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  • 51.
    Arad, Boaz
    et al.
    Department of Computer Science, 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.
    Barnea, Ehud
    Department of Computer Science, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
    Harel, Ben
    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.
    Ben-Shahar, Ohad
    Department of Computer Science, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
    Controlled Lighting and Illumination-Independent Target Detection for Real-Time Cost-Efficient Applications. The Case Study of Sweet Pepper Robotic Harvesting2019In: Sensors, E-ISSN 1424-8220, Vol. 19, no 6, article id 1390Article in journal (Refereed)
    Abstract [en]

    Current harvesting robots are limited by low detection rates due to the unstructured and dynamic nature of both the objects and the environment. State-of-the-art algorithms include color- and texture-based detection, which are highly sensitive to the illumination conditions. Deep learning algorithms promise robustness at the cost of significant computational resources and the requirement for intensive databases. In this paper we present a Flash-No-Flash (FNF) controlled illumination acquisition protocol that frees the system from most ambient illumination effects and facilitates robust target detection while using only modest computational resources and no supervised training. The approach relies on the simultaneous acquisition of two images—with/without strong artificial lighting (“Flash”/“no-Flash”). The difference between these images represents the appearance of the target scene as if only the artificial light was present, allowing a tight control over ambient light for color-based detection. A performance evaluation database was acquired in greenhouse conditions using an eye-in-hand RGB camera mounted on a robotic manipulator. The database includes 156 scenes with 468 images containing a total of 344 yellow sweet peppers. Performance of both color blob and deep-learning detection algorithms are compared on Flash-only and FNF images. The collected database is made public.

  • 52.
    Arain, Muhammad Asif
    Mehran University of Engineering & Technology, Pakistan.
    Navobot formula 2: a navigation and handling implementation2006Conference paper (Refereed)
  • 53.
    Arain, Muhammad Asif
    et al.
    Mehran University of Engineering & Technology, Pakistan.
    Ansari, Muhammad Adil
    Khatri, Chandan Kumar
    Maheshwari, Bheesham Kumar
    Kazi, Sheryar Anwer
    Design, Mathematical Modeling & Simulation of a Robot System with 3-DOF2005Conference paper (Refereed)
  • 54.
    Arain, Muhammad Asif
    et al.
    Örebro University, School of Science and Technology.
    Fan, Han
    Örebro University, School of Science and Technology.
    Hernandez Bennetts, Victor
    Örebro University, School of Science and Technology.
    Schaffernicht, Erik
    Örebro University, School of Science and Technology.
    Lilienthal, Achim J.
    Örebro University, School of Science and Technology.
    Improving Gas Tomography With Mobile Robots: An Evaluation of Sensing Geometries in Complex Environments2017In: 2017 ISOCS/IEEE International Symposium on Olfaction andElectronic Nose (ISOEN 2017) Proceedings, IEEE, 2017, article id 7968895Conference paper (Refereed)
    Abstract [en]

    An accurate model of gas emissions is of high importance in several real-world applications related to monitoring and surveillance. Gas tomography is a non-intrusive optical method to estimate the spatial distribution of gas concentrations using remote sensors. The choice of sensing geometry, which is the arrangement of sensing positions to perform gas tomography, directly affects the reconstruction quality of the obtained gas distribution maps. In this paper, we present an investigation of criteria that allow to determine suitable sensing geometries for gas tomography. We consider an actuated remote gas sensor installed on a mobile robot, and evaluated a large number of sensing configurations. Experiments in complex settings were conducted using a state-of-the-art CFD-based filament gas dispersal simulator. Our quantitative comparison yields preferred sensing geometries for sensor planning, which allows to better reconstruct gas distributions.

  • 55.
    Arain, Muhammad Asif
    et al.
    Örebro University, School of Science and Technology.
    Havoutis, Ioannis
    Department of Advanced Robotics, Istituto Italiano di Tecnologia, Genova, Italy.
    Semini, Claudio
    Department of Advanced Robotics,Istituto Italiano di Tecnologia, Genova, Italy.
    Buchli, Jonas
    Eidgenössische Technische Hochschule Zürich (ETH), Zurich, Schweiz.
    Caldwell, Darwin G.
    Department of Advanced Robotics, Istituto Italiano di Tecnologia, Genova, Italy.
    A comparison of search-based planners for a legged robot2013Conference paper (Refereed)
    Abstract [en]

    Path planning for multi-DoF legged robots is achallenging task due to the high dimensionality and complexityof the planning space. We present our first attempt to builda path planning framework for the hydraulic quadruped -HyQ. Our approach adopts a similar strategy to [1], whereplanning is divided into a task-space and a joint-space part.The task-space planner finds a path for the center of gravity(COG) of the robot, while then the footstep planner generates theappropriate footholds under reachability and stability criteria.Next the joint-space planner translates the task-space COGtrajectories into robot joint angles. We present a comparisonof a set of search-based planning algorithms; Dijkstra, A* andARA*, and evaluate these over a set of given terrains and anumber of varying start and end points. All test runs supportthat our approach is a simple yet robust solution. We reportcomparisons in path length, computation time, and path cost,between the aforementioned planning algorithms.

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    Arain_RoMoCo13
  • 56.
    Arain, Muhammad Asif
    et al.
    University of Genova , Genova, Italy; Warsaw University of Technology, Warshaw, Poland.
    Hultmann Ayala, Helon Vicente
    University of Genova , Genova, Italy; Warsaw University of Technology, Warshaw, Poland.
    Ansari, Muhammad Adil
    Science & Technology , Quaid-e-Awam University of Engineering, Sindh, Pakistan.
    Nonlinear System Identification Using Neural Network2012In: Emerging Trends and Applications in Information Communication Technologies: Second International Multi Topic Conference, IMTIC 2012, Jamshoro, Pakistan, March 28-30, 2012: Proceedings / [ed] Bhawani Shankar Chowdhry; Faisal Karim Shaikh; Dil Muhammad Akbar Hussain; Muhammad Aslam Uqaili, Springer, 2012, Vol. 281, p. 122-131Conference paper (Refereed)
    Abstract [en]

    Magneto-rheological damper is a nonlinear system. In this case study, system has been identified using Neural Network tool. Optimization between number of neurons in the hidden layer and number of epochs has been achieved and discussed by using multilayer perceptron Neural Network.

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    fulltext
  • 57.
    Arain, Muhammad Asif
    et al.
    Örebro University, School of Science and Technology.
    Schaffernicht, Erik
    Örebro University, School of Science and Technology.
    Hernandez Bennetts, Victor
    Örebro University, School of Science and Technology.
    Lilienthal, Achim J.
    Örebro University, School of Science and Technology.
    The Right Direction to Smell: Efficient Sensor Planning Strategies for Robot Assisted Gas Tomography2016In: 2016 IEEE International Conference on Robotics and Automation (ICRA), New York, USA: IEEE Robotics and Automation Society, 2016, p. 4275-4281Conference paper (Refereed)
    Abstract [en]

    Creating an accurate model of gas emissions is an important task in monitoring and surveillance applications. A promising solution for a range of real-world applications are gas-sensitive mobile robots with spectroscopy-based remote sensors that are used to create a tomographic reconstruction of the gas distribution. The quality of these reconstructions depends crucially on the chosen sensing geometry. In this paper we address the problem of sensor planning by investigating sensing geometries that minimize reconstruction errors, and then formulate an optimization algorithm that chooses sensing configurations accordingly. The algorithm decouples sensor planning for single high concentration regions (hotspots) and subsequently fuses the individual solutions to a global solution consisting of sensing poses and the shortest path between them. The proposed algorithm compares favorably to a template matching technique in a simple simulation and in a real-world experiment. In the latter, we also compare the proposed sensor planning strategy to the sensing strategy of a human expert and find indications that the quality of the reconstructed map is higher with the proposed algorithm.

