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  • 1.
    Abdul Khaliq, Ali
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Pecora, Federico
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Saffiotti, Alessandro
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Point-to-point safe navigation of a mobile robot using stigmergy and RFID technology2016Ingår i: 2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Institute of Electrical and Electronics Engineers (IEEE), 2016, s. 1497-1504, artikel-id 7759243Konferensbidrag (Refereegranskat)
    Abstract [en]

    Reliable autonomous navigation is still a challenging problem for robots with simple and inexpensive hardware. A key difficulty is the need to maintain an internal map of the environment and an accurate estimate of the robot’s position in this map. Recently, a stigmergic approach has been proposed in which a navigation map is stored into the environment, on a grid of RFID tags, and robots use it to optimally reach predefined goal points without the need for internal maps. While effective,this approach is limited to a predefined set of goal points. In this paper, we extend this approach to enable robots to travel to any point on the RFID floor, even if it was not previously identified as a goal location, as well as to keep a safe distance from any given critical location. Our approach produces safe, repeatable and quasi-optimal trajectories without the use of internal maps, self localization, or path planning. We report experiments run in a real apartment equipped with an RFID floor, in which a service robot either reaches or avoids a user who wears slippers equipped with an RFID tag reader.

  • 2.
    Abdullah, Muhammad
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Mobile Robot Navigation using potential fields andmarket based optimization2013Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    A team of mobile robots moving in a shared area raises the problem of safe and autonomous navigation. While avoiding static and dynamic obstacles, mobile robots in a team can lead to complicated and irregular movements. Local reactive approaches are used to deal with situations where robots are moving in dynamic environment; these approaches help in safe navigation of robots but do not give optimal solution. In this work a 2-D navigation strategy is implemented, where a potential field method is used for obstacle avoidance. This potential field method is improved using fuzzy rules, traffic rules and market based optimization (MBO). Fuzzy rules are used to deform repulsive potential fields in the vicinity of obstacles. Traffic rules are used to deal situations where two robots are crossing each other. Market based optimization (MBO) is used to strengthen or weaken repulsive potential fields generated by other robots based on their importance. For the verification of this strategy on more realistic vehicles this navigation strategy is implemented and tested in simulation. Issues while implementing this method and limitations of this navigation strategy are also discussed. Extensive experiments are performed to examine the validity of MBO navigation strategy over traditional potential field (PF) method.

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  • 3.
    Adolfsson, Daniel
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Lowry, Stephanie
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Andreasson, Henrik
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Improving Localisation Accuracy using Submaps in warehouses2018Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    This paper presents a method for localisation in hybrid metric-topological maps built using only local information that is, only measurements that were captured by the robot when it was in a nearby location. The motivation is that observations are typically range and viewpoint dependent and that a map a discrete map representation might not be able to explain the full structure within a voxel. The localisation system uses a method to select submap based on how frequently and where from each submap was updated. This allow the system to select the most descriptive submap, thereby improving the localisation and increasing performance by up to 40%.

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    Improving Localisation Accuracy using Submaps in warehouses
  • 4.
    Adolfsson, Daniel
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Magnusson, Martin
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Alhashimi, Anas
    Örebro University, Örebro, Sweden; Computer Engineering Department, University of Baghdad, Baghdad, Iraq.
    Lilienthal, Achim
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Andreasson, Henrik
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Lidar-Level Localization With Radar? The CFEAR Approach to Accurate, Fast, and Robust Large-Scale Radar Odometry in Diverse Environments2023Ingår i: IEEE Transactions on robotics, ISSN 1552-3098, E-ISSN 1941-0468, Vol. 39, nr 2, s. 1476-1495Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This article presents an accurate, highly efficient, and learning-free method for large-scale odometry estimation using spinning radar, empirically found to generalize well across very diverse environments—outdoors, from urban to woodland, and indoors in warehouses and mines—without changing parameters. Our method integrates motion compensation within a sweep with one-to-many scan registration that minimizes distances between nearby oriented surface points and mitigates outliers with a robust loss function. Extending our previous approach conservative filtering for efficient and accurate radar odometry (CFEAR), we present an in-depth investigation on a wider range of datasets, quantifying the importance of filtering, resolution, registration cost and loss functions, keyframe history, and motion compensation. We present a new solving strategy and configuration that overcomes previous issues with sparsity and bias, and improves our state-of-the-art by 38%, thus, surprisingly, outperforming radar simultaneous localization and mapping (SLAM) and approaching lidar SLAM. The most accurate configuration achieves 1.09% error at 5 Hz on the Oxford benchmark, and the fastest achieves 1.79% error at 160 Hz.

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    Lidar-level localization with radar? The CFEAR approach to accurate, fast and robust large-scale radar odometry in diverse environments
  • 5.
    Afanasyev, Ilya
    et al.
    Innopolis University, Innopolis, Russia.
    Kolotov, Alexander
    Innopolis University, Innopolis, Russia.
    Rezin, Ruslan
    Innopolis University, Innopolis, Russia.
    Danilov, Konstantin
    Innopolis University, Innopolis, Russia.
    Mazzara, Manuel
    Innopolis University, Innopolis, Russia.
    Chakraborty, Subham
    Innopolis University, Innopolis, Russia.
    Kashevnik, Alexey
    ITMO University, St.Petersburg, Russia.
    Chechulin, Andrey
    ITMO University, St.Petersburg, Russia.
    Kapitonov, Aleksandr
    ITMO University, St.Petersburg, Russia.
    Jotsov, Vladimir
    University of Library Studies and Information, Sofia, Bulgaria.
    Topalov, Andon
    Technical University of Sofia, Branch Plovdiv, Plovdiv, Bulgaria.
    Shakev, Nikola
    Technical University of Sofia, Branch Plovdiv, Plovdiv, Bulgaria.
    Ahmed, Sevil
    Technical University of Sofia, Branch Plovdiv, Plovdiv, Bulgaria.
    Towards Blockchain-based Multi-Agent Robotic Systems: Analysis, Classification and Applications2019Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Decentralization, immutability and transparency make of Blockchain one of the most innovative technology of recent years. This paper presents an overview of solutions based on Blockchain technology for multi-agent robotic systems, and provide an analysis and classification of this emerging field. The reasons for implementing Blockchain in a multi-robot network may be to increase the interaction efficiency between agents by providing more trusted information exchange, reaching a consensus in trustless conditions, assessing robot productivity or detecting performance problems, identifying intruders, allocating plans and tasks, deploying distributed solutions and joint missions. Blockchain-based applications are discussed to demonstrate how distributed ledger can be used to extend the number of research platforms and libraries for multi-agent robotic systems.

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    Towards Blockchain-based Multi-Agent Robotic Systems: Analysis, Classification and Applications
  • 6.
    Afanasyev, Ilya
    et al.
    Innopolis University, Innopolis, Russia.
    Mazzara, Manuel
    Innopolis University, Innopolis, Russia.
    Chakraborty, Subham
    Innopolis University, Innopolis, Russia.
    Zhuchkov, Nikita
    Innopolis University, Innopolis, Russia.
    Maksatbek, Aizhan
    Yildiz Technical University, Istanbul, Turkey.
    Kassab, Mohamad
    Pennsylvania State University, PA, United States.
    Distefano, Salvatore
    University of Messina, Messina, Italy.
    Towards the Internet of Robotic Things: Analysis, Architecture, Components and Challenges2019Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Internet of Things (IoT) and robotics cannot be considered two separate domains these days. Internet of Robotics Things (IoRT) is a concept that has been recently introduced to describe the integration of robotics technologies in IoT scenarios. As a consequence, these two research fields have started interacting, and thus linking research communities. In this paper we intend to make further steps in joining the two communities and broaden the discussion on the development of this interdisciplinary field. The paper provides an overview, analysis and challenges of possible solutions for the Internet of Robotic Things, discussing the issues of the IoRT architecture, the integration of smart spaces and robotic applications.

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    Towards the Internet of Robotic Things: Analysis, Architecture, Components and Challenges
  • 7.
    Afshar, Sara
    et al.
    Mälardalens högskola, Inbyggda system.
    Moghaddami Khalilzad, Nima
    Mälardalens högskola, Inbyggda system.
    Nemati, Farhang
    Mälardalens högskola, Inbyggda system.
    Nolte, Thomas
    Mälardalens högskola, Inbyggda system.
    Resource Sharing among Prioritized Real-Time Applications on Multiprocessors2015Ingår i: ACM SIGBED Review - Special Issue on the 6th International Workshop on Compositional Theory and Technology for Real-Time Embedded Systems Homepage archiveVolume 12 Issue 1, 2015, s. 46-55Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, we propose a new protocol for handling resource sharing among prioritized real-time applications composed on a multiprocessor platform. We propose an optimal priority assignment algorithm which assigns unique priorities to the applications based on information in their interfaces. We have performed experimental evaluations to compare the proposed protocol (called MSOS-Priority) to the current state of the art locking protocols under multiprocessor partitioned scheduling, i.e., MPCP, MSRP, FMLP, MSOS, and OMLP. The valuations show that MSOS-Priority mostly performs significantly better than alternative approaches.

