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  • 1.
    Röijezon, Ulrik
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Prellwitz, Maria
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Ahlmark, Daniel Innala
    van Deventer, Jan
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Hyyppä, Kalevi
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    A haptic navigation aid for individuals with visual impairments: Indoor and outdoor feasibility evaluations of the LaserNavigator2019Ingår i: Journal of Visual Impairment & Blindness, ISSN 0145-482X, E-ISSN 1559-1476, Vol. 113, nr 2, s. 194-201Artikel i tidskrift (Refereegranskat)
  • 2.
    Jafari, Hedyeh
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Pauelsen, Mascha
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Röijezon, Ulrik
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Nyberg, Lars
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Gustafsson, Thomas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    A novel data driven model of ageing postural control2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    Background

    Postural control is a complex system. Based on sensorimotor integration, the central nervous system (CNS) maintains balance by sending suitable motor commands to the muscles. Physiological decline due to ageing, affects balance performance through failing postural control – and in turn affects falls self-efficacy and activity participation. Understanding how the CNS adapts to these changes and predicts the appropriate motor commands to stabilize the body, has been a challenge for postural control research the latest years.

    Aims

    To understand and model the performance of the central nervous system as the controller of the human body.

    Methods

    Modelling was based on postural control data from 45 older adults (70 years and older). Ankle, knee and hip joint kinematics were measured during quiet stance using a motion capture system. Principal component analysis was used in order to reduce the measured multidimensional kinematics from a set of correlated discrete time series to a set of principal components. The outcome was utilized to predict the motor commands. The adaptive behaviour of the CNS was modelled by recurrent neural network including the efference copy for rapid predictions. The data from joint kinematics and electromyography (EMG) signals of the lower limb muscles were measured and separated into training and test data sets.

    Results

    The model can predict postural motor commands with very high accuracy regardless of a large physiological variability or balancing strategies. This model has three characteristics: a) presents an adaptive scheme to individual variability, 2) showcases the existence of an efference copy, and 3) is human experimental data driven.

    Conclusion

    The model can adapt to physical body characteristics and individual differences in balancing behaviour, while successfully predict motor commands. It should therefore be utilised in the continued pursuit of a better understanding of ageing postural control.

  • 3.
    Mansouri, Sina Sharif
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Arranz, Miguel Castano
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Kanellakis, Christoforos
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Autonomous MAV Navigation in Underground Mines Using Darkness Contours Detection2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    This article considers a low-cost and light weight platform for the task of autonomous flying for inspection in underground mine tunnels. The main contribution of this paper is integrating simple, efficient and well-established methods in the computer vision community in a state of the art vision-based system for Micro Aerial Vehicle (MAV) navigation in dark tunnels. These methods include Otsu's threshold and Moore-Neighborhood object tracing. The vision system can detect the position of low-illuminated tunnels in image frame by exploiting the inherent darkness in the longitudinal direction. In the sequel, it is converted from the pixel coordinates to the heading rate command of the MAV for adjusting the heading towards the center of the tunnel. The efficacy of the proposed framework has been evaluated in multiple experimental field trials in an underground mine in Sweden, thus demonstrating the capability of low-cost and resource-constrained aerial vehicles to fly autonomously through tunnel confined spaces.

  • 4.
    Kanellakis, Christoforos
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Guidance for Autonomous Aerial Manipulator Using Stereo Vision2019Ingår i: Journal of Intelligent and Robotic Systems, ISSN 0921-0296, E-ISSN 1573-0409Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Combining the agility of Micro Aerial Vehicles (MAV) with the dexterity of robotic arms leads to a new era of Aerial Robotic Workers (ARW) targeting infrastructure inspection and maintenance tasks. Towards this vision, this work focuses on the autonomous guidance of the aerial end-effector to either reach or keep desired distance from areas/objects of interest. The proposed system: 1) is structured around a real-time object tracker, 2) employs stereo depth perception to extract the target location within the surrounding scene, and finally 3) generates feasible poses for both the arm and the MAV relative to the target. The performance of the proposed scheme is experimentally demonstrated in multiple scenarios of increasing complexity.

  • 5.
    Eleftheroglou, Nick
    et al.
    Faculty of Aerospace Engineering, TU Delft, the Netherlands.
    Mansouri, Sina Sharif
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Loutas, Theodoros
    Department of Mechanical Engineering & Aeronautics, University of Patras, Greece.
    Karvelis, Petros
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Georgoulas, George
    Department of Mechanical Engineering & Aeronautics, University of Patras, Greece.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Zarouchas, Dimitrios
    Faculty of Aerospace Engineering, TU Delft, the Netherlands.
    Intelligent data-driven prognostic methodologies for the real-time remaining useful life until the end-of-discharge estimation of the Lithium-Polymer batteries of unmanned aerial vehicles with uncertainty quantification2019Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 254, artikel-id 113677Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper, the discharge voltage is utilized as a critical indicator towards the probabilistic estimation of the Remaining Useful Life until the End-of-Discharge of the Lithium-Polymer batteries of unmanned aerial vehicles. Several discharge voltage histories obtained during actual flights constitute the in-house developed training dataset. Three data-driven prognostic methodologies are presented based on state-of-the-art as well as innovative mathematical models i.e. Gradient Boosted Trees, Bayesian Neural Networks and Non-Homogeneous Hidden Semi Markov Models. The training and testing process of all models is described in detail. Remaining Useful Life prognostics in unseen data are obtained from all three methodologies. Beyond the mean estimates, the uncertainty associated with the point predictions is quantified and upper/lower confidence bounds are also provided. The Remaining Useful Life prognostics during six random flights starting from fully charged batteries are presented, discussed and the pros and cons of each methodology are highlighted. Several special metrics are utilized to assess the performance of the prognostic algorithms and conclusions are drawn regarding their prognostic capabilities and potential.

  • 6.
    Koval, Anton
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Mansouri, Sina Sharif
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Online Multi-Agent Based Cooperative Exploration and Coverage in Complex Environment2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this article, an online collaborative exploration and coverage method is proposed for the unknown complex environment with multiple agents. The exploration and coverage is based on Boustrophedon motion, while the detection conditions for backtracking points have been modified based on mission requirements, the battery charge level of each agent is considered to reduce agent loss, and collision free paths are generated. The proposed method is evaluated in simulation, where complex environment with multiple branches is explored by multiple agents.

  • 7.
    Jafari, Hedyeh
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Gustafsson, Thomas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Stabilization of an Inverted Pendulum via Human Brain Inspired Controller Design2019Konferensbidrag (Refereegranskat)
  • 8.
    Kanellakis, Christoforos
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Mansouri, Sina Sharif
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Georgoulas, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Towards Autonomous Surveying of Underground Mine using MAVs geogeo2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    Micro Aerial Vehicles (MAVs) are platforms that received great attention during the last decade. Recently, the mining industry has been considering the usage of aerial autonomous platforms in their processes. This article initially investigates potential application scenarios for this technology in mining. Moreover, one of the main tasks refer to surveillance and maintenance of infrastructure assets. Employing these robots for underground surveillance processes of areas like shafts, tunnels or large voids after blasting, requires among others the development of elaborate navigation modules. This paper proposes a method to assist the navigation capabilities of MAVs in challenging mine environments, like tunnels and vertical shafts. The proposed method considers the use of Potential Fields method, tailored to implement a sense-and-avoid system using a minimal ultrasound-based sensory system. Simulation results demonstrate the effectiveness of the proposed strategy.

