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  • 201.
    Kucner, Tomasz Piotr
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Lilienthal, Achim
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Magnusson, Martin
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Palmieri, L.
    Corporate Research, Robert Bosch GmbH, Renningen, Germany.
    Swaminathan, Chittaranjan Srinivas
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Maps of Dynamics2020Inngår i: Probabilistic Mapping of Spatial Motion Patterns for Mobile Robots, Springer, 2020, s. 15-32Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    The task of building maps of dynamics is the key focus of this book, as well as how to use them for motion planning. In this chapter, we present a categorisation and overview of different types of maps of dynamics. Furthermore, we give an overview of approaches to motion planning in dynamic environments, with a focus on motion planning over maps of dynamics. 

  • 202.
    Kucner, Tomasz Piotr
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Lilienthal, Achim
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Magnusson, Martin
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Palmieri, L.
    Corporate Research, Robert Bosch GmbH, Renningen, Germany.
    Swaminathan, Chittaranjan Srinivas
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Motion Planning Using MoDs2020Inngår i: Probabilistic Mapping of Spatial Motion Patterns for Mobile Robots, Springer, 2020, s. 115-141Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    Maps of dynamics can be beneficial for motion planning. Information about motion patterns in the environment can lead to finding flow-aware paths, allowing robots to align better to the expected motion: either of other agents in the environment or the flow of air or another medium. The key idea of flow-aware motion planning is to include adherence to the flow represented in the MoD into the motion planning algorithm’s sub-units (i.e. cost function, sampling mechanism), thereby biasing the motion planner into obeying local and implicit traffic rules. 

  • 203.
    Kucner, Tomasz Piotr
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Lilienthal, Achim
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Magnusson, Martin
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Palmieri, Luigi
    Corporate Research, Robert Bosch GmbH, Renningen, Germany.
    Swaminathan, Chittaranjan Srinivas
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Probabilistic Mapping of Spatial Motion Patterns for Mobile Robots2020Bok (Annet vitenskapelig)
    Abstract [en]

    This book describes how robots can make sense of motion in their surroundings and use the patterns they observe to blend in better in dynamic environments shared with humans.The world around us is constantly changing. Nonetheless, we can find our way and aren’t overwhelmed by all the buzz, since motion often follows discernible patterns. Just like humans, robots need to understand the patterns behind the dynamics in their surroundings to be able to efficiently operate e.g. in a busy airport. Yet robotic mapping has traditionally been based on the static world assumption, which disregards motion altogether. In this book, the authors describe how robots can instead explicitly learn patterns of dynamic change from observations, store those patterns in Maps of Dynamics (MoDs), and use MoDs to plan less intrusive, safer and more efficient paths. The authors discuss the pros and cons of recently introduced MoDs and approaches to MoD-informed motion planning, and provide an outlook on future work in this emerging, fascinating field. 

  • 204.
    Kucner, Tomasz Piotr
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Magnusson, Martin
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Schaffernicht, Erik
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Hernandez Bennetts, Victor Manuel
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Lilienthal, Achim J.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Enabling Flow Awareness for Mobile Robots in Partially Observable Environments2017Inngår i: IEEE Robotics and Automation Letters, ISSN 2377-3766, E-ISSN 1949-3045, Vol. 2, nr 2, s. 1093-1100Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Understanding the environment is a key requirement for any autonomous robot operation. There is extensive research on mapping geometric structure and perceiving objects. However, the environment is also defined by the movement patterns in it. Information about human motion patterns can, e.g., lead to safer and socially more acceptable robot trajectories. Airflow pattern information allow to plan energy efficient paths for flying robots and improve gas distribution mapping. However, modelling the motion of objects (e.g., people) and flow of continuous media (e.g., air) is a challenging task. We present a probabilistic approach for general flow mapping, which can readily handle both of these examples. Moreover, we present and compare two data imputation methods allowing to build dense maps from sparsely distributed measurements. The methods are evaluated using two different data sets: one with pedestrian data and one with wind measurements. Our results show that it is possible to accurately represent multimodal, turbulent flow using a set of Gaussian Mixture Models, and also to reconstruct a dense representation based on sparsely distributed locations.

    Fulltekst (pdf)
    Enabling Flow Awareness for Mobile Robots in Partially Observable Environments
  • 205.
    Kucner, Tomasz Piotr
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Magnusson, Martin
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Swaminathan, Chittaranjan Srinivas
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Lilienthal, Achim
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Palmieri, L.
    Corporate Research Robert Bosch GmbH, Renningen, Germany.
    Preface2020Inngår i: Probabilistic Mapping of Spatial Motion Patterns for Mobile Robots, Springer, 2020, s. vii-xKapittel i bok, del av antologi (Fagfellevurdert)
  • 206.
    Kucner, Tomasz
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Sarinen, Jari
    Aalto university, Helsinki, Finland.
    Magnusson, Martin
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Lilienthal, Achim J.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Conditional transition maps: learning motion patterns in dynamic environments2013Inngår i: IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE, 2013, s. 1196-1201Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper we introduce a method for learning motion patterns in dynamic environments. Representations of dynamic environments have recently received an increasing amount of attention in the research community. Understanding dynamic environments is seen as one of the key challenges in order to enable autonomous navigation in real-world scenarios. However, representing the temporal dimension is a challenge yet to be solved. In this paper we introduce a spatial representation, which encapsulates the statistical dynamic behavior observed in the environment. The proposed Conditional Transition Map (CTMap) is a grid-based representation that associates a probability distribution for an object exiting the cell, given its entry direction. The transition parameters are learned from a temporal signal of occupancy on cells by using a local-neighborhood cross-correlation method. In this paper, we introduce the CTMap, the learning approach and present a proof-of-concept method for estimating future paths of dynamic objects, called Conditional Probability Propagation Tree (CPPTree). The evaluation is done using a real-world data-set collected at a busy roundabout.

    Fulltekst (pdf)
    ctmap.pdf
  • 207.
    Kurtser, Polina
    et al.
    Department of Industrial Engineering and Management, Ben-Gurion University of the Negev, Beer Sheva, Israel.
    Edan, Yael
    Department of Industrial Engineering and Management, Ben-Gurion University of the Negev, Beer Sheva, Israel.
    Statistical models for fruit detectability: spatial and temporal analyses of sweet peppers2018Inngår i: Biosystems Engineering, ISSN 1537-5110, E-ISSN 1537-5129, Vol. 171, s. 272-289Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Statistical models for fruit detectability were developed to provide insights into preferable variable configurations for better robotic harvesting performance.

    The methodology includes several steps: definition of controllable and measurable variables, data acquisition protocol design, data processing, definition of performance measures and statistical modelling procedures. Given the controllable and measurable variables, a data acquisition protocol is defined to allow adequate variation in the variables, and determine the dataset size to ensure significant statistical analyses. Performance measures are defined for each combination of controllable and measurable variables identified in the protocol. Descriptive statistics of the measures allow insights into preferable configurations of controllable variables given the measurable variables values. The statistical model is performed by back-elimination Poisson regression with a loglink function process. Spatial and temporal analyses are performed.

    The methodology was applied to develop statistical models for sweet pepper (Capsicum annuum) detectability and revealed best viewpoints. 1312 images acquired from 10 to 14 viewpoints for 56 scenes were collected in commercial greenhouses, using an eye-in-hand configuration of a 6 DOF manipulator equipped with a RGB sensor and an illumination rig. Three databases from different sweet-pepper varieties were collected along different growing seasons.

    Target detectability highly depends on the imaging acquisition distance and the sensing system tilt. A minimum of 12 training scenes are necessary to discover the statistically significant spatial variables. Better prediction was achieved at the beginning of the season with slightly better prediction achieved in a temporal split of training and testing sets.

