Investigation of the sensitivity of a high-precision weighing cell to disturbances caused by the adjustment system. - In: Proceedings of the 23rd International Conference of the European Society for Precision Engineering and Nanotechnology, (2023), S. 223-224
Highly reproducible force application for a tool-changing system in nanofabrication machines. - In: Proceedings of the 23rd International Conference of the European Society for Precision Engineering and Nanotechnology, (2023), S. 73-74
Modeling of very thin flexure hinges considering surface topography. - In: Proceedings of the 23rd International Conference of the European Society for Precision Engineering and Nanotechnology, (2023), S. 71-72
Investigating the kinematic performance of a positioning device with subatomic resolution. - In: Proceedings of the 23rd International Conference of the European Society for Precision Engineering and Nanotechnology, (2023), S. 51-54
Novel method for determining the mechanical stiffness of weighing cells. - In: SMSI 2023 Conference - Sensor and Measurement Science International, (2023), S. 139-140
Weighing cells with electromagnetic force compensation are frequently used in precision balances and mass comparators. The kinematic structure is given by a compliant mechanism with concentrated compliances. Thin flexure hinges enable highly reproducible motion but limit the sensitivity to mass changes due to their rotational stiffness. To achieve the desired sensitivity, the stiffness of the mechanism must be further reduced by mechanical adjustments. To optimize the adjustment parameters, the initial stiffness of the mechanism needs to be characterized accurately. For this purpose, a novel self-testing method was developed. It allows accurate determination of the elastic stiffness of the weighing cell and the geometric stiffness caused by the masses of the linkages. The method uses static stiffness measurements in three orientations. The gravity vector must be orthogonal to the plane of motion to characterize the elastic stiffness. Determining the geometric stiffness requires the system to be in the working orientation. The upside-down orientation is used to confirm the results. This paper considers the novel method analytically and simulates using a rigid body model and the finite element method. The measurement of the stiffness of a weighing cell prototype is taken to validate the method.
https://doi.org/10.5162/SMSI2023/B7.4
The use of range-resolved interferometry for multi-parameter sensing in a wind tunnel. - In: European Workshop on Optical Fibre Sensors (EWOFS 2023), (2023), 1264303, S. 1264303-1-1264303-4
The work presented demonstrates that key parameters in aerodynamic structural characterisation of pressure, strain, and structural dynamics, can be all measured via optical fibre sensors interrogated using the principles of range-resolved interferometry (RRI). When used to interrogate sensors simultaneously deployed on a high lift wind in a wind tunnel, the approach yielded resolutions of 31 μPa/ &worte; Hz and 1 nε/ &worte; Hz at a bandwidth of 1526 Hz for pressure and strain, respectively, demonstrating the accuracy and versatility of the RRI signal processing technique.
https://doi.org/10.1117/12.2679414
Evaluation of hysteresis response in achiral edges of graphene nanoribbons on semi-insulating SiC. - In: Materials science forum, ISSN 1662-9752, Bd. 1089 (2023), S. 15-22
Hysteresis response of epitaxially grown graphene nanoribbons devices on semi-insulating 4H-SiC in the armchair and zigzag directions is evaluated and studied. The influence of the orientation of fabrication and dimensions of graphene nanoribbons on the hysteresis effect reveals the metallic and semiconducting nature graphene nanoribbons. The hysteresis response of armchair based graphene nanoribbon side gate and top gated devices implies the influence of gate field electric strength and the contribution of surface traps, adsorbents, and initial defects on graphene as the primary sources of hysteresis. Additionally, passivation with AlOx and top gate modulation decreased the hysteresis and improved the current-voltage characteristics.
https://doi.org/10.4028/p-i2s1cm
Systematic optimisation process for an eBike drive unit in a highly variable environment. - In: Proceedings of the Design Society, ISSN 2732-527X, Bd. 3 (2023), S. 3305-3314
Drive units of eBikes are used in every type of bicycle and for different riding scenarios and riders. Due to the different riders and bike types, an enormous variety of influencing parameters and load spectra must be considered during the design process. Therefore, in this paper, a systematic approach for the optimization of the drive unit is presented, which adopts and combines several approaches from design theory. The focus is on efficient modeling and simulation of the relevant parameters and load spectra to minimize uncertainties in the design process. Based on a system analysis, dimension-reduced parameter spaces are formed for the simulation of the system, meta-models are integrated into the simulation model and the results of the simulation are transferred into a data-based surrogate model to cover the parameter space in an efficient way with a minimum number of time consuming FE simulations. Furthermore, a coordinate-based evaluation method is presented for the FE model in order to form the input for the surrogate model, reduces the amount of data, and to allows a geometry- and mesh-independent evaluation to compare different models.
https://doi.org/10.1017/pds.2023.331
Perspectives on robust design - an overview of challenges and research areas across industry fields. - In: Proceedings of the Design Society, ISSN 2732-527X, Bd. 3 (2023), S. 2885-2894
Robust Design offers a coherent and widely appreciated approach for the parametric exploration of the design space by means of simulation or experimentation, which is well-established in the quality-by design domain. From the perspective of design research, however, this only addresses a relatively narrow part of the design process and is not fully integrated with other design decisions such as concept exploration, the suitable configuration of system elements, or the design of interfaces. Particularly in light of the growing importance of developing technologically advanced and “smart” systems, it seems that a new methodical perspective on Robust Design is needed. Against this background, this paper consolidates knowledge and insights from different research fields and industry sectors. On this basis, new angles to the discussion on product robustness in different domains are explored in order to suggests directions for action and new research areas, both with respect to a methodical RD approach as well as the question of systematic research procedures.
https://doi.org/10.1017/pds.2023.289
Model-based systems engineering using security design patterns in the context of ISO/SAE 21434. - In: Proceedings of the Design Society, ISSN 2732-527X, Bd. 3 (2023), S. 2675-2684
The development of modern vehicles is complex, especially regarding compliance with security and safety. ISO/SAE 21434 considers security and safety along the entire product life cycle. According to the standard, a system architecture, a risk analysis, and the application of countermeasures are carried out in the early system design. Design patterns are solutions to known design problems. Security Design Patterns (SDP) describe countermeasures and are used to reduce risk. After our literature review, we did not find a suitable approach that presents SDPs that would be applicable in early system design. In this paper, we present 10 SDPs for early system design, which we evaluated during an 11-week student project with 28 teams. We present the results of the quantitative analysis and the evaluation of the feedback.
https://doi.org/10.1017/pds.2023.268