Design of an Accurate and Stiff Wooden Industrial Robot: First Steps towards Robot Eco-sustainable Mechanical Design

International audienceThis paper investigates the feasibility of replacing metal robot links by wooden bodies for eco-sustainable design's purpose. Wood is a material with low environmental impact, and a good mass-to-stiffness ratio. However, it has significant dimensional and mechanical variabilities. This is an issue for industrial robots that must be accurate and stiff. To guarantee stiffness and accuracy performance of a wooden robot, we propose an integrated design process combining (i) proper wood selection, (ii) adequate sensor-based control strategies to ensure robot accuracy and (iii) a robust design approach dealing with wood uncertainties. Based on the use of this integrated design process, a prototype of a wooden five-bar mechanism is designed and manufactured. Experimental results show that it is realistic to design a wooden robot with performance compatible with Industry requirements in terms of stiffness (deformations lower than 400 microns for 20 N loads) and accuracy (repeatabil-ity lower than 60 microns), guaranteed in a workspace of 800 mm × 200 mm. These works provide a first step towards the eco-sustainable mechanical design of robots

A methodology for evaluating the performance of tow-steered composite technology over a range of planform configurations

Tow-steered composite technology allows for composite fibers to be arranged in customized curving paths rather than in conventional straight lines. This additional design freedom can provide passive load alleviation and increased load path efficiency, which can lead to reduced structural weight, higher wing aspect ratio, and ultimately better vehicle performance. To best take advantage of this technology the weight reduction should be accounted for during the conceptual design stage, when the vehicle’s configuration is still fluid. Since the technology effect could depend on the planform it must be assessed across the range of potential planforms, motivating the development of the thesis methodology. Evaluating tow steering’s technology benefit presents a challenge: due to a lack of historical data the effects must be quantified with parametric physics-based analysis, incurring both development and computational expenses. Additionally, determining the benefit requires repeatedly performing the analysis to solve a high-dimensional constrained optimization problem. In order to better leverage existing weight estimation programs and lessen the impact of computational expense the methodology pursues a surrogate modeling approach. Two main research focuses were addressed while developing the methodology. The first explored how to cope with the large number of dimensions when making the surrogate and applied an active subspace approach to attempt to reduce the dimensionality of the associated constrained optimization problem. The second focus investigated how to most efficiently collect data to build the surrogate and led to the development of an adaptive sampling technique for families of related optimization problems. The findings from these efforts were synthesized to form the thesis methodology, which was then demonstrated in an example use case. The results from this use case were examined to assess the methodology’s successes and limitations, and to provide insight into the behavior of tow-steered composites.Ph.D

Software Visualization in 3D: Implementation, Evaluation, and Applicability

The focus of this thesis is on the implementation, the evaluation and the useful application of the third dimension in software visualization. Software engineering is characterized by a complex interplay of different stakeholders that produce and use several artifacts. Software visualization is used as one mean to address this increasing complexity. It provides role- and task-specific views of artifacts that contain information about structure, behavior, and evolution of a software system in its entirety. The main potential of the third dimension is the possibility to provide multiple views in one software visualization for all three aspects. However, empirical findings concerning the role of the third dimension in software visualization are rare. Furthermore, there are only few 3D software visualizations that provide multiple views of a software system including all three aspects. Finally, the current tool support lacks of generating easy integrateable, scalable, and platform independent 2D, 2.5D, and 3D software visualizations automatically. Hence, the objective is to develop a software visualization that represents all important structural entities and relations of a software system, that can display behavioral and evolutionary aspects of a software system as well, and that can be generated automatically. In order to achieve this objective the following research methods are applied. A literature study is conducted, a software visualization generator is conceptualized and prototypically implemented, a structured approach to plan and design controlled experiments in software visualization is developed, and a controlled experiment is designed and performed to investigate the role of the third dimension in software visualization. The main contributions are an overview of the state-of-the-art in 3D software visualization, a structured approach including a theoretical model to control influence factors during controlled experiments in software visualization, an Eclipse-based generator for producing automatically role- and task-specific 2D, 2.5D, and 3D software visualizations, the controlled experiment investigating the role of the third dimension in software visualization, and the recursive disk metaphor combining the findings with focus on the structure of software including useful applications of the third dimension regarding behavior and evolution

The Meaning of UML Models

The Unified Modelling Language (UML) is intended to express complex ideas in an intuitive and easily understood way. It is important because it is widely used in software engineering and other disciplines. Although an official definition document exists, there is much debate over the precise meaning of UML models. ¶ In response, the academic community have put forward many different proposals for formalising UML, but it is not at all obvious how to decide between them. Indeed, given that UML practitioners are inclined to reject formalisms as non-intuitive, it is not even obvious that the definition should be “formal” at all. Rather than searching for yet another formalisation of UML, our main aim is to determine what would constitute a good definition of UML. ¶ The first chapter sets the UML definition problem in a broad context, relating it to work in logic and the philosophy of science. ..

Safety and Reliability - Safe Societies in a Changing World

The contributions cover a wide range of methodologies and application areas for safety and reliability that contribute to safe societies in a changing world. These methodologies and applications include: - foundations of risk and reliability assessment and management - mathematical methods in reliability and safety - risk assessment - risk management - system reliability - uncertainty analysis - digitalization and big data - prognostics and system health management - occupational safety - accident and incident modeling - maintenance modeling and applications - simulation for safety and reliability analysis - dynamic risk and barrier management - organizational factors and safety culture - human factors and human reliability - resilience engineering - structural reliability - natural hazards - security - economic analysis in risk managemen

Video Vortex reader : responses to Youtube

The Video Vortex Reader is the first collection of critical texts to deal with the rapidly emerging world of online video – from its explosive rise in 2005 with YouTube, to its future as a significant form of personal media. After years of talk about digital convergence and crossmedia platforms we now witness the merger of the Internet and television at a pace no-one predicted. These contributions from scholars, artists and curators evolved from the first two Video Vortex conferences in Brussels and Amsterdam in 2007 which focused on responses to YouTube, and address key issues around independent production and distribution of online video content. What does this new distribution platform mean for artists and activists? What are the alternatives

Modular modeling with a computational twist in Metamod

Model-driven engineering (MDE) is a software development methodology that promises to alleviate the complex task of writing software. To achieve its goals, MDE makes use of models. Although models are concise representations of the knowledge in a domain, they can become large and complex. In dealing with complexity, modularity has proven to be a good ally for engineers in general software development. Inspired by this, we set to explore modularity for models. To this end, we incorporated two mechanisms: grouping and fragment abstractions. The second ingredient, in particular, gives rise to an interesting combination between modeling elements and computational elements. To test our ideas, we have implemented a prototype metamodeling language called MetaMod. To highlight MetaMod's essential features we have included a small example for train tracks.</p