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    Arain_etal_ICRA-2016
  • 58.
    Arunachalam, Ajay
    et al.
    Department of Computer Science, Graduate School of Applied Statistics, National Institute of Development Administration, Thailand.
    Sornil, Ohm
    Department of Computer Science, Graduate School of Applied Statistics, National Institute of Development Administration, Thailand.
    A broadcast based random query gossip algorithm for resource search in non-DHT mobile Peer-to-Peer networks2017In: Diànnǎo xuékān (Journal of Computers), ISSN 1991-1599, Vol. 28, no 1, p. 209-223Article in journal (Refereed)
    Abstract [en]

    This paper presents a resource discovery scheme for decentralized non-DHT Mobile Peer-to-Peer (MP2P) networks. In a mobile environment, the energy of mobile device is very critical. The aim of the proposed technique is to reduce the network overhead, lower battery power consumption and minimize query delay while improving the chance to resolve the query at every successive stage. Peer-to-Peer applications have gained a lot of attention in past years due to its decentralized nature. Resource searching algorithms are one of the major focuses of P2P network. Mobile Ad hoc Network (MANET) with its changing topology further poses additional challenges and thus increasing the search effort. Methods like flooding, random walk and probabilistic forwarding techniques are good candidates to run over such dynamic network. In this work, we study the flooding, random walk and gossip based resource discovery protocols on a P2P Mobile Ad hoc Network. We observed that the classic gossip algorithm does not work well under MANET as in the case of a wired network. We focus to improve the algorithm to suit and work better under such dynamic network scenario. The proposed system presents a light weight resource discovery design to suit the mobility requirement of ad hoc networks to optimize the search performance while at the same time minimize the extra usage of mobile and network resources. For quick and energy efficient search scheme, we explore a novel addressed jumping approach. Our algorithm is entirely distributed, and hence will scale well even to the growing size of the network. The efficiency of our proposed algorithm is validated through extensive NS-2 simulations. The results show that our proposed scheme gives better performance than the widely used techniques. We also validate through statistical hypothesis testing of simulation data.

  • 59.
    Arunachalam, Ajay
    et al.
    Department of Computer Science, Graduate School of Applied Statistics, National Institute of Development Administration, Thailand.
    Sornil, Ohm
    Department of Computer Science, Graduate School of Applied Statistics, National Institute of Development Administration, Thailand.
    Minimizing Redundant Messages and Improving Search Efficiency under Highly Dynamic Mobile P2P Network2016In: Journal of Engineering Science and Technology Review, ISSN 1791-9320, E-ISSN 1791-2377, Vol. 9, no 1, p. 23-35Article in journal (Refereed)
    Abstract [en]

    Resource Searching is one of the key functional tasks in large complex networks. With the P2P architecture, millions of peers connect together instantly building a communication pattern. Searching in mobile networks faces additional limitations and challenges. Flooding technique can cope up with the churn and searches aggressively by visiting almost all the nodes. But it exponentially increases the network traffic and thus does not scale well. Further the duplicated query messages consume extra battery power and network bandwidth. The blind flooding also suffers from long delay problem in P2P networks. In this paper, we propose optimal density based flooding resource discovery schemes. Our first model takes into account local graph topology information to supplement the resource discovery process while in our extended version we also consider the neighboring node topology information along with the local node information to further effectively use the mobile and network resources. Our proposed method reduces collision at the same time minimizes effect of redundant messages and failures. Overall the methods reduce network overhead, battery power consumption, query delay, routing load, MAC load and bandwidth usage while also achieving good success rate in comparison to the other techniques. We also perform a comprehensive analysis of the resource discovery schemes to verify the impact of varying node speed and different network conditions.

  • 60.
    Arunachalam, Ajay
    et al.
    Department of Computer Science, School of Applied Statistics, National Institute of Development Administration, Bangkok, Thailand.
    Sornil, Ohm
    Department of Computer Science, School of Applied Statistics, National Institute of Development Administration, Bangkok, Thailand.
    Reducing Routing Overhead in random walk protocol under MP2P Network2016In: International Journal of Electrical and Computer Engineering, ISSN 2088-8708, Vol. 6, no 6, p. 3121-3130Article in journal (Refereed)
    Abstract [en]

    Due to network dynamics in self-organizing networks the resource discovery effort increases. To discover objects in unstructured peer-to-peer network, peers rely on traditional methods like flooding, random walk and probabilistic forwarding methods. With inadequate knowledge of paths, the peers have to flood the query message which creates incredible network traffic and overhead. Many of the previous works based on random walk were done in wired network. In this context random walk was better than flooding. But under MANETs random walk approach behaved differently increasing the overhead, due to frequent link failures incurred by mobility. Decentralized applications based on peer-to-peer computing are best candidates to run over such dynamic network. Issues of P2P service discovery in wired networks have been well addressed in several earlier works. This article evaluates the performance of random walk based resource discovery protocol over P2P Mobile Adhoc Network (MP2P) and suggests an improved scheme to suit MANET. Our version reduces the network overhead, lowers the battery power consumption, minimizes the query delay while providing equally good success rate. The protocol is validated through extensive NS-2 simulations. It is clear from the results that our proposed scheme is an alternative to the existing ones for such highly dynamic mobile network scenario.

  • 61.
    Asadi, Sahar
    et al.
    Örebro University, School of Science and Technology.
    Pashami, Sepideh
    Örebro University, School of Science and Technology.
    Loutfi, Amy
    Örebro University, School of Science and Technology.
    Lilienthal, Achim J.
    Örebro University, School of Science and Technology.
    TD Kernel DM+V: time-dependent statistical gas distribution modelling on simulated measurements2011In: Olfaction and Electronic Nose: proceedings of the 14th International Symposium on Olfaction and Electronic Nose (ISOEN) / [ed] Perena Gouma, Springer Science+Business Media B.V., 2011, p. 281-282Conference paper (Refereed)
    Abstract [en]

    To study gas dispersion, several statistical gas distribution modelling approaches have been proposed recently. A crucial assumption in these approaches is that gas distribution models are learned from measurements that are generated by a time-invariant random process. While a time-independent random process can capture certain fluctuations in the gas distribution, more accurate models can be obtained by modelling changes in the random process over time. In this work we propose a time-scale parameter that relates the age of measurements to their validity for building the gas distribution model in a recency function. The parameters of the recency function define a time-scale and can be learned. The time-scale represents a compromise between two conflicting requirements for obtaining accurate gas distribution models: using as many measurements as possible and using only very recent measurements. We have studied several recency functions in a time-dependent extension of the Kernel DM+V algorithm (TD Kernel DM+V). Based on real-world experiments and simulations of gas dispersal (presented in this paper) we demonstrate that TD Kernel DM+V improves the obtained gas distribution models in dynamic situations. This represents an important step towards statistical modelling of evolving gas distributions.