  • 9.
    Mansouri, Sina Sharif
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Karvelis, Petros
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Kanellakis, Christoforos
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Kominiak, Dariusz
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Vision-based MAV Navigation in Underground Mine Using Convolutional Neural Network2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    This article presents a Convolutional Neural Network (CNN) method to enable autonomous navigation of low-cost Micro Aerial Vehicle (MAV) platforms along dark underground mine environments. The proposed CNN component provides on-line heading rate commands for the MAV by utilising the image stream from the on-board camera, thus allowing the platform to follow a collision-free path along the tunnel axis. A novel part of the developed method consists of the generation of the data-set used for training the CNN. More specifically, inspired from single image haze removal algorithms, various image data-sets collected from real tunnel environments have been processed offline to provide an estimation of the depth information of the scene, where ground truth is not available. The calculated depth map is used to extract the open space in the tunnel, expressed through the area centroid and is finally provided in the training of the CNN. The method considers the MAV as a floating object, thus accurate pose estimation is not required. Finally, the capability of the proposed method has been successfully experimentally evaluated in field trials in an underground mine in Sweden.

  • 10.
    Mansouri, Sina Sharif
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Karvelis, Petros
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Kanellakis, Christoforos
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Koval, Anton
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Visual Subterranean Junction Recognition for MAVs based on Convolutional Neural Networks2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    This article proposes a novel visual framework for detecting tunnel crossings/junctions in underground mine areas towards the autonomous navigation of Micro Aeril Vehicles (MAVs). Usually mine environments have complex geometries, including multiple crossings with different tunnels that challenge the autonomous planning of aerial robots. Towards the envisioned scenario of autonomous or semi-autonomous deployment of MAVs with limited Line-of-Sight in subterranean environments, the proposed module acknowledges the existence of junctions by providing crucial information to the autonomy and planning layers of the aerial vehicle. The capability for a junction detection is necessary in the majority of mission scenarios, including unknown area exploration, known area inspection and robot homing missions. The proposed novel method has the ability to feed the image stream from the vehicles’ on-board forward facing camera in a Convolutional Neural Network (CNN) classification architecture, expressed in four categories: 1) left junction, 2) right junction, 3) left & right junction, and 4) no junction in the local vicinity of the vehicle. The core contribution stems for the incorporation of AlexNet in a transfer learning scheme for detecting multiple branches in a subterranean environment. The validity of the proposed method has been validated through multiple data-sets collected from real underground environments, demonstrating the performance and merits of the proposed module.

  • 11.
    Andrikopoulos, Georgios
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Vortex Actuation via Electric Ducted Fans: an Experimental Study2019Ingår i: Journal of Intelligent and Robotic Systems, ISSN 0921-0296, E-ISSN 1573-0409, Vol. 95, nr 3-4, s. 955-973Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The presented work investigates the potential of utilizing commercially available Electric Ducted Fans (EDFs) as adhesion actuators, while providing a novel insight on the analysis of the adhesion nature related to negative pressure and thrust force generation against a target surface. To this goal, a novel EDF-based Vortex Actuation Setup (VAS) is proposed for monitoring important properties such as adhesion force, pressure distribution, current draw, motor temperature etc. during the VAS’ operation when placed in variable distances from a test surface. In addition, this work is contributing towards the novel evaluation of different design variables and modifications to original EDF structures, with the goal of analyzing their effect on the prototype VAS, while optimizing its adhesion efficiency for its future incorporation in a wall-climbing robot for inspection and repair purposes.

  • 12.
    Mansouri, Sina Sharif
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Kanellakis, Christoforos
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Georgoulas, Georgios
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Kominiak, Dariusz
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Gustafsson, Thomas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    2D visual area coverage and path planning coupled with camera footprints2018Ingår i: Control Engineering Practice, ISSN 0967-0661, E-ISSN 1873-6939, Vol. 75, s. 1-16Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Unmanned Aerial Vehicles (UAVs) equipped with visual sensors are widely used in area coverage missions. Guaranteeing full coverage coupled with camera footprint is one of the most challenging tasks, thus, in the presented novel approach a coverage path planner for the inspection of 2D areas is established, a 3 Degree of Freedom (DoF) camera movement is considered and the shortest path from the taking off to the landing station is generated, while covering the target area. The proposed scheme requires a priori information about the boundaries of the target area and generates the paths in an offline process. The efficacy and the overall performance of the proposed method has been experimentally evaluated in multiple indoor inspection experiments with convex and non convex areas. Furthermore, the image streams collected during the coverage tasks were post-processed using image stitching for obtaining a single overview of the covered scene.

    Publikationen är tillgänglig i fulltext från 2020-06-01 11:15
  • 13.
    Fresk, Emil
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    A generalized Frame Adaptive MPC for the low-level control of UAVs2018Ingår i: 2018 European Control Conference (ECC), Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2018, s. 1815-1820Konferensbidrag (Refereegranskat)
    Abstract [en]

    The aim of this article is to establish an adaptiveModel Predictive Control (MPC) scheme for the angular rate and thrust control of a multirotor Unmanned Aerial Vehicle (UAV). The proposed model adaptiveness comes from estimating the movement of the Center of Gravity (CoG) combined withthe thrust constant of the motors, making the system robust to disturbances and fast to adapt to changing parameters, while also taking under consideration the control signal bounds in order to guarantee for no motor stalls, while flying. The linear requirements of the MPC are adhered to by transforming the estimation and control problem into a control signal squared domain, making the system linear. The efficacy of the proposed estimation and control scheme is presented in simulations where worst case scenarios have been considered.

  • 14.
    Zachiotis, Georgios
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Andrikopoulos, Georgios
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Gornez, Randy
    Honda Research Institute of Japan Co. Ltd., Wako, Japan.
    Nakamura, Keisuke
    Honda Research Institute of Japan Co. Ltd., Wako, Japan.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    A Survey on the Application Trends of Home Service Robotics2018Ingår i: 2018 IEEE International Conference on Robotics and Biomimetics (ROBIO), IEEE, 2018, s. 1999-2006Konferensbidrag (Refereegranskat)
    Abstract [en]

    The area of service robots has steadily gained interest over the years as an attempt for deploying robots to tackle problems faced in our everyday lives. In this article, a survey on the application areas of home service robots is presented. A collection of robotic appliances is selected to be introduced based on their application objective of being an active part in a home environment. The dominant application areas of robotic home service are identified and overviewed through the governing dipole of: a) consumer, and b) research. The functional capabilities of each robot are addressed from a design and specification point of view, in order to highlight their key enabling features and justify their inclusion to each application area.

