Advances in Robot Kinematics : Proceedings of the 15th international conference on Advances in Robot Kinematics

International audienceThe motion of mechanisms, kinematics, is one of the most fundamental aspect of robot design, analysis and control but is also relevant to other scientific domains such as biome- chanics, molecular biology, . . . . The series of books on Advances in Robot Kinematics (ARK) report the latest achievement in this field. ARK has a long history as the first book was published in 1991 and since then new issues have been published every 2 years. Each book is the follow-up of a single-track symposium in which the participants exchange their results and opinions in a meeting that bring together the best of world’s researchers and scientists together with young students. Since 1992 the ARK symposia have come under the patronage of the International Federation for the Promotion of Machine Science-IFToMM.This book is the 13th in the series and is the result of peer-review process intended to select the newest and most original achievements in this field. For the first time the articles of this symposium will be published in a green open-access archive to favor free dissemination of the results. However the book will also be o↵ered as a on-demand printed book.The papers proposed in this book show that robot kinematics is an exciting domain with an immense number of research challenges that go well beyond the field of robotics.The last symposium related with this book was organized by the French National Re- search Institute in Computer Science and Control Theory (INRIA) in Grasse, France

Robotic manipulators for in situ inspections of jet engines

Jet engines need to be inspected periodically and, in some instances, repaired. Currently, some of these maintenance operations require the engine to be removed from the wing and dismantled, which has a significant associated cost. The capability of performing some of these inspections and repairs while the engine is on-wing could lead to important cost savings. However, existing technology for on-wing operations is limited, and does not suffice to satisfy some of the needs. In this work, the problem of performing on-wing operations such as inspection and repair is analysed, and after an extensive literature review, a novel robotic system for the on-wing insertion and deployment of probes or other tools is proposed. The system consists of a fine-positioner, which is a miniature and dexterous robotic manipulator; a gross-positioner, which is a device to insert the fine-positioner to the engine region of interest; an end-effector, such as a probe; a deployment mechanism, which is a passive device to ensure correct contact between probe and component; and a feedback system that provides information about the robot state for control. The research and development work conducted to address the main challenges to create this robotic system is presented in this thesis. The work is focussed on the fine-positioner, as it is the most relevant and complex part of the system. After a literature review of relevant work, and as part of the exploration of potential robot concepts for the system, the kinematic capabilities of concentric tube robots (CTRs) are first investigated. The complete set of stable trajectories that can be traced in follow-the-leader motion is discovered. A case study involving simulations and an experiment is then presented to showcase and verify the work. The research findings indicate that CTRs are not suitable for the fine-positioner. However, they show that CTRs with non-annular cross section can be used for the gross-positioner. In addition, the new trajectories discovered show promise in minimally invasive surgery (MIS). Soft robotic manipulators with fluidic actuation are then selected as the most suitable concept for the fine-positioner. The design of soft robotic manipulators with fluidic actuation is investigated from a general perspective. A general framework for the design of these devices is proposed, and a set of design principles are derived. These principles are first applied in a MIS case study to illustrate and verify the work. Finite element (FE) simulations are then reported to perform design optimisation, and thus complete the case study. The design study is then applied to determine the most suitable design for the fine-positioner. An additional analytical derivation is developed, followed by FE simulations, which extend those of the case study. Eventually, this work yields a final design of the fine-positioner. The final design found is different from existing ones, and is shown to provide an important performance improvement with respect to existing soft robots in terms of wrenches it can support. The control of soft and continuum robots relevant to the fine-positioner is also studied. The full kinematics of continuum robots with constant curvature bending and extending capabilities are first investigated, which correspond to a preliminary design concept conceived for the fine-positioner. Closed-form solutions are derived, closing an open problem. These kinematics, however, do not exactly match the final fine-positioner design selected. Thus, an alternative control approach based on closed-loop control laws is then adopted. For this, a mechanical model is first developed. Closed-loop control laws are then derived based on this mechanical model for planar operation of a segment of the fine-positioner. The control laws obtained represent the foundation for the subsequent development of control laws for a full fine-positioner operating in 3D. Furthermore, work on path planning for nonholonomic systems is also reported, and a new algorithm is presented, which can be applied for the insertion of the overall robotic system. Solutions to the other parts of the robotic system for on-wing operations are also reported. A gross-positioner consisting of a non-annular CTR is proposed. Solutions for a deployment mechanism are also presented. Potential feedback systems are outlined. In addition, methods for the fabrication of the systems are reported, and the electronics and systems required for the assembly of the different parts are described. Finally, the use of the robotic system to perform on-wing inspections in a representative case study is studied to determine the viability. Inspection strategies are shortlisted, and simulations and experiments are used to study them. The results, however, indicate that inspection is not viable since the signal to noise ratio is excessively low. Nonetheless, the robotic system proposed, and the research conducted, are still expected to be useful to perform a range of on-wing operations that require the insertion and deployment of a probe or other end-effector. In addition, the trajectories discovered for CTRs, the design found for the fine-positioner, and the advances on control, also have significant potential in MIS, where there is an important need for miniature robotic manipulators and similar devices.Open Acces

