Low Coherence Interferometric Scanning System

To address the Air Force need for a new technique for automation of aircraft skin attachment and assembly and Outer Mold Line (OML) control, Physical Optics Corporation (POC) proposed and successfully demonstrated in Phase I a new metrology system for precise thickness measurements of composite panels and fast measurements of steps and gaps between the panels in the aircraft assembly, utilizing a Low Coherence Interferometric Scanning System (LCISS). The innovation in the LCISS design enabled OML measurements with better than 0.001-in. accuracy and with the required production line operation speed. Based on the demonstrated manufacturing readiness level (MRL) 4, POC proposes to continue development to achieve MRL 7 at the end of Phase II. The proposed system will consist of four major components: LCISS measurement systems to measure step and gap between panels on the F-35 center fuselage; a handheld automatic composite skin-thickness measurement system; software to integrate the thickness measurement system with the LCISS step and gap measurements and calculate the correct shim size for each fastener hole; and optical projection systems mounted on the assembly stations to provide guidance to the assembly technicians projecting button thickness directly on the aircraft at each button location. BENEFIT: The proposed development will facilitate achieving the required production rate of military aircraft with significant reduction of required labor and improved assembly quality. In addition to fabrication of military aircraft, the LCISS system will find applications in the assembly of commercial aircraft, ship building, automotive industry, and other industries, where the automation of the assembly process allows for the reduction of component manufacturing tolerances. This system will reduce the manufacturing cost by simplifying the assembly process and reducing labor cost. It also will improve product quality by providing a better fit of the product parts to the assembly.