  • 15.
    Kostopoulos, V.
    et al.
    Department of Mechanical Engineering & Aeronautics, University of Patras, Patra, Greece.
    Psarras, S.
    Department of Mechanical Engineering & Aeronautics, University of Patras, Patra, Greece.
    Loutas, T.
    Department of Mechanical Engineering & Aeronautics, University of Patras, Patra, Greece.
    Sotiriadis, G.
    Department of Mechanical Engineering & Aeronautics, University of Patras, Patra, Greece.
    Gray, I.
    School of Aerospace, Transportation and Manufacturing, Cranfield University, College Road, Cranfield, United Kingdom.
    Padiyar, M.
    School of Aerospace, Transportation and Manufacturing, Cranfield University, College Road, Cranfield, United Kingdom.
    Petrunin, I.
    School of Aerospace, Transportation and Manufacturing, Cranfield University, College Road, Cranfield, United Kingdom.
    Raposo, J.
    School of Aerospace, Transportation and Manufacturing, Cranfield University, College Road, Cranfield, United Kingdom.
    Fragonara, L.Z.
    School of Aerospace, Transportation and Manufacturing, Cranfield University, College Road, Cranfield, United Kingdom.
    Tzitzilonis, V.
    Exis Innovation Ltd, Wilbury Way, Hitchin, United Kingdom.
    Dassios, K.
    Department of Materials Science and Engineering, University of Ioannina, Ioannina, Greece.
    Exarchos, D.
    Department of Materials Science and Engineering, University of Ioannina, Ioannina, Greece.
    Andrikopoulos, Georgios
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Autonomous Inspection and Repair of Aircraft Composite Structures2018Ingår i: 18th IFAC Conference on Technology, Culture and International Stability TECIS 2018 / [ed] P. Kopacek; B. Ibrahimov, Elsevier, 2018, Vol. 51, s. 554-557Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper deals with the development of an innovative approach for inspection and repair of damage in aeronautical composites that took place in the first two years of the H2020 Compinnova project which. The aim is a newly designed robotic platform for autonomous inspection using combined infrared thermography (IRT) and phased array (PA) non-destructive investigation for damage detection and characterization, while integrated with laser repaircapabilities. This will affect the increasing societal need for safer aircraft in the lowest possible cost, while new and effective techniques of inspection are needed because of the rapidly expanding use of composites in the aerospace industry.

  • 16.
    Mansouri, Sina Sharif
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Kanellakis, Christoforos
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Fresk, Emil
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Kominiak, Dariusz
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Cooperative coverage path planning for visual inspection2018Ingår i: Control Engineering Practice, ISSN 0967-0661, E-ISSN 1873-6939, Vol. 74, s. 118-131Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This article addresses the inspection problem of a complex 3D infrastructure using multiple Unmanned Aerial Vehicles (UAVs). The main novelty of the proposed scheme stems from the establishment of a theoretical framework capable of providing a path for accomplishing a full coverage of the infrastructure, without any further simplifications (number of considered representation points), by slicing it by horizontal planes to identify branches and assign specific areas to each agent as a solution to an overall optimization problem. Furthermore, the image streams collected during the coverage task are post-processed using Structure from Motion, stereo SLAM and mesh reconstruction algorithms, while the resulting 3D mesh can be used for further visual inspection purposes. The performance of the proposed Collaborative-Coverage Path Planning (C-CPP) has been experimentally evaluated in multiple indoor and realistic outdoor infrastructure inspection experiments and as such it is also contributing significantly towards real life applications for UAVs.

    Publikationen är tillgänglig i fulltext från 2020-05-01 11:28
  • 17.
    Kanellakis, Christoforos
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Mansouri, Sina Sharif
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Fresk, Emil
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Kominiak, Dariusz
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Cooperative UAVs as a Tool for Aerial Inspection of Large Scale Aging Infrastructure2018Ingår i: 2018 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Piscataway, NJ: IEEE, 2018, s. 5040-5040Konferensbidrag (Refereegranskat)
    Abstract [en]

    This work presents an aerial tool towards the autonomous cooperative coverage and inspection of a large scale 3D infrastructure using multiple Unmanned Aerial Vehicles (UAVs). In the presented approach the UAVs are relying only on their onboard computer and sensory system, deployed for inspection of the 3D structure. In this application each agent covers a different part of the scene autonomously, while avoiding collisions. The autonomous navigation of each platform on the designed path is enabled by the localization system that fuses Ultra Wideband with inertial measurements through an Error- State Kalman Filter. The visual information collected from the aerial team is collaboratively processed to create the 3D model. The performance of the overall setup has been experimentally evaluated in realistic wind turbine inspection experiments, providing dense 3D reconstruction of the inspected structures.

  • 18.
    Nayl, Thaker
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Gustafsson, Thomas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Kominiak, Dariusz
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nyberg, Rickard
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Design and experimental evaluation of a novel sliding mode controller for an articulated vehicle2018Ingår i: Robotics and Autonomous Systems, ISSN 0921-8890, E-ISSN 1872-793X, Vol. 103, s. 213-221Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This article presents the design and experimental evaluation of a novel sliding mode control scheme, being applied to the case of an articulated vehicle. The proposed sliding mode controller is based on a novel continuous sliding surface, being introduced for reducing the chattering phenomenon, while achieving a better tracking performance and a fast minimization of the corresponding tracking error. The derivation of the sliding mode controller relies on the fully nonlinear kinematic model of the articulated vehicle, while the overall stability of the control scheme is proven based on the Lyapunov's stability condition. The performance of the established control scheme is being experimentally evaluated through multiple path tracking scenarios on a small scale and fully realistic articulated vehicle

  • 19.
    Andrikopoulos, Georgios
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Design, Development and Experimental Evaluation of a Vortex Actuation System2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this article, the potential of utilizing a commercially available Electric Ducted Fan (EDF) as a negative-pressure actuator for adhesion purposes is experimentally tested. To this purpose, a novel EDF-based Vortex Actuation System (VAS) is proposed and presented from a design, development and experimental evaluation perspective. The effect of different EDF design properties and design alterations to the actuation system is analyzed, for providing novel considerations on optimizing the adhesion efficiency of such a system.

  • 20.
    Andrikopoulos, George
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    HUmanoid Robotic Leg via pneumatic muscle actuators: implementation and control2018Ingår i: Meccanica (Milano. Print), ISSN 0025-6455, E-ISSN 1572-9648, Vol. 53, nr 1-2, s. 465-480Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this article, a HUmanoid Robotic Leg (HURL) via the utilization of pneumatic muscle actuators (PMAs) is presented. PMAs are a pneumatic form of actuation possessing crucial attributes for the implementation of a design that mimics the motion characteristics of a human ankle. HURL acts as a feasibility study in the conceptual goal of developing a 10 degree-of-freedom (DoF) lower-limb humanoid for compliance and postural control, while serving as a knowledge basis for its future alternative use in prosthetic robotics. HURL’s design properties are described in detail, while its 2-DoF motion capabilities (dorsiflexion–plantar flexion, eversion–inversion) are experimentally evaluated via an advanced nonlinear PID-based control algorithm.