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    fulltext
  • 62.
    Asnafi, Nader
    Örebro University, School of Science and Technology.
    Proceedings of the International Conference on Mechanical, Electric and Industrial Engineering (MEIE2018)2018Conference proceedings (editor) (Refereed)
  • 63.
    Asnafi, Nader
    Örebro University, School of Science and Technology.
    The Fourth International Conference on Mechanical, Electric and Industrial Engineering (MEIE2021) 22-24 May 2021, Kunming, China2021Conference proceedings (editor) (Refereed)
  • 64.
    Asnafi, Nader
    Örebro University, School of Science and Technology.
    The Second International Conference on Mechanical, Electric and Industrial Engineering, 25–27 May 2019, Hangzhou, China2019Conference proceedings (editor) (Refereed)
  • 65.
    Asnafi, Nader
    Örebro University, School of Science and Technology.
    Third International Conference on Mechanical, Electric and Industrial Engineering, 23-25 May 2020, Kunming, China2020Conference proceedings (editor) (Refereed)
  • 66.
    Ata'a, A.W.
    et al.
    University of Baghdad, Baghdad, Baghdad, Iraq.
    Abdullah, S.N.
    Electronic and Communication Engineering Department, College of Engineering, University of Baghdad, Baghdad, Iraq.
    Deinterleaving of radar signals and PRF identification algorithms2007In: IET radar, sonar & navigation, ISSN 1751-8784, E-ISSN 1751-8792, Vol. 1, no 5, p. 340-347Article in journal (Refereed)
    Abstract [en]

    Electronic warfare (EW) receivers are passive receivers which receive emissions from other platforms, and do certain analysis on these emissions. Some EW receivers receive radar pulses, measure the parameter of each pulse received and group the pulses that belongs to the same emitter together to determine the radar parameters for each emitter. These parameters are then compared with values stored for known radar types, to identify the emitter type. Two parts are focused, emitters deinterleaving and PRF-type identification. The deinterleaving is done through parameters clustering. Two parameters are selected for clustering direction of arrival and radio frequency. A self-organising neural network called Fuzzy ART is proposed for clustering. This algorithm has a very good clustering quality and can run in real-time applications. The PRF-type identification is done through time-of-arrival (TOA) analysis. Three previously presented algorithms are combined in new scheme to do the TOA analysis (or PRF-type identification). These algorithms are difference TOA histogram, TOA folding histogram and sequence search algorithm. The complete proposed system has been tested using three different tests. These tests are simple PRI test, jittered PRI test and staggered PRI test. The proposed system identifies up to 90 simple emitters, 20 jittered emitters and 20 staggered emitters. In all tests, the data were simulated and generated using software.

  • 67. Bacciu, D.
    et al.
    Broxvall, Mathias
    Örebro University, School of Science and Technology.
    Coleman, S.
    Dragone, M.
    Gallicchio, C.
    Gennaro, C.
    Guzmán, R.
    Lopez, R.
    Lozano-Peiteado, H.
    Ray, A.
    Renteria, A.
    Saffiotti, Alessandro
    Örebro University, School of Science and Technology.
    Vairo, C.
    Self-sustaining learning for robotic ecologies2012Conference paper (Refereed)
    Abstract [en]

    The most common use of wireless sensor networks (WSNs) is to collect environmental data from a specificarea, and to channel it to a central processing node for on-line or off-line analysis. The WSN technology,however, can be used for much more ambitious goals. We claim that merging the concepts and technology ofWSN with the concepts and technology of distributed robotics and multi-agent systems can open new waysto design systems able to provide intelligent services in our homes and working places. We also claim thatendowing these systems with learning capabilities can greatly increase their viability and acceptability, bysimplifying design, customization and adaptation to changing user needs. To support these claims, we illus-trate our architecture for an adaptive robotic ecology, named RUBICON, consisting of a network of sensors,effectors and mobile robots.

  • 68.
    Bacciu, Davide
    et al.
    Dipartimento di Informatica, Università di Pisa, Pisa, Italy.
    Gallicchio, Claudio
    Dipartimento di Informatica, Università di Pisa, Pisa, Italy.
    Micheli, Alessio
    Dipartimento di Informatica, Università di Pisa, Pisa, Italy.
    Di Rocco, Maurizio
    Örebro University, School of Science and Technology.
    Saffiotti, Alessandro
    Örebro University, School of Science and Technology.
    Learning context-aware mobile robot navigation in home environments2014In: IISA 2014: The 5th International Conference on Information, Intelligence, Systems and Applications, New York: Institute of Electrical and Electronics Engineers (IEEE), 2014, p. 57-62, article id 6878733Conference paper (Refereed)
    Abstract [en]

    We present an approach to make planning adaptive in order to enable context-aware mobile robot navigation. We integrate a model-based planner with a distributed learning system based on reservoir computing, to yield personalized planning and resource allocations that account for user preferences and environmental changes. We demonstrate our approach in a real robot ecology, and show that the learning system can effectively exploit historical data about navigation performance to modify the models in the planner, without any prior information oncerning the phenomenon being modeled. The plans produced by the adapted CL fail more rarely than the ones generated by a non-adaptive planner. The distributed learning system handles the new learning task autonomously, and is able to automatically identify the sensorial information most relevant for the task, thus reducing the communication and computational overhead of the predictive task.

  • 69.
    Balkmar, Dag
    Örebro University, School of Humanities, Education and Social Sciences.
    Masculinity and Autonomous Vehicles: From automotive emotions to transport robots2020Conference paper (Refereed)
  • 70.
    Banaee, Hadi
    et al.
    Örebro University, School of Science and Technology.
    Ahmed, Mobyen Uddin
    Örebro University, School of Science and Technology.
    Loutfi, Amy
    Örebro University, School of Science and Technology.
    Towards NLG for Physiological Data Monitoring with Body Area Networks2013In: 14th European Workshop on Natural Language Generation, 2013, p. 193-197Conference paper (Refereed)
    Abstract [en]

    This position paper presents an on-goingwork on a natural language generationframework that is particularly tailored fornatural language generation from bodyarea networks. We present an overview ofthe main challenges when considering thistype of sensor devices used for at homemonitoring of health parameters. The paperpresents the first steps towards the implementationof a system which collectsinformation from heart rate and respirationusing a wearable sensor.

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    fulltext
  • 71.
    Bandaru, Vamsi Krishna
    et al.
    Örebro University, School of Science and Technology.
    Balasubramanian, Rajasekaran
    Örebro University, School of Science and Technology.
    OBJECT RECOGNITION USINGDIALOGUES AND SEMANTICANCHORING2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This report explains in detail the implemented system containing a robot and a sensor

    network that is deployed in a test apartment in an elderly residence area. The report

    focuses on the creation and maintenance (anchoring) of the connection between the

    semantic information present in the dialog with perceived actual physical objects in the

    home. Semantic knowledge about concepts and their correlations are retrieved from online

    resources and ontologies, e.g. Word-Net and sensors information are provided by

    cameras distributed in the apartment.

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    fulltext
  • 72.
    Barber, Ramón
    et al.
    Robotics Lab, Universidad Carlos III de Madrid, Avda. de la Universidad, Leganés, Spain.
    Ortiz, Francisco J.
    Department of Automation, Electrical Engineering and Electronics Technology, Universidad Politécnica de Cartagena, Cartagena, Spain.
    Garrido, Santiago
    Robotics Lab, Universidad Carlos III de Madrid, Avda. de la Universidad, Leganés, Spain.
    Calatrava Nicolás, Francisco
    Örebro University, School of Science and Technology.
    Mora, Alicia
    Robotics Lab, Universidad Carlos III de Madrid, Avda. de la Universidad, Leganés, Spain.
    Prados, Adrián
    Robotics Lab, Universidad Carlos III de Madrid, Avda. de la Universidad, Leganés, Spain.
    Vera-Repullo, José Alfonso
    Department of Automation, Electrical Engineering and Electronics Technology, Universidad Politécnica de Cartagena, Cartagena, Spain.
    Roca-González, Joaquín
    Department of Automation, Electrical Engineering and Electronics Technology, Universidad Politécnica de Cartagena, Cartagena, Spain.
    Méndez, Inmaculada
    Department of Evolutionary and Educational Psychology, Faculty of Psychology, University of Murcia, Murcia, Spain.
    Martinez Mozos, Oscar
    Örebro University, School of Science and Technology.
    A Multirobot System in an Assisted Home Environment to Support the Elderly in Their Daily Lives2022In: Sensors, E-ISSN 1424-8220, Vol. 22, no 20, article id 7983Article in journal (Refereed)
    Abstract [en]

    The increasing isolation of the elderly both in their own homes and in care homes has made the problem of caring for elderly people who live alone an urgent priority. This article presents a proposed design for a heterogeneous multirobot system consisting of (i) a small mobile robot to monitor the well-being of elderly people who live alone and suggest activities to keep them positive and active and (ii) a domestic mobile manipulating robot that helps to perform household tasks. The entire system is integrated in an automated home environment (AAL), which also includes a set of low-cost automation sensors, a medical monitoring bracelet and an Android application to propose emotional coaching activities to the person who lives alone. The heterogeneous system uses ROS, IoT technologies, such as Node-RED, and the Home Assistant Platform. Both platforms with the home automation system have been tested over a long period of time and integrated in a real test environment, with good results. The semantic segmentation of the navigation and planning environment in the mobile manipulator for navigation and movement in the manipulation area facilitated the tasks of the later planners. Results about the interactions of users with the applications are presented and the use of artificial intelligence to predict mood is discussed. The experiments support the conclusion that the assistance robot correctly proposes activities, such as calling a relative, exercising, etc., during the day, according to the user's detected emotional state, making this is an innovative proposal aimed at empowering the elderly so that they can be autonomous in their homes and have a good quality of life.

