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  • 1.
    Autioniemi, J
    et al.
    Lapland University of Applied Sciences.
    Autioniemi, M
    Lapland University of Applied Sciences.
    Casselgren, Johan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Konttaniemi, H
    Lapland University of Applied Sciences.
    Sukuvaara, T
    FMI-Arctic Research Centre, Sodankylä.
    Ylitalo, R
    FMI-Arctic Research Centre, Sodankylä.
    Intelligent Road2015Rapport (Övrigt vetenskapligt)
    Abstract [en]

    Project Intelligent Road is a common effort of four main partners: Rovaniemi University of Applied Sciences (RAMK), Luleå Technical University (LTU), Finnish Meteorological Institute (FMI), Kaakkois-Suomen ELY-keskus (KaS ELY) – and representatives of business sector of the region. The overall objective of the project is to support the development of business community in Northern Scandinavian region by testing and improvement of existing innovative products concerned with road safety provision in Nordic weather conditions. The specific objective of the project is to create a demo of sustainable and marketable Intelligent Road System providing location-based short-term road weather information to the road user passing by the area. Target Groups, which are directly and positively affected by the project are businesses and above mentioned project partners. All these actors have exclusive know-how in the area and are each equally important for the implementation of the project and its success. Final beneficiaries of this project are business community of the Northern Scandinavian Region; Ministry of Transport and Communications of Finland, represented by KaS ELY and Finnish Transport Safety Agency; Swedish Ministry of Enterprise, Energy and Communications; and of course local municipalities, as Luleå Municipality, and road users.

  • 2.
    Bruzelius, F
    et al.
    Volvo Technology.
    Svendenius, J
    Haldex.
    Yngve, S
    Volvo Cars.
    Olsson, G
    Saab Automobile.
    Casselgren, Johan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Andersson, M
    Volvo Technology.
    Rönnberg, J
    Saab Automobile.
    Löfving, S.
    Evaluation of tyre to road friction estimators: test methods and metrics2010Ingår i: International Journal of Vehicle Systems Modelling and Testing, ISSN 1745-6436, E-ISSN 1745-6444, Vol. 5, nr 2-3, s. 213-236Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The tyre to road contact friction is one of the most important properties when it comes to manoeuvrability of ground vehicles and information, to driver and vehicle, is of vital importance in critical situations. Different characteristics of different friction estimation methods make it hard to determine and compare performance of estimators. This article is an attempt to define and evaluate the performance of tyre to road friction estimators. The objective of the performance evaluation is to define and grade the performance of estimators based on all sorts of approaches and combinations of these. The result may be used in the context of benchmarking as well as a tool in the development process of the estimator. The test methods and metrics presented are illustrated with a comparative study of three different estimation approaches.

  • 3.
    Casselgren, Johan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Road surface characterization using near infrared spectroscopy2011Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Denna avhandling presenterar en teknik och metod för att klassificera och beskriva olika vägförhållanden som torr asfalt och asfalt täckt med vatten, is och snö. Metoden använder ljuskällor av olika våglängder för att belysa vägbanan och en detektor för att mäta det reflekterade ljuset från vägbanan, beroende på hur ytan har absorberats, spritt och polariserat ljuset är det möjligt att klassificera de olika vägförhållanden. Men att veta vad för beläggning som är på asfalt är inte tillräckligt för att göra en bra uppskattning av väggreppet. Därför, genom att tillämpa en ljuspropageringsmodell och skatta parametrar såsom porositet, ojämnhet och djup i beläggningen är det möjligt att få mer information som kan förbättra en uppskattning av väggreppet. Dessa undersökningar genomfördes både i laboratoriemiljö och på verkliga vägar.Tekniken som presenteras i denna avhandling visar potential för att klassificera och beskriva olika väglag. Statistiken visar att många trafikolyckor med dödlig utgång kan relateras till halt väglag. De mest riskfyllda väglagen är de som är svåra för föraren att upptäcka och som uppkommer plötsligt på vägen. En sensor som kan klassificera vägförhållanden, skulle kunna förbättra trafiksäkerheten avsevärt. Information om rådande vägförhållanden skulle kunna användas i flera tillämpningar, exempelvis i det egna fordonet både för att informera föraren och till olika system i fordonet som t ex elektroniska stabilitetsprogrammet (ESP), låsningsfria bromsar (ABS) eller antispinnsystem (TCS). Sådan information kan även överföras till andra förare och till infrastrukturen, vilket gör det möjligt att planera en resväg beroende på rådande vägförhållanden. Men även för vägunderhåll och då på en lokal nivå på de vägsträckor där det verkligen behövs.Eftersom det finns ett antal prototyper och idéer hur man kan uppskatta väggrepp, är det viktigt att olika metoder utvärderas och testas på samma sätt. Därför innehåller denna avhandling en testmetod och ett antal mått för att kontrollera de olika systemen och undersöka svagheter och styrkor hos olika tekniker. Den teknik som har undersökts i denna avhandling har även utvärderats enligt denna metod.

