Lockheed Martin Corp.’s Aeronautics unit designs and manufactures cutting-edge aircraft platforms, including the F-35 Lightning II. Advanced manufacturing technology solutions are critical to achieving needed performance, while meeting cost and schedule commitments for this 5th-generation fighter.
Metrology technologies such as laser and structured light scanning have advanced significantly over the past decade in their ability to capture the “as-built” reality of objects, producing an as-built digital twin.
My definition of an as-built digital twin is a design augmented with reality to do stuff. That “stuff” can be as simple as validating the engineering design by comparing scan data to 3D models; however, there are much more interesting uses of the technology, such as enabling virtual assembly operations to significantly drive down aircraft manufacturing costs.
As mentioned, product validation is a simple application of 3D scanning, although it has limitations. More loosely toleranced components, such as tubes and part/assembly surface profiles, are easily captured and analyzed for conformance. Automated tube inspection is quicker and more capable than legacy manual checks and provides a digital record. However, many aircraft components have tighter tolerances and occluded features that would drive inspections to more expensive systems such as coordinate measuring machines and industrial computed tomography.
Lockheed Martin has implemented similar 3D-scanning technologies and techniques in novel ways to digitally transform F-35 manufacturing processes. Using commercially available 3D-scanning systems and custom software routines, the company implemented a virtual weapons fit check system that performs a virtual fit check between tubes and harnesses in the F-35 weapons bays and the volume occupied by any of the weapons in the weapons suite.
The technology has led to time savings, less rework on the critical build path, fewer ergonomic risk factors, and increased traceability of data to perform trend analyses and drive design and manufacturing changes. After implementing the F-35 weapons bay, we quickly expanded use to other F-35 and X-59 aircraft bays. Leveraging the same basic platform led to rapid integration of a virtual fit check system for the F-35’s main landing gear bay and X-59 engine bay, mitigating the need for expensive tooling and creating a digital record of conformance absent in legacy processes.
Predictive shimming is another example of using these reality capture tools to digitally transform a process. Aircraft assembly requires near-perfect part fit—despite part and assembly variations. Shimming is a common method to mitigate variation by filling any gaps. The legacy method to shim involves physically assembling parts, measuring gaps with tools such as feeler gages, then building a shim, installing it, and checking the final assembly. This is a lengthy process and often needs repetition to meet requirements.
In a predictive shimming process, parts and structures are independently 3D scanned for their as-built condition; the components are then virtually assembled in a digital environment to determine the resultant shim. This process drastically reduces the repetition of legacy methods and increases overall quality of the assembly.
Reality capture technologies will continue to improve in accuracy, point density, and data acquisition speeds. With these advancements, Lockheed Martin expects to continue to drive innovation through product validation, virtual assembly, and other digitally transformed processes to produce all aircraft better, faster, and cheaper.
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