Estimation and its Role in Engineering Design - An Introduction

in Proceedings of the 17th International Conference on Engineering Design (2009)

Estimation is assumed to be a relevant method for problem solving in product development due to the deficiencies in information availability and certainty, as well because of short resources. Nevertheless ... [more ▼]

Estimation is assumed to be a relevant method for problem solving in product development due to the deficiencies in information availability and certainty, as well because of short resources. Nevertheless estimation as a method is hardly mentioned in literature on product development nor is it part of engineering education. As a consequence good performance in estimation and the development of estimation competence is left to chance, i.e. expected to be built up through experience. We believe that estimation can be supported and taught. Hence estimation competence can be developed purposive and more quickly. The aims of the research introduced in this paper are to understand relevance and functioning of estimation in engineering design, and to develop support for engineering practice and education based on this understanding. This paper focuses on demonstrating the topics’ relevance by addressing the following questions: •Why is estimation important for engineering design? •What is the state of the art in understanding estimation in general? •What is the state of the art of estimation as a method in engineering design? On the basis of this initial investigation we propose our research framework. After goal, approach and scope of our research, the main research questions on estimation in engineering design we wish to answer are formulated, and the research methods we are using. Furthermore first results on characteristics of estimation in engineering design identified by tests, as well as video and protocol analysis are summarized. At least an outlook on the prospect research is given. [less ▲]

Etude biomécanique comparative de cinq différents systèmes de fixation utilisés dans les cas d'ostéotomies tibiales valgisantes: Essais expérimentaux et simulations numériques incluant les forces musculaires

Doctoral thesis (2016)

This research project was carried out in partnership with the Orthopaedic and Traumatology service of the “clinique d’Eich” of the Centre Hospitalier de Luxembourg. The main objective consisted in a ... [more ▼]

This research project was carried out in partnership with the Orthopaedic and Traumatology service of the “clinique d’Eich” of the Centre Hospitalier de Luxembourg. The main objective consisted in a comparative biomechanical study of the stability of five different currently used implants for open-wedge high tibial osteotomy (HTO). The following implants were tested in the comparative biomechanical study: Contour Lock HTO, PEEKPower HTO, iBalance HTO, TomoFix standard and TomoFix small stature. The implants were chosen freely from the market and there has not been any funding or link to any of the manufacturers. The comparison was first made experimentally using static compression loading to failure and dynamic loading to failure tests, then computationally using simulations by mean of the finite element method. Muscle forces were predicted using musculoskeletal modeling and applied to the finite element models of the lower limb that simulated the stance phase of the gait cycle. The finite element models created included all the bones of the lower limb, except those of the foot, as well as the menisci, the articular cartilage layers of the knee and the patellar tendon which was modelled by springs. The comparative study using numerical simulations was done considering two separate loadings: (1) application of a compressive load on the tibial plateau and (2) consideration of muscle forces. The comparison of the two types of loading (1) and (2) showed that loading (1) used during the mechanical tests is compatible with a realistic loading of the tibia with the leg at 15 % of the gait cycle during slow walking. Observations from numerical simulations considering loading (2) emphasized the necessity to take into account the muscle forces in the testing protocols and implant design process. The results of the numerical simulations considering loading (1) were in line with the findings of the experimental study. All the implants tested showed sufficient stability during static loading. All the specimens failed due to fracture of the opposite cortical bone. In regards to the results of this study, the implant iBalance offered the best mechanical stability to the operated tibia, and the PEEKPower plate the worst. Simplifications were made to reduce the complexity of the different physical and numerical models; hence the transposition of the obtained results to clinical settings should be done with precaution. There is no conflict of interest in relation to this work. [less ▲]

European Conference on Data Analysis 2013. Book of Abstracts.

Book published by University of Luxembourg (2013)

Evaluating the reliability of the Utility-Based Dynamic OD Estimation on Large Networks

Scientific Conference (2018, January)

An evaluation of low-cost consumer-grade UAS systems for 3D reality capture

Poster (2016, September 22)

During the last years, small lightweight and low cost remotely piloted aerial systems (RPAS) commonly referred as Drones have rapidly developed into capable low-cost Unmanned Aerial Systems (UAS). Fuelled ... [more ▼]

During the last years, small lightweight and low cost remotely piloted aerial systems (RPAS) commonly referred as Drones have rapidly developed into capable low-cost Unmanned Aerial Systems (UAS). Fuelled by a vibrant community of scientists, professionals and hobby enthusiasts enabling technologies have matured quickly, and prices of consumer grade as well as semi-professional systems fell sharply. Especially multirotor vertical take-off and landing (VTOL) UAS have proven to be versatile and flexible platforms which can be equipped with a range of sensors capable of capturing aerial data for a variety of 2D and 3D mapping applications. Consumer grade, low weight systems as the DJI Phantom or 3DR Solo have a limited payload and can carry low weight action cameras like the GoPro Hero models which are capable of collecting video as well as still RGB and near-infrared imagery. Applying traditional Photogrammetric methods to imagery from low-cost UAS systems proved complex and impractical in the past. However modern the state-of-the-art structure from motion algorithms implemented in off the shelf software packages (sometimes referred as new Photogrammetry), cloud processing environments and available via open source libraries promise to generate dense 3D point clouds, textured models and orthomosaics in high quality and without much effort. How accurate and how reliable are data products generated from such systems? Expanding from a preliminary study (BACKES & TEASDALE 2015) we review the every progressing capabilities and features of COTS (commercial of the shelf) user and semi-professional UAS systems under the aspects of deployable sensors, ease of use, reliability as well as safety. We show the workflow from flight planning, data collection to dense pointclould matching using a range of software products. The resulting point clouds are evaluated and benchmarked using a highly accurate and dense reference data acquired via geodetic terrestrial survey and Laserscanning. The results of this evaluations allow conclusions on the current accuracy capabilities of this such low-cost systems. [less ▲]