  • 208.
    Kurtser, Polina
    et al.
    Ben-Gurion University of the Negev, Department of Industrial Engineering and Management, Beer-Sheva, Israel.
    Edan, Yael
    Ben-Gurion University of the Negev, Department of Industrial Engineering and Management, Beer-Sheva, Israel.
    The use of dynamic sensing strategies to improve detection for a pepper harvesting robot2018Inngår i: IEEE International Conference on Intelligent Robots and Systems. Proceedings, ISSN 2153-0858, E-ISSN 2153-0866, s. 8286-8293Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper presents the use of dynamic sensing strategies to improve detection results for a pepper harvesting robot. The algorithm decides if an additional viewpoint is needed and selects the best-fit viewpoint location from a predefined set of locations based on the predicted profitability of such an action. The suggestion of a possible additional viewpoint is based on image analysis for fruit and occlusion level detection, prediction of the expected number of additional targets sensed from that viewpoint, and final decision if choosing the additional viewpoint is beneficial. The developed heuristic was applied on 96 greenhouse images of 30 sweet peppers and resulted in up to 19% improved detection. The harvesting utility cost function decreased by up to 10% compared to the conventional single viewpoint strategy.

  • 209.
    Larsson, Johan
    et al.
    Örebro universitet, Institutionen för teknik.
    Broxvall, Mathias
    Örebro universitet, Institutionen för teknik.
    Saffiotti, Alessandro
    Örebro universitet, Institutionen för teknik.
    A navigation system for automated loaders in underground mines2006Inngår i: Field and Service Robotics: results of the 5th international conference / [ed] Peter Corke, Salah Sukkariah, Berlin: Springer Berlin/Heidelberg, 2006, s. 129-140Konferansepaper (Fagfellevurdert)
    Abstract [en]

    For underground mining operations human operated LHD vehicles are typically used for transporting ore. Because of security issues and of the cost of human operators, alternative solutions such as tele-operated vehicles are often in use. Tele-operation, however, leads to reduced efficiency, and it is not an ideal solution. Full automation of the LHD vehicles is a challenging task, which is expected to result in increased operational efficiency, cost efficiency, and safety. In this paper, we present our approach to a fully automated solution currently under development. We use a fuzzy behavior-based approach for navigation, and develop a cheap and robust localization technique based on the deployment of inexpensive passive radio frequency identification (RFID) tags at key points in the mine.

  • 210.
    Larsson, Johan
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Broxvall, Mathias
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Saffiotti, Alessandro
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Laser-based corridor detection for reactive navigation2008Inngår i: Industrial robot, ISSN 0143-991X, E-ISSN 1758-5791, Vol. 35, nr 1, s. 69-79Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    For mobile robots operating in real-world environments, reactive navigation is a useful complement (or even replacement) to pure plan-based metric navigation. Reactive navigation is performed with respect to local perceived features, rather than a global metric reference frame, and can provide reduced installation costs, increased flexibility, and robustness to changes in the environment. To be effective, however, reactive navigation requires fast and reliable perception of the relevant features in the environment. Corridor-like structures are one of the most common features that are used for this purpose. In this paper, we propose a new method for corridor detection from laser data, based on the Hough transform, which is fast, reliable, and noise tolerant. We describe the algorithm, report an extensive experimental evaluation of its performance, and motivate the research with a real application involving the autonomous operation of a loader vehicle in an underground mine.

  • 211.
    Larsson, Sören
    et al.
    Örebro universitet, Institutionen för teknik.
    Kjellander, Johan A. P.
    Örebro universitet, Institutionen för teknik.
    Path planning for laser scanning with an industrial robot2008Inngår i: Robotics and Autonomous Systems, ISSN 0921-8890, E-ISSN 1872-793X, Vol. 56, nr 7, s. 615-624Artikkel i tidsskrift (Fagfellevurdert)
  • 212.
    Lennvall, Tomas
    et al.
    ABB AB Corporate Research, Västerås, Sweden.
    Frey, Jan-Erik
    ABB AB System Automation, Västerås, Sweden.
    Gidlund, Mikael
    ABB AB Corporate Research, Västerås, Sweden.
    Wireless Sensor Networks for Automation2015Inngår i: Industrial communication technology handbook / [ed] R. Zurawski, Boca Raton: CRC Press , 2015, 2, s. 36-1-36-1Kapittel i bok, del av antologi (Fagfellevurdert)
  • 213.
    Lennvall, Tomas
    et al.
    RISE SICS, Västerås, Sweden.
    Gidlund, Mikael
    Mid Sweden University, Sundsvall, Sweden.
    Åkerberg, Johan
    ABB Corporate Research, Västerås, Sweden.
    Challenges when bringing IoT into Industrial Automation2017Inngår i: 2017 IEEE AFRICON: Science, Technology and Innovation for Africa, AFRICON 2017 / [ed] Darryn R. Cornish, IEEE, 2017, s. 905-910, artikkel-id 8095602Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The Internet of Things (IoT) is captivating the society because of its potential to rapidly transform businesses and people’s lives. It is widely believed that IoT will also transform the industrial automation business in terms of improved productivity, less cost, flexibility, and increased revenues. Hence, there are some challenges that needs to be addressed when IoT is introduced to the industrial automation domain. This paperaims to present realistic requirements and highlights identified challenges such as security, interoperability, deterministic and low latency communication, and how the required availability (uptime) can be kept. Moreover, the paper also point out the need of standardization and sustainable business models. The conclusion is that introducing IoT devices and connecting them directly to cloud services is not straightforward for process automation.

    Fulltekst (pdf)
    Challenges when bringing IoT into Industrial Automation
  • 214.
    Lennvall, Tomas
    et al.
    ABB AB Corporate Research, Västerås, Sweden.
    Landernäs, Krister
    ABB AB Corporate Research, Västerås, Sweden.
    Gidlund, Mikael
    ABB AB Corporate Research, Västerås, Sweden.
    Åkerberg, Johan
    ABB AB Corporate Research, Västerås, Sweden.
    Industrial WSN Standards2013Inngår i: Industrial wireless sensor networks: applications, protocols, and standards / [ed] V. Çağrı Güngör and Gerhard P. Hancke, Boca Raton: Taylor & Francis , 2013, s. 339-358Kapittel i bok, del av antologi (Fagfellevurdert)
  • 215.
    Levi-Bliech, Michal
    et al.
    Department of Industrial Engineering and Management, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
    Kurtser, Polina
    Department of Industrial Engineering and Management, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
    Pliskin, Nava
    Department of Industrial Engineering and Management, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
    Fink, Lior
    Department of Industrial Engineering and Management, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
    Mobile apps and employee behavior: An empirical investigation of the implementation of a fleet-management app2019Inngår i: International Journal of Information Management, ISSN 0268-4012, E-ISSN 1873-4707, Vol. 49, s. 355-365Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Whereas implementing a mobile application (app) in support of organizational processes is quite common in contemporary organizations, only few empirical studies have investigated the impact of app implementation in an organizational context. This study explores the association between the driving behavior of employed drivers and pre-driving app use of a fleet-management app. Users can get from the app not only real-time notifications while driving but can also take advantage of a unique app capability, that more traditional driving technologies do not provide, and receive feedback about their driving before their next drive. We hypothesize that pre-driving app use is associated with reduced risky driving behavior, and that this association is mitigated by real-time notifications and enhanced by experience with the app. The supportive results of the study confirm the organizational impact of implementing a fleet-management app via better driving behavior of employees who engage in pre-driving app use.

