PT

P.T. Tempel

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3 records found

Journal article (2023) - M.W.E.M. Alfeld, P. Tempel, V. van der Wijk
The acquisition of elemental and chemical distribution images on the surface of cultural heritage objects has provided us new insights into our past. The techniques commonly employed, such as macroscopic X-ray fluorescence imaging (MA-XRF), in general require pointwise or whisk-broom scanning of an object under constant measurement geometry for optimal results. Most scanners in this field use stacked linear motorized stages, which are a proven solution for 2D sample positioning. Instead of these serial systems, we propose the use of a parallel cable robot to position the measurement head relative to the object investigated. In this article, we illustrate the significance of the issue and present our own cable robot prototype and test its capabilities, but also discuss the current shortcomings of the concept. With this, we demonstrate the potential of cable robots as platforms for MA-XRF and similar imaging techniques. ...

A cable robot for inspecting and scanning artwork

Cultural heritage science envisages understanding of methods and techniques used by past painters and sculptors in creating their masterpieces of art. Existing devices for in situ and non-destructive, automated scanning are large and bulky and built around the assumption of a perfectly planar surface. We are developing a lightweight, portable robot for scanning of paintings, marbles, or statues while explicitly allowing for their out-of-plane surface. This paper presents the kinematic design and analysis of the wrench-feasible workspace of a cable-driven parallel robot capable of positioning an imaging device with three translational and two rotational degrees of freedom. At the end stand geometric parameters optimized for the application requirements allowing for pan and tilt of 70 each in total, making scanning of the spatial surface of art objects possible. ...
Journal article (2020) - F. Eger, C. Reiff, P. Tempel, M. C. Magnanini, D. Caputo, A. Lechler, A. Verl
In many sectors such as the aerospace industry, the manufacturing of rotating components is based on multi-stage production systems to achieve the complex requirements of high quality products. Even in the presence of Industry 4.0 and the increasing connectivity, these systems are very prone to failure due to the high level of potential influences of both the system and the products, ultimately leading to defects. The project “ForZDM”, funded by the EU under Horizon2020, envisions reducing scrap rate by avoiding and compensating defects at an early stage thus guaranteeing a high quality product. This paper presents an approach using an existing manufacturing line to compensate the dimensional deviations of an inner contour of a turbine shaft at an early stage. Based on measurements of the inner contour, a new rotation axis for the subsequent manufacturing processes is calculated in order to avoid unbalances at the end-of-line control. Different algorithms are developed and integrated in a web-based application to find an optimal rotation axis under consideration of the to-be-manufactured outer contour in an operator-friendly usage on the shop floor. The application is connected with the measurement system and the subsequent CNC machine which enables automatic execution and data transfer. ...