An Iterative Approach for Collision Feee Routing and Scheduling in Multirobot Stations

This work is inspired by the problem of planning sequences of operations, as welding, in car manufacturing stations where multiple industrial robots cooperate. The goal is to minimize the station cycle time, \emph{i.e.} the time it takes for the last robot to finish its cycle. This is done by dispatching the tasks among the robots, and by routing and scheduling the robots in a collision-free way, such that they perform all predefined tasks. We propose an iterative and decoupled approach in order to cope with the high complexity of the problem. First, collisions among robots are neglected, leading to a min-max Multiple Generalized Traveling Salesman Problem (MGTSP). Then, when the sets of robot loads have been obtained and fixed, we sequence and schedule their tasks, with the aim to avoid conflicts. The first problem (min-max MGTSP) is solved by an exact branch and bound method, where different lower bounds are presented by combining the solutions of a min-max set partitioning problem and of a Generalized Traveling Salesman Problem (GTSP). The second problem is approached by assuming that robots move synchronously: a novel transformation of this synchronous problem into a GTSP is presented. Eventually, in order to provide complete robot solutions, we include path planning functionalities, allowing the robots to avoid collisions with the static environment and among themselves. These steps are iterated until a satisfying solution is obtained. Experimental results are shown for both problems and for their combination. We even show the results of the iterative method, applied to an industrial test case adapted from a stud welding station in a car manufacturing line

Energy and Route Optimization of Moving Devices

This thesis highlights our efforts in energy and route optimization of moving devices. We have focused on three categories of such devices; industrial robots in a multi-robot environment, generic vehicles in a vehicle routing problem (VRP) context, automatedguided vehicles (AGVs) in a large-scale flexible manufacturing system (FMS). In the first category, the aim is to develop a non-intrusive energy optimization technique, based on a given set of paths and sequences of operations, such that the original cycle time is not exceeded. We develop an optimization procedure based on a mathematical programming model that aims to minimize the energy consumption and peak power. Our technique has several advantages. It is non-intrusive, i.e. it requires limited changes in the robot program and can be implemented easily. Moreover,it is model-free, in the sense that no particular, and perhaps secret, parameter or dynamic model is required. Furthermore, the optimization can be done offline, within seconds using a generic solver. Through careful experiments, we have shown that it is possible to reduce energy and peak-power up to about 30% and 50% respectively. The second category of moving devices comprises of generic vehicles in a VRP context. We have developed a hybrid optimization approach that integrates a distributed algorithm based on a gossip protocol with a column generation (CG) algorithm, which manages to solve the tested problems faster than the CG algorithm alone. The algorithm is developed for a VRP variation including time windows (VRPTW), which is meant to model the task of scheduling and routing of caregivers in the context of home healthcare routing and scheduling problems (HHRSPs). Moreover,the developed algorithm can easily be parallelized to further increase its efficiency. The last category deals with AGVs. The choice of AGVs was not arbitrary; by design, we decided to transfer our knowledge of energy optimization and routing algorithms to a class of moving devices in which both techniques are of interest. Initially, we improve an existing method of conflict-free AGV scheduling and routing, such that the new algorithm can manage larger problems. A heuristic version of the algorithm manages to solve the problem instances in a reasonable amount of time. Later, we develop strategies to reduce the energy consumption. The study is carried out using an AGV system installed at Volvo Cars. The results are promising; (1)the algorithm reduces performance measures such as makespan up to 50%, while reducing the total travelled distance of the vehicles about 14%, leading to an energy saving of roughly 14%, compared to the results obtained from the original traffic controller. (2) It is possible to reduce the cruise velocities such that more energy is saved, up to 20%, while the new makespan remains better than the original one

Development of service-oriented architectures using model-driven development : a mapping study

Context: Model-Driven Development (MDD) and Service-Oriented Architecture (SOA) are two challenging research areas in software engineering. MDD is about improving software development whilst SOA is a service-based conceptual development style, therefore investigating the available proposals in the literature to use MDD when developing SOA may be insightful. However, no studies have been found with this purpose. Objective: This work aims at assessing the state of the art in MDD for SOA systems. It mainly focuses on: what are the characteristics of MDD approaches that support SOA; what types of SOA are supported; how do they handle non-functional requirements. Method: We conducted a mapping study following a rigorous protocol. We identified the representative set of venues that should be included in the study. We applied a search string over the set of selected venues. As result, 129 papers were selected and analysed (both frequency analysis and correlation analysis) with respect to the defined classification criteria derived from the research questions. Threats to validity were identified and mitigated whenever possible. Results: The analysis allows us to answer the research questions. We highlight: (1) predominance of papers from Europe and written by researchers only; (2) predominance of top-down transformation in software development activities; (3) inexistence of consolidated methods; (4) significant percentage of works without tool support; (5) SOA systems and service compositions more targeted than single services and SOA enterprise systems; (6) limited use of metamodels; (7) very limited use of NFRs; and (8) limited application in real cases. Conclusion: This mapping study does not just provide the state of the art in the topic, but also identifies several issues that deserve investigation in the future, for instance the need of methods for activities other than software development (e.g., migration) or the need of conducting more real case studies.Peer ReviewedPostprint (author's final draft

