Spatial alignment of joining partners without fixtures, based on component-inherent markings

•New approach for the fixtureless assembly of space frame structures.•Detection of the spatial position and orientation of parts based on component-inherent markings.•Compensation of process-related deviations during part alignment by industrial robots.

Light-weight aluminum space frame structures are frequently used for small-volume products, such as sports cars. The assembly of these products has so far been mainly manual and requires the use of complex and expensive fixtures. To increase the profitability the research conducted at wbk Institute of Production Science is aiming to achieve an automated, fixtureless assembly of such structures by the use of industrial robots. To achieve the required accuracies regarding the alignment of the joining partners, a new approach based on component-inherent markings has been developed. Different tests have already been conducted in order to validate the approach. The test results demonstrate that the approach is suitable for the spatial alignment of components.This article describes the theoretical foundations of the required measurement approach as well as the experimental results.