  • 4.
    Casselgren, Johan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Road surface classification using near infrared spectroscopy2007Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Statistics shows that most traffic accidents with fatal outcome can be related to slippery road conditions. The most hazardous road conditions are the ones that are hard for the driver to detect and that appears sudden on the road. A sensor that classify the road condition in front of the vehicle, warning both the driver and the systems in the vehicle that are incorporated to help the driver, like the electronic stability program (ESP), anti-lock brake system (ABS) or the traction control system (TCS), could help to reduce these accidents. There are several prototypes for classification of road conditions available but they are not yet fully functional. In this thesis a method that makes it possible to classify the four distinct road conditions dry asphalt and asphalt covered with water, ice and snow, respectively, with a low probability of wrong classification using three wavelengths is presented. A prototype sensor built on the a technique using two laser diodes and a photo detector is tested in a real environment and compared with laboratory measurements which shows a promising result characterizing dry asphalt and asphalt covered with ice and snow. Both theory and experiments are presented. The most difficult road conditions to classify from each other are water and clear ice for which a method using polarized light is investigated. The investigation shows that using polarized light for illumination and a polarizer as an analyzer for classification of water and ice on asphalt is a more reliable method than using unpolarized light. All three investigations show promising results in developing an actual sensor to reduce fatal accidents in traffic.

  • 5.
    Casselgren, Johan
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Bodin, Ulf
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Reusable road condition information system for traffic safety and targeted maintenance2017Ingår i: IET Intelligent Transport Systems, ISSN 1751-956X, E-ISSN 1751-9578, Vol. 11, nr 4, s. 230-238Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Driver awareness of current winter road conditions (RCs) is known to affect the frequency of accidents due to sudden changes in these conditions. For example, partially icy roads that appear during autumn in northern areas typically result in collisions and ditch runs unless the drivers are generally aware of the situation. Availing motorists who drive under winter RCs of enhanced information is therefore highly desirable to increase their awareness of hazardous driving conditions. Such conditions need to be predicted ahead of time and presented to drivers before they attempt slippery road sections. Moreover, the identification of slippery RCs should quickly trigger targeted road maintenance to reduce the risk of accidents. This study presents a scalable and reusable collaborative intelligent transport system, herein referred to as an RC information system (RCIS). RCIS provides accurate RC predictions and forecasts based on RC measurements, road weather observations, and short-term weather forecasts. The prediction methods in the context of the distributed RCIS have been tested using a prototype implementation. These tests confirmed that these inputs could be combined into useful and accurate information about winter RCs that can be adapted for different types of users.

  • 6.
    Casselgren, Johan
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Engström, Niclas
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Rosendahl, Sara
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Fransson, Lennart
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Investigation of ice surface change during vehicle testing2014Ingår i: International Journal of Vehicle Systems Modelling and Testing, ISSN 1745-6436, E-ISSN 1745-6444, Vol. 9, nr 2, s. 137-150Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Today, there are a lot of vehicles and tyre testing carried out on lake ice surfaces. Thus, it is important to have knowledge about parameters that affect roadgrip. The thesis within this paper is that the liquid like layer which appears due to increasing temperature can be reduced by manipulating the ice roughness. This in turn should decrease the temperature dependence of the roadgrip in temperatures around 0°C. In order to investigate this, measurements of temperature, surface roughness and hardness and roadgrip were performed on three outdoor ice surfaces using an IR thermometer, an optical sensor with three IR-diodes, a steel ball drop indentation test and an RT3 curve, respectively. Additional ice roughness measurements were also made on two tempered ice surfaces in an ice hall. Results show a clear connection between ice temperature and roadgrip, unfortunately the created ice roughness was too small to influence the change in roadgrip