Conceptual Key Competency Model for Smart Factories in Production Processes

AbstractBackground and Purpose: The aim of the study is to develop a conceptual key competency model for smart factories in production processes, focused on the automotive industry, as innovation and continuous development in this industry are at the forefront and represent the key to its long-term success.Methodology: For the purpose of the research, we used a semi-structured interview as a method of data collection. Participants were segmented into three homogeneous groups, which are industry experts, university professors and secondary education teachers, and government experts. In order to analyse the qualitative data, we used the method of content analysis.Results: Based on the analysis of the data collected by structured interviews, we identified the key competencies that workers in smart factories in the automotive industry will need. The key competencies are technical skills, ICT skills, innovation and creativity, openness to learning, ability to accept and adapt to change, and various soft skills.Conclusion: Our research provides insights for managers working in organisations that are transformed by Industry 4.0. For instance, human resource managers can use our results to study what competencies potential candidates need to perform well on the job, particularly in regards to planning future job profiles in regards related to production processes. Moreover, they can design competency models in a way that is coherent with the trends of Industry 4.0. Educational policy makers should design curricula that develop mentioned competencies. In the future, the results presented here can be compared and contrasted with findings obtained by applying other empirical methods

A human-factors approach to capture medical device safety, performance and usability

Advances in medical technology including computer aided and robotic surgery, digital health and increased use of portable devices have improved patient care in both hospital and home environments. These advancements have brought an increased level of complexity in patient care with new challenges to both patients and clinicians. The available performance data on medical devices (MD) is scarce and of variable quality despite work from regulatory bodies, with multiple associated challenges and lack of effective systems in place for its collection. This research used human factor methods to address i) the current state of safety and performance data availability for MDs and ii) methods of capturing safety and usability data in hospital and home environments by using human factor methods. Part A of this thesis concentrated on hospital based devices whilst Part B addressed home use MDs. End user experiences were utilised throughout to gain an understanding of the current system including its challenges and reasons leading to lack of data. Patients, clinicians, manufacturers, human factor specialists and MHRA were involved at all stages of this research. The studies led to the developments of the pathway map to reporting and information transfer in operating theatres and furthermore the development and initial evaluation of the MD-PRS concept (Medical Device Performance Reporting System) as a single dedicated method of reporting all MD malfunctions/ failures. The My-VID usability tool (My Voice in Design) was developed and evaluated as a method for collecting usability data directly from patients on home use MDs. In conclusion, this thesis used human factor methods to better understand the current system of data collection, available data sources on MDs and challenges faced prior to developing methods for improvement, based on end user experiences . Finally, methods of applying this research to clinical practice were addressed in the final chapter.Open Acces

