Researchers at Penn State are testing the use of photogrammetry to replicate precision parts while bypassing traditional manufacturing processes. Photogrammetry involves capturing hundreds, even thousands, of images of an object from multiple angles to create a point cloud. The point cloud is then used to create a 3D representation of the object, which is then used to create a precise CAD file for 3D printing.
While photogrammetry has been in use for almost a decade, advances in cameras and processing has made such models easier than ever to create with a high level of detail and accuracy. The technique could almost eliminate the design stage for some parts, allowing cameras and processing to do the work.
Michael Immel, instructor at the Harold and Inge Marcus Department of Industrial and Manufacturing Engineering at Penn State, said that the technique could reduce the use of expensive and time-consuming manufacturing methods. “If we can take pictures of the parts and use commercial software to create the point cloud file from the images, we can come up with the dimensions within some reasonable amount of accuracy and apply it in industry, said Immel.
Immel and his research team designed a studio for imaging, selected some parts, then created photogrammetry point cloud files and compared them with original CAD files. Researchers analyzed the variance between the files and found photogrammetry has proven to be “an accurate approach for applications where tight tolerances are not necessary.”
Researchers also believe photogrammetry has the potential to make the quality control process faster, less expensive and more efficient. With a traditional process, manufacturers have to make large quantities of parts in quick succession, then go through hands-on quality control measures. Immel said application of photogrammetry also could be used to increase the efficiency of ensuring quality control with a “vision system” of fixed cameras taking continuous, high-resolution photos. “Live data could be sent back to an engineer or a quality control employee and they could compare the point cloud that has been derived from the digital images,” said Immel.
Photogrammetry is already being used as a shortcut for 3D modeling. The drone industry is using it to create aerial maps and renderings of buildings, while artists and 3D printing hobbyists are using photogrammetry to create models. A Forbes article said NASA is also testing the technology to allow astronauts to easily make parts in space by simply scanning objects to replicate them with a 3D printer using Autodesk’s Remake software. Tatjana Dzambazova, Autodesk senior product manager, said that as imagery and scanning improves, she envisions a future where production of an object can go from scanning to 3D printing without even using CAD. “We’re working on ways to go directly from scan to print to optimize the process,” said Dzambazova.