  • 7.
    Casselgren, Johan
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Kutila, Matti
    VTT Technical Research Centre of Finland, Espoo.
    Jokela, Maria
    VTT Technical Research Centre of Finland, Espoo.
    Slippery road detection by using different methods of polarised light2012Ingår i: Advanced Microsystems for Automotive Applications 2012: Smart Systems for Safe, Sustainable and Networked Vehicles / [ed] Meyer Gereon, Berlin: Springer Science+Business Media B.V., 2012, s. 207-220Konferensbidrag (Refereegranskat)
    Abstract [en]

    Road friction measurement is an important issue for active safety systems on vehicles; hence knowledge of this key parameter can significantly improve the interventions on vehicle dynamics. This study compares two different on-board sensors for the classification of road conditions with polarised infrared light. Several tests are performed on a dedicated track, with focus on detection of dry or wet surfaces, and the presence of ice or snow. The work shows the capability of both sensors to provide a correct classification. In particular, results indicate how the monitored area, the presence of active illumination and the mounting position influence measurements and response times. It is concluded that both systems classify different road conditions in all cases. Performance of the RoadEye system varied from 80 to 90 % whereas the camera based IcOR achieved 70-80 % accuracy level. Since these are being prototype sensors more development is needed before implemented into advanced safety applications.

  • 8.
    Casselgren, Johan
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Olofsson, Ulf
    Machine Design, KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden.
    Zhu, Yi
    Machine Design, KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden.
    Löfving, Sten
    Optical sensors.
    Mayer, Laura
    Stockholm Public Transport.
    Nilsson, Rickard
    Stockholm Public Transport.
    An optical sensor for the identification of low adhesion in the wheel–rail contact2012Ingår i: The international Journal of railway technology, ISSN 2049-5358, E-ISSN 2053-602X, Vol. 1, nr 3, s. 97-110Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Low adhesion between railway wheel and rail, usually induced by contaminants such as water, oil, and leaves, affects railway performance and safety. This study uses an optical sensor to identify various surface layers that cause low adhesion. In both a laboratory set-up and field tests under various conditions, the surface layers were identified by the optical sensor; in addition, the friction coefficients for the same surface layers were measured. The results indicate that the sensor can distinguish between different surface layers. This information, together with friction coefficient data, can be used in a prediction system for use by railway operators.

  • 9.
    Casselgren, Johan
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Rosendahl, Sara
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Eliasson, Jens
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Road surface information system2013Ingår i: Proceedings of the 16th SIRWEC conference: Helsinki, FInland (23-25th May 2012), Standing International Road Weather Commission , 2013Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    In order to classify the road condition, dry asphalt and asphalt covered with water, ice and snow a technique using a sensor called Road eye is presented. The Road eye sensor uses three wavelengths and one photo detector to determine the intensities that are reflected from the road surface and is then able to estimate the road condition. By linking the Road eye sensor to a GPS and a Mulle, a miniature wireless Embedded Internet System, the road conditions can be associated with the correct road position, making it possible to use the information in many different applications.

  • 10.
    Casselgren, Johan
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Rosendahl, Sara
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Engström, Niclas
    LKAB, SE-981-86 Kiruna, Sweden.
    Grönlund, Ulrika
    Autoliv Sverige AB, Active Saftey Tech Center, Linköping, Sweden.
    Evaluation of velocity and curvature dependence for roadgrip measured by low lateral slip2017Ingår i: International Journal of Vehicle Systems Modelling and Testing, ISSN 1745-6436, E-ISSN 1745-6444, Vol. 12, nr 1/2, s. 1-16Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Roadgrip is an important parameter for vehicle testing and road maintenance. Therefore, an evaluation of the velocity and curvature effects on roadgrip measurement was performed on asphalt roads and on two ice tracks using the continuous roadgrip apparatus RT3 Curve. The aim was to find suitable driving patterns for measurements on public roads and test tracks to ensure the repeatability of roadgrip measurements. During the evaluation, it was concluded that in order to achieve a reliable roadgrip value, regardless of road conditions, the radius of curvature should not be less than 20 m. The velocity dependency of the RT3 Curve is different for the two road conditions, with the measurements on ice being much more sensitive to velocity changes than the measurements on the dry asphalt.

