Robotic automated specimen preparation (RASP): applied to air pluviation

A fully Robotic Automated Specimen Preparation (RASP) approach is introduced for granular soils using the single-nozzle dry air pluviation method. For this purpose, a nozzle is installed at the tool end of a 6-axis collaborative robot (cobot). Over 80 specimens were automatically prepared using two different granular materials and analyzed via local density measurements. Additionally, manually prepared specimens were generated for comparison. More than 1000 local density measurements have been conducted. The results demonstrate that the proposed RASP method enables a reproducible and homogeneous preparation of sand specimens, with density variations significantly lower than those observed in manually prepared specimens. The RASP enables a detailed analysis of specific preparation-influencing factors such as pluviation pattern, fall height, nozzle diameter, and nozzle velocity. In addition to the improved quality of the sand specimen preparation, the proposed RASP technique will increase efficiency and reduce economic costs in soil mechanical laboratories in the near future. Besides, the data obtained during the specimen preparation enables a data-based documentation and quality assurance of the entire preparation process.