  • 8.
    Ahmed, Mobyen Uddin
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Banaee, Hadi
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Loutfi, Amy
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Health monitoring for elderly: an application using case-based reasoning and cluster analysis2013Ingår i: ISRN Artificial Intelligence, ISSN 2090-7435, E-ISSN 2090-7443, Vol. 2013, nr 2013, s. 1-11Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents a framework to process and analyze data from a pulse oximeter which measures pulse rate and blood oxygen saturation from a set of individuals remotely. Using case-based reasoning (CBR) as the backbone to the framework, records are analyzed and categorized according to how well they are similar. Record collection has been performed using a personalized health profiling approach where participants wore a pulse oximeter sensor for a fixed period of time and performed specific activities for pre-determined intervals. Using a variety of feature extraction in time, frequency and time-frequency domains, and data processing techniques, the data is fed into a CBR system which retrieves most similar cases and generates alarm and flag according to the case outcomes. The system has been compared with an expert's classification and 90% match is achieved between the expert's and CBR classification. Again, considering the clustered measurements the CBR approach classifies 93% correctly both for the pulse rate and oxygen saturation. Along with the proposed methodology, this paper provides a basis for which the system can be used in analysis of continuous health monitoring and be used as a suitable method as in home/remote monitoring systems.

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  • 9.
    Ahmed, Mobyen Uddin
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Islam, Asif Moinul
    Örebro University, Örebro, Sweden.
    Loutfi, Amy
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    A case-based patient identification system using pulseoximeter and a personalized health profile2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper proposes a case-based system framework in order to identify patient using their health parameters taken with physiological sensors. It combines a personalized health profiling protocol with a Case-Based Reasoning (CBR) approach. The personalized health profiling helps to determine a number of individual parameters which are important inputs for a clinician to make the final diagnosis and treatment plan. The proposed system uses a pulse oximeter that measures pulse rate and blood oxygen saturation. The measurements are taken through an android application in a smart phone which is connected with the pulseoximeter and bluetooth communication. The CBR approach helps clinicians to make a diagnosis, classification and treatment plan by retrieving the most similar previous case. The case may also be used to follow the treatment progress. Here, the cases are formulated with person’s contextual information and extracted features from sensor signal measurements. The features are extracted considering three domain analysis:1) time domain features using statistical measurement, 2) frequency domain features applying Fast Fourier Transform (FFT), and 3) time-frequency domain features applying Discrete Wavelet Transform (DWT). The initial result is acceptable that shows the advancement of the system while combining the personalized health profiling together with CBR.

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  • 10.
    Ahmed, Muhammad Rehan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Compliance Control of Robot Manipulator for Safe Physical Human Robot Interaction2011Doktorsavhandling, monografi (Övrigt vetenskapligt)
    Abstract [en]

    Inspiration from biological systems suggests that robots should demonstrate same level of capabilities that are embedded in biological systems in performing safe and successful interaction with the humans. The major challenge in physical human robot interaction tasks in anthropic environment is the safe sharing of robot work space such that robot will not cause harm or injury to the human under any operating condition.

    Embedding human like adaptable compliance characteristics into robot manipulators can provide safe physical human robot interaction in constrained motion tasks. In robotics, this property can be achieved by using active, passive and semi active compliant actuation devices. Traditional methods of active and passive compliance lead to complex control systems and complex mechanical design.

    In this thesis we present compliant robot manipulator system with semi active compliant device having magneto rheological fluid based actuation mechanism. Human like adaptable compliance is achieved by controlling the properties of the magneto rheological fluid inside joint actuator. This method offers high operational accuracy, intrinsic safety and high absorption to impacts. Safety is assured by mechanism design rather than by conventional approach based on advance control. Control schemes for implementing adaptable compliance are implemented in parallel with the robot motion control that brings much simple interaction control strategy compared to other methods.

    Here we address two main issues: human robot collision safety and robot motion performance.We present existing human robot collision safety standards and evaluate the proposed actuation mechanism on the basis of static and dynamic collision tests. Static collision safety analysis is based on Yamada’s safety criterion and the adaptable compliance control scheme keeps the robot in the safe region of operation. For the dynamic collision safety analysis, Yamada’s impact force criterion and head injury criterion are employed. Experimental results validate the effectiveness of our solution. In addition, the results with head injury criterion showed the need to investigate human bio-mechanics in more details in order to acquire adequate knowledge for estimating the injury severity index for robots interacting with humans.

    We analyzed the robot motion performance in several physical human robot interaction tasks. Three interaction scenarios are studied to simulate human robot physical contact in direct and inadvertent contact situations. Respective control disciplines for the joint actuators are designed and implemented with much simplified adaptable compliance control scheme.

    The series of experimental tests in direct and inadvertent contact situations validate our solution of implementing human like adaptable compliance during robot motion and prove the safe interaction with humans in anthropic domains.

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  • 11.
    Ahmed, Muhammad Rehan
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Kalaykov, Ivan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Semi-active compliant robot enabling collision safety for human robot interaction2010Ingår i: 2010 International Conference on Mechatronics and Automation (ICMA), IEEE, 2010, s. 1932-1937Konferensbidrag (Refereegranskat)
    Abstract [en]

    Human robot interaction (HRI) tasks requires robots to have safe sharing of work space and to demonstrate adaptable compliant behavior enabling eminent collision safety as well as maintaining high position accuracy. Robot compliance control normally can be achieved by using active compliance control of actuators based on various sensor data. Alternatively, passive devices allow controllable compliance motion but usually are mechanically complex. We proposed a unique method using semi-active compliant actuation mechanism having magneto-rheological (MR) fluid based actuator that introduces reconfigurable compliance characteristics into the robot joints. This enables high intrinsic safety coming from fluid mechanics as well as, it offers simpler interaction control strategy compared to other concurrent approaches. In this studies, we have described three essential modes of motions required for physical human system interaction. Furthermore, we have demonstrated robot collision safety in terms of static collision and experimentally validates the performance of robot manipulator enabling safe human robot interaction.

  • 12.
    Ahmed, Muhammad Rehan
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Kalaykov, Ivan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Static and dynamic collisionsafety for human robot interaction using magneto-rheological fluid based compliant robot manipulator2010Ingår i: IEEE international conference on robotics and biomimetics (ROBIO), 2010, IEEE conference proceedings, 2010, s. 370-375Konferensbidrag (Refereegranskat)
    Abstract [en]

    The success of human robot interaction (HRI) tasks is characterized by evaluating robot performance in terms of collision safety and position accuracy. Hence, both position accuracy and collision safety are equally indispensable. HRI refers to cognitive as well as physical interaction. Cognitive human robot interaction based on perception and awareness where as physical human robot interaction demands direct contact with the humans exhibiting adaptable compliant behavior. Therefore, development of ideal safe robot manipulator having adaptable compliant actuation is inevitable. Adaptable compliance can be achieved by using active compliant actuation requiring various sensor data or by using passive compliant devices with high mechanical complexity. We present magneto rheological fluid based compliant actuation mechanism introducing adaptable compliance directly into robotic joint with much simpler interaction control and higher intrinsic safety originating from fluid mechanics. In this study, we have discussed adaptable compliance in terms of essential modes of motion for safe physical HRI and evaluated the safety performance of our robot for static collision testing and dynamic collision testing based on impact force and head injury criterion. Finally, the experimental results validate the significance of our proposed method for both human robot collision safety and high position accuracy.

