Challenges and prospects of automated disassembly of fuel cells for a circular economy

The hydrogen economy is driven by the growing share of renewable energy and electrification of the transportation sector. The essential components of a hydrogen economy are fuel cells and electrolysis systems. The scarcity of the resources to build these components and the negative environmental impact of their mining requires a circular economy. Concerning disassembly, economical, ergonomic, and safety reasons make a higher degree of automation necessary. Our work outlines the challenges and prospects on automated disassembly of fuel cell stacks. This is carried out by summarizing the state-of-the-art approaches in disassembly and conducting manual non-/destructive disassembly experiments of end-of-life fuel cell stacks. Based on that, a chemical and mechanical analysis of the fuel cell components is performed. From this, an automation potential for the disassembly processes is derived and possible disassembly process routes are modeled. Moreover, recommendations are given regarding disassembly system requirements using a morphological box

Robotic disassembly of electronic components to support end‐of‐life recycling of electric vehicles

This thesis reports on the research undertaken to analyse the factors affecting End-of-Life (EoL) recycling of future Electric Vehicles (EVs). The principle objective of the research is to generate an understanding of challenges and opportunities for the development and implementation of an automated robotic disassembly approach to aid with EoL management of electrical and electronic components within EVs. The research contributions are considered in three main parts. The first part contains a review of advancement in the development of automotive technology, and in particular the alternative fuel vehicles. A review of existing industrial recycling technologies and processes has been conducted which highlighted a number of key challenges in the adoption of current recycling technologies for EVs. The review concludes that there is a need to develop novel recycling technologies and processes to deal with the increased part complexity and material mixture in such vehicles. In this context, the second part of the research details a framework for EoL management of EV components. This framework presents a comprehensive automated robotic disassembly approach in which three specific steps are defined, namely manual disassembly to develop an understanding of product design, initial automated disassembly to test process capability, and optimisation and validation to improve repeatability and efficiency of the robotic disassembly operations. The framework also includes the development of a multi-criteria decision-making tool that assesses the environmental, technological and economic benefits of such robotic disassembly approach. The applicability of the research concepts has been demonstrated via three case studies. The results have highlighted the applicability of the automated robotic disassembly approach in a variety of scenarios of different design complexity and recovery rate. The results indicate that the adoption of this robotic disassembly enhances the pre-concentration of Strategically Important Materials (SIMs) and leads to minimisation of environmental impacts and increased material recovery value

End-of-Life Efficient Disassembly of Complex Structures Using Product and Process Focused Approach