  • 11.
    Casselgren, Johan
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Rosendahl, Sara
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Sjödahl, Mikael
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Jonsson, Patrik
    Combitech AB, Mittuniversitetet, Department of Information Technology and Media, Mid-Sweden University.
    Road condition analysis using NIR illumination and compensating for surrounding light2016Ingår i: Optics and lasers in engineering, ISSN 0143-8166, E-ISSN 1873-0302, Vol. 77, s. 175-182Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An investigation of a NIR camera system for road surface classification has been conducted for several road conditions. The surfaces were illuminated with three wavelengths, 980 nm, 1310 nm and 1550 nm and a halogen lamp, to simulate a real environment application with surrounding light. A measuring scheme to deal with surrounding light has been implemented enabling road condition classification from NIR images in a real environment. The retrieved camera images have been analyzed and an RGB representation of the different surfaces has been created to classify the different road conditions. The investigation shows that it is possible to distinguish between dry, moist, wet, frosty, icy and snowy road surfaces using a NIR camera system in a disturbed environment.

  • 12.
    Casselgren, Johan
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Sjödahl, Mikael
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Polarization resolved classification of winter road condition in the near-infrared region2012Ingår i: Applied Optics, ISSN 1559-128X, E-ISSN 2155-3165, Vol. 51, nr 15, s. 3036-3045Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Three different configurations utilizing polarized short-wave infrared light to classify winter road conditions have been investigated. In the first configuration, polarized broadband light was detected in the specular and backward directions, and the quotient between the detected intensities was used as the classification parameter. Best results were obtained for the SS-configuration. This sensor was shown to be able to distinguish between the smooth road conditions of water and ice from the diffuse road conditions of snow and dry asphalt with a probability of wrong classification as low as 7%. The second sensor configuration was a pure backward architecture utilizing polarized light with two distinct wavelengths. This configuration was shown to be effective for the important problem of distinguishing water from ice with a probability of wrong classification of only 1.5%. The third configuration was a combination of the two previous ones. This combined sensor utilizing bispectral illumination and bidirectional detection resulted in a probability of wrong classification as low as 2% among all four surfaces.

  • 13.
    Casselgren, Johan
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik.
    Sjödahl, Mikael
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Leblanc, James
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Angular spectral response from covered asphalt2007Ingår i: Applied Optics, ISSN 1559-128X, E-ISSN 2155-3165, Vol. 46, nr 20, s. 4277-4288Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    By measuring the spectral reflection from the four different road conditions dry, wet, icy, and snowy asphalt, a method of classification for the different surfaces -- using two and three wavelengths -- is developed. The method is tested against measurements to ascertain the probability of wrong classification between the surfaces. From the angular spectral response, the fact that asphalt and snow are diffuse reflectors and water and ice are reflective are confirmed.

  • 14.
    Casselgren, Johan
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Sjödahl, Mikael
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Leblanc, James
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Model-based winter road classification2012Ingår i: International Journal of Vehicle Systems Modelling and Testing, ISSN 1745-6436, E-ISSN 1745-6444, Vol. 7, nr 3, s. 268-284Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An investigation of different road conditions has been conducted using a short-wave infrared (SWIR) light online sensor to examine the possibility of estimating road condition parameters such as porosity, depth and roughness. These parameters are essential for non-contact road friction estimation. The investigation show that it is possible to detect changes of depths of water and ice as well as classify different types of ice, by utilising polarised short-wave infrared (SWIR) light and a modified Hapke directional reflectance model

  • 15. Casselgren, Johan
    et al.
    Sjödahl, Mikael
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Sanfridsson, M
    Volvo Technology.
    Woxneryd, S
    Volvo Technology.
    Classification of road conditions - to improve safety2007Ingår i: Advanced microsystems for automotive applications 2007 / [ed] Jürgen Valldorf; Wolfgang Gessner, 2007, s. 47-59Konferensbidrag (Refereegranskat)
    Abstract [en]

    Measuring the road condition in front of a vehicle could prevent accidents and make technologies like electronic stability control (ESP) more efficient. By making three investigations of the classifications of the four road conditions dry asphalt, asphalt covered with water, ice and snow the possibility of a preview sensor is exploited. By measuring the reflectance from the different surfaces with a halogen light and an actual sensor (Road eye) in a laboratory surroundings the advantage and disadvantage are revealed. The sensor is also mounted in a Volvo truck for real-life condition measurements.