  • 13.
    Ahmed, Muhammad Rehan
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Kalaykov, Ivan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Static collision analysis of semi active compliant robot for safe human robot interaction2010Ingår i: Proceedings of the 12th Mechatronics Forum Biennial International Conference, IWF Institute of Machine tools and manufacturing , 2010, s. 220-227Konferensbidrag (Refereegranskat)
  • 14.
    Ahmed, Muhammad Rehan
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Kalaykov, Ivan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Two link compliant robot manipulator for physical human robot collision safety2012Ingår i: Biomedical Engineering Systems and Technologies / [ed] Ana Fred, Joaquim Filipe, Hugo Gamboa, Springer, 2012Konferensbidrag (Refereegranskat)
  • 15.
    Ahmed, Rehan M.
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Ananiev, Anani V.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Kalaykov, Ivan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Compliant motion control for safe human robot interaction2009Ingår i: Robot motion and control 2009 / [ed] Krzysztof R. Kozłowski, Berlin: Springer , 2009, s. 265-274Konferensbidrag (Refereegranskat)
    Abstract [en]

    Robots have recently been foreseen to work side by side and share workspace with humans in assisting them in tasks that include physical human-robot (HR) interaction. The physical contact with human tasks under uncertainty has to be performed in a stable and safe manner [6]. However, current industrial robot manipulators are still very far from HR coexisting environments, because of their unreliable safety, rigidity and heavy structure. Besides this, the industrial norms separate the two spaces occupied by a human and a robot by means of physical fence or wall [9]. Therefore, the success of such physical HR interaction is possible if the robot is enabled to handle this interaction in a smart way to prevent injuries and damages.

  • 16.
    Ahmed, Rehan M.
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Ananiev, Anani V.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Kalaykov, Ivan G.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Safe robot with reconfigurable compliance/stiffness actuation2009Ingår i: Proceedings of ASME/IFToMM International Conference on Reconfigurable Mechanisms and Robots. ReMAR'2009 / [ed] J. S. Dai, M. Zoppi, X. W. Kong, IEEE, 2009, s. 633-638Konferensbidrag (Refereegranskat)
    Abstract [en]

    Human robot interaction (HRI) in constrained motion tasks requires robots to have safe sharing of work space and to demonstrate adaptable compliant behavior Compliance control of industrial robots, normally can be achieved by using active compliance control of actuators based on various sensor data. Alternatively, passive devices allow controllable compliance motion but usually are mechanically complex. We present a unique method using a novel actuation mechanism based on magneto-rheological fluid (MRF) that incorporates reconfigurable compliance directly into the robot joints. This brings much simple interaction control strategy compared to other antagonistic methods. In this studies, we have described three essential modes of motions required for physical human system interaction. Then we have discussed their respective control disciplines. Finally, we have presented functional performance of reconfigurable MRF actuation mechanism in constrained motion tasks by simulating various HRI scenarios.

  • 17.
    Ahmed, Rehan M.
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Kalaykov, Ivan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Ananiev, Anani
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Modeling of magneto rheological fluid actuator enabling safe human-robot interaction2008Ingår i: IEEE International Conference on Emerging Technologies and Factory Automation, 2008. ETFA 2008, 2008, s. 974-979Konferensbidrag (Refereegranskat)
    Abstract [en]

    Impedance control and compliant behavior for safe human-robot physical interaction of industrial robots normally can be achieved by using active compliance control of actuators based on various sensor data. Alternatively, passive devices allow controllable compliance motion but usually are mechanically complex. We present another approach using a novel actuation mechanism based on magneto-rheological fluid (MRF) that incorporates variable stiffness directly into the joints. In this paper, we have investigated and analyzed principle characteristics of MRF actuation mechanism and presented the analytical-model. Then we have developed the static and dynamic model based on experimental test results and have discussed three essential modes of motion needed for human-robot manipulation interactive tasks.

  • 18.
    Akalin, Neziha
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Kiselev, Andrey
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Kristoffersson, Annica
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Loutfi, Amy
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    An Evaluation Tool of the Effect of Robots in Eldercare on the Sense of Safety and Security2017Ingår i: Social Robotics: 9th International Conference, ICSR 2017, Tsukuba, Japan, November 22-24, 2017, Proceedings / [ed] Kheddar, A.; Yoshida, E.; Ge, S.S.; Suzuki, K.; Cabibihan, J-J:, Eyssel, F:, He, H., Springer International Publishing , 2017, s. 628-637Konferensbidrag (Refereegranskat)
    Abstract [en]

    The aim of the study presented in this paper is to develop a quantitative evaluation tool of the sense of safety and security for robots in eldercare. By investigating the literature on measurement of safety and security in human-robot interaction, we propose new evaluation tools. These tools are semantic differential scale questionnaires. In experimental validation, we used the Pepper robot, programmed in the way to exhibit social behaviors, and constructed four experimental conditions varying the degree of the robot’s non-verbal behaviors from no gestures at all to full head and hand movements. The experimental results suggest that both questionnaires (for the sense of safety and the sense of security) have good internal consistency.

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    An Evaluation Tool of the Effect of Robots in Eldercare on the Sense of Safety and Security
  • 19.
    Akalin, Neziha
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Kiselev, Andrey
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Kristoffersson, Annica
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Loutfi, Amy
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Enhancing Social Human-Robot Interaction with Deep Reinforcement Learning.2018Ingår i: Proc. FAIM/ISCA Workshop on Artificial Intelligence for Multimodal Human Robot Interaction, 2018, MHRI , 2018, s. 48-50Konferensbidrag (Refereegranskat)
    Abstract [en]

    This research aims to develop an autonomous social robot for elderly individuals. The robot will learn from the interaction and change its behaviors in order to enhance the interaction and improve the user experience. For this purpose, we aim to use Deep Reinforcement Learning. The robot will observe the user’s verbal and nonverbal social cues by using its camera and microphone, the reward will be positive valence and engagement of the user.

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    Enhancing Social Human-Robot Interaction with Deep Reinforcement Learning
  • 20.
    Akalin, Neziha
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Kiselev, Andrey
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Kristoffersson, Annica
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Loutfi, Amy
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    The Relevance of Social Cues in Assistive Training with a Social Robot2018Ingår i: 10th International Conference on Social Robotics, ICSR 2018, Proceedings / [ed] Ge, S.S., Cabibihan, J.-J., Salichs, M.A., Broadbent, E., He, H., Wagner, A., Castro-González, Á., Springer, 2018, s. 462-471Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper examines whether social cues, such as facial expressions, can be used to adapt and tailor a robot-assisted training in order to maximize performance and comfort. Specifically, this paper serves as a basis in determining whether key facial signals, including emotions and facial actions, are common among participants during a physical and cognitive training scenario. In the experiment, participants performed basic arm exercises with a social robot as a guide. We extracted facial features from video recordings of participants and applied a recursive feature elimination algorithm to select a subset of discriminating facial features. These features are correlated with the performance of the user and the level of difficulty of the exercises. The long-term aim of this work, building upon the work presented here, is to develop an algorithm that can eventually be used in robot-assisted training to allow a robot to tailor a training program based on the physical capabilities as well as the social cues of the users.

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    The Relevance of Social Cues in Assistive Training with a Social Robot
  • 21.
    Akalin, Neziha
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Kristoffersson, Annica
    School of Innovation, Design and Engineering, Mälardalen University, Västerås, Sweden.
    Loutfi, Amy
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Do you feel safe with your robot? Factors influencing perceived safety in human-robot interaction based on subjective and objective measures2022Ingår i: International journal of human-computer studies, ISSN 1071-5819, E-ISSN 1095-9300, Vol. 158, artikel-id 102744Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Safety in human-robot interaction can be divided into physical safety and perceived safety, where the later is still under-addressed in the literature. Investigating perceived safety in human-robot interaction requires a multidisciplinary perspective. Indeed, perceived safety is often considered as being associated with several common factors studied in other disciplines, i.e., comfort, predictability, sense of control, and trust. In this paper, we investigated the relationship between these factors and perceived safety in human-robot interaction using subjective and objective measures. We conducted a two-by-five mixed-subjects design experiment. There were two between-subjects conditions: the faulty robot was experienced at the beginning or the end of the interaction. The five within-subjects conditions correspond to (1) baseline, and the manipulations of robot behaviors to stimulate: (2) discomfort, (3) decreased perceived safety, (4) decreased sense of control and (5) distrust. The idea of triggering a deprivation of these factors was motivated by the definition of safety in the literature where safety is often defined by the absence of it. Twenty-seven young adult participants took part in the experiments. Participants were asked to answer questionnaires that measure the manipulated factors after within-subjects conditions. Besides questionnaire data, we collected objective measures such as videos and physiological data. The questionnaire results show a correlation between comfort, sense of control, trust, and perceived safety. Since these factors are the main factors that influence perceived safety, they should be considered in human-robot interaction design decisions. We also discuss the effect of individual human characteristics (such as personality and gender) that they could be predictors of perceived safety. We used the physiological signal data and facial affect from videos for estimating perceived safety where participants’ subjective ratings were utilized as labels. The data from objective measures revealed that the prediction rate was higher from physiological signal data. This paper can play an important role in the goal of better understanding perceived safety in human-robot interaction.