  • 21.
    Wopereis, Han
    et al.
    Robotics and Mechatronics (RAM), University of Twente, Lichtenvoorde, 7131 TK, Netherlands.
    van de Ridder, L. W.
    University of Twente, Netherlands.
    Lankhorst, Tom J. W.
    University of Twente, Netherlands.
    Klooster, Lucian
    Mechanical Engineering, University of Twente, Enschede, 7514DN, Netherlands.
    Bukai, Evyatar
    University of Twente, Netherlands.
    Wuthier, David
    Mechanical engineering, Aalborg university Copenhagen, Copenhagen, 2450, Denmark.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Stramigioli, Stefano
    EWI, University of Twente, Enschede, 7500AE, Netherlands.
    Engelen, Johan B. C.
    Robotics and Mechatronics, University of Twente, Enschede, 7500AE, Netherlands.
    Fumagalli, Matteo
    Robotics, Vision and Machine Intelligence, Aalborg University, Copenhagen, 2450, Denmark.
    Multimodal Aerial Locomotion: An Approach to Active Tool Handling 10 Author2018Ingår i: IEEE robotics & automation magazine, ISSN 1070-9932, E-ISSN 1558-223X, Vol. 25, nr 4, s. 57-65, artikel-id 8491265Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The research focus in aerial robotics is shifting from contactless inspection toward interaction and manipulation, with the number of potential applications rapidly increasing [1]. Eventually, aerial manipulators, i.e., unmanned aerial vehicles (UAVs) equipped with manipulators, will likely take on hazardous maintenance tasks now performed by humans. For this to happen, aerial manipulators must be able to perform all the different operations required in these maintenance routines.

  • 22.
    Jafari, Hedyeh
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Pauelsen, Mascha
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Röijezon, Ulrik
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Nyberg, Lars
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Gustafsson, Thomas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    On Internal Modeling of the Upright Postural Control in Elderly2018Konferensbidrag (Refereegranskat)
  • 23.
    Kanellakis, Christoforos
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Terreran, Matteo
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Kominiak, Dariusz
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    On vision enabled aerial manipulation for multirotors2018Ingår i: IEEE International Conference on Emerging Technologies and Factory Automation (ETFA), Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    This article presents an integrated vision-based guiding system for aerial manipulation. More specifically, a 4 DoF planar dexterous manipulator, with a stereo camera attached on the end-effector, is endowed to a multirotor aerial platform enabling active manipulation capabilities. The proposed novel approach combines a visual processing scheme for object detection and tracking, as well as a manipulator positioning for allowing the aerial platform to approach the surface of interaction efficiently. In the developed scheme, the object detection is based on correlation filters to track the target robustly, while the depth information, from the stereo camera on board the manipulator, is used to extract the centroid of the manipulated object, compute its relative configuration with respect to the UAV and align the end-effector properly with the grasping point. The effectiveness of the proposed scheme is demonstrated in multiple experimental trials and simulations, highlighting it's applicability towards autonomous aerial manipulation.

    Publikationen är tillgänglig i fulltext från 2020-01-08 13:21
  • 24.
    Fresk, Emil
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Gustafsson, Thomas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    A Generalized Reduced-Complexity Inertial Navigation System for Unmanned Aerial Vehicles2017Ingår i: IEEE Transactions on Control Systems Technology, ISSN 1063-6536, E-ISSN 1558-0865, Vol. 25, nr 1, s. 192-207Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper, a generic approach to attitude and position estimation, suited for any type of unmanned aerial vehicle, is presented. This will be achieved by establishing a generic framework, which can be extended using adaptive methods to determine the thrust properties of the engines and the mass of the aircraft, while keeping the overall computational complexity of the system low. Furthermore, the effect of magnetic disturbances will be reduced in a novel way by confining the magnetic errors to affect only heading, without compromising the pitch and roll estimation of the system with error-based estimation. The efficacy of the proposed framework will be evaluated through extended simulations and experimental validations on a multirotor. Finally, guidelines will be provided toward: 1) an implementation with a reduced computational complexity and 2) the utilization of the square-root formulations of the extended Kalman filter for extending the dynamic range of the filter.  

  • 25. Wuthier, David
    et al.
    Kominiak, Dariusz
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Fresk, Emil
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    A Geometric Pulling Force Controller for Aerial Robotic Workers2017Ingår i: IFAC-PapersOnLine, ISSN 1045-0823, E-ISSN 1797-318X, Vol. 50, nr 1, s. 10287-10292Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of this article is to establish a geometric, pulling force control scheme in order to enable the concept of Aerial Robotic Workers (ARWs), where the capabilities of the Unmanned Aerial Vehicles (UAVs) are enhanced by aerial manipulators in order to exert known pulling forces on the environment, with characteristic applications such as levers actuation, debris removal and safety assessments. The proposed novel approach consists of interfacing a cascaded position control scheme with a manipulation framework in such a way that the UAV, together with the manipulator are being controlled in a complete system The validity of the proposed scheme as well as the ability of the UAV to track a desired pulling force is validated through a real-world experiment.

  • 26.
    Karvelis, Petros
    et al.
    Laboratory of Knowledge and Intelligent Computing, Department of Computer Engineering, Technological Educational Institute of Epirus.
    Röijezon, Ulrik
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Faleij, Ragnar
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Georgoulas, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Mansouri, Sina Sharif
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    A Laser Dot Tracking Method for the Assessment of Sensorimotor Function of the Hand2017Ingår i: 2017 25th Mediterranean Conference on Control and Automation, MED 2017, Piscataway. NJ: Institute of Electrical and Electronics Engineers (IEEE), 2017, s. 217-222, artikel-id 7984121Konferensbidrag (Refereegranskat)
    Abstract [en]

    Assessment of sensorimotor function is crucial during the rehabilitation process of various physical disorders, including impairments of the hand. While moment performance can be accurately assessed in movement science laboratories involving highly specialized personnel and facilities there is a lack of feasible objective methods for the general clinic. This paper describes a novel approach to sensorimotor assessment using an intuitive test and a specifically tailored image processing pipeline for the quantification of the test. More specifically the test relies on the patient being instructed on following a zig-zag pattern using a handled laser pointer. The movement of the pointer is tracked using image processing algorithm capable of automating the whole procedure. The method has potential for feasible objective clinical assessment of the hand and other body parts

  • 27.
    Georgoulas, Georgios
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Climente-Alarcón, Vicente
    Department of Electrical Engineering and Automation, Aalto University.
    Antonino-Daviu, José Alfonso
    Instituto Tecnologico de la Energia, Universitat Politècnica de València.
    Stylios, Chrysostomos D.
    Laboratory of Knowledge and Intelligent Computing, Department of Computer Engineering, TEI of Epirus, Artas, Kostakioi.
    Arkkio, Antero
    Department of Electrical Engineering and Automation, Aalto University.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    A Multi-label Classification Approach for the Detection of Broken Bars and Mixed Eccentricity Faults Using the Start-up Transient2017Ingår i: IEEE International Conference on Industrial Informatics (INDIN), Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2017, s. 430-433, artikel-id 7819198Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this article a data driven approach for the classification of simultaneously occurring faults in an induction motor is presented. The problem is treated as a multi-label classification problem with each label corresponding to one specific fault, using the power-set approach. The faulty conditions examined, include the existence of a broken bar fault and the presence of mixed eccentricity with various degrees of static and dynamic eccentricity. For the feature extraction stage, the time-frequency representation, resulting from the application of the short time Fourier transform of the start-up current is exploited. The proposed approach is validated using simulation data with promising results.