  • 216.
    Levi-Bliech, Michal
    et al.
    Ben-Gurion University of the Negev.
    Kurtser, Polina
    Ben-Gurion University of the Negev.
    Pliskin, Nava
    Ben-Gurion University of the Negev.
    Fink, Lior
    Ben-Gurion University of the Negev.
    The effects of a fleet-management app on driver behavior2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Whereas implementing a mobile application (app) in support of organizational processes is quite common in contemporary organizations, only few empirical studies have investigated the effects of app implementation on employee behavior. This study aims at exploring the effects of a fleet-management app on the behavior of drivers, in particular the extent to which they are involved in risky behavior. We hypothesize that use of the app before driving reduces such behavior, and that this effect is mitigated by the existence of notifications while driving. These hypotheses are tested with data about 11,805 trips by 109 drivers employed in a large-scale organization. The preliminary results support the research hypotheses and confirm that the implementation of a fleet-management app has an organizational impact via an app-induced change in driver behavior.

  • 217. Liao, Qianfang
    et al.
    Sun, Da
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Interaction Measures for Control Configuration Selection Based on Interval Type-2 Takagi-Sugeno Fuzzy Model2018Inngår i: IEEE transactions on fuzzy systems, ISSN 1063-6706, E-ISSN 1941-0034, Vol. 26, nr 5, s. 2510-2523Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Interaction measure determines decentralized and parse control configurations for a multivariable process control. This paper investigates interval type-2 Takagi–Sugeno fuzzy (IT2TSF) model based interactionmeasures using two different criteria, one is controllability and observability gramians, the other is relative normalized gain array (RNGA). The main contributions are: first, a data-driven IT2TSF modeling method is introduced; econd, explicit formulas to execute the two measures based on IT2TSF models are given; third, two interaction indexes are defined from RNGA to select sparse control configuration; fourth, the calculations to derive sensitivities of the two measures with respect to parametric variations in the IT2TSF models are developed; and fifth, the discussion to compare the two measures is presented. Three multivariable processes are used as examples to show that the results calculated from IT2TSF models are more accurate than that from their type-1 counterparts, and compared to gramian-basedmeasure, RNGA selectsmore reasonable control configurations and is more robust to the parametric uncertainties.

    Fulltekst (pdf)
    Type-1 and Type-2 Effective Tagaki-Sugeno Fuzzy Models for Decentralized Control of Multi-Input-Multi-Output Processes
  • 218. Liao, Qianfang
    et al.
    Sun, Da
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Sparse and Decoupling Control Strategies based on Takagi-Sugeno Fuzzy Models2019Inngår i: IEEE transactions on systems, man and cybernetics. Part B. Cybernetics, ISSN 1083-4419, E-ISSN 1941-0492Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In order to better handle the coupling effects when controlling multiple-input multiple-output (MIMO) systems, taking the decentralized control structure as the basis, this paper proposes a sparse control strategy and a decoupling control strategy. Type-1 and type-2 Takagi-Sugeno (T-S) fuzzy models are used to describe the MIMO system, and the relative normalized gain array (RNGA) based criterion is employed to measure the coupling effects. The main contributions include: i). compared to the previous studies, a manner with less computational cost to build fuzzy models for the MIMO systems is provided, and a more accurate method to construct the so-called effective T-S fuzzy model (ETSM) to express the coupling effects is developed; ii). for the sparse control strategy, four indexes are defined in order to extend a decentralized control structure to a sparse one. Afterwards, an ETSM-based method is presented that a sparse control system can be realized by designing multiple independent single-input single-output (SISO) control-loops; iii). for the decoupling control strategy, a novel and simple ETSM-based decoupling compensator is developed that can effectively compensate for both steady and dynamic coupling effects. As a result, the MIMO controller design can be transformed to multiple non-interacting SISO controller designs. Both of the sparse and decoupling strategies allow to use linear SISO control algorithms to regulate a closely coupled nonlinear MIMO system without knowing its exact mathematical functions. Two examples are used to show the effectiveness of the proposed strategies

    Fulltekst (pdf)
    Sparse and Decoupling Control Strategies based on Takagi-Sugeno Fuzzy Models
  • 219.
    Liao, Qianfang
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Sun, Da
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Andreasson, Henrik
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Point Set Registration for 3D Range Scans Using Fuzzy Cluster-based Metric and Efficient Global OptimizationInngår i: IEEE Transaction on Pattern Analysis and Machine Intelligence, ISSN 0162-8828, E-ISSN 1939-3539Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This study presents a new point set registration method to align 3D range scans. In our method, fuzzy clusters are utilized to represent a scan, and the registration of two given scans is realized by minimizing a fuzzy weighted sum of the distances between their fuzzy cluster centers. This fuzzy cluster-based metric has a broad basin of convergence and is robust to noise. Moreover, this metric provides analytic gradients, allowing standard gradient-based algorithms to be applied for optimization. Based on this metric, the outlier issues are addressed. In addition, for the first time in rigid point set registration, a registration quality assessment in the absence of ground truth is provided. Furthermore, given specified rotation and translation spaces, we derive the upper and lower bounds of the fuzzy cluster-based metric and develop a branch-and-bound (BnB)-based optimization scheme, which can globally minimize the metric regardless of the initialization. This optimization scheme is performed in an efficient coarse-to-fine fashion: First, fuzzy clustering is applied to describe each of the two given scans by a small number of fuzzy clusters. Then, a global search, which integrates BnB and gradient-based algorithms, is implemented to achieve a coarse alignment for the two scans. During the global search, the registration quality assessment offers a beneficial stop criterion to detect whether a good result is obtained. Afterwards, a relatively large number of points of the two scans are directly taken as the fuzzy cluster centers, and then, the coarse solution is refined to be an exact alignment using the gradient-based local convergence. Compared to existing counterparts, this optimization scheme makes a large improvementin terms of robustness and efficiency by virtue of the fuzzy cluster-based metric and the registration quality assessment. In the experiments, the registration results of several 3D range scan pairs demonstrate the accuracy and effectiveness of the proposed method, as well as its superiority to state-of-the-art registration approaches.

    Fulltekst (pdf)
    Point Set Registration for 3D Range Scans Using Fuzzy Cluster-based Metric and Efficient Global Optimization
  • 220.
    Liao, Qianfang
    et al.
    School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, Singapore.
    Sun, Da
    Department of Biomedical Engineering, National University, Singapore, Singapore.
    Cai, Wen-Jian
    School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, Singapore.
    Li, Shao-Yuan
    Department of Automation, Shanghai Jiao Tong University, Shanghai, PR China.
    Wang, You-Li
    School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, Singapore.
    Type-1 and Type-2 effective Takagi-Sugeno fuzzy models for decentralized control of multi-input-multi-output processes2017Inngår i: Journal of Process Control, ISSN 0959-1524, E-ISSN 1873-2771, Vol. 52, s. 26-44Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    tEffective model is a novel tool for decentralized controller design to handle the interconnected inter-actions in a multi-input-multi-output (MIMO) process. In this paper, Type-1 and Type-2 effectiveTakagi-Sugeno fuzzy models (ETSM) are investigated. By means of the loop pairing criterion, simple cal-culations are given to build Type-1/Type-2 ETSMs which are used to describe a group of non-interactingequivalent single-input-single-output (SISO) systems to represent an MIMO process, consequently thedecentralized controller design can be converted to multiple independent single-loop controller designs,and enjoy the well-developed linear control algorithms. The main contributions of this paper are: i)Compared to the existing T-S fuzzy model based decentralized control methods using extra terms tocharacterize interactions, ETSM is a simple feasible alternative; ii) Compared to the existing effectivemodel methods using linear transfer functions, ETSM can be carried out without requiring exact mathe-matical process functions, and lays a basis to develop robust controllers since fuzzy system is powerful tohandle uncertainties; iii) Type-1 and Type-2 ETSMs are presented under a unified framework to provideobjective comparisons. A nonlinear MIMO process is used to demonstrate the ETSMs’ superiority overthe effective transfer function (ETF) counterparts as well as the evident advantage of Type-2 ETSMs interms of robustness. A multi-evaporator refrigeration system is employed to validate the practicabilityof the proposed methods.