  • 22.
    Akalin, Neziha
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Loutfi, Amy
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Reinforcement Learning Approaches in Social Robotics2021Ingår i: Sensors, E-ISSN 1424-8220, Vol. 21, nr 4, artikel-id 1292Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    This article surveys reinforcement learning approaches in social robotics. Reinforcement learning is a framework for decision-making problems in which an agent interacts through trial-and-error with its environment to discover an optimal behavior. Since interaction is a key component in both reinforcement learning and social robotics, it can be a well-suited approach for real-world interactions with physically embodied social robots. The scope of the paper is focused particularly on studies that include social physical robots and real-world human-robot interactions with users. We present a thorough analysis of reinforcement learning approaches in social robotics. In addition to a survey, we categorize existent reinforcement learning approaches based on the used method and the design of the reward mechanisms. Moreover, since communication capability is a prominent feature of social robots, we discuss and group the papers based on the communication medium used for reward formulation. Considering the importance of designing the reward function, we also provide a categorization of the papers based on the nature of the reward. This categorization includes three major themes: interactive reinforcement learning, intrinsically motivated methods, and task performance-driven methods. The benefits and challenges of reinforcement learning in social robotics, evaluation methods of the papers regarding whether or not they use subjective and algorithmic measures, a discussion in the view of real-world reinforcement learning challenges and proposed solutions, the points that remain to be explored, including the approaches that have thus far received less attention is also given in the paper. Thus, this paper aims to become a starting point for researchers interested in using and applying reinforcement learning methods in this particular research field.

  • 23.
    Albitar, Houssam
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Enabling a Robot for Underwater Surface Cleaning2017Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Biofouling build-up on submerged structures such as ships, petroleum and gas storage tanks, electric power plants, bridges, oil rigs etc. is a major problem that affects the surface material of the structure, the eventual hydrodynamic quality of the surface and in some cases the efficacy of cooling systems. Underwater cleaning is a solution to maintain submerged structures in order to assure proper functioning for as long as possible. Consequently, there has been an increased interest in the development of new technologies for robotised underwater cleaning systems.

    This thesis presents a new concept of a flexible crawling mechanism for an industrial underwater cleaning robot, which is evaluated from the viewpoint of its capability to work underwater, scanning the desired surface, and perform a cleaning task. The main research questions investigated in this thesis are: (1.) how to select the most important features in choosing the platform mechanism to fulfil the surface scanning operation, (2.) how to design the platform in order to bear the forces related to the cleaning task, (3.) how to maintain surface contact throughout cleaning, (4.) determine the significant parameters to be monitored in order to ensure stable positioning on the surface during the cleaning process and (5.) how to develop the control of actuators to realise the locomotion and to follow the desired trajectory.

    This thesis begins with a classification and discussion of the available solutions for underwater operation, taking into consideration the benefits and drawbacks, overall efficiency and environmental and human safety issues. From this survey, an underwater mobile robotic platform is designed to address the main requirements and industrial needs. Further, a study and simulation of its mobility and stability on the surface is performed and a complete scenario of the entire cleaning operation is presented. In addition, an overview of the required sensors and the control system is given. Finally, a new robotised system was developed to clean underwater surfaces with minimum active degrees of freedom. A successful simulation and real experimental results were obtained with a simplified lab-scale prototype. The thesis concludes with a summary of future works and outlook for the growing field of underwater cleaning robots.

    Delarbeten
    1. Underwater Robotics: Surface Cleaning Technics, Adhesion and Locomotion Systems
    Öppna denna publikation i ny flik eller fönster >>Underwater Robotics: Surface Cleaning Technics, Adhesion and Locomotion Systems
    2016 (Engelska)Ingår i: International Journal of Advanced Robotic Systems, ISSN 1729-8806, E-ISSN 1729-8814, Vol. 13, artikel-id 7Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Underwater robots are being developed for various applications ranging from inspection to maintenance and cleaning of submerged surfaces and constructions. These platforms should be able to travel on these surfaces. Furthermore, these platforms should adapt and reconfigure for underwater environment conditions and should be autonomous. Regarding the adhesion to the surface, they should produce a proper attaching force using a light-weight technics. Taking these facts into consideration, this paper presents a survey of different technologies used for underwater cleaning and the available underwater robotics solutions for the locomotion and the adhesion to surfaces.

    Ort, förlag, år, upplaga, sidor
    INTECH, 2016
    Nyckelord
    Underwater Robot, Underwater Cleaning, Bio-fouling, Adhesion, Locomotion
    Nationell ämneskategori
    Datavetenskap (datalogi)
    Forskningsämne
    Datavetenskap
    Identifikatorer
    urn:nbn:se:oru:diva-47813 (URN)10.5772/62060 (DOI)000368630700001 ()2-s2.0-85002271299 (Scopus ID)
    Tillgänglig från: 2016-01-28 Skapad: 2016-01-28 Senast uppdaterad: 2018-01-10Bibliografiskt granskad
    2. New concept of in-water surface cleaning robot
    Öppna denna publikation i ny flik eller fönster >>New concept of in-water surface cleaning robot
    2013 (Engelska)Ingår i: Mechatronics and Automation (ICMA), 2013 IEEE International Conference onDate 4-7 Aug. 2013, IEEE conference proceedings, 2013, s. 1582-1587Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    This paper introduces a new concept of flexible crawling mechanism to design an industrial underwater cleaning robot, which is evaluated from the viewpoint of the capability to work underwater, scanning the desired surface, and bearing the reactions. This can be used as a robotic application in underwater surface cleaning and maintenance. We designed a robot that realizes the motion by contraction and extraction using DC-motors and vacuum technology. In this study we first focused on realizing the adhesion, bearing reactions, and achieving a stable locomotion on the surface.

    Ort, förlag, år, upplaga, sidor
    IEEE conference proceedings, 2013
    Nyckelord
    climbing robot; inspection
    Nationell ämneskategori
    Datavetenskap (datalogi)
    Forskningsämne
    Datavetenskap
    Identifikatorer
    urn:nbn:se:oru:diva-30340 (URN)10.1109/ICMA.2013.6618150 (DOI)000335375900267 ()2-s2.0-84887901379 (Scopus ID)978-1-4673-5557-5 (ISBN)
    Konferens
    2013 IEEE International Conference on Mechatronics and Automation (ICMA), 4-7 aug. 2013, Takamatsu, Japan
    Tillgänglig från: 2013-08-27 Skapad: 2013-08-27 Senast uppdaterad: 2018-01-11Bibliografiskt granskad
    3. In-water surface cleaning robot: concept, locomotion and stability
    Öppna denna publikation i ny flik eller fönster >>In-water surface cleaning robot: concept, locomotion and stability
    2014 (Engelska)Ingår i: International Journal of Mechatronics and Automation, ISSN 2045-1067, Vol. 4, nr 2, s. 104-115Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    This paper introduces a new concept of flexible crawling mechanism in the design ofindustrial in-water cleaning robot, which is evaluated from the viewpoint of work and operationon an underwater surface. It enables the scanning and cleaning process performed by water jets,while keeping stable robot position on the surface by its capacity to bear and compensate the jetreactions. Such robotic platform can be used for cleaning and maintenance of various underwatersurfaces, including moving ships in the open sea. The designed robot implements its motions bycontraction and expansion of legged mechanism using standard motors and suction cupstechnology. In this study we focus at the conditions for achieving enough adhesion for keepingcontinuous contact between the robot and the surface and robot stability in different situations forthe basic locomotions.

    Ort, förlag, år, upplaga, sidor
    IEEE, 2014
    Nyckelord
    underwater robot, crawling robot, underwater surface cleaning
    Nationell ämneskategori
    Datavetenskap (datalogi)
    Identifikatorer
    urn:nbn:se:oru:diva-35987 (URN)10.1504/IJMA.2014.062338 (DOI)2-s2.0-84904859302 (Scopus ID)
    Tillgänglig från: 2014-08-19 Skapad: 2014-08-19 Senast uppdaterad: 2019-08-30Bibliografiskt granskad
    4. Stability study of underwater crawling robot on non-horizontal surface
    Öppna denna publikation i ny flik eller fönster >>Stability study of underwater crawling robot on non-horizontal surface
    2014 (Engelska)Ingår i: Mobile Service Robotics: Clawar 2014: 17th International Conference on Climbing and Walking Robots and the Support Technologies for Mobile Machines: Poznan, Poland 21 - 23 July 2014, Singapore: World Scientific, 2014, s. 511-519Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    This paper introduces a study of a concept of exible crawling mechanism todesign an industrial underwater cleaning robot, which is evaluated from theviewpoint of the capability to work underwater, scanning the desired surface,and bearing the reactions. This can be used as a robotic application in under-water surface cleaning and maintenance. In this study we focused on realizingthe adhesion on the surface in stationary and in motion, bearing reactions,enabling the needed locomotion types for scanning, and achieving the stabilityin dierent situations on the surface.

