The accuracy of measurements can make or break a business delivering physical goods to market or an organization performing critical research. For this reason, it is important that the right measurement or metrology tools and technologies are used.
One popular technology used within the fields of manufacturing, engineering, research and development, quality assurance, and prototyping is GOM Photogrammetry. However, not everyone in the industry is familiar with this powerful technology, so in this article we will provide an introduction to the concept, the benefits, and some common use cases to help you get started.
What is Photogrammetry?
To begin to understand the specifics of GOM Photogrammetry, we will start with an introduction to photogrammetry in general. Purdue University defines photogrammetry as “the science, art, and technology of obtaining reliable information from photographs”, and this succinct definition is a good place for us to start exploring the topic.
Generally, the “reliable information” captured from photographs comes in the form of measurements that enable us to build highly precise models and simulations. As photogrammetry.com points out, given this information, the root words that make up photogrammetry make more sense: photo means “light”, “gram” means “drawing”, and “metry” means measurement. In short, photogrammetry deals with capturing measurements based on pictures.
One of the first applications for photogrammetry is still a common use case that many of us can relate to today: maps created based upon photos taken from an aerial viewpoint (e.g. airplanes and drones). Other popular use cases exist in the like military, agriculture, and geology. All of these examples of photogrammetry use fall in the category of “aerial photogrammetry” and generally deal with large areas (for example, a topological map).
However, there are also a number of use cases that leverage photogrammetry at the ground level (“terrestrial photogrammetry”) and at close range. Many of the close range uses of photogrammetry can prove helpful in business processes related to engineering, quality assurance, and manufacturing as photogrammetry can provide a reliable, cost effective means to create precise measurements and models of a wide variety of products that vary in scale from small to very large.
Whether the application is aerial or terrestrial, small or large, the underlying concept is the same. A number of pictures are captured and triangulated against to produce measurements that have highly granular details. In addition to deliverables like maps, the outputs of photogrammetric technology and software can be CAD drawings or point clouds.
What is GOM Photogrammetry?
GOM Photogrammetry is a type of digital photogrammetry that is ideal for a variety of use cases requiring fast dimensional inspection and precise measurement data. In manufacturing, photogrammetry is used as a type of quality control and coordinate measuring system.
GOM Photogrammetry, which includes both the TRITOP standalone photogrammetry system and the ATOS Plus Box which is used in conjunction with the ATOS structured blue light scanner, can be used as an alternative to more traditional coordinate measuring machines, like touch probe CMMs, and even in certain situations in place of portable 3d scanners, laser scanners, or structured light scanners.
We’ll discuss the advantages of GOM Photogrammetry relative to other measurement systems, using the TRITOP and ATOS Plus as reference. GOM Photogrammetry falls into the category of photogrammetry that would be referred to as “close range” and is used to enable a variety of engineering and quality inspection tasks.
What are the Advantages of GOM Photogrammetry?
There are many benefits to adding GOM Photogrammetry to your repertoire of metrology solutions. Like any measuring and inspection system, there are circumstances where photogrammetry will be the best solution for your inspection needs; there are also other situations where a different type of metrology system will work better. We’ll go over the advantages to give you a fuller understanding of the GOM Photogrammetry products:
Minimal hardware
Unlike many other metrology solutions, TRITOP does not require heavy hardware that requires complex maintenance. TRITOP consists of an advanced camera especially designed for photogrammetry along with a laptop and inspection software for easily calculations. To see the system yourself, check out this video to see TRITOP and GOM photogrammetry in action. This enables businesses to complete advanced metrology tasks with minimal labor.
Non-contact, no wear and tear
GOM Photogrammetry is inherently “no contact” in that it does not require a probe or physical contact with the object to be measured. Since photos work based on line of sight, the necessary metrology tasks can be completed without any interference with the object and without compromising on data quality. Lack of interference is essential for some measuring tasks; for example, when historical artifacts are being measured but cannot be touched for preservation reasons. This is an advantage for the system, too—your TRITOP photogrammetry system will last a long time without needing frequent repairs.
High levels of precision and accuracy, even on large objects
Using GOM Photogrammetry enables high levels of precision and accuracy in measurements in a way that can scale significantly. For example, the TRITOP can be used to measure objects of up to 20m and has a camera resolution of up to 24 million pixels (the higher quality the pictures, the higher quality the measurements can be). Additionally, given their self-calibrating and self-checking features, TRITOP helps ensure reproducible and reliable results.
Check out this video of the US Army Aviation and Missile Research Development and Engineering Center (AMRDEC) using TRITOP photogrammetry in combination with the ATOS blue light scanner to collect data on an older model of a large boat. TRITOP is easy to use to collect data on very large objects that other metrology systems would have difficulty with.
Environmentally robust
TRITOP and ATOS Plus can operate in a variety of environmental conditions that other metrology solutions may struggle with. Given the nature of the underlying technology they can be used in open air, climatic chambers, industrial environments and more.
Use cases for GOM Photogrammetry
In this section, we will dive into some of the popular use cases for GOM Photogrammetry. Given the importance of accurate measurements across industries, there are a wide variety of applications where GOM Photogrammetry can prove useful and this section will help you conceptualize that and maybe even inspire you to generate your own ideas.
Quality control of large objects
Quality control is vital to manufacturers of all sorts of physical goods, and as the size of those goods scale, so can the importance of quality control. Photogrammetry can be used to get detailed measurement information about an object, and then that data can be compared to the CAD file to check for any issues.
Deformation analysis
Physical deformities or damage to objects like ships, turbines, and aircraft must be identified as soon as possible to avoid catastrophic failures. GOM Photogrammetry can capture data about surface deformations like dents that may not otherwise be visible to the naked eye, as seen in the AMRDEC video mentioned above.
First article inspections
First article inspections are an important part of bringing a manufactured good to market. Oftentimes a significant amount of research and development and engineering time went into ensuring that the product meets predefined specifications. GOM Photogrammetry can be leveraged to help verify that the first article that is delivered meets those specifications.
Random sample testing
To ensure the high quality products are consistently being delivered and the quality of finished goods is consistent with the desired standard, random sampling is often employed. GOM Photogrammetry can add a high level of precision and accuracy to random sample testing that helps organizations ensure quality is up to par.
Where to learn more
At this point, you may have a number of ideas about how GOM Photogrammetry can benefit your business, but are not sure where to start or what tools are right for you. Our dedicated team of experts at Capture 3D are ready and willing to help you find the right solution to help meet your needs. Our solutions feature workflows that are optimized to specific industries and we specialize in helping you select the best solution for your unique use case. Contact us today to learn more!