf explains. "It's extremely hard to keep a handle of a construction site of this size, remotely."
In fact, on construction sites of any size, items often end up missing and, in some cases, must be replaced simply because they cannot readily be found. The value of some assets that are lost could be in the hundreds of thousands of dollars. In the meantime, high-salaried staff members might be forced to wait onsite for those missing objects to be located or replaced, before they can resume their work. In some instances, a subassembly might be constructed twice due to employees losing track of a piece already assembled. With all of that in mind, de Graaf says, an RFID system to track every item could potentially save millions of dollars.
The oil company already utilizes a SAP inventory-management system, and needs an RFID solution to feed location data into that system. But it also seeks a solution that will require as few readers as possible—fewer readers result in fewer obstacles to construction traffic—and that will be robust enough to survive harsh conditions, since temperatures can reach 124 degrees Fahrenheit (51 degrees Celsius).
The site measures 1 kilometer by 2 kilometers (0.6 mile to 1.2 miles). Approximately 240 Intelleflex FMR-6000 fixed readers, installed within explosion-proof enclosures, would need to be installed on metal poles, so that the reader would cover an area measuring 100 meters by 100 meters (328 feet by 328 feet).
As an item arrives at the construction site, readers in the vicinity would awaken the tag, causing it to transmit its ID number and other data. Eight pairs of antennas would be wired to each interrogator, in order to provide angle-of-arrival data regarding tag transmission. The construction site will be equipped with a Wi-Fi network, enabling the readers to send the information to the oil company's back-end system via a Wi-Fi connection. That data would be received by the Industrial Automation Group software, which would determine the tag's location to within about 5 meters (16.4 feet), and forward that information to the company's SAP system.
Industrial Automation Group has already tested the technology at an area on the site measuring 25 meters by 25 meters (82 feet by 82 feet), de Graaf says, where a single reader with eight antennas was installed. "More testing needs to be done," he notes, in order to ensure that tags can be interrogated as the items to which they are attached are moved around the site, along with multiple other objects that could obstruct transmissions. Specific details about the number of readers to be used for this testing, however, have yet to be finalized.
Ultimately, de Graaf says, once the system is in place, management would be able to log into the SAP system and watch construction underway, simply by knowing the location of the subassemblies and other materials, and by viewing them on a map of the site as icons linked to each tag's RFID number, as well as details about the item to which that tag is attached. If a specific asset could be located, staff members on site, or at the remote office, would be able to simply access the SAP system and identify that item's location to within 5 meters (16.4 feet).
By reducing the risk of losing equipment on the construction site, de Graaf says, the technology could pay for itself within a few days, by ensuring that work is never halted due to a missing item, and that no asset is unnecessarily replaced.