  • 28.
    Röijezon, Ulrik
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Faleij, Ragnar
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Hälsa och rehabilitering.
    Kravelis, Petros S.
    Laboratory of Knowledge and Intelligent Computing, Department of Computer Engineering, Technological Educational Institute of Epirus, Arta.
    Georgoulas, Georgios
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    A new clinical test for sensorimotor function of the hand: development and preliminary validation2017Ingår i: BMC Musculoskeletal Disorders, ISSN 1471-2474, E-ISSN 1471-2474, Vol. 18, nr 1, artikel-id 407Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background

    Sensorimotor disturbances of the hand such as altered neuromuscular control and reduced proprioception have been reported for various musculoskeletal disorders. This can have major impact on daily activities such as dressing, cooking and manual work, especially when involving high demands on precision and therefore needs to be considered in the assessment and rehabilitation of hand disorders. There is however a lack of feasible and accurate objective methods for the assessment of movement behavior, including proprioception tests, of the hand in the clinic today. The objective of this observational cross- sectional study was to develop and conduct preliminary validation testing of a new method for clinical assessment of movement sense of the wrist using a laser pointer and an automatic scoring system of test results.

    Methods

    Fifty physiotherapists performed a tracking task with a hand-held laser pointer by following a zig-zag pattern as accurately as possible. The task was performed with left and right hand in both left and right directions, with three trials for each hand movement. Each trial was video recorded and analysed with a specifically tailored image processing pipeline for automatic quantification of the test. The main outcome variable was Acuity, calculated as the percent of the time the laser dot was on the target line during the trial.

    Results

    The results showed a significantly better Acuity for the dominant compared to non-dominant hand. Participants with right hand pain within the last 12 months had a significantly reduced acuity (p < 0.05), and although not significant there was also a similar trend for reduced Acuity also for participants with left hand pain. Furthermore, there was a clear negative correlation between Acuity and Speed indicating a speed-accuracy trade off commonly found in manual tasks. The repeatability of the test showed acceptable intra class correlation (ICC2.1) values (0.68-0.81) and standard error of measurement values ranging between 5.0–6.3 for Acuity.

    Conclusions

    The initial results suggest that the test may be a valid and feasible test for assessment of the movement sense of the hand. Future research should include assessments on different patient groups and reliability evaluations over time and between testers.

  • 29.
    Castaño Arranz, Miguel
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Birk, Wolfgang
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    A Survey on Control Configuration Selection and New Challenges in Relation to Wireless Sensor and Actuator Networks2017Ingår i: IFAC-PapersOnLine, ISSN 1045-0823, E-ISSN 1797-318X, Vol. 50, nr 1, s. 8810-8825Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This survey on Control Configuration Selection (CCS) includes methods based on relative gains, gramian-based interaction measures, methods based on optimization schemes, plantwide control, and methods for the reconfiguration of control systems. The CCS problem is discussed, and a set of desirable properties of a CCS method are defined. Open questions and research tracks are discussed, with the focus on new challenges in relation to the emerging area of Wireless Sensors and Actuator Networks.

  • 30.
    Georgoulas, Georgios
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Karvelis, Petros
    Laboratory of Knowledge and Intelligent Computing, Department of Computer Engineering, Technological Educational Institute of Epirus.
    Gavrilis, Dimitris
    Department of Electrical Engineering and Computer Technology, University of Patras.
    Stylios, Chrysostomos D.
    Laboratory of Knowledge and Intelligent Computing, Department of Computer Engineering, TEI of Epirus, Artas, Kostakioi.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    An ordinal classification approach for CTG categorization2017Ingår i: 2017 39th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), Piscataway, NJ: IEEE, 2017, s. 2642-2645, artikel-id 8037400Konferensbidrag (Refereegranskat)
    Abstract [en]

    Evaluation of cardiotocogram (CTG) is a standard approach employed during pregnancy and delivery. But, its interpretation requires high level expertise to decide whether the recording is Normal, Suspicious or Pathological. Therefore, a number of attempts have been carried out over the past three decades for development automated sophisticated systems. These systems are usually (multiclass) classification systems that assign a category to the respective CTG. However most of these systems usually do not take into consideration the natural ordering of the categories associated with CTG recordings. In this work, an algorithm that explicitly takes into consideration the ordering of CTG categories, based on binary decomposition method, is investigated. Achieved results, using as a base classifier the C4.5 decision tree classifier, prove that the ordinal classification approach is marginally better than the traditional multiclass classification approach, which utilizes the standard C4.5 algorithm for several performance criteria.

  • 31.
    Goldin, E.
    et al.
    GSTAT, Israel.
    Feldman, D.
    GSTAT, Israel.
    Georgoulas, Georgios
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Castaño Arranz, Miguel
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Cloud computing for big data analytics in the Process Control Industry2017Ingår i: 2017 25th Mediterranean Conference on Control and Automation, MED 2017, Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2017, s. 1373-1378, artikel-id 7984310Konferensbidrag (Refereegranskat)
    Abstract [en]

    The aim of this article is to present an example of a novel cloud computing infrastructure for big data analytics in the Process Control Industry. Latest innovations in the field of Process Analyzer Techniques (PAT), big data and wireless technologies have created a new environment in which almost all stages of the industrial process can be recorded and utilized, not only for safety, but also for real time optimization. Based on analysis of historical sensor data, machine learning based optimization models can be developed and deployed in real time closed control loops. However, still the local implementation of those systems requires a huge investment in hardware and software, as a direct result of the big data nature of sensors data being recorded continuously. The current technological advancements in cloud computing for big data processing, open new opportunities for the industry, while acting as an enabler for a significant reduction in costs, making the technology available to plants of all sizes. The main contribution of this article stems from the presentation for a fist time ever of a pilot cloud based architecture for the application of a data driven modeling and optimal control configuration for the field of Process Control. As it will be presented, these developments have been carried in close relationship with the process industry and pave a way for a generalized application of the cloud based approaches, towards the future of Industry 4.0

  • 32.
    Adaldo, Antonio
    et al.
    Department of Automatic Control, School of Electrical Engineering, KTH Royal Institute of Technology.
    Mansouri, Sina Sharif
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Kanellakis, Christoforos
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Dimarogonas, Dimos V.
    Department of Automatic Control, School of Electrical Engineering, KTH Royal Institute of Technology.
    Johansson, Karl H.
    Department of Automatic Control, School of Electrical Engineering, KTH Royal Institute of Technology.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Cooperative coverage for surveillance of 3D structures2017Ingår i: IEEE International Conference on Intelligent Robots and Systems, Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2017, s. 1838-1845, artikel-id 8205999Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this article, we propose a planning algorithm for coverage of complex structures with a network of robotic sensing agents, with multi-robot surveillance missions as our main motivating application. The sensors are deployed to monitor the external surface of a 3D structure. The algorithm controls the motion of each sensor so that a measure of the collective coverage attained by the network is nondecreasing, while the sensors converge to an equilibrium configuration. A modified version of the algorithm is also provided to introduce collision avoidance properties. The effectiveness of the algorithm is demonstrated in a simulation and validated experimentally by executing the planned paths on an aerial robot.

