Imagine if parts could be manufactured quickly and inexpensively by simply taking a series of digital photos of an object shot in close-range.
Michael Immel had originally thought about the technique—referred to as photogrammetry—for another project, but realized it had serious potential in the manufacturing space.
The photogrammetry uses digital images of an object taken at various angles to create a point cloud—a large collection of points used to create a 3-D model of existing structures—from which a computer-aided design (CAD) file can be produced.
Andrew Bellows, a graduate student in mechanical engineering, takes photos of a bottle opener from different angles in order to generate a point cloud from which the object can be 3-D-printed. (Image Credit: Pamela Krewson Wertz/Penn State)
The CAD file and 3-D model created from it could then be used to rebuild the part, or 3-D print it, to its original specifications without the use of traditional methods, in effect saving time and money.
“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.
Over the summer, Immel and three engineering students set out to test the accuracy of photogrammetry after receiving a seed grant to explore the concept further. Andrew Bellows is a graduate student in mechanical engineering; Benjamin Sattler is an undergraduate mechanical engineering student and a Schreyer’s Scholar; and Xinyi Xiao is an industrial engineering graduate student.
The team worked on parts that they already had CAD files for in order to compare them to the photogrammetry-created point cloud files.
Pictures similar to this were taken of the object from all angles to encompass the entire object and create an accurate model. Many aspects had to be utilized to produce usable images, such as baby powder to eliminate the shine on the metal, and a ruler to use as a scale. (Image Credit: Pamela Krewson Wertz/Penn State)
“The ideal application of photogrammetry in the industry setting would be to have a vision system in a manufacturing plant that included cameras fixed on the machines making the parts, taking continuous photos,” said Immel. “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 to the point cloud of the original file and determine if the part is within tolerance or not.”
After their summer research, Immel and the team concluded that photogrammetry has the potential to make the quality control process quicker, less expensive and more efficient for manufacturers.
Story via Penn State University.
