May 2002

Building Bots

Construction sites go wireless.

By Kevin Hogan

Keeping accurate tabs on every element of a construction project, from piles of earth to stacks of steel beams, is complicated and expensive. To ease the burden on builders, engineers at the National Institute of Standards and Technology are developing information networks that could automate the process.

In one experiment, a construction site is rigged with a Global Positioning System antenna, a computer equipped with a wireless Ethernet connection and a laser-based measuring device. The laser scanner analyzes the size of an object-say a mound of excavated dirt; measurements are sent via wireless Ethernet to databases and file servers that can be accessed by contractors and engineers both on and off the site. Software puts the data into an intelligible form-say, a 3-D model for monitoring job status-and can provide precise measurements for billing purposes. "Right now, many estimates for jobs like ground removal are taken only by how many trucks were used to haul the stuff away," says Geraldine S. Cheok, a research structural engineer at NIST. "This will make the numbers much more exact."

Ultimately, the NIST system would go beyond measuring dirt piles. Researchers plan to use radio frequency identification tags to track every pipe, beam and hammer that enters or leaves a site. While the researchers expect to have the technology ready for field use by 2006, the building industry is notoriously slow in adopting new techniques, says Ken Eickmann, director of the Austin, TX-based Construction Industry Institute, a research organization that looks for better construction practices. "But if it proves to be a cost saver," he says, "you will see it in practice."