Annals of Scientific Society for Assembly, Handling and Industrial Robotics 2021

This Open Access proceedings presents a good overview of the current research landscape of assembly, handling and industrial robotics. The objective of MHI Colloquium is the successful networking at both academic and management level. Thereby, the colloquium focuses an academic exchange at a high level in order to distribute the obtained research results, to determine synergy effects and trends, to connect the actors in person and in conclusion, to strengthen the research field as well as the MHI community. In addition, there is the possibility to become acquatined with the organizing institute. Primary audience is formed by members of the scientific society for assembly, handling and industrial robotics (WGMHI)

Numerical simulation and statistical analysis of a cascaded flexure hinge for use in a cryogenic working environment

Due to their many advantages, flexible structures are increasingly being used as guide and transmission elements in handling systems. Prismatic solid-state joints with a concentrated cross-sectional reduction are predominantly used as flexure pivots for both microscopic and macroscopic designs. A transfer of these geometries to applications in cryogenic working environments is not easily possible at temperatures below -130 °C due to the changed material properties. In this paper, the further development of swivel joints as cascaded solid state joints for such a cryogenic environment is illustrated by the targeted adaptation of certain joint parameters and dimensions. By means of a comprehensive FEM simulation, it can be shown how the influence of specific parameters affects movement accuracy, process forces and shape stability and to what extent these geometric parameters influence each other in their effect

Correlation between Geometric Component Properties and Physical Parameters of an Aerodynamic Feeding System

In previous research, an aerodynamic feeding system was developed, which autonomously adapts to different components by using a genetic algorithm that controls the physical parameters of the system (e.g. angle of inclination, nozzle pressure). The algorithm starts with two individuals with random values, generated within the boundaries of the parameters set by the user. Due to this, the setting time - the time that passes until a satisfactory orientation rate is reached - is hard to predict. The aim of this work is to identify basic interactions of geometric component properties with the physical parameters of the aerodynamic feeding system to determine in which areas of the workspace a satisfactory solution can be expected. By doing so, the initial population of the genetic algorithm can be generated based on certain geometric properties and would therefore no longer be random, presumably reducing setting time. To identify interactions of component properties and system parameters, exemplary components were developed. They represent relevant single properties that have significant impact on the aerodynamic orientation process. These components were then fed into the aerodynamic orientation process and their behavior was documented. To identify correlations between certain geometric properties and physical parameters of the feeding system, the tests were planned and carried out using Design of Experiments methods. The results of the tests were also used to determine the direct interrelations of said properties and the suitability for aerodynamic orientation

Development of a Methodology for the Determination of Conceptual Automated Disassembly Systems

At a certain point in its life cycle, a product will reach a condition where it partly or completely loses its functionality. When this happens, the disassembly has the ambition to regenerate a product-value or to enable an environmental friendly product recycling. With regard to the high workload and costs for manual labor one approach to increase the productivity of disassembly tasks is the use of automated disassembly systems (ADS). Depending on different life cycle scenarios, requirements on automated disassembly systems vary. Concerning this problem, a general methodology is developed, which enables the determination of a conceptual ADS by assigning automated modules that are processing the product disassembly. In the first place the objective of a disassembly is determined, followed by a closer investigation of the product. Thereby target components are defined, which has to disassembled. By looking at the connections between these target components suitable separation procedures are derived. Finally, modules of the automated disassembly system are determined

Combined Structural and Dimensional Synthesis of a Parallel Robot for Cryogenic Handling Tasks

The combined structural and dimensional synthesis is a tool for finding the robot structure that is suited best for a given task by means of global optimization. The handling task in cryogenic environments gives strong constraints on the robot synthesis, which are translated by an engineering design step into the combined synthesis algorithm. This allows to reduce the effort of the combined synthesis, which provides concepts for alternative robot designs and indications on how to modify the existing design prototype, a linear Delta robot with flexure hinges. Promising design candidates are the 3PRRU and 3PRUR, which outperform the linear Delta (3PUU) regarding necessary actuator force

LiDAR-Based Localization for Formation Control of Multi-Robot Systems

Controlling the formation of several mobile robots allows for the connection of these robots to a larger virtual unit. This enables the group of mobile robots to carry out tasks that a single robot could not perform. In order to control all robots like a unit, a formation controller is required, the accuracy of which determines the performance of the group. As shown in various publications and our previous work, the accuracy and control performance of this controller depends heavily on the quality of the localization of the individual robots in the formation, which itself depends on the ability of the robots to locate themselves within a map. Other errors are caused by inaccuracies in the map. To avoid any errors related to the map or external sensors, we plan to calculate the relative positions and velocities directly from the LiDAR data. To do this, we designed an algorithm which uses the LiDAR data to detect the outline of individual robots. Based on this detection, we estimate the robots pose and combine this estimate with the odometry to improve the accuracy. Lastly, we perform a qualitative evaluation of the algorithm using a Faro laser tracker in a realistic indoor environment, showing benefits in localization accuracy for environments with a low density of landmarks

