Combined ground-based and UAS SfM-MVS approach for determination of geometric parameters of the large-scale industrial facility – Case study

Abstract

The geometric parameters of large-scale machinery are checked by traditional geodetic and measuring methods. For a rotary kiln (RK), it is a matter of determining the geometry of the real longitudinal axis of the RK and the deformation of its shell. From geodetic methods, it is possible to use a conventional measurement of 3D coordinates of points using a total station (TS) or a more modern terrestrial laser scanning (TLS) method. In our research, we used these two methods as ground-truth references. We verify and evaluate the SfM-MVS approach in 3D modeling and derivation of rotary kiln geometry as a non-traditional approach for similar machinery. The evaluation of combined ground-based and UAS photogrammetry was performed regarding the accuracy and effectiveness of this method. Geometric analyzes were performed by comparing point clouds using the cloud-to-cloud approach. RMSE values were calculated when fitting cylindrical bodies to partial pointclouds. For mutual comparing of pointclouds, differences were evaluated for several intervals of values. Derived results are evaluated numerically and graphically. Our results confirm that the SfM approach can be considered a suitable alternative to conventional surveying techniques.