    Fulltekst (pdf)
    fulltext
  • 221.
    Lilienthal, Achim J.
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Duckett, TomLincoln School of Computer Science, University of Lincoln, Lincoln, UK.
    Proceedings of the 5th European Conference on Mobile Robots ECMR 2011: September 7-9, 2011, Örebro, Sweden2011Konferanseproceedings (Annet vitenskapelig)
  • 222.
    Lilienthal, Achim J.
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Trincavelli, Marco
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Schaffernicht, Erik
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    It's always smelly around here! Modeling the Spatial Distribution of Gas Detection Events with BASED Grid Maps2013Inngår i: Proceedings of the 15th International Symposium on Olfaction and Electronic Nose (ISOEN 2013), 2013Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper we introduce a novel gas distribution mapping algorithm, Bayesian Spatial Event Distribution (BASED), that, instead of modeling the spatial distribution of the gas concentration, models the spatial distribution of events of detection and non-detection of a target gas. The proposed algorithm is based on the Bayesian inference framework and models the likelihood of events at a certain location with a Bernoulli distribution. In order to avoid overfitting a Bayesian approach is used with a beta distribution prior for the parameter u that governs the Bernoulli distribution. In this way, the posterior distribution maintains the same form of the prior, i.e. will be a beta distribution, enabling a simple approach for sequential learning. To learn a field of beta distributions, we discretize the inspection area into a grid map and extrapolate from local measurements using Gaussian kernels. We demonstrate the proposed algorithm for different sensors mounted on a mobile robot and show how qualitatively similar maps are obtained from very different gas sensors.

  • 223.
    Lopez-Paredes, Adolfo
    et al.
    INSISOC, Universidad de Valladolid, Escuela de Ingenierias Industriales Paseo del Cauce, Valladolid, Spain.
    Edmonds, Bruce
    Centre for Policy Modelling, Manchester Metropolitan University, Manchester, United Kingdom.
    Klügl, Franziska
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Special issue: Agent based simulation of complex social systems2012Inngår i: Simulation (San Diego, Calif.), ISSN 0037-5497, E-ISSN 1741-3133, Vol. 88, nr 1, s. 4-6Artikkel i tidsskrift (Fagfellevurdert)
  • 224.
    Louloudi, Athanasia
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Mosallam, Ahmed
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Marturi, Naresh
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Janse, Pieter
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Hernandez Bennetts, Victor
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Integration of the humanoid robot Nao inside a smart home: a case study2010Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents a case study demonstrating the integration of the humanoid robotic platform Nao within a Network Robot System (NRS) application. The specific scenario of interest takes place in a smart home environment; the task being that of bringing a can of soda from a fridge to a human user. We use this concrete scenario to evaluate how the performance of such a robot can be affected by being embedded inside an intelligent domestic environment. This study points out that, by cooperating with different components on the network the overall performance of the robot is increased.

  • 225.
    Loutfi, Amy
    et al.
    Örebro universitet, Institutionen för teknik.
    Broxvall, Mathias
    Örebro universitet, Institutionen för teknik.
    Coradeschi, Silvia
    Örebro universitet, Institutionen för teknik.
    Karlsson, Lars
    Örebro universitet, Institutionen för teknik.
    Object recognition: a new application for smelling robots2005Inngår i: Robotics and Autonomous Systems, ISSN 0921-8890, E-ISSN 1872-793X, Vol. 52, nr 4, s. 272-289Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Olfaction is a challenging new sensing modality for intelligent systems. With the emergence of electronic noses, it is now possible to detect and recognize a range of different odours for a variety of applications. In this work, we introduce a new application where electronic olfaction is used in cooperation with other types of sensors on a mobile robot in order to acquire the odour property of objects.We examine the problem of deciding when, how and where the electronic nose (e-nose) should be activated by planning for active perception and we consider the problem of integrating the information provided by the e-nose with both prior information and information from other sensors (e.g., vision). Experiments performed on a mobile robot equipped with an e-nose are presented.

  • 226.
    Lowry, Stephanie
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Similarity criteria: evaluating perceptual change for visual localization2019Inngår i: 2019 European Conference on Mobile Robots (ECMR), IEEE, 2019, artikkel-id 8870962Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Visual localization systems may operate in environments that exhibit considerable perceptual change. This paper proposes a method of evaluating the degree of appearance change using a similarity criteria based on comparing the subspaces spanned by the principal components of the observed image descriptors. We propose two criteria - θmin measures the minimum angle between subspaces and Stotal measures the total similarity between the subspaces. These criteria are introspective - they evaluate the performance of the image descriptor using nothing more than the image descriptor itself. Furthermore, we demonstrate that these similarity criteria reflect the ability of the image descriptor to perform visual localization successfully, thus allowing a measure of quality control on the localization output.

    Fulltekst (pdf)
    Similarity criteria: Evaluating perceptual change for visual localization
  • 227.
    Lunardini, Francesca
    et al.
    Politecnico Di Milano, Milan, Italy.
    Luperto, Matteo
    University of Milan, Milan, Italy.
    Romeo, Marta
    University of Manchester, Manchester, UK.
    Renoux, Jennifer
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Basilico, Nicola
    University of Milan, Milan, Italy.
    Krpič, Andrej
    Smart Com, Ljubljana, Slovenia.
    Borghese, Nunzio Alberto
    University of Milan, Milan, Italy.
    Ferrante, Simona
    Politecnico di Milano, Milan, Italy.
    The MOVECARE project: Home-based monitoring of frailty2019Inngår i: 2019 IEEE EMBS International Conference on Biomedical & Health Informatics (BHI): Proceedings, IEEE, 2019, artikkel-id 8834482Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Concerning frailty, the use of home-based technology able to continuously and transparently monitor the independent elder may represent a useful tool to support the traditional geriatric assessment in the identification of elderly people at risk of frailty, with the final aim of guiding the development of early preventive interventions. To this aim, the European MoveCare project develops an ICT platform to support the independent living of the elder at home. Here, we describe how home-based monitoring of frailty is addressed within MoveCare, specifically for the five Fried criteria. The platform leverages a net of heterogeneous sensors a service robot, and the use of gamification to achieve ecological monitoring of frailty through quantitative measurements transparently recorded during common daily-life activities. The indicators collected over time are fed to the reasoning entity of the platform to provide informal caregivers with relevant information on the elder's status.

  • 228.
    Magnusson, Martin
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Kucner, Tomasz Piotr
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Gholami Shahbandi, Saeed
    IS lab, Halmstad University, Halmstad, Sweden.
    Andreasson, Henrik
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Lilienthal, Achim
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Semi-Supervised 3D Place Categorisation by Descriptor Clustering2017Inngår i: 2017 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Institute of Electrical and Electronics Engineers (IEEE), 2017, s. 620-625Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Place categorisation; i. e., learning to group perception data into categories based on appearance; typically uses supervised learning and either visual or 2D range data.

    This paper shows place categorisation from 3D data without any training phase. We show that, by leveraging the NDT histogram descriptor to compactly encode 3D point cloud appearance, in combination with standard clustering techniques, it is possible to classify public indoor data sets with accuracy comparable to, and sometimes better than, previous supervised training methods. We also demonstrate the effectiveness of this approach to outdoor data, with an added benefit of being able to hierarchically categorise places into sub-categories based on a user-selected threshold.

    This technique relieves users of providing relevant training data, and only requires them to adjust the sensitivity to the number of place categories, and provide a semantic label to each category after the process is completed.