Industrial Segment Anything -- a Case Study in Aircraft Manufacturing, Intralogistics, Maintenance, Repair, and Overhaul

Deploying deep learning-based applications in specialized domains like the aircraft production industry typically suffers from the training data availability problem. Only a few datasets represent non-everyday objects, situations, and tasks. Recent advantages in research around Vision Foundation Models (VFM) opened a new area of tasks and models with high generalization capabilities in non-semantic and semantic predictions. As recently demonstrated by the Segment Anything Project, exploiting VFM's zero-shot capabilities is a promising direction in tackling the boundaries spanned by data, context, and sensor variety. Although, investigating its application within specific domains is subject to ongoing research. This paper contributes here by surveying applications of the SAM in aircraft production-specific use cases. We include manufacturing, intralogistics, as well as maintenance, repair, and overhaul processes, also representing a variety of other neighboring industrial domains. Besides presenting the various use cases, we further discuss the injection of domain knowledge

Automated selection and assembly of sets of blades for jet engine compressors and turbines

Aircraft engines need to pass regular maintenance intervals, which go along with a complete disassembly, part inspection (with necessary repair or replacement) and finally reassembly. Especially the manual composition and assembly of blades are time-consuming processes. Increasing air traffic and growing pressure on costs in aviation MRO, demand more efficient approaches. This paper introduces an automated approach for increasing efficiency in selection and assembly of sets of blades for jet engines. Chapter 1 gives a short overview on different designs for compressor and turbine stages. Additionally, the process of adjusting and mounting a set of blades into a circumferential groove is described. Furthermore, a potential for an automated assembly process is determined. Chapter 2 gives an overview of the overall concept, including robotic blade handling, measuring of blades, balancing a set of blades and gap measurement. Chapter 3 focusses on the two measuring tasks. For measuring the width of the blades, optical and tactile approaches are compared. Image processing and laser triangulation are compared to current use of feeler gauges for the gap measurement. In chapter 4 a force-guided assembly strategy, using a force-torque-sensor is presented. Chapter 5 concludes with a brief overview of the planned future work

Investigation of a force-guided assembly strategy for radial mounting of jet engine blades

Increasing air traffic and growing pressure on costs in aviation MRO, especially for jet engines, demand for an increase of process efficiency. While research concentrates on inspection and repair methods, the potential for automated reassembly is thereby mostly neglected. An approach for automated assembly of compressor and turbine blades is introduced in [1]. Part of this approach is a force-guided assembly, which is performed by an industrial robot. The aim of this force-guidance is to compensate positioning deviations, which can occur at different steps throughout the assembly process. Furthermore, sticking of blades during tangential movement, as a consequence of tilting, needs to be avoided. In this paper the proposed force-guided assembly strategy is investigated concerning its capacity of fulfilling the two claims stated above. Therefore, the hardware setup which is used to conduct the assembly and the process execution are described, as well as sources of positioning deviations are identified. Furthermore, the implementation of the force-control on the specific type of robot controller is described. Applying this force-control multiple experiments with defined positioning deviations are conducted. Furthermore, variations of additional assembly parameters are taken into account. The subsequent evaluation will allow a comparison of deviations, occurring during assembly process and the ability to compensate them. Potential for further optimization is stated in the conclusion

Modellierung einer mobilen Hybridkinematik und Umsetzung am Beispiel der Flugzeuginspektion

Diese Dissertation beschäftigt sich mit der Modellierung von mobilen Hybridkinematiken. Im Kern werden Methoden zur Auswahl der Teilmechanismen, zur modularen Berechnung der kinematischen Transformation, zur Überwachung der Annäherung an singuläre Posen und zur Optimierung und Auslegung der mechanischen Struktur entwickelt. Diese Verfahren werden am Beispiel der Entwicklung eines Roboters für die Flugzeuginspektion praktisch validiert.This Thesis deals with kinematic modelling of a mobile hybrid mechanism. Essentially, methods for selecting the partial mechanism, a modular calculation method for the kinematic transformation, a novel approach to detect the proximity to singularities and a simulation tool to design and optimize the mechanical structure is developed. The methods are approved in practice by developing a mobile hybrid robot for aircraft inspection