RÉSUMÉ Le démantèlement durable des avions, contenant un nombre élevé de composants métalliques et non métalliques, devient, de nos jours, un problème de plus en plus urgent dans l’industrie aéronautique. Le désassemblage de la structure, en tant que principale tâche de cette procédure, a toujours été un défi considérable que ce soit en matière d’efforts requis qu’en termes de valeur économique apportée. Ce processus est, depuis toujours, apparu comme un service couteux et pas forcément écologique. La revue de la littérature indique que le désassemblage semi-destructif a des bénéfices significatifs contrairement à la destruction totale voir la non-destruction des appareils. Malgré un grand champ d’applications, à l’heure actuelle, il n’existe aucun moyen d’évaluer, indépendamment d’estimations subjectives, quantitativement l’effort nécessaire pour appliquer une telle méthode sur des structures métalliques complexes telles que celles d’un avion. Le but de cette thèse est donc, de développer une échelle d’évaluation à multiples variables afin de déterminer la performance de chaque opération avant de commencer le travail matériel. Ce modèle serait capable d’évaluer la facilité de désassembler la structure, et ce de manière quantitative, incorporant les aspects relatifs au produit ainsi qu’au procédé. Dans chacune de ces deux catégories (c’est à dire produit et procédé), différents facteurs déterminants, peuvent amener à un résultat économique, environnemental et /ou social décevant, s’ils ne sont pas pris en considération. C’est pourquoi cette méthode explore divers facteurs tels que le temps, la difficulté, la compatibilité des matériaux utilisés dans les pièces/modules de la structure afin que la stratégie choisie corresponde aux objectifs techniques, économiques, et environnementaux. Dans cette étude de cas, un stabilisateur horizontal provenant d’un appareil Bombardier CRJ series a été sélectionné afin d’évaluer la pertinence et l’efficacité de l’approche proposée. La partie expérimentale s’est appuyée sur des travaux pratiques de désassemblage établis sur une période de plus de deux ans, des analyses des documents de maintenance appartenant à cet avion, ainsi que des entretiens avec des spécialistes de ce domaine. Les résultats ont démontré que l’approche proposée est à la fois facilement réalisable, plus rapide et permet une meilleure récupération des matériaux en comparaison avec d’autres méthodes. Enfin, avec de tels avantages, ce procédé apporte une importante contribution dans le domaine du désassemblage de la structure puisqu'il est aisément exploitable par les sites de désassemblage, pour les fabricants et propriétaires d'avions.----------ABSTRACT Sustainable decommissioning of aircraft with a high content of metallic and non-metallic components is becoming an urgent issue in today’s aviation industry. Airframe disassembly, as a principal step in this procedure, has always been a challenge in terms of the required effort and regained values. This process has historically appeared to be economically costly, socially unviable, and not necessarily environmentally benign. Literature indicates that, unlike entirely destructive and totally non-destructive techniques, semi-destructive disassembly may bring significant benefits. However, despite their use in a wide variety of applications, there are currently no feasible solutions on how to measure the associated physical difficulties and required efforts without any dependencies on expert views or filling out spreadsheet-like forms. The purpose of this dissertation is then to develop a multiple-variable model in order to determine the performance of each disassembly operation prior to the physical work. The model could accurately evaluate the disassembly easiness of an airframe quantitatively incorporating both product and process features. There are various driving factors in each of these categories (i.e., process and product features) that failing to appropriately address them could result in either significant economic loss, environmental and/or social inconvenience. The methodology used in this study is one of the first investigations in this field, known as a Multivariable Disassembly Evaluator (MDE). It explores 1- time; 2- difficulty; and 3- material compatibility of the airframe parts/modules to ensure that the defined disassembly strategies meet technical, economic and environmental objectives. A horizontal stabilizer of Bombardier CRJ series was selected as a case study to provide a detailed vision of disassembly evaluating the suitability and effectiveness of the proposed approach. The experimental investigations are based upon the real disassembly works for over two years, aircraft maintenance documentation analysis and discussions with technical domain specialists. The findings demonstrated that the proposed method is easier to fulfil, faster and allows the user to gain more recovery than other current approaches. These advantages should make an important contribution to the field of airframe disassembly since they can be readily used by disassembly sites, aircraft owners and manufacturers

Reuse of safety certification artefacts across standards and domains: A systematic approach

Reuse of systems and subsystem is a common practice in safety-critical systems engineering. Reuse can improve system development and assurance, and there are recommendations on reuse for some domains. Cross-domain reuse, in which a previously certified product typically needs to be assessed against different safety standards, has however received little attention. No guidance exists for this reuse scenario despite its relevance in industry, thus practitioners need new means to tackle it. This paper aims to fill this gap by presenting a systematic approach for reuse of safety certification artefacts across standards and domains. The approach is based on the analysis of the similarities and on the specification of maps between standards. These maps are used to determine the safety certification artefacts that can be reused from one domain to another and reuse consequences. The approach has been validated with practitioners in a case study on the reuse of an execution platform from railway to avionics. The results show that the approach can be effectively applied and that it can reduce the cost of safety certification across standards and domains. Therefore, the approach is a promising way of making cross-domain reuse more cost-effective in industry.European Commission's FP7 programm