    Fulltekst (pdf)
    fulltext
  • 229.
    Mastinu, Enzo
    et al.
    Department of Electrical Engineering, Chalmers University of Technology, Gothenburg, Sweden.
    Ahlberg, Johan
    Kungliga Tekniska Högskolan, Stockholm, Sweden.
    Lendaro, Eva
    Department of Electrical Engineering, Chalmers University of Technology, Gothenburg, Sweden.
    Hermansson, Liselotte
    Örebro universitet, Institutionen för hälsovetenskaper. Region Örebro län. Department of Prosthetics and Orthotics, Örebro University Hospital, Örebro, Sweden.
    Håkansson, Bo
    Department of Electrical Engineering, Chalmers University of Technology, Gothenburg, Sweden.
    Ortiz-Catalan, Max
    Department of Electrical Engineering, Chalmers University of Technology, Gothenburg, Sweden.
    An Alternative Myoelectric Pattern Recognition Approach for the Control of Hand Prostheses: A Case Study of Use in Daily Life by a Dysmelia Subject2018Inngår i: IEEE Journal of Translational Engineering in Health and Medicine, E-ISSN 2168-2372, Vol. 6, artikkel-id 2600112Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The functionality of upper limb prostheses can be improved by intuitive control strategies that use bioelectric signals measured at the stump level. One such strategy is the decoding of motor volition via myoelectric pattern recognition (MPR), which has shown promising results in controlled environments and more recently in clinical practice. Moreover, not much has been reported about daily life implementation and real-time accuracy of these decoding algorithms. This paper introduces an alternative approach in which MPR allows intuitive control of four different grips and open/close in a multifunctional prosthetic hand. We conducted a clinical proof-of-concept in activities of daily life by constructing a self-contained, MPR-controlled, transradial prosthetic system provided with a novel user interface meant to log errors during real-time operation. The system was used for five days by a unilateral dysmelia subject whose hand had never developed, and who nevertheless learned to generate patterns of myoelectric activity, reported as intuitive, for multi-functional prosthetic control. The subject was instructed to manually log errors when they occurred via the user interface mounted on the prosthesis. This allowed the collection of information about prosthesis usage and real-time classification accuracy. The assessment of capacity for myoelectric control test was used to compare the proposed approach to the conventional prosthetic control approach, direct control. Regarding the MPR approach, the subject reported a more intuitive control when selecting the different grips, but also a higher uncertainty during proportional continuous movements. This paper represents an alternative to the conventional use of MPR, and this alternative may be particularly suitable for a certain type of amputee patients. Moreover, it represents a further validation of MPR with dysmelia cases.

  • 230.
    Mathew Martin, Poothullil John
    Department of Outreach & Extension Services, AYJNIHH, New Delhi, India.
    Web Accessibility for Persons with Disabilities: Evidence from India2008Inngår i: Communicator, ISSN 0588-8093, Vol. XLIII, nr 1, s. 28-56Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Websites are today the face of an organization, with Global reach. The Information and Technology (IT) Act 2000 of India, is entirely silent on the subject of web accessibility. However the United Nations Convention on the Rights of Persons with Disabilities (UNCRPD) guidelines of 2009, which has been ratified by Govt. of India, of which Article 9.2 (g) & (h) especially lays down that, states should facilitate access for Persons with disabilities (PWDs) to new information and communication technologies, especially the Internet. A study was undertaken on 3rd December 2009, to analyze the qualities of a website designed by Government Organizations (GOs) and Non-Government Organizations (NGOs) working for PWDs in terms of Information & Dissemination, Accessibility, Design and Interactive participatory features. The main contribution of this study is to illuminate the features of websites used by GOs and NGOs working for PWDs in India and its accessibility.

    Fulltekst (pdf)
    fulltext
  • 231.
    Memedi, Mevludin
    et al.
    School of Technology and Business Studies, Computer Engineering, Dalarna University, Falun, Sweden.
    Aghanavesi, Somayeh
    School of Technology and Business Studies, Computer Engineering, Dalarna University, Falun, Sweden.
    Westin, Jerker
    School of Technology and Business Studies, Computer Engineering, Dalarna University, Falun, Sweden.
    A method for measuring Parkinson's disease related temporal irregularity in spiral drawings2016Inngår i: 2016 IEEE International Conference on Biomedical and Health Informatics, New York: Institute of Electrical and Electronics Engineers (IEEE), 2016, s. 410-413Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The objective of this paper was to develop and evaluate clinimetric properties of a method for measuring Parkinson's disease (PD)-related temporal irregularities using digital spiral analysis. In total, 108 (98 patients in different stages of PD and 10 healthy elderly subjects) performed repeated spiral drawing tasks in their home environments using a touch screen device. A score was developed for representing the amount of temporal irregularity during spiral drawing tasks, using Approximate Entropy (ApEn) technique. In addition, two previously published spiral scoring methods were adapted and their scores were analyzed. The mean temporal irregularity score differed significantly between healthy elderly subjects and advanced PD patients (P<0.005). The ApEn-based method had a better responsiveness and test-retest reliability when compared to the other two methods. In contrast to the other methods, the mean scores of the ApEn-based method improved significantly during a 3 year clinical study, indicating a possible impact of pathological basal ganglia oscillations in temporal control during spiral drawing tasks. In conclusion, the ApEn-based method could be used for differentiating between patients in different stages of PD and healthy subjects. The responsiveness and test-retest reliability were good for the ApEn-based method indicating that this method is useful for measuring upper limb temporal irregularity at a micro-level.

  • 232.
    Memedi, Mevludin
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Westin, Jerker
    Academy of Industry and Society, Computer Engineering, Dalarna University, Borlänge, Sweden.
    Methods for detection of handwriting/drawing impairment using inputs from touch screens2011Inngår i: Recent Patents on Signal Processing, ISSN 1877-6124, Vol. 1, nr 2, s. 156-162Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Fine motor dysfunction in patients with movement disorders, such as Parkinson’s disease, is characterized by slowness of movements, decrease of reaction time and involuntary movements. In this article, recent patents on detecting and assessing the said dysfunction are reviewed; their implementation in telemedicine settings, design considerations and ability to assist in dose and time adjustments are discussed. These patents explain application of signal processing techniques in analysis and interpretation of digitized handwriting/drawing information of individuals based on data gathered using touch screens. The study reveals that measures concerning forces, accelerations and radial displacements are the most relevant measurements to detect fine movement anomalies. These findings demonstrate that digitized analysis of handwriting/drawing movements may be useful in clinical trials evaluating fine motor control. This review further depicts the role of employing event-based data acquisition and signal processing techniques suitable for nonstationary signals, such as Wavelet transform, in systems for patient home-monitoring.

  • 233.
    Mielle, Malcolm
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Magnusson, Martin
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Andreasson, Henrik
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Lilienthal, Achim
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Using emergency maps to add not yet explored places into SLAM2017Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    While using robots in search and rescue missions would help ensure the safety of first responders, a key issue is the time needed by the robot to operate. Even though SLAM is faster and faster, it might still be too slow to enable the use of robots in critical situations. One way to speed up operation time is to use prior information.

    We aim at integrating emergency-maps into SLAM to complete the SLAM map with information about not yet explored part of the environment. By integrating prior information, we can speed up exploration time or provide valuable prior information for navigation, for example, in case of sensor blackout/failure. However, while extensively used by firemen in their operations, emergency maps are not easy to integrate in SLAM since they are often not up to date or with non consistent scales.

    The main challenge we are tackling is in dealing with the imperfect scale of the rough emergency maps and integrate it with the online SLAM map in addition to challenges due to incorrect matches between these two types of map. We developed a formulation of graph-based SLAM incorporating information from an emergency map into SLAM, and propose a novel optimization process adapted to this formulation.