  • 73.
    Beeson, Patrick
    et al.
    TRACLabs Inc., Webster TX, USA.
    Kortenkamp, David
    TRACLabs Inc., Webster TX, USA.
    Bonasso, R. Peter
    TRACLabs Inc., Webster TX, USA.
    Persson, Andreas
    Örebro University, School of Science and Technology.
    Loutfi, Amy
    Örebro University, School of Science and Technology.
    Bona, Jonathan P
    State University of New York, Buffalo, USA.
    An Ontology-Based Symbol Grounding System for Human-Robot Interaction2014In: Artificial Intelligence for Human-Robot Interaction: 2014 AAAI Fall Symposium, AAAI Press, 2014, p. 48-50Conference paper (Refereed)
    Abstract [en]

    This paper presents an ongoing collaboration to develop a perceptual anchoring framework which creates and maintains the symbol-percept links concerning household objects. The paper presents an approach to non-trivialize the symbol system using ontologies and allow for HRI via enabling queries about objects properties, their affordances, and their perceptual characteristics as viewed from the robot (e.g. last seen). This position paper describes in brief the objective of creating a long term perceptual anchoring framework for HRI and outlines the preliminary work done this far.

  • 74.
    Bennetts, Victor Hernandez
    et al.
    Örebro University, School of Science and Technology.
    Schaffernicht, Erik
    Örebro University, School of Science and Technology.
    Stoyanov, Todor
    Örebro University, School of Science and Technology.
    Lilienthal, Achim J.
    Örebro University, School of Science and Technology.
    Trincavelli, Marco
    Örebro University, School of Science and Technology.
    Robot Assisted Gas Tomography - Localizing Methane Leaks in Outdoor Environments2014In: 2014 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION (ICRA), IEEE conference proceedings, 2014, p. 6362-6367Conference paper (Refereed)
    Abstract [en]

    In this paper we present an inspection robot to produce gas distribution maps and localize gas sources in large outdoor environments. The robot is equipped with a 3D laser range finder and a remote gas sensor that returns integral concentration measurements. We apply principles of tomography to create a spatial gas distribution model from integral gas concentration measurements. The gas distribution algorithm is framed as a convex optimization problem and it models the mean distribution and the fluctuations of gases. This is important since gas dispersion is not an static phenomenon and furthermore, areas of high fluctuation can be correlated with the location of an emitting source. We use a compact surface representation created from the measurements of the 3D laser range finder with a state of the art mapping algorithm to get a very accurate localization and estimation of the path of the laser beams. In addition, a conic model for the beam of the remote gas sensor is introduced. We observe a substantial improvement in the gas source localization capabilities over previous state-of-the-art in our evaluation carried out in an open field environment.

  • 75.
    Bennewitz, Maren
    et al.
    University of Freiburg.
    Burgard, Wolfram
    University of Freiburg.
    Cielniak, Grzegorz
    Örebro University, Department of Technology.
    Thrun, Sebastian
    Carnegie Mellon University.
    Learning motion patterns of people for compliant robot motion2005In: The international journal of robotics research, ISSN 0278-3649, E-ISSN 1741-3176, Vol. 24, no 1, p. 31-48Article in journal (Refereed)
    Abstract [en]

    Whenever people move through their environments they do not move randomly. Instead, they usually follow specific trajectories or motion patterns corresponding to their intentions. Knowledge about such patterns enables a mobile robot to robustly keep track of persons in its environment and to improve its behavior. This paper proposes a technique for learning collections of trajectories that characterize typical motion patterns of persons. Data recorded with laser-range finders is clustered using the expectation maximization algorithm. Based on the result of the clustering process we derive a Hidden Markov Model (HMM) that is applied to estimate the current and future positions of persons based on sensory input. We also describe how to incorporate the probabilistic belief about the potential trajectories of persons into the path planning process. We present several experiments carried out in different environments with a mobile robot equipped with a laser range scanner and a camera system. The results demonstrate that our approach can reliably learn motion patterns of persons, can robustly estimate and predict positions of persons, and can be used to improve the navigation behavior of a mobile robot.

  • 76.
    Bergsten, Pontus
    et al.
    Örebro University, Department of Technology.
    Palm, Rainer
    Siemens AG Corporate Technology, Munich, Germany.
    Driankov, Dimiter
    Örebro University, Department of Technology.
    Fuzzy Observers2001In: The 10th IEEE International Conference on Fuzzy Systems (Volym:3): Meeting the grand challenge: Machines that serve people, New York, USA: IEEE conference proceedings, 2001, p. 700-703Conference paper (Refereed)
    Abstract [en]

    We consider the analysis and design of three different types of nonlinear observers for dynamic Takagi-Sugeno fuzzy systems. Our approach is based on extending existing nonlinear observer schemes, namely Thau-Luenberger and sliding mode observers, to the case of interpolated multiple local affine linear models. Then linear matrix inequality based techniques are used for observer analysis and design.

  • 77.
    Bergstrand, Simon
    Örebro University, School of Science and Technology.
    Programmering av styrutrustning för vridbord vid radarmätplats2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    When calibrating a radars antenna the radar is placed on a turntable that points it to a measuring point on a tower. The main task for the thesis was to write a program in National Instruments programming environment LabVIEW that can turn the turntable with an accuracy of 0.1 milliradians. The program shall be able to be used as a DLL (Dynamic-link library) in LabWindows/CVI where a number of different functions shall be able to control the turntable. Because all of the hardware is from National Instruments the software development became easy. The challenge was instead to measure the lengths and angles of the turntable and at testing be so precise that is necessary. All requirements were met but the lack of accuracy when testing makes the results a bit uncertain.Another part of the thesis was to write documents that specify requirements, interfaces and also describes how the software will be designed, tested and calibrated. For these documents the MIL-STD-498 was used that used to be an American military standard.

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  • 78.
    Bergström, Per
    et al.
    Department of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå, Sweden.
    Khodadad, Davood
    Department of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå, Sweden.
    Hällstig, Emil
    Optronic Partner Dp AB, Skellefteå, Sweden.
    Sjödahl, Mikael
    Department of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå, Sweden.
    Dual-wavelength digital holography: single-shot shape evaluation using speckle displacements and regularization2014In: Applied Optics, ISSN 1559-128X, E-ISSN 2155-3165, Vol. 53, no 1, p. 123-131Article in journal (Refereed)
    Abstract [en]

    This paper discusses the possibility of evaluating the shape of a free-form object in comparison with its shape prescribed by a CAD model. Measurements are made based on a single-shot recording using dual-wavelength holography with a synthetic wavelength of 1.4 mm. Each hologram is numerically propagated to different focus planes and correlated. The result is a vector field of speckle displacements that is linearly dependent on the local distance between the measured surface and the focus plane. From these speckle displacements, a gradient field of the measured surface is extracted through a proportional relationship. The gradient field obtained from the measurement is then aligned to the shape of the CAD model using the iterative closest point (ICP) algorithm and regularization. Deviations between the measured shape and the CAD model are found from the phase difference field, giving a high precision shape evaluation. The phase differences and the CAD model are also used to find a representation of the measured shape. The standard deviation of the measured shape relative the CAD model varies between 7 and 19 μm, depending on the slope.