  • 33.
    Mansouri, Sina Sharif
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Kanellakis, Christoforos
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Fresk, Emil
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Kominiak, Dariusz
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Cooperative UAVs as a tool for Aerial Inspection of the Aging Infrastructure2017Ingår i: Field and Service Robotics: Results of the 11th International Conference / [ed] Marco Hutter, Roland Siegwart, Cham: Springer, 2017, s. 177-189Konferensbidrag (Refereegranskat)
    Abstract [en]

    This article presents an aerial tool towards the autonomous cooperative coverage and inspection of a 3D infrastructure using multiple Unmanned Aerial Vehicles (UAVs). In the presented approach the UAVs are relying only on their onboard computer and sensory system, deployed for inspection of the 3D structure. In this application each agent covers a different part of the scene autonomously, while avoiding collisions. The visual information collected from the aerial team is collaboratively processed to create the 3D model. The performance of the overall setup has been experimentally evaluated in a realistic outdoor infrastructure inspection experiments, providing sparse and dense 3D reconstruction of the inspected structures.

  • 34.
    Herceg, Domagoj
    et al.
    IMT School for Advanced Studies Lucca.
    Georgoulas, Georgios
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Sopasakis, Pantelis
    KU Leuven, Department of Electrical Engineering (ESAT), STADIUS Center for Dynamical Systems, Signal Processing and Data Analytics.
    Castaño Arranz, Miguel
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Patrinos, Panagiotis K.
    KU Leuven, Department of Electrical Engineering (ESAT), STADIUS Center for Dynamical Systems, Signal Processing and Data Analytics.
    Bemporad, Alberto
    IMT School for Advanced Studies Lucca.
    Niemi, Jan
    Swerea MEFOS, Box 812, Lulea.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Data-driven Modelling, Learning and Stochastic Predictive Control for the Steel Industry2017Ingår i: 2017 25th Mediterranean Conference on Control and Automation, MED 2017, Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2017, s. 1361-1366, artikel-id 7984308Konferensbidrag (Refereegranskat)
    Abstract [en]

    The steel industry involves energy-intensive processessuch as combustion processes whose accurate modellingvia first principles is both challenging and unlikely to leadto accurate models let alone cast time-varying dynamics anddescribe the inevitable wear and tear. In this paper we addressthe main objective which is the reduction of energy consumptionand emissions along with the enhancement of the autonomy ofthe controlled process by online modelling and uncertaintyawarepredictive control. We propose a risk-sensitive modelselection procedure which makes use of the modern theoryof risk measures and obtain dynamical models using processdata from our experimental setting: a walking beam furnaceat Swerea MEFOS. We use a scenario-based model predictivecontroller to track given temperature references at the threeheating zones of the furnace and we train a classifier whichpredicts possible drops in the excess of Oxygen in each heatingzone below acceptable levels. This information is then used torecalibrate the controller in order to maintain a high qualityof combustion, therefore, higher thermal efficiency and loweremissions

  • 35.
    Andrikopoulos, Georgios
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Design, development and control of a human-inspired two-arm robot via Pneumatic Artificial Muscles2017Ingår i: 2017 25th Mediterranean Conference on Control and Automation, MED 2017, Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2017, s. 241-246, artikel-id 7984125Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this article, the design and implementation of a 10 Degree-of-Freedom (DoF) human-inspired two-arm robot is presented. Multiple Pneumatic Artificial Muscles (PAMs) in antagonistic formations are incorporated for undertaking the two arms' movements, while the design goal is the replication of human-like motion patterns, described by smoothness, inherent compliance and accuracy. To evaluate the feasibility of the proposed concept, the 10-DoF robot is developed and experimentally tested in open and closed-loop control scenarios via the use of a multiple Advanced Nonlinear PID (ANPID) based scheme.

  • 36.
    Kanellakis, Christoforos
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Mansouri, Sina Sharif
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Dynamic visual sensing based on MPC controlled UAVs2017Ingår i: 2017 25th Mediterranean Conference on Control and Automation, MED 2017, Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2017, s. 1201-1206, artikel-id 7984281Konferensbidrag (Refereegranskat)
    Abstract [en]

    This article considers the establishment of a dynamic visual sensor from monocular cameras to enable a reconfigurable environmental perception. The cameras are mounted on Micro Aerial Vehicles (MAV) which are coordinated by a Model Predictive Control (MPC) scheme to retain overlapping field of views and form a global sensor with varying baseline. The specific merits of the proposed scheme are: a) the ability to form a configurable stereo rig, according to the application needs, and b) the simple design, the reduction of the payload and the corresponding cost. Moreover, the proposed configurable sensor provides a glpobal 3D reconstruction of the surrounding area, based on a modified Structure from Motion approach. The efficiency of the suggested flexible visual sensor is demonstrated in simulation results that highlight the novel concept of cooperative flying cameras and their 3D reconstruction capabilities

  • 37.
    Fresk, Emil
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Wuthier, David
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Generalized center of gravity compensation for multirotors with application to aerial manipulation2017Ingår i: IEEE International Conference on Intelligent Robots and Systems, Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2017, s. 4424-4429, artikel-id 8206307Konferensbidrag (Refereegranskat)
    Abstract [en]

    The aim of this paper is to establish a generalized parameter estimation scheme to online estimate the Center of Gravity (COG) for multirotors, while using a geometric controller to perform position tracking for applications in aerial manipulation. The proposed scheme is developed so the controller uses the estimated COG to compensate and remove constant offset in the position tracking. The efficiency and validity of the proposed parameter estimation and compensation scheme is proved through two experimental evaluations, one when step changes to the COG are applied and one tracking experiment where a compact aerial manipulator is attached to the multirotor and performs sweeping motions.

