Publikationen

This proceedings volume gathers the outcomes of the International Conference on Engineering Research and Applications (ICERA 2019), which was held at Thai Nguyen University of Technology, Vietnam, on December 1-2, 2019 and provided an international forum for disseminating the latest theories and practices in engineering research and applications. The conference focused on original research work in a broad range of areas, including Mechanical Engineering, Materials and Mechanics of Materials, Mechatronics and Micromechatronics, Automotive Engineering, Electrical and Electronics Engineering, and Information and Communication Technology. By sharing the latest advances in these fields, the book will help academics and professionals alike to revisit their thinking on sustainable development.

Availability of a common, shared benchmark to provide repeatable, quantifiable, and comparable results is an added value for any scientific community. International consortia provide benchmarks in a wide range of domains, being normally used by industry, vendors, and researchers for evaluating their software products. In this regard, a benchmark of untimed Petri net models was developed to be used in a yearly software competition driven by the Petri net community. However, to the best of our knowledge there is not a similar benchmark to evaluate solution techniques for Petri nets with timing extensions. In this paper, we propose an evaluation framework for the comparative analysis of generalized stochastic Petri nets (GSPNs) simulation techniques. Although we focus on simulation techniques, our framework provides a baseline for a comparative analysis of different GSPN solvers (e.g., simulators, numerical solvers, or other techniques). The evaluation framework encompasses a set of 50 GSPN models including test cases and case studies from the literature, and a set of evaluation guidelines for the comparative analysis. In order to show the applicability of the proposed framework, we carry out a comparative analysis of steady-state simulators implemented in three academic software tools, namely, GreatSPN, PeabraiN, and TimeNET. The results allow us to validate the trustfulness of these academic software tools, as well as to point out potential problems and algorithmic optimization opportunities.

Automatic Optical Inspection (AOI) is an important part of modern electronics manufacturing. While profilometric technologies are very present in inspection systems specialized on surface mounted technologies (SMT), through hole technology (THT) oriented inspection still mostly relies on two-dimensional data. Solder joints of THT connections have highly reflective metallic surfaces and thus are a very challenging object for typical light based profilometric measurement systems. A new approach is presented, which uses specular reflections of angled illuminations to reconstruct the surface of THT solder joints for inline inspection. The observed reflections depend on the position of the angled light sources, as well as the surface angle of the inspected object and its relative position to the observing camera. The reflections of each angled illumination are observed separately and processed as a stack of images. To reduce the complexity the image stack is transformed into a polar coordinate system leveraging the rotation symmetry of THT solder connections. The surface angle of every observed pixel is estimated based on the observation stack and corrected for its position relative to the camera and illumination. The surface angle then gets integrated along the transformed coordinate axis. This results in the estimation of the surface profile of the solder connection. After retransformation into the source coordinate system, this can be used to classify the solder joint for defects and insufficient solder volume.