    Ort, förlag, år, upplaga, sidor
    Singapore: World Scientific, 2014
    Nyckelord
    Crawling robot, underwater, locomotion, stability
    Nationell ämneskategori
    Datavetenskap (datalogi)
    Identifikatorer
    urn:nbn:se:oru:diva-35985 (URN)000342693100061 ()2-s2.0-85007347787 (Scopus ID)978-981-4623-34-6 (ISBN)
    Konferens
    Clawar 2014: 17th International Conference on Climbing and Walking Robots CLAWAR, Poznan, Poland, 21 - 23 July, 2014
    Tillgänglig från: 2014-08-19 Skapad: 2014-08-19 Senast uppdaterad: 2018-01-11Bibliografiskt granskad
    5. Layered mission control architecture and strategy for crawling underwater cleaning robot
    Öppna denna publikation i ny flik eller fönster >>Layered mission control architecture and strategy for crawling underwater cleaning robot
    2015 (Engelska)Ingår i: International Journal of Mechatronics and Automation, ISSN 2045-1059, Vol. 5, nr 2/3, s. 114-124Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    This paper presents the mechanical design and the control system architecture of anunderwater robot, developed for bio-fouling cleaning surfaces. The robotic system presented herehas been designed to improve the productivity, reduce the environmental impacts, and excludethe hazards for the operators. The control system has a layered structure which is distributed intotwo blocks: cleaning robot, and on-board base station connected with power and control cablesand a water hose, to facilitate different modes of operations and to increase the system reliability.A low level control has been implemented on the robotic platform. The onboard station designedto be in different layers of the control system: manual, semiautonomous and autonomous modes.A scaled prototype has been implemented and tested to prove the concept, and to make certainthat the mechanical design and the chosen control system are perfectly suited to the mainfunctions of the robotic system.

    Ort, förlag, år, upplaga, sidor
    InderScience Publishers, 2015
    Nyckelord
    underwater robots, layered control system, crawling robots, bio-fouling cleaning
    Nationell ämneskategori
    Datavetenskap (datalogi)
    Forskningsämne
    Datavetenskap
    Identifikatorer
    urn:nbn:se:oru:diva-49753 (URN)10.1504/IJMA.2015.075957 (DOI)2-s2.0-84973596360 (Scopus ID)
    Tillgänglig från: 2016-04-11 Skapad: 2016-04-11 Senast uppdaterad: 2018-01-10Bibliografiskt granskad
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    Cover
  • 24.
    Alhashimi, Anas
    University of Baghdad, Baghdad, Iraq.
    Design and implementation of fast three stages SLA battery charger for PLC systems2011Ingår i: Journal of Engineering, ISSN 1726-4073, Vol. 17, nr 3, s. 448-465Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    New fast sealed lead acid (SLA) battery chargers must be able to charge the fully discharged batteries in a short time. In the same time, the charger must monitor the battery state of health in order to prevent over charge and to extend the battery life time.

    In this paper a Fast charger was presented to charge SLA batteries in short time and monitor the battery voltage to prevent over charge. The design was implemented practically. And 150 charger of similar type was produced for commercial use. They are now in service in different Mobile base station sites around Baghdad. It can charge a fully discharged 12V, 4.5Ah battery in less than 5 hours. To supply PLC control system on DC power to about 24 hour of continuous operation during main electricity faults.

    During one and half year of continuous operation three faults have been recorded in the 150 chargers. All of the three cases were because of bad components manufacturing.

    Ladda ner fulltext (pdf)
    Design and implementation of fast three stages SLA battery charger for PLC systems
  • 25.
    Alhashimi, Anas
    University of Baghdad, Baghdad, Iraq.
    The application of auto regressive spectrum modeling for identification of the intercepted radar signal frequency modulation2012Ingår i: Inventi Impact - Telecom, ISSN 2249-1414, Vol. 2012, nr 3Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In the Electronic Warfare receivers, it is important to know the type of modulation of the intercepted Radar signals (MOP modulation on pulse). This information can be very helpful in identifying the type of Radar present and to take the appropriate actions against it. In this paper, a new signal processing method is presented to identify the FM (Frequency Modulation) pattern from the received Radar pulses. The proposed processing method based on Auto Regressive Spectrum Modelling used for digital modulation classification [1]. This model uses the instantaneous frequency and instantaneous bandwidth as obtained from the roots of the autoregressive polynomial. The instantaneous frequency and instantaneous bandwidth together were used to identify the type of modulation in the Radar pulse. Another feature derived from the instantaneous frequency is the frequency rate of change. The frequency rate of change was used to extract the pattern of the frequency change. Results show that this method works properly even for low signal to noise ratios.

  • 26.
    Alhashimi, Anas
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik. Luleå University of Technology, Luleå, Sweden.
    Del Favero, Simone
    Varagnolo, Damiano
    Luleå University of Technology, Luleå, Sweden.
    Gustafsson, Thomas
    Luleå University of Technology, Luleå, Sweden.
    Pillonetto, Gianluigi
    Bayesian strategies for calibrating heteroskedastic static sensors with unknown model structures2018Ingår i: 2018 European Control Conference (ECC), IEEE, 2018, s. 2447-2453Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper investigates the problem of calibrating sensors affected by (i) heteroskedastic measurement noise and (ii) a polynomial bias, describing a systematic distortion of the measured quantity. First, a set of increasingly complex statistical models for the measurement process was proposed. Then, for each model the authors design a Bayesian parameters estimation method handling heteroskedasticity and capable to exploit prior information about the model parameters. The Bayesian problem is solved using MCMC methods and reconstructing the unknown parameters posterior in sampled form. The authors then test the proposed techniques on a practically relevant case study, the calibration of Light Detection and Ranging (Lidar) sensor, and evaluate the different proposed procedures using both artificial and field data.

  • 27.
    Alhashimi, Anas
    et al.
    Automatic Control Group at Computer Science, Electrical and Space Engineering, Luleå, University of Technology, Luleå, Sweden.
    Hostettler, Roland
    Automatic Control Group at Computer Science, Electrical and Space Engineering, Luleå, University of Technology, Luleå, Sweden.
    Gustafsson, Thomas
    Automatic Control Group at Computer Science, Electrical and Space Engineering, Luleå, University of Technology, Luleå, Sweden.
    An Improvement in the Observation Model for Monte Carlo Localization2014Ingår i: Proceedings of the 11th International Conference on Informatics in Control, Automation and Robotics - Volume 1: ICINCO / [ed] Joaquim Filipe, Oleg Gusikhin, Kurosh Madani and Jurek Sasiadek, SciTePress , 2014, s. 498-505Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    Accurate and robust mobile robot localization is very important in many robot applications. Monte Carlo localization (MCL) is one of the robust probabilistic solutions to robot localization problems. The sensor model used in MCL directly influence the accuracy and robustness of the pose estimation process. The classical beam models assumes independent noise in each individual measurement beam at the same scan. In practice, the noise in adjacent beams maybe largely correlated. This will result in peaks in the likelihood measurement function. These peaks leads to incorrect particles distribution in the MCL. In this research, an adaptive sub-sampling of the measurements is proposed to reduce the peaks in the likelihood function. The sampling is based on the complete scan analysis. The specified measurement is accepted or not based on the relative distance to other points in the 2D point cloud. The proposed technique has been implemented in ROS and stage simulator. The result shows that selecting suitable value of distance between accepted scans can improve the localization error and reduce the required computations effectively.