  • 38.
    Brusell, Angelica
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Andrikopoulos, Georgios
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Novel considerations on the negative pressure adhesion of electric ducted fans: An experimental study2017Ingår i: 2017 25th Mediterranean Conference on Control and Automation, MED 2017, Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2017, s. 1404-1409, artikel-id 7984315Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this article, the potential of utilizing an Electric Ducted Fan (EDF) as an adhesion actuator is investigated in detail, where an experimental setup is implemented for evaluating the EDF's ability to adhere to a test surface through negative pressure generation. Different design variables and modifications to the original EDF structure are tested, while their impact on the adhesion efficiency is experimentally evaluated. The presented investigation acts as a preliminary study to the goal of incorporating the resulting optimized negative pressure-based actuation method in a wall-climbing robot for inspection of aircraft fuselages

  • 39.
    Jafari, Hedyeh
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Castaño Arranz, Miguel
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Gustafsson, Thomas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    On Control Structure Design for a Walking Beam Furnace2017Ingår i: 2017 25th Mediterranean Conference on Control and Automation, MED 2017, Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2017, s. 1355-1360, artikel-id 7984307Konferensbidrag (Refereegranskat)
    Abstract [en]

    The aim of this article is to introduce a novel sparse controller design for the temperature control of an experimental walking beam furnace in steel industry. Adequate tracking of temperature references is essential for the quality of the heated slabs. However, the design of the temperature control is hindered by the multivariable (non-square) dynamic behavior of the furnace. These dynamics include significant loop interactions and time delays. Furthermore, a novel data-driven model, based on real life experimental data that relies on a subspace state representation in a closed loop approach is introduced. In the sequel, the derived model is utilized to investigate the controller's structure. By applying the relative gain array approach a decentralized feedback controller is designed. However, in spite of the optimal and sparse design of the controller, there exists interaction between loops. By analyzing the interaction between the inputs-outputs with the Σ2 Gramian-based interaction methodology, a decoupled multi-variable controller is implied. The simulation result, based on the experimental modeling of the furnace, shows that the controller can successfully decrease the interaction between the loops and track the reference temperature set-points.

  • 40.
    Mansouri, Sina Sharif
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Georgoulas, Georgios
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Gustafsson, Thomas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    On the covering of a polygonal region with fixed size rectangles with an application towards aerial inspection2017Ingår i: 2017 25th Mediterranean Conference on Control and Automation, MED 2017, Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2017, s. 1316-1320, artikel-id 7984300Konferensbidrag (Refereegranskat)
    Abstract [en]

    Unmanned Aerial Vehicles (UAVs) equipped with remote visual sensing can be used in wide range of applications. However, guaranteeing the full coverage of the area and translating this coverage in a path planning problem, it is a quite challenging task. Thus, in this article a well-known and well-investigated family of hard optimization problems, covering a polygonal region (target area) with fixed size rectangles (camera frustrum), is studied. The problem is formulated mathematically and solved using metaheuristic optimization algorithms. The proposed novel algorithmic scheme requires an a priori 2D model of the target area, while it tries to maximize the coverage with a minimum number of fixed size rectangles. Finally, multiple simulation results are presented that prove the efficacy of the proposed scheme

  • 41.
    Andrikopoulos, Georgios
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    On the design, development and motion control of a HUmanoid Robotic Leg via pneumatic artificial muscles2017Ingår i: 2016 IEEE International Conference on Robotics and Biomimetics, ROBIO 2016, Piscataway, NJ, 2017, s. 1637-1642, artikel-id 7866562Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this article, the design and implementation of a HUmanoid Robotic Leg (HURL) is presented. The motion of the HURL is achieved via pneumatic muscle actuators, a pneumatic form of actuation possessing crucial attributes for the implementation of a biomimetic design that mimics the motion characteristics of a human ankle. The HURL's properties are described in detail, while its 2-DoF motion capabilities (dorsiflexion - plantar flexion, eversion - inversion) are experimentally evaluated via an advanced nonlinear PID-based control algorithm

  • 42.
    Fresk, Emil
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Mansouri, Sina Sharif
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Kanellakis, Christoforos
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Halén, Erik
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Reduced complexity calibration of MEMS IMUs2017Ingår i: 2017 25th Mediterranean Conference on Control and Automation, MED 2017, Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2017, s. 1316-1320, artikel-id 7984300Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this article a reduced complexity calibration method for Micro-Electro-Mechanical Systems (MEMS) Inertial Measurement Units (IMUs) will be presented, which does not need the rotating reference tables, commonly used in the gyroscope calibration. As it will be presented, in the proposed novel scheme fixed angle rotations have been utilized to observe the integral of the gyroscope signals to find the corresponding sensitivity, axis misalignment and acceleration sensitivity matrices. This appraoch has the significant merit of high norm accuracy, easiness of use, low cost and simplicity in construction, thus allowing anyone with a basic electronics knowledge to calibrate an IMU.

  • 43.
    Mansouri, Sina Sharif
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Karvelis, Petros
    Laboratory of Knowledge and Intelligent Computing, Department of Computer Engineering, Technological Educational Institute of Epirus.
    Georgoulas, Georgios
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Remaining Useful Battery Life Prediction for UAVs based on Machine Learning2017Ingår i: IFAC-PapersOnLine, ISSN 1045-0823, E-ISSN 1797-318X, Vol. 50, nr 1, s. 4727-4732Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Unmanned Aerial Vehicles are becoming part of many industrial applications. The advancements in battery technologies played a crucial part for this trend. However, no matter what the advancements are, all batteries have a fixed capacity and after some time drain out. In order to extend the flying time window, the prediction of the time that the battery will no longer be able to support a flying condition is crucial. This in fact can be cast as a standard Remaining Useful Life prognostic problem, similarly encountered in many fields. In this article, the problem of Remaining Useful Life estimation of a battery, under different flight conditions, is tackled using four machine learning techniques: a linear sparse model, a variant of support vector regression, a multilayer perceptron and an advanced tree based algorithm. The efficiency of the overall proposed machine learning techniques, in the field of batteries prognostics, is evaluated based on multiple experimental data from different flight conditions.

  • 44.
    Edrees, Tarek
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och brand. College of Engineering, Department of Civil Engineering, University of Mosul, Mosul, Iraq.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Dritsas, Leonidas
    University of Patras, Department of Electrical Engineering.
    Semi-active control of flexible structures using closed-loop input shaping techniques2017Ingår i: Structural Control and Health Monitoring: The Bulletin of ACS, ISSN 1545-2255, E-ISSN 1545-2263, Vol. 24, nr 5, artikel-id e1913Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this research effort, a novel approach on the control of structures with magnetorheological (MR) dampers is presented, based on an appropriately adapted closed-loop version of the generic input shaping control theory. The MR damper is a very promising kind of semi-active control system (actuator), mixing the advantages of the active and passive structural control systems, hence their increasing use as attenuators that reject the effects of dynamic loads on civil engineering structures. The main contribution of this article is the application and performance evaluation of the novel ‘Linear Matrix Inequality-based’ feedback version of the input shaping control theory for the first time in the area of structural control. The need for the use of a feedback version of input shaping control stems from the design trade-off between robustness and speed of response requirements. A simulation of a benchmark three-story building with one MR damper is employed to verify the efficiency of the proposed control approach. The nonlinear behaviour of the MR damper, rigidly connected between the first floor of the structure and the ground, is captured by the well-known Bouc–Wen model. The superiority and effectiveness of the proposed scheme in reducing the responses of the structure were proved using seven quantifiable evaluation criteria and by comparing these results with those achieved by classical and well-established alternative control schemes.