  • 79.
    Bergström, Per
    et al.
    Department of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå, Sweden.
    Khodadad, Davood
    Department of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå, Sweden.
    Hällstig, Emil
    Optronic Partner dp AB, Skellefteå, Sweden.
    Sjödahl, Mikael
    Department of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå, Sweden.
    Single Shot Shape Evaluation Using Dual-Wavelength Holographic Reconstructions and Regularization2014In: Fringe 2013: 7th International Workshop on Advanced Optical Imaging and Metrology / [ed] Wolfgang Osten, Springer Berlin/Heidelberg, 2014, p. 103-108Conference paper (Refereed)
    Abstract [en]

    The aim of this work is to evaluate the shape of a free form object using single shot digital holography. The digital holography results in a gradient field and wrapped phase maps representing the shape of the object. The task is then to find a surface representation from this data which is an inverse problem. To solve this inverse problem we are using regularization with additional shape information from the CAD-model of the measured object.

  • 80.
    Berna, Amalia
    et al.
    CSIRO Ecosystem Sciences and CSIRO Food Futures Flagship, Canberra, Australian Capital Territory (ACT), Australia.
    Vergara, Alexander
    University of California, San Diego, USA.
    Trincavelli, Marco
    Örebro University, School of Science and Technology.
    Huerta, Ramon
    University of California, San Diego, USA.
    Afonja, Ayo
    Department of Chemistry, University College London, London, UK.
    Parkin, Ivan
    Binions, Russell
    Trowell, Stephen
    Evaluating zeolite-modified sensors: towards a faster set of chemical sensors2011In: 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, American Institute of Physics (AIP), 2011, p. 50-52Conference paper (Refereed)
    Abstract [en]

    The response of zeolite-modified sensors, prepared by screen printing layers of chromium titanium oxide (CTO), were compared to unmodified tin oxide sensors using amplitude and transient responses. For transient responses we used a family of features, derived from the exponential moving average (EMA), to characterize chemo-resistive responses. All sensors were tested simultaneously against 20 individual volatile compounds from four chemical groups. The responses of the two types of sensors showed some independence. The zeolite modified CTO sensors discriminated compounds better using either amplitude response or EMA features and CTO-modified sensors also responded three times faster.

  • 81. Birk, Andreas
    et al.
    Poppinga, Jann
    Stoyanov, Todor
    Örebro University, School of Science and Technology.
    Nevatia, Yashodhan
    Planetary Exploration in USARSim: A Case Study including Real World Data from Mars2009In: RoboCup 2008: Robot Soccer World Cup XII / [ed] Volume editors: Luca Iocchi, Hitoshi Matsubara, Alfredo Weitzenfeld, Changjiu Zhou, Springer Berlin Heidelberg , 2009, p. 463-472Conference paper (Refereed)
    Abstract [en]

     Intelligent Mobile Robots are increasingly used in unstructured domains; one particularly challenging example for this is, planetary exploration. The preparation of according missions is highly non-trivial, especially as it is difficult to carry out realistic experiments without, very sophisticated infrastructures. In this paper, we argue that, the, Unified System for Automation and Robot Simulation (USARSim) offers interesting opportunities for research on planetary exploration by mobile robots. With the example of work on terrain classification, it, is shown how synthetic as well as real world data, from Mars call be used to test an algorithm's performance in USARSim. Concretely, experiments with an algorithm for the detection of negotiable ground oil a, planetary surface are presented. It is shown that the approach performs fast; and robust on planetary surfaces.

  • 82. Birk, Andreas
    et al.
    Stoyanov, Todor
    Örebro University, School of Science and Technology.
    Nevatia, Yashodhan
    Ambrus, Rares
    Poppinga, Jan
    Pathak, Kaustubh
    Terrain Classification for Autonomous Robot Mobility: from Safety, Security Rescue Robotics to Planetary Exploration2008Conference paper (Refereed)
  • 83.
    Birkelöf, Jonas
    Örebro University, School of Science and Technology.
    Framtagning av demonstratorer2009Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    På Alfred Nobelmuseet i Karlskoga finns en avdelning som kallas Fiffiga huset. Där finns många experiment som besökare kan prova på, samt montrar som visar hur olika tekniska och maskinella apparater fungerar. Till utställningen och öppnandet sommaren 2009 ville de ha två nya demonstratorer. I rapporten kallas dem för reaktionstidsväggen och baklängesprataren. Reaktionstidsväggen skulle mäta besökarens reaktionstid genom att tryckknappar, med inbyggda dioder som slumpvis tänds, trycks ned i rätt ordning. Baklängesprataren skulle spela in besökarens tal och sedan spela upp det baklänges. Tanken var att besökaren skulle försöka prata baklänges och få det att låta rätt vid uppspelning. Arbetet gick ut på att bygga dessa demonstratorer och montera dem i Fiffiga huset. Reaktionstidsväggen styrdes med hjälp av en mikroprocessor ATMega16 från Atmel. Dess jobb var att läsa av knapptryckningar samt skicka information till dioder och display. Även baklängesprataren skulle styras med hjälp av mikroprocessorn ATMega16. En enkel mikrofonförstärkare samt filter till högtalarna skulle anslutas till processorn. Det inbyggda minnet skulle inte räcka till så ett extern minne behövde anslutas.Endast reaktionstidsväggen hann bli färdig inom projektets ramar eftersom all gammal elektronik som medföljde från Nobelmuseet var komplex, samt att många kortslutningar och avbrott gjorde felsökning till en tidskrävande procedur.

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  • 84.
    Blad, Samuel
    et al.
    Örebro University, School of Science and Technology. Nexer.
    Längkvist, Martin
    Örebro University, School of Science and Technology.
    Klügl, Franziska
    Örebro University, School of Science and Technology.
    Loutfi, Amy
    Örebro University, School of Science and Technology.
    Empirical analysis of the convergence of Double DQN in relation to reward sparsity2022In: 21st IEEE International Conference on Machine Learning and Applications. ICMLA 2022: Proceedings / [ed] Wani, MA; Kantardzic, M; Palade, V; Neagu, D; Yang, L; Chan, KY, IEEE, 2022, p. 591-596Conference paper (Refereed)
    Abstract [en]

    Q-Networks are used in Reinforcement Learning to model the expected return from every action at a given state. When training Q-Networks, external reward signals are propagated to the previously performed actions leading up to each reward. If many actions are required before experiencing a reward, the reward signal is distributed across all those actions, where some actions may have greater impact on the reward than others. As the number of significant actions between rewards increases, the relative importance of each action decreases. If actions have too small importance, their impact might be over-shadowed by noise in a deep neural network model, potentially causing convergence issues. In this work, we empirically test the limits of increasing the number of actions leading up to a reward in a simple grid-world environment. We show in our experiments that even though the training error surpasses the reward signal attributed to each action, the model is still able to learn a smooth enough value representation.

  • 85.
    Blomqvist, Eva
    et al.
    Linköping University, Linköping, Sweden.
    Alirezaie, Marjan
    Örebro University, School of Science and Technology.
    Santini, Marina
    RISE, Research Institutes of Sweden.
    Towards Causal Knowledge Graphs - Position Paper2020In: Proceedings of the 5th International Workshop on Knowledge Discovery in Healthcare Data co-located with 24th European Conference on Artificial Intelligence (ECAI 2020) / [ed] Kerstin Bach, Razvan Bunescu, Cindy Marling, Nirmalie Wiratunga, Technical University of Aachen , 2020, Vol. 2675, p. 58-62Conference paper (Refereed)
    Abstract [en]

    In this position paper, we highlight that being able to analyse the cause-effect relationships for determining the causal status among a set of events is an essential requirement in many contexts and argue that cannot be overlooked when building systems targeting real-world use cases. This is especially true for medical contexts where the understanding of the cause(s) of a symptom, or observation, is of vital importance. However, most approaches purely based on Machine Learning (ML) do not explicitly represent and reason with causal relations, and may therefore mistake correlation for causation. In the paper, we therefore argue for an approach to extract causal relations from text, and represent them in the form of Knowledge Graphs (KG), to empower downstream ML applications, or AI systems in general, with the ability to distinguish correlation from causation and reason with causality in an explicit manner. So far, the bottlenecks in KG creation have been scalability and accuracy of automated methods, hence, we argue that two novel features are required from methods for addressing these challenges, i.e. (i) the use of Knowledge Patterns to guide the KG generation process towards a certain resulting knowledge structure, and (ii) the use of a semantic referee to automatically curate the extracted knowledge. We claim that this will be an important step forward for supporting interpretable AI systems, and integrating ML and knowledge representation approaches, such as KGs, which should also generalise well to other types of relations, apart from causality.

