In conventional aerospace assembly, manual shim processes lead to significant efficiency losses. Iterative correction loops, time-consuming coordination and extensive documentation obligations extend throughput times and retain valuable specialists. In addition, the complex, sometimes difficult to predict deformation properties of large-area CFRP components make it hard to achieve consistently high process quality.

In the SHILA project, this manual approach was replaced by a fully digitized and automatable process chain. A central element here is an edge device that was used to create a digital twin of both the machine and the machined component. This edge device captures all relevant process data and links it to a comprehensive digital image of the manufacturing process.

In addition, special algorithms have been developed that integrate intelligent geometry, deformation and machining models into the digital process. Based on the geometry model, the measurement technology precisely determines the real deviations of the thin-walled aircraft structures. The deformation model, together with newly developed 6D manipulators, then enables real-time and stress-free forming of the components, so that they are optimally prepared for the following processing steps.

With targeted material removal, the component can be brought to the required final contour supported by the geometry and deformation model. This eliminates the need to manually apply the previously used shims. The interaction between the geometry model and the deformation model enables optimized planning of the machining paths for the PowerRace robot, taking into account the deformation of the component by the acting machining forces. This enables high-precision material removal and an optimal machining strategy, while automatically generated machining programs efficiently support the manufacturing process. A modern position control system ensures that the machining tools are guided precisely at all times. In addition, the close integration of measuring and machining methods ensures that the entire process is continuously monitored and controlled.

Another technological advance has been achieved by improving the static and dynamic compensation in the PowerRace robot. New mathematical models significantly increased the robot’s path accuracy and thus enabled even more precise machining results.

As an overall result, the SHILA project resulted in an automated system that enables both the stress-free forming of large CFRP structural parts and their precise, robot-assisted contour processing. The new digital process chain significantly increases efficiency, process reliability and component quality, while at the same time sustainably reducing the manual effort involved in the assembly of aircraft structures.

Broetje-Automation and the project partners are thus making an important contribution to the further development of modern assembly processes and to the future viability of the aviation industry.

The project “SHILA – Shimless Assembly” was funded as part of the German government’s aviation research programme (LuFo 6.3). The result and a technology demonstrator of the project will be exhibited at ILA Berlin from 9 to 14 June 2026 in Berlin at the stand of the Federal Ministry of Economics (Hall C, Stand 230).