Large Volume Measuring Systems for Aircraft Final Assembly
New Optimization Algorithm Minimizes Measurement UncertaintiesCopyright: © Airbus
The large-volume measurements initially cover the entire relevant assembly area but cannot measure positions in concealed areas such as inside the cabin due to optical signals. The Fraunhofer IFF developed special local sensor technology for precisely these critical areas, which can be used, for example, to measure the flatness of the car floor during assembly. To make this measurement data available factory-wide, a Kalman filter-based method was developed that transfers the local measurement data into the coordinate system of the large-volume measurement system. In addition to the measured value, the measurement uncertainty is also transferred so that an overall measurement uncertainty can be collected as a result of the merged measurements. Two main results were achieved by this: First, all position data relevant to final aircraft assembly can be referenced to a coordinate system factory-wide, which enables a holistic evaluation of the assembly condition and component quality over large component dimensions. On the other hand, the consideration of the measurement uncertainty of the interlinked measurement systems allows a higher-level evaluation of the process capability and an associated conclusion on the testability of tolerances.
The methodology developed in the project was successfully validated on real Airbus components and a demonstrator for aircraft fuselage assembly in collaboration with the Fraunhofer IFF. Future steps will deal with the utilization and further development of the results in aircraft final assembly production operations and in the research field of lineless mobile assembly systems at the WZL.