Metrology and measurement data evaluation for the geometrical product verification within a holistic tolerance management

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The research group FOR 2271 is investigating from a fundamental research point of view, how a holistic approach and efficient tools for the management of geometric deviations during product development needs to be designed. The findings are verified using a model factory. The subproject 3 participates in the research group by the determination the form deviations and the associated measurement uncertainty as well as the usage of this information within a function-oriented tolerance specification. During the first funding phase, the subproject aimed at developing suitable approaches to provide the associated single point uncertainties (SPU) for given measurement data, using various tactile, optical and tomographic measurement methods. Based on these findings, methods for the description and correction of the systematic form deviations were developed. Furthermore, fusion and regression algorithms considering the SPU as weighting factors were designed. These contributions combined with the provision of the SPU of the deviation representation and the supply of the uncertainty of single features as well as the metrological set-up for validating the demonstrator complement the input of the subproject towards the research group.Based on the knowledge gained during the first funding phase, necessary data processing operations along the measurement chain will be optimized during the second funding phase with the aim of reducing the measurement uncertainty associated with every measurement during the determination of the form deviations of tolerated work pieces. Here, algorithms that are more complex will be used to generate an exploitable information yield, while the substantially increased resulting computational demand will be compensated by the consequent implementation of GPGPU-programing techniques. A reduction of the measurement uncertainty of the geometric characterisation usually enables the possibility of defining smaller tolerances. The planned project also includes metrological examinations of tooth flanks topography measurements of the influence of the expected wear and tear onto the tolerance specification. Additionally, approaches aimed at optimising the algorithms used for the weighted geometric registration of measurement data against nominal and reference data will be examined. Thus, the influence of the registration routine on the data processing and consequently the local measurement uncertainty of tolerated geometry elements will be characterised and reduced. Within a collective effort with the project collaborates, the transferability of the determination of the SPU of geometry elements onto edge regions will be examined in order to assess the influence of the hereby occurring measurement uncertainty on the associated tolerance specification. The cooperation will be complemented by the standardised geometrical characterisation of the mechanical components of the X-ray aperture test stand.