    We extract corners from the emergency map and the SLAM map, in between which we find correspondences using a distance measure. We then build a graph representation associating information from the emergency map and the SLAM map. Corners in the emergency map, corners in the robot map, and robot poses are added as nodes in the graph, while odometry, corner observations, walls in the emergency map, and corner associations are added as edges. To conserve the topology of the emergency map, but correct its possible errors in scale, edges representing the emergency map's walls are given a covariance so that they are easy to extend or shrink but hard to rotate. Correspondences between corners represent a zero transformation for the optimization to match them as close as possible. The graph optimization is done by using a combination robust kernels. We first use the Huber kernel, to converge toward a good solution, followed by Dynamic Covariance Scaling, to handle the remaining errors.

    We demonstrate our system in an office environment. We run the SLAM online during the exploration. Using the map enhanced by information from the emergency map, the robot was able to plan the shortest path toward a place it has not yet explored. This capability can be a real asset in complex buildings where exploration can take up a long time. It can also reduce exploration time by avoiding exploration of dead-ends, or search of specific places since the robot knows where it is in the emergency map.

  • 234.
    Mielle, Malcolm
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Magnusson, Martin
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Lilienthal, Achim J.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    A method to segment maps from different modalities using free space layout MAORIS: map of ripples segmentation2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    How to divide floor plans or navigation maps into semantic representations, such as rooms and corridors, is an important research question in fields such as human-robot interaction, place categorization, or semantic mapping. While most works focus on segmenting robot built maps, those are not the only types of map a robot, or its user, can use. We present a method for segmenting maps from different modalities, focusing on robot built maps and hand-drawn sketch maps, and show better results than state of the art for both types.

    Our method segments the map by doing a convolution between the distance image of the map and a circular kernel, and grouping pixels of the same value. Segmentation is done by detecting ripple-like patterns where pixel values vary quickly, and merging neighboring regions with similar values.

    We identify a flaw in the segmentation evaluation metric used in recent works and propose a metric based on Matthews correlation coefficient (MCC). We compare our results to ground-truth segmentations of maps from a publicly available dataset, on which we obtain a better MCC than the state of the art with 0.98 compared to 0.65 for a recent Voronoi-based segmentation method and 0.70 for the DuDe segmentation method.

    We also provide a dataset of sketches of an indoor environment, with two possible sets of ground truth segmentations, on which our method obtains an MCC of 0.56 against 0.28 for the Voronoi-based segmentation method and 0.30 for DuDe.

    Fulltekst (pdf)
    A method to segment maps from different modalities using free space layout MAORIS: map of ripples segmentation
  • 235.
    Mitsioni, Ioanna
    et al.
    Division of Robotics, Perception and Learning (RPL), CAS, EECS, KTH Royal Institute of Technology, Stockholm, Sweden.
    Karayiannidis, Yiannis
    Division of Systems and Control, Department of Electrical Engineering, Chalmers University of Technology, Gothenburg, Sweden.
    Stork, Johannes Andreas
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Kragic, Danica
    Division of Robotics, Perception and Learning (RPL), CAS, EECS, KTH Royal Institute of Technology, Stockholm, Sweden.
    Data-Driven Model Predictive Control for Food-CuttingManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Modelling of contact-rich tasks is challenging and cannot be entirely solved using classical control approaches due to the difficulty of constructing an analytic description of the contact dynamics. Additionally, in a manipulation task like food-cutting, purely learning-based methods such as Reinforcement Learning, require either a vast amount of data that is expensive to collect on a real robot, or a highly realistic simulation environment, which is currently not available. This paper presents a data-driven control approach that employs a recurrent neural network to model the dynamics for a Model Predictive Controller. We extend on previous work that was limited to torque-controlled robots by incorporating Force/Torque sensor measurements and formulate the control problem so that it can be applied to the more common velocity controlled robots. We evaluate the performance on objects used for training, as well as on unknown objects, by means of the cutting rates achieved and demonstrate that the method can efficiently treat different cases with only one dynamic model. Finally we investigate the behavior of the system during force-critical instances of cutting and illustrate its adaptive behavior in difficult cases.

  • 236.
    Mojtahedzadeh, Rasoul
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Bouguerra, Abdelbaki
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Lilienthal, Achim J.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Automatic relational scene representation for safe robotic manipulation tasks2013Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper, we propose a new approach forautomatically building symbolic relational descriptions of staticconfigurations of objects to be manipulated by a robotic system.The main goal of our work is to provide advanced cognitiveabilities for such robotic systems to make them more aware ofthe outcome of their actions. We describe how such symbolicrelations are automatically extracted for configurations ofbox-shaped objects using notions from geometry and staticequilibrium in classical mechanics. We also present extensivesimulation results as well as some real-world experiments aimedat verifying the output of the proposed approach.

    Fulltekst (pdf)
    Mojtahedzadeh_etal_2013-IROS-Automatic_Relational_Scene_Representation_for_Safe_Robotic_Manipulation_Tasks.pdf
  • 237. Monroy, Javier G.
    et al.
    Lilienthal, Achim J.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Blanco, Jose Luis
    González-Jimenez, Javier
    Trincavelli, Marco
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Calibration of mox gas sensors in open sampling systems based on gaussian processes2012Inngår i: Proceedings of the IEEE Sensors Conference, 2012, IEEE conference proceedings, 2012, s. 1-4Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Calibration of metal oxide (MOX) gas sensor for continuous monitoring is a complex problem due to the highly dynamic characteristics of the gas sensor signal when exposed to natural environment (Open Sampling System - OSS). This work presents a probabilistic approach to the calibration of a MOX gas sensor based on Gaussian Processes (GP). The proposed approach estimates for every sensor measurement a probability distribution of the gas concentration. This enables the calculation of confidence intervals for the predicted concentrations. This is particularly important since exact calibration is hard to obtain due to the chaotic nature that dominates gas dispersal. The proposed approach has been tested with an experimental setup where an array of MOX sensors and a Photo Ionization Detector (PID) are placed downwind w.r.t. the gas source. The PID is used to obtain ground truth concentration. Comparison with standard calibration methods demonstrates the advantage of the proposed approach.

  • 238.
    Monroy, Javier
    et al.
    Machine Perception and Intelligent Robotics group (MAPIR), Instituto de Investigación Biomedica de Malaga (IBIMA), Universidad de Malaga, Malaga, Spain.
    Hernandez Bennetts, Victor
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Fan, Han
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Lilienthal, Achim
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Gonzalez-Jimenez, Javier
    Machine Perception and Intelligent Robotics group (MAPIR), Instituto de Investigación Biomedica de Malaga (IBIMA), Universidad de Malaga, Malaga, Spain.
    GADEN: A 3D Gas Dispersion Simulator for Mobile Robot Olfaction in Realistic Environments2017Inngår i: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 17, nr 7, s. 1479-1494Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This work presents a simulation framework developed under the widely used Robot Operating System (ROS) to enable the validation of robotics systems and gas sensing algorithms under realistic environments. The framework is rooted in the principles of computational fluid dynamics and filament dispersion theory, modeling wind flow and gas dispersion in 3D real-world scenarios (i.e., accounting for walls, furniture, etc.). Moreover, it integrates the simulation of different environmental sensors, such as metal oxide gas sensors, photo ionization detectors, or anemometers. We illustrate the potential and applicability of the proposed tool by presenting a simulation case in a complex and realistic office-like environment where gas leaks of different chemicals occur simultaneously. Furthermore, we accomplish quantitative and qualitative validation by comparing our simulated results against real-world data recorded inside a wind tunnel where methane was released under different wind flow profiles. Based on these results, we conclude that our simulation framework can provide a good approximation to real world measurements when advective airflows are present in the environment.

