The use of the TI² manufacturing system on a double-curvature aerospace panel

Abstract

The aircraft manufacturing industry is continually seeking new techniques for the automation of manufacturing and assembly tasks. The application of automation is limited by the size and compliance of the structures, the low manufacturing volumes and the inherent dimensional variability between assemblies. In addition, a further requirement is to reduce the reliance on complex fixturing systems through the adoption of techniques enabling a ‘jigless assembly’ philosophy. The University of Nottingham recently completed a study as part of the Engineering and Physical Science Research Council (EPSRC)-funded Jigless Aerospace Manufacturing (JAM) Project into the use of the TI2 system to meet the objectives outlined above. The paper presents the practical work completed and the results obtained from the machining of a double curvature aircraft panel.

Error significance analysis and compensation for HPKMs

“…For each of these errors, a value was obtained for the severity criteria using either published data or data gathered empirically. The application under consideration was for small batch machining operations (drilling, routing, riveting) on large size aerospace components such as fuselage panels or wingboxes (Eastwood et al, 2001(Eastwood et al, , 2003. Using this type of application as a framework, the values for the other two criteria were completed, and the scores multiplied to produce the ESN for each error class number, as shown in Table I.…”

An evaluation of the TI2 manufacturing system for the machining of airframe subassemblies

“…Initial trials with the TI 2 focused on the system's capability when used with single-flat and double-curvature sheet components [9]. To validate the system with more complex structures a typical aero-structure subassembly was used.…”

A gravitational deflection compensation strategy for HPKMs

“…There is significant additional potential for these machines in large scale, low volume applications such as those found in the aerospace industry, and some of this potential has been realised by the integration of HPKMs with online measurement systems such as photogrammetry [1,2]. Such systems operate satisfactorily but the high additional cost associated with the photogrammetry equipment can preclude their use and counteracts one of the primary advantages of HPKMs, namely their relatively low cost when compared to machine tools and dedicated automated systems.…”

“…As part of a wider scope of work considering the potential for automation within the manufacture of aerospace assemblies [2], previous work at the University of Nottingham has considered the most significant sources of error associated with the Tricept TR600 HPKM. Whilst static geometrical errors due to manufacturing tolerances, permanent deformation or wear can lead to significant inaccuracies at the tool centre point this assessment included an investigation into both the magnitude of errors and their potential for correction, and this work identified three primary errors that were selected for further work [11].…”