Vene emakeelega õpilaste etniline identiteet Eestis haridusmuutuste tingimustes

Väitekirja elektrooniline versioon ei sisalda publikatsioone.Me elame kiiresti muutuvas maailmas ja puutume üha enam kokku keelelis-kultuurilise mitmekesisusega, end teostades ja oma kohta otsides. Just seetõttu on olulised sellised küsimused nagu Kes ma olen? ja Kuhu kuulun? Mida üks või teine kuuluvus tähendab minu jaoks? Need küsimused on aktuaalsetena teadvustatud nii ühiskonna tasandil, igapäevaelus kui ka teadusliku uurimisprobleemina. Enese etnilise grupi liikmena määratlemine ei pruugi olla teadvustatud ja oluline pidevalt ja kõigis situatsioonides, kuid see sotsiaalse identiteedi aspekt võib siiski olla piisav alus, et end väärtustlikuna või tõrjutuna tunda. Etnilisel sotsialiseerumisel on peetud olulisemaks keskkonnaks perekonda. Kuid ka hariduskeskkonda on peetud grupikuuluvuste kujunemise seisukohast oluliseks. Käesoleva töö fookuseks on Eesti venekeelsete õpilaste etnilise identiteedi kujunemine ühe olulisema haridusmuutuse ehk eestikeelsele õppele ülemineku kontekstis. Doktoritöö raames läbi viidud uuringutest ilmneb, et etniline enesemääratlus ja õppekeele ei seostu otseselt, samas on emakeel oluline enesemääratluse aluseks olev tunnus. Õpilaste nägemuses erinevad koolid õppekeeleti eelkõige selle poolest, missugusel tasemel on võimalik mingis koolis erinevaid keeli (vene, eesti) omandada. Seda, et ootused haridussüsteemile on pigem seotud sellega, kuivõrd on võimalik omandada teadmised ja oskused, mis on vajalikud edukaks ja soovitud haridusteeks ning karjääriks, kinnitavad ka (vanemate poolt) tehtud kooli valikud, sh õppekeeltest lähtuvalt. Tulemustest ilmneb selgelt, et Eesti ühiskonnas on võimalik olla edukas heal tasemel eesti keelt osates. Uuringute tulemustele toetudes võib järeldada, et keeltel on Eesti ühiskonnas tugev sümboolne väärtus, õppekeel ei ole vaid teadmiste ja oskuste omandamise vahend, vaid ka etniliste gruppide staatust väljendav nähtus, millest tingituna tajutakse vene õppekeele asendumist gümnaasiumiastmes riskina etnilisele identiteedile. Etnilise identiteedi kujunemisel haridusmuutuste tingimustes on olulised erinevad kommunikatiivsed seosed etnilise identiteedi, haridussüsteemi ja ühiskonna vahel: kuidas ühiskonnas toimunud muutusi kooli tasandil ja indiviidide poolt tõlgendatakse ning missuguseid valikuid nende tõlgenduste baasil tehakse.We live in a rapidly changing and increasingly diverse world in which we have to succeed. The questions like What I am? and Where do I belong? and What does this mean to me? are therefore essential, considering also ethnicity , and have to be continuously addressed at the level of society, in everyday life and as a problem that has to be researched. Ethnic self-identification may not be important in all situations, but this aspect of social identity could be essential to a feeling for being valued and not marginalized. The most important environment for ethnic socializing is considered to be in the family. However, the educational environment has been crucial to the development of group affiliations. This thesis focuses on the development of the ethnic identity of Russian-speaking students in Estonia in the context of an important educational change, i.e. the transition to instruction in Estonian. The results of the studies show that the ethnic self-identification of students and the languages of instruction are not directly related, but at the same time language is the main basis for ethnic self-identification. According to the opinion of students Estonian-language, Russian-language and language immersion schools and classes differ mainly from the perspective of language learning. In schools with Estonian as the language of instruction, students acquire good proficiency in Estonian and foreign languages, but proficiency in Russian remains poor. In the estimation of students, Russian-language and bilingual (language immersion) classes offer the possibility to acquire the Russian language, also more knowledge about one’s ethnic group. The students’ main expectation related to the education system is to acquire knowledge and skills necessary for successful and the desired education pathway and career. These results are confirmed by parents when they select the school and also the language of instruction for their children. It can be concluded that languages in the Estonian society a strong symbolic value have. The language of instruction is not only a tool for the acquisition of knowledge and skills, but also seen as an expression of status of the ethnic group in society. That could be the reason why the transition to Estonian-medium studies at the upper secondary level is perceived as a risk to ethnic identity. On the basis of the results of the studies carried out it can be concluded that in the development of ethnic identity in the situation of the education change, different communicative relationships between ethnic identity, education system and society are essential. The changes in society are interpreted at school level and by individuals, and what kind of selections among the different choices are made, are based on those interpretations

Adaptive Perception, State Estimation, and Navigation Methods for Mobile Robots

In this cumulative habilitation, publications with focus on robotic perception, self-localization, tracking, navigation, and human-machine interfaces have been selected. While some of the publications present research on a PR2 household robot in the Robotics Learning Lab of the University of California Berkeley on vision and machine learning tasks, most of the publications present research results while working at the AutoNOMOS-Labs at Freie Universität Berlin, with focus on control, planning and object tracking for the autonomous vehicles "MadeInGermany" and "e-Instein"

The strategic impacts of Intelligent Automation for knowledge and service work : An interdisciplinary review

We would like to thank Professor Jarvenpaa and the review team for all the constructive comments and suggestions that were most helpful in revising the paper and in offering a stronger contribution. We would also like to thank Professor Guy Fitzgerald for his constructive comments on earlier versions of the paper. This study was funded by the Chartered Institute of Professional Development (CIPD). The views expressed are those of the authors and not necessarily those of the CIPD.Peer reviewedPublisher PD