    Fulltekst (pdf)
    GADEN: A 3D Gas Dispersion Simulator for Mobile Robot Olfaction in Realistic Environments
  • 239.
    Murguia, Jose
    et al.
    Autónoma de San Luis Potosí, San Luis Potosí, México.
    Vergara, Alexander
    University of California, San Diego, USA.
    Trincavelli, Marco
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Vargas-Olmos, Cecilia
    Autónoma de San Luis Potosí, San Luis Potosí, México.
    Huerta, Ramon
    University of California, San Diego, USA.
    Classification of optical sensor response cues with a bidimensional wavelet transform approach2011Inngår i: Olfaction and electronic nose: proceedings of the 14th International Symposium on Olfaction and Electronic Nose (ISOEN 2011), May 2-5, 2011, New York City, USA, Stony Brook NY: American Institute of Physics (AIP), 2011, s. 255-257Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this work is used the two-dimensional discrete wavelet transform as a feature extractor of time responses from a porous silicon optical gas sensor for gas identification. The wavelet decomposition allows us to have a more in-deep sight of the sensor response. In addition, using a linear support vector machine (SVM) as classifier we evaluate our approach for a six-analyte discrimination problem.

  • 240.
    NAKHOSTIN, SINA
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Toward Simulation of Violin Sound Based on BowingGestures2012Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This Master’s thesis work presents an algorithmic approach for automatic synthesis

    of the violin’s instrumental gesture controls. Focusing on

    ” Détaché”,

    as a sustained bow motion technique, this work aims to give an instrumental

    gesture model generator (a physical performer model) to learn an appropriate

    representative function based on a group of already available contours that

    belong to different performances of the same bowing technique. Contours are

    main physical parameters of bowing which can be used as inputs of a physical

    sound model, i.e virtual violin, in order to produce the expected sound. During

    this work the primary physical parameters are under study, In particular

    bow

    transversal velocity

    (v), bow pressing force(f) and bow-bridge distance(d).

    The result of this work then can be generalized to cover the other bowing

    techniques, in particular sustained techniques like different derivatives of

    legato. B-splines were used in order to devise a parametric, flexible and robust

    model which is capable in capturing subtle variations in the time continuum

    of input parameters. A series of test experiments has been conducted in order

    to evaluate the learned model, where people with strong background in music

    and a considerable proficiency in playing musical instruments were asked to

    evaluate the sounds produced by the synthetic model.

    The results of evaluation were to high extent satisfactory, indicating that

    the quality of the sound produced as the result of artificial gestures (outputs of

    performer model) were close enough to the sound produced by the gestures of

    experienced violin players.

    i

  • 241.
    Neander, Jonas
    et al.
    ABB Corporate Research, ,India.
    Lennvall, Tomas
    ABB Corporate Research, ,India.
    Gidlund, Mikael
    ABB Corporate Research, ,India.
    Prolonging wireless HART network lifetime using packet aggregation2011Inngår i: 2011 IEEE International Symposium on Industrial Electronics, Institute of Electrical and Electronics Engineers (IEEE), 2011, s. 1230-1236Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Wireless sensor networks are becoming more and more adopted into industrial plants and Wireless HART is the first wireless sensor network standard to emerge, which specifically is designed to support the specific requirements posed by the industry. Automation industry requires wireless sensor network devices to have a very long lifetime, often up to 5 - 10 years without a battery change. This puts requirements on how the wireless sensor network technology should be designed to minimize energy consumption while still fulfilling the application requirements. Packet aggregation is an essential technique in mission critical wireless sensor networks for achieving effective transmission and hence better power conservation.

    In this article we propose a flexible packet aggregation scheme for Wireless HART which reduces energy consumption of each device. The proposed scheme only requires a minor change to the Wireless HART standard but still preserves the end-to-end security and retains backward compatibility with non aggregating devices. We show by calculations that our proposed packet aggregation solution reduces energy consumption for a network by up to 50%, which will result in a significant increase in lifetime of Wireless HART devices.

  • 242.
    Neander, Jonas
    et al.
    Mälardalen University, Västerås, Sweden.
    Sjödin, Mikael
    Mälardalen University, Västerås, Sweden.
    Björkman, Mats
    Mälardalen University, Västerås, Sweden.
    Svensson, Stefan
    ABB AB, Västerås, Sweden.
    Lennvall, Tomas
    ABB AB, Västerås, Sweden .
    Wireless Vibration Monitoring (WiVib) - An Industrial Case Study2007Inngår i: 2007 IEEE Conference on Emerging Technologies and Factory Automation (EFTA 2007), Institute of Electrical and Electronics Engineers (IEEE), 2007, s. 920-923Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Testing in realistic environments is often overlooked in the early development of new technology. This paper describes a test to evaluate the whole chain from an accelerometer mounted on a motor to a sensor node sending wireless data to an access point. A pilot gives a great opportunity to get input from end-users (which could be very useful at the initial stages of a project), and provide potential contacts for next pilots.

    The goal of the pilot was to get a better understanding of the targeted environment and possible interference It may also lead to the discovery of issues not yet thought of, issues important for the resulting design of the end product.

  • 243.
    Nemati, Farhang
    et al.
    Mälardalen Real-Time Research Centre, Mälardalen University, Västerås, Sweden.
    Behnam, Moris
    Mälardalen Real-Time Research Centre, Mälardalen University, Västerås, Sweden.
    Nolte, Thomas
    Mälardalen Real-Time Research Centre, Mälardalen University, Västerås, Sweden.
    An Investigation of Synchronization under Multiprocessors Hierarchical Scheduling2009Inngår i: Proceedings of the Work-In-Progress (WIP) session of the 21st Euromicro Conference on Real-Time Systems (ECRTS'09), 2009Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In the multi-core and multiprocessor research community, considerable work has been done on real-time multiprocessor scheduling algorithms where it is assumed the tasks are independent. However in practice a typical real-time system includes tasks that share resources. On the other hand, synchronization in the multiprocessor context has not received enough attention.

    In this paper we propose an extension to multiprocessor hierarchical scheduling to support resource sharing. We extend the scheduling framework with an existing synchronization protocol for global scheduling in multi-core systems.

  • 244.
    Nemati, Farhang
    et al.
    Mälardalen Real-Time Research Centre, Mälardalen University, Sweden.
    Inam, Rafia
    Mälardalen Real-Time Research Centre, Mälardalen University, Sweden.
    Nolte, Thomas
    Mälardalen Real-Time Research Centre, Mälardalen University, Sweden.
    Sjödin, Mikael
    M ̈alardalen Real-Time Research Centre, Mälardalen University, Sweden.
    Towards Resource Sharing by Message Passing among Real-Time Components on Multi-cores2011Inngår i: IEEE International Conference on Emerging Technologies and Factory Automation, ETFA 2011 / [ed] Mammeri, Z, IEEE, 2011Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper we propose a message passing synchronization protocol for resource sharing among real-time applications on multi-core platforms where each application is allocated on a cluster of cores. In this protocol the resources that are only used within an application (local resources) are handled by shared memory synchronization while the resources shared cross applications (global resources) are accessed by means of message passing. In our protocol the global resources are safely accessed without requiring to lock the resources explicitly. The goal is to avoid resource locking using shared memory, since accessing shared memory in multi-cores is very time consuming, whereas message passing has the potential to be much more efficient in systems with deep memory hierarchies.

  • 245.
    Nemati, Farhang
    et al.
    Mälardalen Real-Time Research Centre, Mälardalen University, Västerås, Sweden.
    Nolte, Thomas
    Mälardalen Real-Time Research Centre, Mälardalen University, Västerås, Sweden.
    Resource Hold Times under Multiprocessor Static-Priority Global Scheduling2011Inngår i: 2011 IEEE 17th International Conference on Embedded and Real-Time Computing Systems and Applications. Volume 1: Proceedings, IEEE Computer Society , 2011, s. 197-206Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Recently there has been a lot of interest in coexisting of multiple independently-developed real-time applications on a shared open platform. On the other hand, emerging of multi-core platforms and the performance and possibilities they offer has attracted a lot of attention in multiprocessor real-time analysis, protocols and techniques. Co-executing independently- developedreal-time applications on a shared multiprocessor system, where each application executes on a dedicated sub set of processors, requires to overcome the problem of handling mutually exclusive shared resources among those applications. To handle resource sharing, it is important to determine the Resource Hold Time (RHT), i.e., the maximum duration of time that an application locks a shared resource.