Model-based operator guidance in interactive, semi-automated production processes

This contribution focuses on the task of guiding and supervision of technical processes realized by human operators. The review of publications of the last decades discloses that especially technical processes with strong interconnection of human operator and manufacturing process are not adequately addressed by the evolved automation approaches. Integrating human process knowledge and experience into the resulting automation system is still a major concern. Besides the introduction of automation in a handcrafting process that is increasing the overall system complexity, the design of the human-machine interface to the automation system is of central importance. Within this thesis, the trade-off between manual manufacturing and automation is addressed by a semi-automation approach. The application example is the no-bake molding process, a mold manufacturing process for casts that is traditionally handmade. Within this process the human operator plays a central role (i.e. knowledge and expertise), whereas the (intelligent) automation is carrying out physical operation, which is guided and supervised by the human operator. This is achieved by experimentally identified quality representing process variables that allow for in-process feedback to the human operator. Process guiding assistance is given using a formalization approach of the human-automation-interaction. By deducing situative information of interest from the resulting human-automation-system model with respect to the current process goal, the established process model is used for supervision and assistance of the overall process. The design of the human-machine-interface is based on a detailed analysis of the handcrafted process and is realized as a direct, intuitively usable, marker-based interaction technique. The integrated human-automation-system and the corresponding human-machine-interface with process guidance assistance functionality is initially evaluated. The results are discussed for the future work with respect to the individual, human operator-specific process understanding and process reproducibility.Diese Arbeit befasst sich mit Fachkraftaufgaben in der Führung und Überwachung von technischen Prozessen. Die Übersicht der Publikationen der letzten Jahrzehnte eröffnet, dass insbesondere technische Prozesse mit enger Verknüpfung von Mensch und Herstellungsprozess bei den entwickelten Automatisierungsansätzen nicht hinreichend berücksichtigt werden. Die Integration von Prozesswissen und -erfahrung in das resultierende Automatisierungssystem bleibt eine offene Fragestellung. Neben der Einführung von Automation in Handarbeitsprozesse, die die Komplexität des Gesamtsystems erhöhen, ist die Gestaltung der Mensch-Maschine-Schnittstelle zum Automatisierungssystem von zentraler Bedeutung. Der Konflikt zwischen Handarbeit und Automatisierung wird in dieser Arbeit durch die Einführung einer Teilautomatisierung gelöst. Das Anwendungsbeispiel ist das Kaltharzverfahren, ein traditionell in Handarbeit bewältigter Herstellungsprozess für Gussformen. In diesem Prozess spielt die Fachkraft eine zentrale Rolle (z. B. durch ihr Prozesswissen und ihre Expertise), während die (intelligente) Automatisierung –geführt und überwacht durch die Fachkraft– anfallende physische Aktionen ausführt. Dies wird durch experimentell ermit- telte qualitäts-beschreibende Prozessgrößen erreicht, die eine in-prozess Rückführung zum Bedienpersonal ermöglichen. Prozessführungsassistenz ist basierend auf die Formalisierung der Mensch-Automation-Interaktion gegeben. Durch die Bestimmung von situativen Informationen hoher Wichtigkeit aus dem resultierenden Mensch-Automation-System Modell bezogen auf das aktuelle Prozessziel, wird das bestehende Prozessmodell zur Überwachung und Prozessführungsassistenz des Gesamtprozesses genutzt. Die Gestaltung der Mensch-Maschine-Schnittstelle basiert auf einer detaillierten Analyse des Handarbeitsprozesses und ist als direkte, intuitiv bedienbare, markerbasierte Interaktionstechnik realisiert. Das integrierte Mensch-Automation-System sowie die zugehörige Mensch-Maschine-Schnittstelle inklusive Prozessführungsassistenzfunktionen wurden initial evaluiert. Die erzielten Ergebnisse werden hinsichtlich des individuellen, fachkraftabhängigen Prozesswissens und der Reproduzierbarkeit für den Ausblick diskutiert