Automatic Disassembly Task Sequence Planning of Aircrafts at their End-of-Life

RÉSUMÉ Une prise de conscience des problèmes environnementaux à l'échelle mondiale ainsi que des avantages économiques a stimulé les chercheurs à trouver les possibilités de réutiliser et de recycler les produits en fin de vie. Chaque année plusieurs centaines d'avions atteignent globalement fin de leur navigabilité et doivent être retirés du service actif. De ce fait, une attention accrue est maintenant accordée à la fin de vie des avions. Désassemblage joue un rôle important dans la prise de décision de fin de vie. La faisabilité économique du processus de démontage avec beaucoup d'incertitudes est une préoccupation majeure limitant sa mise en oeuvre dans la pratique de l'industrie. De nombreuses recherches dans le domaine de la planification et des opérations de processus de démontage a été fait, qui visent de plus en plus la faisabilité économique du démontage avec la réduction des temps de démontage de proposer des séquences de démontage optimisées. Par conséquent, ces dernières années, de nombreux chercheurs ont publié des articles sur la planification de la séquence de démontage des produits en fin de vie qui est un problème NP-complet optimisation combinatoire. Néanmoins, il y a eu un peu d'attention à la planification de la séquence de démontage d'avions en fin de vie. Cette thèse aborde la planification de séquence de démontage des pièces réutilisables d'avions en fin de vie avant le démantèlement pour le recyclage. Puisque les composants récupérés vont être utilisés à nouveau, une approche non-destructive tout en respectant les instructions fournies dans le manuel d'entretien d'avion intitulé « Aircraft Maintenance Manuel » (AMM) pour le retrait des pièces est prise en considération. Ordonnancement de désassemblage dans cette recherche ne traite pas le séquençage le démontage des pièces comme dans d'autres études, mais il planifie séquence de tâches de démontage dans l'AMM. Une tâche de démontage consiste combinaison d'opérations pour la préparation du démontage ou le procède de démontage pour un ou plusieurs pièces. Tout d'abord, un modèle de séquençage de démontage est proposé par l'examen structure des tâches de démontage dans l'AMM. Ensuite, un code Matlab est développé qui lit la base de données énuméré des tâches et sous-tâches qui sont acquises à partir de l'AMM et génère la séquence de démontage des tâches et sous-tâches automatiquement en utilisant le modèle proposé. Le code est capable de générer des séquences de désassemblage de tâches pour n’importe quelle pièce sollicitée.----------ABSTRACT An awareness of the world’s environmental problems plus economic benefits has stimulated researchers to seek the opportunities to reuse and recycle end-of-life (EOL) products. Each year hundreds of aircraft globally reach end of their airworthiness and should be withdrawn from active service. Due to this fact, increased attention is now being paid to EOL of aircrafts. Disassembly plays an important role in EOL decision making. The economic feasibility of the disassembly process with lots of uncertainties is a main concern limiting its implementation in industry practice. Many researches in the field of disassembly process planning and operations has been done that aim increasing economic feasibility of disassembly with reducing disassembly times with proposing optimized disassembly sequences. Consequently, in recent years, many scholars have published articles on disassembly sequence planning of EOL products that is a NP-complete combinatorial optimization problem. Nevertheless, there has been a scant attention towards disassembly sequence planning of EOL aircrafts. This thesis addresses disassembly sequence planning of reusable components of EOL aircrafts before dismantling it for recycling. Since retrieved components are going to be used again, a nondestructive approach with respecting all instructions provided in aircraft maintenance manual (AMM) for removal of parts is taken into consideration. Disassembly scheduling in this work does not deal with scheduling disassembly of components as in other works but it schedules sequence of removal Tasks in AMM. A removal task consists combination of operations for preparation of disassembly or process of disassembly for a part or multiple parts. At first, a disassembly sequencing model with considering structure of disassembly tasks in AMM is proposed. Afterwards a Matlab code is developed which reads from enumerated database of tasks and subtasks that are acquired from AMM and generates disassembly sequence of tasks and subtasks automatically using the proposed model. The code is capable of generating disassembly sequences of tasks for any given removal task of solicited part. Finally, a greedy and an adaptive greedy algorithm are proposed to optimize disassembly sequence of tasks with minimizing changes in visited zones of disassembly operations. Results generated in Matlab code, suggests effectiveness of proposed adaptive greedy algorithm