Student's System Allows Better Construction Monitoring

7/1/2010

CEE student Mani Golparvar-Fard develops a new modeling technique that uses photos to visualize and automatically track construction progress in four dimensions.

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Golparvar-Fard poses with images from his 4D augmented reality models of Ikenberry hall and the Yeh Center construction project.

The use of digital photos to monitor construction projects has become commonplace, thanks to inexpensive cameras, low-cost memory and Internet access on construction sites. CEE student Mani Golparvar-Fard (PhD 10) developed a new modeling technique that uses such common photos to visualize and automatically track construction progress in four dimensions, offering construction professionals a new, low-cost way to monitor projects.

To develop the system that generates these D4AR – 4D Augmented Reality models, Golparvar-Fard worked with his advisers, Feniosky Peña-Mora, formerly on the CEE faculty and now Dean of Engineering and Applied Science at Columbia University, and Silvio Savarese of the Department of Electrical Engineering at the University of Michigan.

D4AR model of the Ikenberry Residence Hall Project reconstructed with 160 photos with 2 megapixels quality.

Using digital photos of modest resolution, the system constructs dense, three-dimensional point cloud models of the construction site, automatically computing each photo’s viewpoint. Using different photo collections taken over time, it generates four-dimensional (3D plus time) point cloud models. Finally, Building Information Models (BIM) are linked with construction schedules and superimposed with the point cloud models. The results are D4AR models that visualize actual and expected models together and automatically color code progress deviations based on a simple traffic light metaphor.

“Imagine you are sitting at your office and would like to conduct a walk-through on your job site, but you are miles away,” Golparvar-Fard says. “What you can do now, is to make a phone call to your construction site and ask your superintendents and field engineers to walk around the site, take photos and send them back to you. You can automatically reconstruct actual 3D models of the site using these photos and register the 3D model and the photos with as-designed Building Information Models. Using the D4AR models, you would be able to remotely walk through the site and study both the actual and expected status of the project. You can monitor progress, productivity, safety, quality and even analyze constructability and site logistics.”

D4AR model generated for the construction of the Yeh Student Center. In this case, 84 images with 2.5 megapixels quality were used.

The system has already garnered both awards and the attention of industry. The work won Best Student Paper at the 2010 International Conference on Innovation in AEC; the FIATECH CETI award in the outstanding student researcher category; and a first place poster award at the 2009 Construction Research Congress. Several construction companies are studying the feasibility of using the system for their projects. Meanwhile, Golparvar-Fard has demonstrated its usefulness by generating D4AR models for several ongoing or recently completed construction projects, including Ikenberry Student Dining and Residence Hall and the Yeh Student Center, both on the U of I campus.

“A picture is worth a thousand words, so you can imagine the value of hundreds of pictures combined together,” he says.
 
Golparvar-Fard has accepted a faculty position at Virginia Tech in the CEE department and Myers-Lawson School of Construction. For more information, visit www.manigolparvar.com.

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This story was published July 1, 2010.