    Ladda ner fulltext (pdf)
    An Improvement in the Observation Model for Monte Carlo Localization
  • 28.
    Alhashimi, Anas
    et al.
    Control Engineering Group, Department of Computer Science, Electrical and Space Engineering, Luleå University of Technology, Luleå, Sweden; Department of Computer Engineering, University of Baghdad, Baghdad, Iraq.
    Pierobon, Giovanni
    Department of Information Engineering, University of Padova, Padova, Italy.
    Varagnolo, Damiano
    Control Engineering Group, Department of Computer Science, Electrical and Space Engineering, Luleå University of Technology, Luleå, Sweden.
    Gustafsson, Thomas
    Control Engineering Group, Department of Computer Science, Electrical and Space Engineering, Luleå University of Technology, Luleå, Sweden.
    Modeling and Calibrating Triangulation Lidars for Indoor Applications2018Ingår i: Informatics in Control, Automation and Robotics: 13th International Conference, ICINCO 2016 Lisbon, Portugal, 29-31 July, 2016 / [ed] Kurosh Madani, Dimitri Peaucelle, Oleg Gusikhin, Springer, 2018, s. 342-366Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    We present an improved statistical model of the measurement process of triangulation Light Detection and Rangings (Lidars) that takes into account bias and variance effects coming from two different sources of uncertainty: (i) mechanical imperfections on the geometry and properties of their pinhole lens - CCD camera systems, and (ii) inaccuracies in the measurement of the angular displacement of the sensor due to non ideal measurements from the internal encoder of the sensor. This model extends thus the one presented in [2] by adding this second source of errors. Besides proposing the statistical model, this chapter considers: (i) specialized and dedicated model calibration algorithms that exploit Maximum Likelihood (ML)/Akaike Information Criterion (AIC) concepts and that use training datasets collected in a controlled setup, and (ii) tailored statistical strategies that use the calibration results to statistically process the raw sensor measurements in non controlled but structured environments where there is a high chance for the sensor to be detecting objects with flat surfaces (e.g., walls). These newly proposed algorithms are thus specially designed and optimized for inferring precisely the angular orientation of the Lidar sensor with respect to the detected object, a feature that is beneficial especially for indoor navigation purposes.

  • 29.
    Alhashimi, Anas
    et al.
    Luleå University of Technology, Luleå, Sweden.
    Varagnolo, Damiano
    Luleå University of Technology, Luleå, Sweden.
    Gustafsson, Thomas
    Luleå University of Technology, Luleå, Swede.
    Calibrating distance sensors for terrestrial applications without groundtruth information2017Ingår i: IEEE Sensors Journal, ISSN 1530-437X, E-ISSN 1558-1748, Vol. 17, nr 12, s. 3698-3709Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper describes a new calibration procedure for distance sensors that does not require independent sources of groundtruth information, i.e., that is not based on comparing the measurements from the uncalibrated sensor against measurements from a precise device assumed as the groundtruth. Alternatively, the procedure assumes that the uncalibrated distance sensor moves in space on a straight line in an environment with fixed targets, so that the intrinsic parameters of the statistical model of the sensor readings are calibrated without requiring tests in controlled environments, but rather in environments where the sensor follows linear movement and objects do not move. The proposed calibration procedure exploits an approximated expectation maximization scheme on top of two ingredients: an heteroscedastic statistical model describing the measurement process, and a simplified dynamical model describing the linear sensor movement. The procedure is designed to be capable of not just estimating the parameters of one generic distance sensor, but rather integrating the most common sensors in robotic applications, such as Lidars, odometers, and sonar rangers and learn the intrinsic parameters of all these sensors simultaneously. Tests in a controlled environment led to a reduction of the mean squared error of the measurements returned by a commercial triangulation Lidar by a factor between 3 and 6, comparable to the efficiency of other state-of-the art groundtruth-based calibration procedures. Adding odometric and ultrasonic information further improved the performance index of the overall distance estimation strategy by a factor of up to 1.2. Tests also show high robustness against violating the linear movements assumption.

  • 30.
    Alhashimi, Anas
    et al.
    Luleå University of Technology, Luleå, Sweden.
    Varagnolo, Damiano
    Luleå University of Technology, Luleå, Sweden.
    Gustafsson, Thomas
    Luleå University of Technology, Luleå, Sweden.
    Joint Temperature-Lasing Mode Compensation for Time-of-Flight LiDAR Sensors2015Ingår i: Sensors, E-ISSN 1424-8220, Vol. 15, nr 12, s. 31205-31223Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We propose an expectation maximization (EM) strategy for improving the precision of time of flight (ToF) light detection and ranging (LiDAR) scanners. The novel algorithm statistically accounts not only for the bias induced by temperature changes in the laser diode, but also for the multi-modality of the measurement noises that is induced by mode-hopping effects. Instrumental to the proposed EM algorithm, we also describe a general thermal dynamics model that can be learned either from just input-output data or from a combination of simple temperature experiments and information from the laser’s datasheet. We test the strategy on a SICK LMS 200 device and improve its average absolute error by a factor of three.

  • 31.
    Alhashimi, Anas
    et al.
    Luleå University of Technology, Luleå, Sweden.
    Varagnolo, Damiano
    Luleå University of Technology, Luleå, Sweden.
    Gustafsson, Thomas
    Luleå University of Technology, Luleå, Sweden.
    Statistical modeling and calibration of triangulation Lidars2016Ingår i: ICINCO 2016: Proceedings of the 13th International Conference on Informatics in Control, Automation and Robotics / [ed] Oleg Gusikhin; Dimitri Peaucelle; Kurosh Madani, SciTePress, 2016, Vol. 1, s. 308-317Konferensbidrag (Refereegranskat)
    Abstract [en]

    We aim at developing statistical tools that improve the accuracy and precision of the measurements returned by triangulation Light Detection and Rangings (Lidars). To this aim we: i) propose and validate a novel model that describes the statistics of the measurements of these Lidars, and that is built starting from mechanical considerations on the geometry and properties of their pinhole lens - CCD camera systems; ii) build, starting from this novel statistical model, a Maximum Likelihood (ML) / Akaike Information Criterion (AIC) -based sensor calibration algorithm that exploits training information collected in a controlled environment; iii) develop ML and Least Squares (LS) strategies that use the calibration results to statistically process the raw sensor measurements in non controlled environments. The overall technique allowed us to obtain empirical improvements of the normalized Mean Squared Error (MSE) from 0.0789 to 0.0046

  • 32.
    Alirezaie, Marjan
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Kiselev, Andrey
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Längkvist, Martin
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Klügl, Franziska
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Loutfi, Amy
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    An Ontology-Based Reasoning Framework for Querying Satellite Images for Disaster Monitoring2017Ingår i: Sensors, E-ISSN 1424-8220, Vol. 17, nr 11, artikel-id 2545Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents a framework in which satellite images are classified and augmented with additional semantic information to enable queries about what can be found on the map at a particular location, but also about paths that can be taken. This is achieved by a reasoning framework based on qualitative spatial reasoning that is able to find answers to high level queries that may vary on the current situation. This framework called SemCityMap, provides the full pipeline from enriching the raw image data with rudimentary labels to the integration of a knowledge representation and reasoning methods to user interfaces for high level querying. To illustrate the utility of SemCityMap in a disaster scenario, we use an urban environment—central Stockholm—in combination with a flood simulation. We show that the system provides useful answers to high-level queries also with respect to the current flood status. Examples of such queries concern path planning for vehicles or retrieval of safe regions such as “find all regions close to schools and far from the flooded area”. The particular advantage of our approach lies in the fact that ontological information and reasoning is explicitly integrated so that queries can be formulated in a natural way using concepts on appropriate level of abstraction, including additional constraints.

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    fulltext
  • 33.
    Alirezaie, Marjan
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Loutfi, Amy
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Automated reasoning using abduction for interpretation of medical signals2014Ingår i: Journal of Biomedical Semantics, E-ISSN 2041-1480, Vol. 5, artikel-id 35Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper proposes an approach to leverage upon existing ontologies in order to automate the annotation of time series medical data. The annotation is achieved by an abductive reasoner using parsimonious covering theorem in order to determine the best explanation or annotation for specific user defined events in the data. The novelty of this approach resides in part by the system’s flexibility in how events are defined by users and later detected by the system. This is achieved via the use of different ontologies which find relations between medical, lexical and numerical concepts. A second contribution resides in the application of an abductive reasoner which uses the online and existing ontologies to provide annotations. The proposed method is evaluated on datasets collected from ICU patients and the generated annotations are compared against those given by medical experts.

  • 34.
    Alirezaie, Marjan
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Loutfi, Amy
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Reasoning for Improved Sensor Data Interpretation in a Smart Home2014Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper an ontological representation and reasoning paradigm has been proposed for interpretation of time-series signals. The signals come from sensors observing a smart environment. The signal chosen for the annotation process is a set of unintuitive and complexgas sensor data. The ontology of this paradigm is inspired form the SSNontology (Semantic Sensor Network) and used for representation of both the sensor data and the contextual information. The interpretation process is mainly done by an incremental ASP solver which as input receivesa logic program that is generated from the contents of the ontology. The contextual information together with high level domain knowledge given in the ontology are used to infer explanations (answer sets) for changes in the ambient air detected by the gas sensors.