  • 86.
    Bonaccorsi, Manuele
    et al.
    The BioRobotics Institute, Scuola Superiore Sant’Anna, Pisa, Italy.
    Fiorini, Laura
    The BioRobotics Institute, Scuola Superiore Sant’Anna, Pisa, Italy.
    Cavallo, Filippo
    The BioRobotics Institute, Scuola Superiore Sant’Anna, Pisa, Italy.
    Saffiotti, Alessandro
    Örebro University, School of Science and Technology.
    Dario, Paolo
    The BioRobotics Institute, Scuola Superiore Sant’Anna, Pisa, Italy.
    A cloud robotics solution to improve social assistive robots for active and healthy aging2016In: International Journal of Social Robotics, ISSN 1875-4791, E-ISSN 1875-4805, Vol. 8, no 3, p. 393-408Article in journal (Refereed)
    Abstract [en]

    Technological innovation in robotics and ICT represents an effective solution to tackle the challenge of providing social sustainable care services for the ageing population. The recent introduction of cloud technologies is opening new opportunities for the provisioning of advanced robotic services based on the cooperation of a number of connected robots, smart environments and devices improved by the huge cloud computational and storage capability. In this context, this paper aims to investigate and assess the potentialities of a cloud robotic system for the provisioning of assistive services for the promotion of active and healthy ageing. The system comprised two different smart environments, located in Italy and Sweden, where a service robot is connected to a cloud platform for the provisioning of localization based services to the users. The cloud robotic services were tested in the two realistic environments to assess the general feasibility of the solution and demonstrate the ability to provide assistive location based services in a multiple environment framework. The results confirmed the validity of the solution but also suggested a deeper investigation on the dependability of the communication technologies adopted in such kind of systems.

  • 87.
    Bouguerra, Abdelbaki
    Örebro University, Department of Technology.
    A reactive approach for object finding in real world environments2006In: Intelligent Autonomous Systems 9 / [ed] Tamio Arai, Rolf Pfeifer, Tucker Balch, Hiroshi Yokoi, 2006, p. 391-398Conference paper (Other academic)
    Abstract [en]

    In this paper we propose an approach to handle requests of finding objects in real world environments by mobile robots. The proposed approach checks candidate objects based on the likelihood they constitute an answer to the requests in a reactive way. As a result, run-time perceived objects are handled “on the fly” without extra cost. We present the theoretical concepts of the proposed approach, and describe the experiments we run to validate it.

  • 88.
    Boustedt, Katarina
    Örebro University, Department of Technology.
    Flip chip for high frequency applications: materials aspects2007Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Flip chip has since decades been the primary choice for chip interconnect for high performance circuits. Over the last few years, interest from the microwave arena has increased, and at this point in time microwave flip chip is a possible option for volume production.

    This thesis is based on an extensive literature survey in combination with experiments done in collaboration with Ericsson, Flextronics in Linköping and Chalmers University of Technology in Gothenburg. The backbone of the literature survey was published as a chapter on high frequency interconnects in the reference book “Area Array Interconnection Handbook” (2002), edited by Karl Puttlitz and Paul A. Totta, who are known as the fathers of flip chip. This literature study has since then been expanded and the latest search was

    done in June 2007.

    Four groups of experiments are reported in this thesis. The fi rst experiments are on stud bumping thin film substrates for subsequent fl ip-chip bonding. The wire was 17-μm diameter Au1Pd and bumping was uniform and successful, after some initial equipment problems.

    The second is a set of tests on flip-chip bonding using gold stud bumps, gold tin solder-on-substrate, and plated gold pillars on alumina carriers. To evaluate the joining process using these different bumps, chips made of alumina

    with coplanar waveguide transmission lines were thermocompression bonded to the bumped carriers. Bonder parameters were assessed related to the different bump types and materials. The bonding results were analyzed using shear tests, transmissive x-ray and scanning electron microscopy on

    cross-sections.

    The third experiment lot contains early results on reliability of stud-bump flip chip of gallium arsenide microstrip chips. Since the sample availability was very low and the joining process still under development, the results are vague, although it was fruitful to establish adequate methods of analysis and test.

    The fourth set of experiments involved the same alumina on alumina assembly, and flip-chip underfill and its impact measured up to 70 GHz. Three different underfill materials were applied to the test vehicles described above. Before and after underfilling, the test vehicles were measured for S parameters and compared.

    This study concludes that for flip chip on gold pads, the preferred joining process is soldering, just as for silicon chips with aluminum or copper pads. Since solder bumping on gold pads is hard to come by, the second best choice is plated pillars, on carrier or chip, and thirdly, gold wire stud bumping.

    Underfill for microwave applications should not necessarily be dreaded to the extent that it is today. This study has proven that the matching of lines isnot affected and the changes in dips can be considered in the early phases of the design process for chip and carrier.

  • 89.
    Boustedt, Katarina
    et al.
    Örebro University, School of Science and Technology.
    Persson, Katrin
    IMEGO, Gothenburg, Sweden.
    Stranneby, Dag
    Örebro University, School of Science and Technology.
    Flip chip as an enabler for MEMS packaging2002In: 52nd Electronic Components and Technology Conference, 2002. Proceedings., 2002, p. -128Conference paper (Refereed)
    Abstract [en]

    With the recent trends in microelectronics to move more and more towards incorporating MEMS (micro electro mechanical systems) structures, lowering the overall cost becomes vital. One major cost driver in today's MEMS is the packaging. Many of the MEMS structures require some level of low pressure for full quality operation, and some may even need vacuum to function properly. Different MEMS packaging strategies exist on the market and they can be divided into two different approaches. The first one protects the wafer temporarily during wafer scribing or dicing and the second one provides a permanent seal to the wafer through full wafer bonding before scribing and dicing. The latter, permanent methods allows for selecting very low cost packaging without hermeticity as a requirement, whereas in the temporary seal methods the seal is removed after dicing and the sensitive structures become unprotected again. Using flip chip for MEMS has the benefit of providing MEMS structures with a covering lid, the chip itself. A number of flip chip MEMS interconnection methods presented in literature are described.