Eventually everything connects

Speeches/Talks (2018)

If you are reading these lines, you are probably curious about the type of experience that you would have as an attendee of this talk. You might wonder whether the topic would match your interests ... [more ▼]

If you are reading these lines, you are probably curious about the type of experience that you would have as an attendee of this talk. You might wonder whether the topic would match your interests, whether the speaker will be good enough to satisfy your expectations, whether you will feel inspired, exhilarated, or whether you will have concrete tools to bring back to your work. While you are usually the ones shaping people’s experiences, you are striving for nice experiences as well. Designing for human experiences is one of the most challenging yet fascinating activities. It is a responsibility that we should embrace with humility and dedication. To face the complexity of our mission, we need to draw on theoretical knowledge, methodological skills and of course on our shared professional expertise, as a community. While UX practitioners are working hard at the front lines to design better products or services, scientists work in the shadows to develop and consolidate a myriad of novel and highly valuable UX methods. During this talk, you will discover the ever-growing UX toolbox that could greatly support you in collecting richer, insightful and more valid data. From scientific theories to pragmatic methods, from academia to industry, from Luxembourg to Puerto Rico… Eventually everything connects. [less ▲]

Exact and approximate route set generation for resilient partial observability in sensor location problems

in Transportation Research. Part B : Methodological (2017), 105

Sensor positioning is a fundamental problem in transportation networks, as the location of sensors strongly determines how traffic flows are observable and hence manageable. This paper aims to develop a ... [more ▼]

Sensor positioning is a fundamental problem in transportation networks, as the location of sensors strongly determines how traffic flows are observable and hence manageable. This paper aims to develop a methodology to determine sensor locations on a network such that an optimal trade-off solution is found between the amount of sensors installed and the resilience of the sensor set. In particular, we propose exact and heuristic solutions for identifying the optimal route sets such that no other route would include any additional information for finding optimal full and partial observability solutions. This is an important contribution to sensor location problems, as route-based link flow inference problems have non-unique solutions, strongly depending on the used link-route information. The properties of the new methodology are analyzed and illustrated through different case studies, and the advantages of the algorithms are quantified both for full and for partial observability solutions. Due to the route sets found by our approach, we are able to find full observability solutions characterized by a small number of sensors, while yet being efficient also in terms of partial observability. We perform validation tests on both small and real-life sized network instances. © 2017 Elsevier Ltd [less ▲]

Experimental analysis of eGLOSA and eGLODTA transit control strategies

in Proceedings of the 5th IEEE International Conference on Models and Technologies for Intelligent Transportation Systems, MT-ITS 2017 (2017)

Battery powered electric buses have higher energy efficiency, lower emissions and noise when compared to buses with internal combustion engines. However, due to battery charging requirements, their large ... [more ▼]

Battery powered electric buses have higher energy efficiency, lower emissions and noise when compared to buses with internal combustion engines. However, due to battery charging requirements, their large-scale integration into public transport operations is more complex. This study proposes a novel concept supporting said integration via new control strategies, dubbed e-GLOSA and e-GLODTA. These strategies extend the existing Green Light Optimal Speed and Dwell Time Systems (GLOSA/GLODTA) to account for the specific needs of electric buses. That is, they include the goals of minimizing the energy consumption between charging stations, and maximizing available charging time. At the same time, interference with schedule requirements is minimized. The formulated heuristics are tested on a Bus Rapid Transit (BRT) corridor case study, where different scenarios—such as placement of charging stations and bus regularity—are studied to assess under which conditions each action (maintain speed, accelerate or dwell for a longer time at a stop) is beneficial. Results show that eGLOSA contributes to schedule adherence while eGLODTA allows satisfying charging time constraints. [less ▲]

Experimental and Numerical Evaluation of the Residence Time Characteristics on a Forward Acting Grate

in Condensed Matter 2014 (2014)

Experimental Evaluation of a Team of Multiple Unmanned Aerial Vehicles for Cooperative Construction

in IEEE Access (2021)

This article presents a team of multiple Unmanned Aerial Vehicles (UAVs) to perform cooperative missions for autonomous construction. In particular, the UAVs have to build a wall made of bricks that need ... [more ▼]

This article presents a team of multiple Unmanned Aerial Vehicles (UAVs) to perform cooperative missions for autonomous construction. In particular, the UAVs have to build a wall made of bricks that need to be picked and transported from different locations. First, we propose a novel architecture for multi-robot systems operating in outdoor and unstructured environments, where robustness and reliability play a key role. Then, we describe the design of our aerial platforms and grasping mechanisms to pick, transport and place bricks. The system was particularly developed for the Mohamed Bin Zayed International Robotics Challenge (MBZIRC), where Challenge 2 consisted of building a wall cooperatively with multiple UAVs. However, our approach is more general and extensible to other multi-UAV applications involving physical interaction, like package delivery. We present not only our results in the final stage of MBZIRC, but also our simulations and field experiments throughout the previous months to the competition, where we tuned our system and assessed its performance. [less ▲]