  • 45.
    Kanellakis, Christoforos
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Survey on Computer Vision for UAVs: Current Developments and Trends2017Ingår i: Journal of Intelligent and Robotic Systems, ISSN 0921-0296, E-ISSN 1573-0409, Vol. 87, nr 1, s. 141-168Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    During last decade the scientific research on Unmanned Aerial Vehicless (UAVs) increased spectacularly and led to the design of multiple types of aerial platforms. The major challenge today is the development of autonomously operating aerial agents capable of completing missions independently of human interaction. To this extent, visual sensing techniques have been integrated in the control pipeline of the UAVs in order to enhance their navigation and guidance skills. The aim of this article is to present a comprehensive literature review on vision based applications for UAVs focusing mainly on current developments and trends. These applications are sorted in different categories according to the research topics among various research groups. More specifically vision based position-attitude control, pose estimation and mapping, obstacle detection as well as target tracking are the identified components towards autonomous agents. Aerial platforms could reach greater level of autonomy by integrating all these technologies onboard. Additionally, throughout this article the concept of fusion multiple sensors is highlighted, while an overview on the challenges addressed and future trends in autonomous agent development will be also provided.

  • 46.
    Georgoulas, Georgios
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Climente-Alarcón, Vicente
    Department of Electrical Engineering and Automation, Aalto University.
    Antonino-Daviu, José Alfonso
    Instituto Tecnologico de la Energia, Universitat Politècnica de València.
    Tsoumas, Ioannis P.
    ABB Corporate Research, Baden-Dättwil.
    Stylios, Chrysostomos D.
    Laboratory of Knowledge and Intelligent Computing, Department of Computer Engineering, TEI of Epirus, Artas, Kostakioi.
    Arkkio, Antero
    Department of Electrical Engineering and Automation, Aalto University.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    The use of a multilabel classification framework for the detection of broken bars and mixed eccentricity faults based on the start-up transient2017Ingår i: IEEE Transactions on Industrial Informatics, ISSN 1551-3203, E-ISSN 1941-0050, Vol. 13, nr 2, s. 625-634, artikel-id 7778161Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper, a data-driven approach for the classification of simultaneously occurring faults in an induction motor is presented. The problem is treated as a multilabel classification problem, with each label corresponding to one specific fault. The faulty conditions examined include the existence of a broken bar fault and the presence of mixed eccentricity with various degrees of static and dynamic eccentricity, while three 'problem transformation' methods are tested and compared. For the feature extraction stage, the start-up current is exploited using two well-known time-frequency (scale) transformations. This is the first time that a multilabel framework is used for the diagnosis of co-occurring fault conditions using information coming from the start-up current of induction motors. The efficiency of the proposed approach is validated using simulation data with promising results irrespective of the selected time-frequency transformation

  • 47.
    Fresk, Emil
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Ödmark, Kristoffer
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Ultra WideBand enabled Inertial Odometry for Generic Localization2017Ingår i: IFAC-PapersOnLine, ISSN 1045-0823, E-ISSN 1797-318X, Vol. 50, nr 1, s. 11465-11472Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper we will present a inertial odometry localization system, utilizing Ultra WideBand distance measurements for corrections, as a generic localization solution. The proposed scheme is evaluated in two different measurement schemes, one cyclic and one based on stochastic events, which has the strong merit of minimizing the sampling rate, while adhering to covariance constraints on the state, allowing the system to conform with RF regulations. The efficacy of the proposed scheme is evaluated in extended experimental evaluation on an hexacopter Unmanned Aerial Vehicle

  • 48.
    Mustafa, Mohammed Obaid
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Gustafsson, Thomas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Kominiak, Dariusz
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    A Fault Detection Scheme Based on Minimum Uncertainty Bounds Violation for Broken Rotor Bars in Induction Motors2016Ingår i: Control Engineering Practice, ISSN 0967-0661, E-ISSN 1873-6939, Vol. 48, s. 63-77Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this article, a novel method for broken bars fault detection in the case of three-phase induction motors and under different payloads will be presented and experimentally evaluated. In the presented approach, the cases of a partially or full broken rotor bars is being also considered, caused by: a) drilling 4mm and 8mm out of the $13$mm thickness of the same rotor bar, and b) fully drilled (13mm) one, two and three broken bars. The proposed fault detection method is based on the Set Membership Identification (SMI) technique and a novel proposed minimum boundary violation fault detection scheme, applied on the identified motor's parameters. The system identification procedure is being carried out on the simplified equivalent model of the induction motor, during the steady-state operation (non-fault case), while at the same time the proposed scheme is able to calculate on-line the corresponding safety bounds for the identified variables, based on a priori knowledge of the measuring corrupting noise (worst case encountered). The efficiency, the robustness and the overall performance of the established fault detection scheme is being extensively evaluated in multiple experimental studies and under various time instances of faults and load conditions.

  • 49.
    Kanellakis, Christoforos
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    A robust reconfigurable control scheme against pose estimation induced time delays2016Ingår i: 2016 IEEE Conference on Control Applications (CCA): 19-22 Sept. 2016, Piscataway, NU: IEEE Communications Society, 2016, s. 581-586, artikel-id 7587892Konferensbidrag (Refereegranskat)
    Abstract [en]

    Time delays are one of the most common problems when utilizing a visual sensor for pose estimation or navigation in aerial robotics. Such time delays can grow exponentially as a function of the scene's complexity and the size of the mapping during classical Simultaneous Localization and Mapping (SLAM) strategies. In this article, a robust reconfigurable control scheme against pose estimation induced time delays is presented. Initially, an experimental verification of the induced time delays via pose estimation is performed for the attitude problem of a hexacopter, while a switching time delay dependent modeling approach is formulated. In addition, a stability analysis algorithm is introduced in order to evaluate the maximum allowable time delays that the target system can handle for a given LQR controller. The varying nature of the time delays results in a switching system with the latency time to play the role of a switching rule, while simulation results are presented to outline the effects of the time-induced delays in hexarotor-based systems and finally evaluate the overall efficiency of the proposed control scheme.

  • 50.
    Brusell, Angelica
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Andrikopoulos, Georgios
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Nikolakopoulos, George
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    A survey on Pneumatic Wall-Climbing Robots for Inspection2016Ingår i: 24th Mediterranean Conference on Control and Automation MED: June 21-24, Athens, Greece, 2016, Piscataway. NJ: IEEE Communications Society, 2016, s. 220-225, artikel-id 7535885Konferensbidrag (Refereegranskat)
    Abstract [en]

    The aim of this article is to present a survey on inspection applications of Pneumatic Wall-Climbing Robots (PWCR). In general, a PWCR utilizes negative pressure as its adhesion method, through mainly suction cups or negative pressure thrust-based mechanisms. Their main advantage being their ability to climb non-ferromagnetic surfaces, such as glass and composite materials, in comparison with climbing robots based on magnetic adhesion methods. A growing application area is the utilization of PWCRs for inspection purposes for accelerating the otherwise time consuming procedures of manual inspection, while offering the important advantage of protecting human workers from hazardous and/or unreachable environments. This article will summarize the key enabling inspection applications of PWCRs in the following areas: a) Construction, b) Industrial Infrastructures, as well as c) Aircraft applications.

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