  • 90.
    Boustedt, Katarina
    et al.
    Örebro University, School of Science and Technology.
    Persson, Katrin
    IMEGO, Gothenburg, Sweden.
    Stranneby, Dag
    Örebro University, School of Science and Technology.
    Bohman, Sofie
    IMEGO, Gothenburg, Sweden.
    Wafer Bonding Technologies for MEMS Packaging2002In: Proceedings : the IMAPS Nordic Annual Conference : Stockholm, 2002, 29 September-2 October 2002., 2002, p. -127Conference paper (Other academic)
  • 91.
    Brandão, Martim
    et al.
    Department of Informatics, King's College London, London, United Kingdom.
    Mansouri, Masoumeh
    School of Computer Science, University of Birmingham, Birmingham, United Kingdom.
    Magnusson, Martin
    Örebro University, School of Science and Technology.
    Editorial: Responsible Robotics2022In: Frontiers in Robotics and AI, E-ISSN 2296-9144, Vol. 9, article id 937612Article in journal (Refereed)
  • 92.
    Burgués, Javier
    et al.
    Institute for Bioengineering of Catalonia (IBEC),The Barcelona Institute of Science and Technology, Baldiri Reixac, Barcelona, Spain; Department of Electronics and Biomedical Engineering, Universitat de Barcelona, Barcelona, Spain.
    Hernandez Bennetts, Victor
    Örebro University, School of Science and Technology.
    Lilienthal, Achim J.
    Örebro University, School of Science and Technology.
    Marco, Santiago
    Institute for Bioengineering of Catalonia (IBEC),The Barcelona Institute of Science and Technology, Baldiri Reixac, Barcelona, Spain; Department of Electronics and Biomedical Engineering, Universitat de Barcelona, Barcelona, Spain.
    Smelling Nano Aerial Vehicle for Gas Source Localization and Mapping2019In: Sensors, E-ISSN 1424-8220, Vol. 19, no 3, article id 478Article in journal (Refereed)
    Abstract [en]

    This paper describes the development and validation of the currently smallest aerial platform with olfaction capabilities. The developed Smelling Nano Aerial Vehicle (SNAV) is based on a lightweight commercial nano-quadcopter (27 g) equipped with a custom gas sensing board that can host up to two in situ metal oxide semiconductor (MOX) gas sensors. Due to its small form-factor, the SNAV is not a hazard for humans, enabling its use in public areas or inside buildings. It can autonomously carry out gas sensing missions of hazardous environments inaccessible to terrestrial robots and bigger drones, for example searching for victims and hazardous gas leaks inside pockets that form within the wreckage of collapsed buildings in the aftermath of an earthquake or explosion. The first contribution of this work is assessing the impact of the nano-propellers on the MOX sensor signals at different distances to a gas source. A second contribution is adapting the ‘bout’ detection algorithm, proposed by Schmuker et al. (2016) to extract specific features from the derivative of the MOX sensor response, for real-time operation. The third and main contribution is the experimental validation of the SNAV for gas source localization (GSL) and mapping in a large indoor environment (160 m2) with a gas source placed in challenging positions for the drone, for example hidden in the ceiling of the room or inside a power outlet box. Two GSL strategies are compared, one based on the instantaneous gas sensor response and the other one based on the bout frequency. From the measurements collected (in motion) along a predefined sweeping path we built (in less than 3 min) a 3D map of the gas distribution and identified the most likely source location. Using the bout frequency yielded on average a higher localization accuracy than using the instantaneous gas sensor response (1.38 m versus 2.05 m error), however accurate tuning of an additional parameter (the noise threshold) is required in the former case. The main conclusion of this paper is that a nano-drone has the potential to perform gas sensing tasks in complex environments.

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    Smelling Nano Aerial Vehicle for Gas Source Localization and Mapping
  • 93.
    Burgués, Javier
    et al.
    Department of Electronic and Biomedical Engineering, Universitat de Barcelona, Barcelona, Spain; Institute for Bioengineering of Catalonia (IBEC), Barcelona, Spain.
    Hernandez Bennetts, Victor
    Örebro University, School of Science and Technology.
    Lilienthal, Achim
    Örebro University, School of Science and Technology.
    Marco, Santiago
    Department of Electronic and Biomedical Engineering, Universitat de Barcelona, Barcelona, Spain; Institute for Bioengineering of Catalonia (IBEC), Barcelona, Spain.
    3D Gas Distribution with and without Artificial Airflow: An Experimental Study with a Grid of Metal Oxide Semiconductor Gas Sensors2018In: Proceedings, E-ISSN 2504-3900, Vol. 2, no 13, article id 911Article in journal (Refereed)
    Abstract [en]

    Gas distribution modelling can provide potentially life-saving information when assessing the hazards of gaseous emissions and for localization of explosives, toxic or flammable chemicals. In this work, we deployed a three-dimensional (3D) grid of metal oxide semiconductor (MOX) gas sensors deployed in an office room, which allows for novel insights about the complex patterns of indoor gas dispersal. 12 independent experiments were carried out to better understand dispersion patters of a single gas source placed at different locations of the room, including variations in height, release rate and air flow profiles. This dataset is denser and richer than what is currently available, i.e., 2D datasets in wind tunnels. We make it publicly available to enable the community to develop, validate, and compare new approaches related to gas sensing in complex environments.

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    3D Gas Distribution with and without Artificial Airflow: An Experimental Study with a Grid of Metal Oxide Semiconductor Gas Sensors
  • 94.
    Buyukgoz, Sera
    et al.
    SoftBank Robotics Europe, Paris, France; Sorbonne University, Institute for Intelligent Systems and Robotics, CNRS UMR, Paris, France.
    Grosinger, Jasmin
    Örebro University, School of Science and Technology.
    Chetouani, Mohamed
    Sorbonne University, Institute for Intelligent Systems and Robotics, CNRS UMR, Paris, France.
    Saffiotti, Alessandro
    Örebro University, School of Science and Technology.
    Two ways to make your robot proactive: Reasoning about human intentions or reasoning about possible futures2022In: Frontiers in Robotics and AI, E-ISSN 2296-9144, Vol. 9, article id 929267Article in journal (Refereed)
    Abstract [en]

    Robots sharing their space with humans need to be proactive to be helpful. Proactive robots can act on their own initiatives in an anticipatory way to benefit humans. In this work, we investigate two ways to make robots proactive. One way is to recognize human intentions and to act to fulfill them, like opening the door that you are about to cross. The other way is to reason about possible future threats or opportunities and to act to prevent or to foster them, like recommending you to take an umbrella since rain has been forecast. In this article, we present approaches to realize these two types of proactive behavior. We then present an integrated system that can generate proactive robot behavior by reasoning on both factors: intentions and predictions. We illustrate our system on a sample use case including a domestic robot and a human. We first run this use case with the two separate proactive systems, intention-based and prediction-based, and then run it with our integrated system. The results show that the integrated system is able to consider a broader variety of aspects that are required for proactivity.

  • 95.
    Calatrava-Nicolás, Francisco M.
    et al.
    ETSII (Escuela Técnica Superior de Ingeniería Industrial), Technical University of Cartagena, Cartagena, Spain.
    Gutiérrez-Maestro, Eduardo
    Örebro University, School of Science and Technology.
    Bautista-Salinas, Daniel
    The Hamlyn Centre for Robotic Surgery, Imperial College London, London, UK.
    Ortiz, Francisco J.
    ETSII (Escuela Técnica Superior de Ingeniería Industrial), Technical University of Cartagena, Cartagena, Spain.
    González, Joaquín Roca
    ETSII (Escuela Técnica Superior de Ingeniería Industrial), Technical University of Cartagena, Cartagena, Spain.
    Vera-Repullo, José Alfonso
    ETSII (Escuela Técnica Superior de Ingeniería Industrial), Technical University of Cartagena, Cartagena, Spain.
    Jiménez-Buendía, Manuel
    ETSII (Escuela Técnica Superior de Ingeniería Industrial), Technical University of Cartagena, Cartagena, Spain.
    Méndez, Inmaculada
    Department of Evolutionary and Educational Psychology, Faculty of Psychology, Campus Regional Excellence Mare Nostrum, University of Murcia, Murcia, Spain.
    Ruiz-Esteban, Cecilia
    Department of Evolutionary and Educational Psychology, Faculty of Psychology, Campus Regional Excellence Mare Nostrum, University of Murcia, Murcia, Spain.
    Martinez Mozos, Oscar
    Örebro University, School of Science and Technology.
    Robotic-Based Well-Being Monitoring and Coaching System for the Elderly in Their Daily Activities2021In: Sensors, E-ISSN 1424-8220, Vol. 21, no 20, article id 6865Article in journal (Refereed)
    Abstract [en]

    The increasingly ageing population and the tendency to live alone have led science and engineering researchers to search for health care solutions. In the COVID 19 pandemic, the elderly have been seriously affected in addition to suffering from isolation and its associated and psychological consequences. This paper provides an overview of the RobWell (Robotic-based Well-Being Monitoring and Coaching System for the Elderly in their Daily Activities) system. It is a system focused on the field of artificial intelligence for mood prediction and coaching. This paper presents a general overview of the initially proposed system as well as the preliminary results related to the home automation subsystem, autonomous robot navigation and mood estimation through machine learning prior to the final system integration, which will be discussed in future works. The main goal is to improve their mental well-being during their daily household activities. The system is composed of ambient intelligence with intelligent sensors, actuators and a robotic platform that interacts with the user. A test smart home system was set up in which the sensors, actuators and robotic platform were integrated and tested. For artificial intelligence applied to mood prediction, we used machine learning to classify several physiological signals into different moods. In robotics, it was concluded that the ROS autonomous navigation stack and its autodocking algorithm were not reliable enough for this task, while the robot's autonomy was sufficient. Semantic navigation, artificial intelligence and computer vision alternatives are being sought.

