Andreas Trenkle

Quantitative voxel-to-voxel comparison of TriBeam and DCT strontium titanate three-dimensional data sets

Recently, techniques for the acquisition of three-dimensional tomographic and four-dimensional time-resolved data sets have emerged, allowing for the analysis of mm3 volumes of material with nm-scale resolution. The ability to merge multi-modal data sets acquired via multiple techniques for the quantitative analysis of structure, chemistry and phase information is still a significant challenge. Large three-dimensional data sets have been acquired by time-resolved diffraction contrast tomography (DCT) and a new TriBeam tomography technique with high spatial resolution to address grain growth in strontium titanate. A methodology for combining three-dimensional tomographic data has been developed. Algorithms for the alignment of orientation reference frames, unification of sampling grids and automated grain matching have been integrated, and the resulting merged data set permits the simultaneous analysis of all tomographic data on a voxel-by-voxel and grain-by-grain basis. Quantitative analysis of merged data sets collected using DCT and TriBeam tomography shows that the spatial resolution of the DCT technique is limited near grain boundaries and the sample edge, resolving grains down to 10 µm diameter for the reconstruction method used. While the TriBeam technique allows for higher-resolution analysis of boundary plane location, it is a destructive tomography approach and can only be employed at the conclusion of a four-dimensional experiment.

Safety requirements and safety functions for decentralized controlled autonomous systems

Flexibility and safety are important criteria for automated material handling systems. Autonomous and decentralized controlled systems are flexible but they also pose new challenges in safety. We describe KARIS, a decentralized controlled, autonomous intralogistic system and indicate the differences to conventional autonomous guided vehicles. Based on the results of a risk assessment, we point out the particular challenges to safety technology and describe the developed safety functions. They are evaluated and compared to required performance levels determined by the risk assessment.

Der Mensch als Teil von Industrie 4.0: Interaktionsmechanismen bei autonomen Materialflusssystemen

Industrie 4.0 verspricht die enge und erfolgreiche Zusammenarbeit von Mensch und Maschine. Der Beitrag beschreibt Eigenschaften von autonomen Systemen, die die Interaktion mit dem Menschen erleichtern. Die vorgeschlagenen Gestaltungsregeln beschreiben, welche Kriterien bei der Entwicklung der Mensch-Maschine-Schnittstellen fur autonome Systeme relevant sind. Anhand von vier Forschungsprojekten aus der Intralogistik werden neue Ansatze erlautert und die gewunschten Eigenschaften und Gestaltungsregeln fur die Mensch-Maschine-Interaktion dargelegt.

Future Technologies in Intralogistics and Material Handling

This chapter describes future technologies in Intralogistics and Material Handling. Starting from a description of today’s material handling systems (including two case studies) and an analysis of their shortcomings we derive desirable properties for future material handling systems (basic section). The necessary functions for these systems are explained and samples of modern material handling systems are presented which at least partially implement these properties (advanced section). The state of the art of the challenging functions is explained and references for further reading are given.

Interpretation of pointing gestures for the gesture controlled transportation robot “FiFi”

“FiFi” is a gesture controlled transportation robot and facilitates manual transport in internal logistics. It is controlled by detection of people and their gestures with a 3D-camera. In this paper, we describe the functions and applications for FiFi in intralogistics. We introduce a new function: The user points on a line, FiFi plans a path to this line and follows it independently. After explaining our developed control mechanisms we present experiments testing the accuracy of them.

Quantitative Analysis of Correlated 3D Strontium Titanate Datasets Collected by TriBeam and Diffraction Contrast Tomography

Much attention has been paid to the idea of the correlation of analytical techniques such as tomography. Recently, techniques for the acquisition of 3D tomographic and 4D time resolved datasets have emerged allowing for the analysis of mm volumes of material with nm-scale resolution. The TriBeam technique permits the acquisition of 3D EBSD datasets using a femtosecond laser to section material at unprecedented speed [1-2] with low damage [3-4] and high resolution [5]. Diffraction contrast tomography (DCT) [6], a synchrotron based X-ray technique acquires datasets non-destructively, permitting the repeated imaging of samples to collect 4D microstructural evolution [7] in crystalline materials. However, the vast majority of materials tomography datasets have been combined in a purely qualitative sense to date. In this work, a methodology for the precise alignment of tomographic datasets, including the alignment of the sample and orientation reference frames, and simultaneous identification and linking of grain structure between tomography datasets has been developed. The application of these algorithms to a pair of datasets collected from a single strontium titanate (STO) sample using both TriBeam tomography and synchrotron X-ray diffraction contrast tomography (DCT) will be presented. The resulting merged datasets have been quantitatively analyzed on the voxel scale and at the grain scale for the direct comparison of these two tomography techniques.

Three dimensional X-ray diffraction contrast tomography reconstruction of polycrystalline strontium titanate during sintering and electron backscatter diffraction validation

The microstructural evolution of polycrystalline strontium titanate was investigated in three dimensions (3D) using X-ray diffraction contrast tomography (DCT) before and after ex-situ annealing at 1600°C. Post-annealing, the specimen was additionally subjected to phase contrast tomography (PCT) in order to finely resolve the porosities. The resulting microstructure reconstructions were studied with special emphasis on morphology and interface orientation during microstructure evolution. Subsequently, cross-sections of the specimen were studied using electron backscatter diffraction (EBSD). Corresponding cross-sections through the 3D reconstruction were identified and the quality of the reconstruction is validated with special emphasis on the spatial resolution at the grain boundaries, the size and location of pores contained in the material and the accuracy of the orientation determination.