Programming of adaptive repair process chains using repair features and function blocks

• Definition of adaptive repair process chains as cascaded control loops.
• Introduction of repair features as a bridge between measurement input and analytical CAD data for manufacturing.
• Dynamic determination and adjustment of repair features and CAx repair process chain execution based on function blocks.
• Use case study of repairing worn-out turbine blades with repair features and function blocks.

The current trends of product customization and repair of high value parts with individual defects demand automation and a high degree of flexibility of the involved manufacturing process chains. To determine the corresponding requirements this paper gives an overview of manufacturing process chains by distinguishing between horizontal and vertical process chains. The established way of modeling and programming processes with CAx systems and existing approaches is shown. Furthermore, the different types of possible adaptions of a manufacturing process chain are shown and considered as a cascaded control loop. Following this it is discussed which key requirements of repair process chains are unresolved by existing approaches. To overcome the deficits this paper introduces repair features which comprise the idea of geometric features and defines analytical auxiliary geometries based on the measurement input data. This meets challenges normally caused by working directly on reconstructed geometries in the form of triangulated surfaces which are prone to artifacts. Embedded into function blocks, this allows the use of traditional approaches for manufacturing process chains to be applied to adaptive repair process chains.