  • 96.
    Canelhas, Daniel Ricão
    et al.
    Univrses AB, Strängnäs, Sweden.
    Stoyanov, Todor
    Örebro University, School of Science and Technology.
    Lilienthal, Achim J.
    Örebro University, School of Science and Technology.
    A Survey of Voxel Interpolation Methods and an Evaluation of Their Impact on Volumetric Map-Based Visual Odometry2018In: Proceedings of the IEEE International Conference on Robotics and Automation (ICRA),, IEEE Computer Society, 2018, p. 6337-6343Conference paper (Refereed)
    Abstract [en]

    Voxel volumes are simple to implement and lend themselves to many of the tools and algorithms available for 2D images. However, the additional dimension of voxels may be costly to manage in memory when mapping large spaces at high resolutions. While lowering the resolution and using interpolation is common work-around, in the literature we often find that authors either use trilinear interpolation or nearest neighbors and rarely any of the intermediate options. This paper presents a survey of geometric interpolation methods for voxel-based map representations. In particular we study the truncated signed distance field (TSDF) and the impact of using fewer than 8 samples to perform interpolation within a depth-camera pose tracking and mapping scenario. We find that lowering the number of samples fetched to perform the interpolation results in performance similar to the commonly used trilinear interpolation method, but leads to higher framerates. We also report that lower bit-depth generally leads to performance degradation, though not as much as may be expected, with voxels containing as few as 3 bits sometimes resulting in adequate estimation of camera trajectories.

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    A Survey of Voxel Interpolation Methods and an Evaluation of Their Impact on Volumetric Map-Based Visual Odometry
  • 97.
    Carletti, Cristina
    et al.
    Marche Polytechnic University Ancona, Ancona, Italy.
    Di Rocco, Maurizio
    Roma Tre University, Rome, Italy.
    Gasparri, Andrea
    Roma Tre University, Rome, Italy.
    Ulivi, Giovanni
    Roma Tre University, Rome, Italy.
    A distributed transferable belief model for collaborative topological map-building in multi-robot systems2010In: 2010 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), IEEE, 2010, p. 554-560Conference paper (Refereed)
    Abstract [en]

    In this paper the problem of multi-robot collaborative topological map-building is addressed. In this framework, a team of robots is supposed to move in an indoor office-like environment. Each robot, after building a local map by using infrared range-finders, achieves a topological representation of the environment by extracting the most significant features via the Hough transform and comparing them with a set of predefined environmental patterns. The local view of each robot which is significantly constrained by its limited sensing capabilities is then strengthened by a collaborative aggregation schema based on the Transferable Belief Model (TBM). In this way, a better representation of the environment is achieved by each robot with a minimal exchange of information. A preliminary experimental validation carried out by exploiting data collected from a self-made team of robots is proposed.

  • 98.
    Carlson, Jan
    et al.
    Department of Computer Science and Engineering, Mälardalen University, Västerås, Sweden.
    Lennvall, Tomas
    Department of Computer Science and Engineering, Mälardalen University, Västerås, Sweden.
    Fohler, Gerhard
    Department of Computer Science and Engineering, Mälardalen University, Västerås, Sweden.
    Enhancing time triggered scheduling with value based overload handling and task migration2003In: Sixth IEEE International Symposium on Object-Oriented Real-Time Distributed Computing, 2003: Proceedings, IEEE Computer Society, 2003, p. 121-128Conference paper (Refereed)
    Abstract [en]

    Time triggered methods provide deterministic behaviour suitable for critical real-time systems. The), perform less favourably, however if the arrival times of some activities are not known in advance, in particular if overload situations have to be anticipated. In many systems, the criticality of only a subset of activities justify the cost associated with the time triggered methods.

    In this paper we consider distributed systems where a subset of critical activities are handled in a time triggered fashion, via an offline schedule. At runtime, the arrival of aperiodic tasks may cause overload that demands to be handled in such a way that i) time triggered activities still meet all their original constraints, ii) execution of high-valued tasks are prioritised over tasks with lower value, iii) tasks can be quickly migrated to balance the overall system load.

    We give a precise formulation of overload detection and value based task rejection in the presence of offline scheduled tasks, and present a heuristic algorithm to handle overload. To benefit from the distributed setting, the overload handling includes an algorithm that integrates migration of rejected tasks with resource reclaiming and an acceptance test of newly arrived tasks.

    Simulation results underline the effectiveness of the presented approach.

  • 99.
    Carlsson, Johannes
    Örebro University, School of Science and Technology.
    Digital ljudkvalitetsoptimering för hörlurar.2011Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Detta examensarbete har utförts hos Dirac Research AB i Uppsala. Dirac Research är en världsledande programvaruspecialist inom ljudoptimering, rumskorrigering och ljudfältssyntes.

    Dirac har nu velat utreda hur man på bästa sätt kan använda deras programvara Dirac Live för att förbättra ljudet hos hörlurar. I examensarbetet ingick en teoretisk del om örat, hörlurar, mätmetoder och hur en frekvenskurva bör se ut. Det ingick också att mäta impulssvaret för några olika hörlurar. Impulssvaret användes sedan till att förbättra ljudet hos hörlurarna genom att designa digitala filter som användes genom programvaran Dirac Live. När filterdesignen var klar utfördes ett lyssningstest för att få åsikter om hur andra upplevde filtrena.

    Mätningarna utfördes på Karolinska Institutet i Huddingen på ett KEMAR-huvud. Det är ett konsthuvud som ska efterlikna en människas huvud till form och storlek. Där mättes fyra earbuds (intra-concha), tre in-ear (insert), två omslutande (circum-aural) och ett par utanpåliggande (supra-aural) hörlurar upp. Med filterdesignen visade det sig att förbättringar upplevdes på de flesta av hörlurarna. Dock så kompenserades inte de omslutande- och utanpåliggande hörlurarna något. Dessa var endast tänkta att ha som referens.

    Det var en del skillnader mellan de olika hörlurarnas frekvenssvar. Det beror delvis på hörselgångens resonansfrekvens. När omslutande hörlurar mäts kan hörselgången ses som en kvartsvågsresonator medan den vid mätning av in-ear-hörlurar kan ses som halvvågsresonator. Även hörlurarnas konstruktion påverkar skillnaderna för de olika hörlurstyperna.

    Som målkurvor till hörlurarna användes bland annat högtalarmätningar i form av frifältsmätningar och diffusfältsmätningar utöver de hörlurar som användes som referens. Dock upplevdes en frekvensgång med en mjuk topp vid 3 kHz och i övrigt ganska rak frekvensgång som bäst. Vid lyssningstestet var det även den kurvan som fick flest röster hos tre av de fyra hörlurarna som användes vid lyssningstestet.

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    fulltext
  • 100. Carpin, Stefano
    et al.
    Stoyanov, Todor
    Örebro University, School of Science and Technology.
    Nevatia, Yashodhan
    Lewis, M.
    Wang, J.
    Quantitative Assessments of USARSim Accuracy2006Conference paper (Refereed)
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