  • 35.
    Alirezaie, Marjan
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Loutfi, Amy
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Towards Automatic Ontology Alignment for Enriching Sensor Data Analysis2013Ingår i: Communications in Computer and Information Science, ISSN 1865-0929, E-ISSN 1865-0937, Vol. 415, s. 179-193Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this work ontology alignment is used to align an ontology comprising high level knowledge to a structure representing the results of low-level sensor data classification. To resolve inherent uncertainties from the data driven classifier, an ontology about application domain is aligned to the classifier output and the result is recommendation system able to suggest a course of action that will resolve the uncertainty. This work is instantiated in a medical application domain where signals from an electronic nose are classified into different bacteria types. In case of misclassifications resulting from the data driven classifier, the alignment to an ontology representing traditional microbiology tests suggests a subset of tests most relevant to use. The result is a hybrid classification system (electronic nose and traditional testing) that automatically exploits domain knowledge in the identification process.

  • 36.
    Alirezaie, Marjan
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Pecora, Federico
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Loutfi, Amy
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Context Recognition: Towards Automatic Query Generation2015Ingår i: Ambient Intelligence: 12th European Conference, AmI 2015, Athens, Greece, November 11-13, 2015, Proceedings, Springer, 2015, s. 205-218Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, we present an ontology-based approach in designing knowledge model for context recognition (CR) systems. The main focus in this paper is on the use of an ontology to facilitate the generation of user-based queries to the CR system. By leveraging from the ontology, users need not know about sensor details and the structure of the ontology in expressing queries related to events of interest. To validate the approach and demonstrate the flexibility of the ontology for query generation, the ontology has been integrated in two separate application domains. The first domain considers a health care system implemented for the GiraffPlus project where the query generation process is automated to request information about activities of daily living. The second application uses the same ontology for an air quality monitoring application in the home. Since these two systems are independently developed for different purposes, the ease of applying the ontology upon them can be considered as a credit for its generality.

  • 37.
    Alirezaie, Marjan
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Renoux, Jennifer
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Köckemann, Uwe
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Kristoffersson, Annica
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Karlsson, Lars
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Blomqvist, Eva
    RISE SICS East, Linköping, Sweden.
    Tsiftes, Nicolas
    RISE SICS, Stockholm, Sweden.
    Voigt, Thiemo
    RISE SICS, Stockholm, Sweden.
    Loutfi, Amy
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    An Ontology-based Context-aware System for Smart Homes: E-care@home2017Ingår i: Sensors, E-ISSN 1424-8220, Vol. 17, nr 7, artikel-id 1586Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Smart home environments have a significant potential to provide for long-term monitoring of users with special needs in order to promote the possibility to age at home. Such environments are typically equipped with a number of heterogeneous sensors that monitor both health and environmental parameters. This paper presents a framework called E-care@home, consisting of an IoT infrastructure, which provides information with an unambiguous, shared meaning across IoT devices, end-users, relatives, health and care professionals and organizations. We focus on integrating measurements gathered from heterogeneous sources by using ontologies in order to enable semantic interpretation of events and context awareness. Activities are deduced using an incremental answer set solver for stream reasoning. The paper demonstrates the proposed framework using an instantiation of a smart environment that is able to perform context recognition based on the activities and the events occurring in the home.

    Ladda ner fulltext (pdf)
    fulltext
  • 38.
    Amato, Giuseppe
    et al.
    ISTI-CNR, Pisa, Italy.
    Broxvall, Mathias
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Chessa, Stefano
    Università di Pisa, Pisa, Italy.
    Dragone, Mauro
    University College Dublin, Dublin, Ireland.
    Gennaro, Caludio
    ISTI-CNR, Pisa, Italy.
    Lopez, Rafa
    Robotnik Automation, Valencia, Spain.
    Maguire, Liam
    University of Ulster, Coleraine, Ireland.
    McGinnity, Martin T.
    University of Ulster, Coleraine, Ireland.
    Micheli, Alessio
    Università di Pisa, Pisa, Italy.
    Renteria, Arantxa
    Tecnalia, Derio, Spain.
    O’Hare, Gregory M. P.
    University College Dublin, Dublin, Ireland.
    Pecora, Federico
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Robotic UBIquitous COgnitive Network2012Ingår i: Ambient Intelligence: Software and Applications / [ed] Paulo Novais, Kasper Hallenborg, Dante I. Tapia, Juan M. Corchado Rodríguez, Springer-Verlag New York, 2012, s. 191-195Konferensbidrag (Refereegranskat)
    Abstract [en]

    Robotic ecologies are networks of heterogeneous robotic devices pervasively embedded in everyday environments, where they cooperate to perform complex tasks. While their potential makes them increasingly popular, one fundamental problem is how to make them self-adaptive, so as to reduce the amount of preparation, pre-programming and human supervision that they require in real world applications. The EU FP7 project RUBICON develops self-sustaining learning solutions yielding cheaper, adaptive and efficient coordination of robotic ecologies. The approach we pursue builds upon a unique combination of methods from cognitive robotics, agent control systems, wireless sensor networks and machine learning. This paper briefly illustrates how these techniques are being extended, integrated, and applied to AAL applications.

  • 39.
    Andersson, Birgitta
    et al.
    Örebro universitet, Institutionen för teknik.
    Stranneby, Dag
    Örebro universitet, Institutionen för teknik.
    ESD – elektrostatiska urladdningar: risker och skydd vid elektronikhantering2002Bok (Övrig (populärvetenskap, debatt, mm))
  • 40.
    Andersson, Birgitta
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Stranneby, Dag
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Long term charge retention on PWBs2005Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    A sample of printed wiring boards, isolated from ground, has been charged tribo-electrically and the charge decay process has been studied with focus on the long-term charge decay behaviour. It was found that the time constant 1/e did not say much about the proceeding decay process. Instead a second-order approximation model for the measured decay curves has been suggested.

  • 41.
    Andersson, Birgitta
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Stranneby, Dag
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Long term charge retention on PWBs2005Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    A sample of printed wiring boards, isolated from ground, has been charged tribo-electrically and the charge decay process has been studied with focus on the long-term charge decay behaviour. It was found that the time constant 1/e did not say much about the proceeding decay process. Instead a second-order approximation model for the measured decay curves has been suggested.

  • 42.
    Andersson, Birgitta
    et al.
    Örebro universitet, Institutionen för teknik.
    Stranneby, Dag
    Örebro universitet, Institutionen för teknik.
    Long-term charge retention on PWBs2005Ingår i: Journal of Electrostatics, ISSN 0304-3886, E-ISSN 1873-5738, Vol. 63, nr 6-10, s. 597-602Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A sample of printed wiring boards, isolated from ground, has been charged tribo-electrically and the charge decay process has been studied with focus on the long-term charge decay behaviour. It was found that the time constant 1/e did not say much about the proceeding decay process. Instead a second-order approximation model for the measured decay curves has been suggested.

  • 43.
    Andersson, Birgitta
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Stranneby, Dag
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Remote monitoring of Electrostatic Charges in an EPA2007Konferensbidrag (Övrigt vetenskapligt)
  • 44.
    Andreasson, Henrik
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Adolfsson, Daniel
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Stoyanov, Todor
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Magnusson, Martin
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Lilienthal, Achim
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Incorporating Ego-motion Uncertainty Estimates in Range Data Registration2017Ingår i: 2017 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Institute of Electrical and Electronics Engineers (IEEE), 2017, s. 1389-1395Konferensbidrag (Refereegranskat)
    Abstract [en]

    Local scan registration approaches commonlyonly utilize ego-motion estimates (e.g. odometry) as aninitial pose guess in an iterative alignment procedure. Thispaper describes a new method to incorporate ego-motionestimates, including uncertainty, into the objective function of aregistration algorithm. The proposed approach is particularlysuited for feature-poor and self-similar environments,which typically present challenges to current state of theart registration algorithms. Experimental evaluation showssignificant improvements in accuracy when using data acquiredby Automatic Guided Vehicles (AGVs) in industrial productionand warehouse environments.