    In this paper, we study resource hold times under multiprocessor static-priority global scheduling. We present how to compute RHT's for each resource in an application. We also show how to decrease the RHT's without compromising the schedulability of the application. We show that decreasing all RHT's for all shared resources is a multiobjective optimization problem and there can exist multiple Paretooptimal solutions.

  • 246.
    Neumann, Patrick P.
    et al.
    Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany.
    Hirschberger, Paul
    Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany.
    Baurzhan, Zhandos
    Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany.
    Tiebe, Carlo
    Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany.
    Hofmann, Michael
    Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany.
    Hüllmann, Dino
    Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany.
    Bartholmai, Matthias
    Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany.
    Indoor Air Quality Monitoring using flying Nanobots: Design and Experimental Study2019Inngår i: ISOCS/IEEE International Symposium on Olfaction and Electronic Nose (ISOEN), IEEE, 2019, s. 1-3Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper, we introduce a nano aerial robot swarm for Indoor Air Quality (IAQ) monitoring applications such as occupational health and safety of (industrial) workplaces. The robotic swarm is composed of nano Unmanned Aerial Vehicles (UAVs), based on the Crazyflie 2.0 quadrocopter, and small lightweight Metal Oxide (MOX) gas sensors for measuring the Total Volatile Organic Compound (TVOC), which is a measure for IAQ. An indoor localization and positioning system is used to estimate the absolute 3D position of the swarm similar to GPS. A test scenario was built up to validate and optimize the swarm for the intended applications. Besides calibration of the IAQ sensors, we performed experiments to investigate the influence of the rotor downwash on the gas measurements at different altitudes and compared them with stationary measurements. Moreover, we did a first evaluation of the gas distribution mapping performance. Based on this novel IAQ monitoring concept, new algorithms in the field of Mobile Robot Olfaction (MRO) are planned to be developed exploiting the abilities of an aerial robotic swarm.

  • 247.
    Neumann, Patrick P.
    et al.
    Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany.
    Hüllmann, Dino
    Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany.
    Bartholmai, Matthias
    Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany.
    Concept of a gas-sensitive nano aerial robot swarm for indoor air quality monitoring2018Inngår i: 35th Danubia-Adria Symposium on Advances in Experimental Mechanics: Extended abstracts / [ed] D. Ş Pastramă, D. M. Constantinescu, Bukarest, Romania, 2018, s. 139-140Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In industrial environments, airborne by-products such as dust and (toxic) gases, constitute a major risk for the worker’s health. Major changes in automated processes in the industry lead to an increasing demand for solutions in air quality management. Thus, occupational health experts are highly interested in precise dust and gas distribution models for working environments. For practical and economic reasons, high-quality, costly measurements are often available for short time-intervals only. Therefore, current monitoring procedures are carried out sparsely, both in time and space, i.e., measurement data are collected in single day campaigns at selected locations only. Real-time knowledge of contaminant distributions inside the working environment would also provide means for better and more economic control of air impurities. For example, the possibility to regulate the workspace’s ventilation exhaust locations can reduce the concentration of airborne contaminants by 50%. To improve the occupational health and safety of (industrial) workplaces, this work aims for developing a swarm of gas-sensitive aerial nano robots for monitoring indoor air quality and for localizing potential emission sources.

  • 248.
    Neumann, Patrick P.
    et al.
    Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany.
    Hüllmann, Dino
    Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany.
    Krentel, Daniel
    Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany.
    Kluge, Martin
    Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany.
    Kohlhoff, Harald
    Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany.
    Lilienthal, Achim
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Gas Tomography Up In The Air!2018Inngår i: Proceedings of the IEEE Sensors 2018, IEEE, 2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper, we present an autonomous aerial robot to reconstruct tomographic 2D slices of gas plumes in outdoor environments. Our platform, the so-called Unmanned Aerial Vehicle for Remote Gas Sensing (UAV-REGAS) combines a lightweight Tunable Diode Laser Absorption Spectroscopy (TDLAS) sensor with a 3-axis aerial stabilization gimbal for aiming on a versatile octocopter. The TDLAS sensor provides integral gas concentration measurements but no information regarding the distance traveled by the laser diode's beam or the distribution of the gas along the optical path. We complemented the set-up with a laser rangefinder and apply principles of Computed Tomography (CT) to create a model of the spatial gas distribution from these integral concentration measurements. To allow for a rudimentary ground truth evaluation of the applied gas tomography algorithm, we set up a unique outdoor test environment based on two 3D ultrasonic anemometers and a distributed array of 10 infrared gas transmitters. We present first results showing the 2D plume reconstruction capabilities of the system under realistic conditions.

  • 249.
    Neumann, Patrick P.
    et al.
    Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany.
    Kohlhoff, Harald
    Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany.
    Hüllmann, Dino
    Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany.
    Lilienthal, Achim
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Kluge, Martin
    Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Germany.
    Bringing Mobile Robot Olfaction to the Next Dimension - UAV-based Remote Sensing of Gas Clouds and Source Localization2017Inngår i: 2017 IEEE International Conference on Robotics and Automation (ICRA), Institute of Electrical and Electronics Engineers (IEEE), 2017, s. 3910-3916Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper introduces a novel robotic platform for aerial remote gas sensing. Spectroscopic measurement methods for remote sensing of selected gases lend themselves for use on mini-copters, which offer a number of advantages for inspection and surveillance. No direct contact with the target gas is needed and thus the influence of the aerial platform on the measured gas plume can be kept to a minimum. This allows to overcome one of the major issues with gas-sensitive mini-copters. On the other hand, remote gas sensors, most prominently Tunable Diode Laser Absorption Spectroscopy (TDLAS) sensors have been too bulky given the payload and energy restrictions of mini-copters. Here, we introduce and present the Unmanned Aerial Vehicle for Remote Gas Sensing (UAV-REGAS), which combines a novel lightweight TDLAS sensor with a 3-axis aerial stabilization gimbal for aiming on a versatile hexacopter. The proposed system can be deployed in scenarios that cannot be addressed by currently available robots and thus constitutes a significant step forward for the field of Mobile Robot Olfaction (MRO). It enables tomographic reconstruction of gas plumes and a localization of gas sources. We also present first results showing the gas sensing and aiming capabilities under realistic conditions.

  • 250.
    Nevatia, Yashodhan
    et al.
    Univ Bremen, Dept EECS, Robot Lab, D-28725 Bremen, Germany.
    Stoyanov, Todor
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Rathnam, Ravi
    Univ Bremen, Dept EECS, Robot Lab, D-28725 Bremen, Germany.
    Pfingsthorn, Max
    Markov, Stefan
    Ambrus, Rares
    Birk, Andreas
    Augmented Autonomy: Improving human-robot team performance in Urban Search and Rescue2008Inngår i: 2008 IEEE/RSJ International Conference on Robots and Intelligent Systems, vols 1-3, conference proceedings, New York: IEEE Robotics and Automation Society, 2008, s. 2103-2108Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Exploration of unknown environments remains one of the fundamental problems of mobile robotics. It is also a prime example for a task that can benefit significantly from multi-robot teams. We present an integrated system for semi-autonomous cooperative exploration, augmented by an intuitive user interface for efficient human supervision and control. In this preliminary study we demonstrate the effectiveness of the system as a whole and the intuitive interface in particular. Congruent with previous findings, results confirm that having a human in the loop improves task performance, especially with larger numbers of robots. Specific to our interface, we find that even untrained operators can efficiently manage a decently sized team of robots.

2345678 201 - 250 of 415
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