  • 45.
    Andreasson, Henrik
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Bouguerra, Abdelbaki
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Cirillo, Marcello
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Dimitrov, Dimitar Nikolaev
    INRIA - Grenoble, Meylan, France.
    Driankov, Dimiter
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Karlsson, Lars
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Lilienthal, Achim J.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Pecora, Federico
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Saarinen, Jari Pekka
    Örebro universitet, Institutionen för naturvetenskap och teknik. Aalto University, Espo, Finland .
    Sherikov, Aleksander
    Centre de recherche Grenoble Rhône-Alpes, Grenoble, France .
    Stoyanov, Todor
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Autonomous transport vehicles: where we are and what is missing2015Ingår i: IEEE robotics & automation magazine, ISSN 1070-9932, E-ISSN 1558-223X, Vol. 22, nr 1, s. 64-75Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this article, we address the problem of realizing a complete efficient system for automated management of fleets of autonomous ground vehicles in industrial sites. We elicit from current industrial practice and the scientific state of the art the key challenges related to autonomous transport vehicles in industrial environments and relate them to enabling techniques in perception, task allocation, motion planning, coordination, collision prediction, and control. We propose a modular approach based on least commitment, which integrates all modules through a uniform constraint-based paradigm. We describe an instantiation of this system and present a summary of the results, showing evidence of increased flexibility at the control level to adapt to contingencies.

  • 46.
    Andreasson, Henrik
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Larsson, Jonas
    ABB Corporate Research, Västerås, Sweden.
    Lowry, Stephanie
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    A Local Planner for Accurate Positioning for a Multiple Steer-and-Drive Unit Vehicle Using Non-Linear Optimization2022Ingår i: Sensors, E-ISSN 1424-8220, Vol. 22, nr 7, artikel-id 2588Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents a local planning approach that is targeted for pseudo-omnidirectional vehicles: that is, vehicles that can drive sideways and rotate on the spot. This local planner—MSDU–is based on optimal control and formulates a non-linear optimization problem formulation that exploits the omni-motion capabilities of the vehicle to drive the vehicle to the goal in a smooth and efficient manner while avoiding obstacles and singularities. MSDU is designed for a real platform for mobile manipulation where one key function is the capability to drive in narrow and confined areas. The real-world evaluations show that MSDU planned paths that were smoother and more accurate than a comparable local path planner Timed Elastic Band (TEB), with a mean (translational, angular) error for MSDU of (0.0028 m, 0.0010 rad) compared to (0.0033 m, 0.0038 rad) for TEB. MSDU also generated paths that were consistently shorter than TEB, with a mean (translational, angular) distance traveled of (0.6026 m, 1.6130 rad) for MSDU compared to (0.7346 m, 3.7598 rad) for TEB.

    Ladda ner fulltext (pdf)
    A Local Planner for Accurate Positioning for a Multiple Steer-and-Drive Unit Vehicle Using Non-Linear Optimization
  • 47.
    ANGELONE, MARIA LAURA
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    AndroidOS- Robot Command Interface2011Självständigt arbete på avancerad nivå (magisterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
  • 48.
    Antanas, Laura
    et al.
    Department of Computer Science, Katholieke Universiteit Leuven, Belgium.
    Dries, Anton
    Department of Computer Science, Katholieke Universiteit Leuven, Belgium.
    Moreno, Plinio
    Institute for Systems and Robotics, IST, University of Lisboa, Portugal.
    De Raedt, Luc
    Department of Computer Science, Katholieke Universiteit Leuven, Belgium.
    Relational Affordance Learning for Task-Dependent Robot Grasping2018Ingår i: Inductive Logic Programming: 27th International Conference, ILP 2017, Orléans, France, September 4-6, 2017, Revised Selected Papers / [ed] Nicolas Lachiche, Christel Vrain, Cham: Springer International Publishing , 2018, Vol. 10759, s. 1-15Konferensbidrag (Refereegranskat)
    Abstract [en]

    Robot grasping depends on the specific manipulation scenario: the object, its properties, task and grasp constraints. Object-task affordances facilitate semantic reasoning about pre-grasp configurations with respect to the intended tasks, favoring good grasps. We employ probabilistic rule learning to recover such object-task affordances for task-dependent grasping from realistic video data.

  • 49.
    Antanas, Laura
    et al.
    Department of Computer Science, KULeuven, Heverlee, Belgium.
    Moreno, Plinio
    Institute for Systems and Robotics, Lisbon, Portugal.
    Neumann, Marion
    Department of Computer Science and Engineering, Washington University in St Louis, St Louis, USA.
    Pimentel de Figueiredo, Rui
    Institute for Systems and Robotics, Lisbon, Portugal.
    Kersting, Kristian
    Computer Science Department, Technical University of Dortmund, Dortmund, Germany.
    Santos-Victor, José
    Institute for Systems and Robotics, Lisbon, Portugal.
    De Raedt, Luc
    Department of Computer Science, KULeuven, Heverlee, Belgium.
    Semantic and geometric reasoning for robotic grasping: a probabilistic logic approach2019Ingår i: Autonomous Robots, ISSN 0929-5593, E-ISSN 1573-7527, Vol. 43, nr 6, s. 1393-1418Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    While any grasp must satisfy the grasping stability criteria, good grasps depend on the specific manipulation scenario: the object, its properties and functionalities, as well as the task and grasp constraints. We propose a probabilistic logic approach for robot grasping, which improves grasping capabilities by leveraging semantic object parts. It provides the robot with semantic reasoning skills about the most likely object part to be grasped, given the task constraints and object properties, while also dealing with the uncertainty of visual perception and grasp planning. The probabilistic logic framework is task-dependent. It semantically reasons about pre-grasp configurations with respect to the intended task and employs object-task affordances and object/task ontologies to encode rules that generalize over similar object parts and object/task categories. The use of probabilistic logic for task-dependent grasping contrasts with current approaches that usually learn direct mappings from visual perceptions to task-dependent grasping points. The logic-based module receives data from a low-level module that extracts semantic objects parts, and sends information to the low-level grasp planner. These three modules define our probabilistic logic framework, which is able to perform robotic grasping in realistic kitchen-related scenarios.

  • 50.
    Arad, Boaz
    et al.
    Department of Computer Science, Ben‐Gurion University of the Negev, Beer‐Sheva, Israel .
    Balendonck, Jos
    Greenhouse Horticulture, Wageningen University & Research, Wageningen, The Netherlands.
    Barth, Ruud
    Greenhouse Horticulture, Wageningen University & Research, Wageningen, The Netherlands.
    Ben-Shahar, Ohad
    Department of Computer Science, 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 .
    Hellström, Thomas
    Department of Computing Science, Umeå University, Umeå, Sweden.
    Hemming, Jochen
    Greenhouse Horticulture, Wageningen University & Research, Wageningen, The Netherlands.
    Kurtser, Polina
    Department of Industrial Engineering and Management, Ben‐Gurion University of the Negev, Beer‐Sheva, Israel .
    Ringdahl, Ola
    Department of Computing Science, Umeå University, Umeå, Sweden.
    Tielen, Toon
    Greenhouse Horticulture, Wageningen University & Research, Wageningen, The Netherlands.
    van Tuijl, Bart
    Greenhouse Horticulture, Wageningen University & Research, Wageningen, The Netherlands.
    Development of a sweet pepper harvesting robot2020Ingår i: Journal of Field Robotics, ISSN 1556-4959, E-ISSN 1556-4967, Vol. 37, nr 6, s. 1027-1039Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents the development, testing and validation of SWEEPER, a robot for harvesting sweet pepper fruit in greenhouses. The robotic system includes a six degrees of freedom industrial arm equipped with a specially designed end effector, RGB-D camera, high-end computer with graphics processing unit, programmable logic controllers, other electronic equipment, and a small container to store harvested fruit. All is mounted on a cart that autonomously drives on pipe rails and concrete floor in the end-user environment. The overall operation of the harvesting robot is described along with details of the algorithms for fruit detection and localization, grasp pose estimation, and motion control. The main contributions of this paper are the integrated system design and its validation and extensive field testing in a commercial greenhouse for different varieties and growing conditions. A total of 262 fruits were involved in a 4-week long testing period. The average cycle time to harvest a fruit was 24 s. Logistics took approximately 50% of this time (7.8 s for discharge of fruit and 4.7 s for platform movements). Laboratory experiments have proven that the cycle time can be reduced to 15 s by running the robot manipulator at a higher speed. The harvest success rates were 61% for the best fit crop conditions and 18% in current crop conditions. This reveals the importance of finding the best fit crop conditions and crop varieties for successful robotic harvesting. The SWEEPER robot is the first sweet pepper harvesting robot to demonstrate this kind of performance in a commercial greenhouse.

    Ladda ner fulltext (pdf)
    Development ofasweetpepper harvesting robot
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