  • 16.
    Dittes, Nicholas
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Pettersson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Sjödahl, Mikael
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Casselgren, Johan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Marklund, Pär
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Lugt, Piet M.
    SKF Engineering and Research Center, Nieuwegein.
    Optical Attenuation Characterization of Water Contaminated Lubricating Grease2018Ingår i: Tribology Transactions, ISSN 1040-2004, E-ISSN 1547-397X, Vol. 61, nr 4, s. 726-732Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Water-contaminated grease samples are investigated with attenuation spectra in the visible and near-infrared (NIR) regions in this article. The purpose of this investigation was to identify a model with optical attenuation spectra such that the water content of grease samples could be characterized with a simple measurement setup using common methodology from the field of instrumental chemistry. The ratio between two chosen wavelengths of light appears to approximate the water content of grease samples with an acceptable coefficient of determination using a methodology to show what can potentially be done to develop condition monitoring tools. To illustrate the outlined method, a prestudy of grease aging and oxidation levels is also investigated to show that other variables do not significantly change the measurement.

  • 17.
    Eppanapelli, Lavan Kumar
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Casselgren, Johan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Wåhlin, Johan
    Norwegian University of Science and Technology.
    Sjödahl, Mikael
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Investigation of snow single scattering properties of snow based on first order Legendre phase function2017Ingår i: Optics and lasers in engineering, ISSN 0143-8166, E-ISSN 1873-0302, Vol. 91, s. 151-159Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Angularly resolved bidirectional reflectance measurements were modelled by ap- proximating a first order Legendre expanded phase function to retrieve single scattering properties of snow. The measurements from 10 different snow types with known density and specific surface area (SSA) were investigated. A near infrared (NIR) spectrometer was used to measure reflected light above the snow surface over the hemisphere in the wavelength region 900 nm to 1650 nm. A solver based on discrete ordinate radiative transfer (DISORT) model was used to retrieve the estimated Legendre coefficients of the phase function and a cor- relation between the coefficients and physical properties of different snow types is investigated. Results of this study suggest that the first two coefficients of the first order Legendre phase function provide sufficient information about the physical properties of snow where the latter captures the anisotropic behaviour of snow and the former provides a relative estimate of the single scattering albedo of snow. The coefficients of the first order phase function were com- pared with the experimental data and observed that both the coefficients are in good agreement with the experimental data. These findings suggest that our approach can be applied as a qualitative tool to investigate physical properties of snow and also to classify different snow types.

  • 18.
    Eppanapelli, Lavan Kumar
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Forsberg, Fredrik
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Casselgren, Johan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Lycksam, Henrik
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    3D analysis of deformation and porosity of dry natural snow during compaction2019Ingår i: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 12, nr 6, artikel-id 850Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The present study focuses on three-dimensional (3D) microstructure analysis of dry natural snow during compaction. An X-ray computed microtomography (micro-CT) system was used to record a total of 1601 projections of a snow volume. Experiments were performed in-situ at four load states as 0 MPa, 0.3 MPa, 0.6 MPa and 0.8 MPa, to investigate the effect of compaction on structural features of snow grains. The micro-CT system produces high resolution images (4.3 μm voxel) in 6 hours of scanning time. The micro-CT images of the investigated snow volume illustrate that grain shapes are mostly dominated by needles, capped columns and dendrites. It was found that a significant number of grains appeared to have a deep hollow core irrespective of the grain shape. Digital volume correlation (DVC) was applied to investigate displacement and strain fields in the snow volume due to the compaction. Results from the DVC analysis show that grains close to the moving punch experience most of the displacement. The reconstructed snow volume is segmented into several cylinders via horizontal cross-sectioning, to evaluate the vertical heterogeneity of porosity distribution of the snow volume. It was observed that the porosity (for the whole volume) in principle decreases as the level of compaction increases. A distinct vertical heterogeneity is observed in porosity distribution in response to compaction. The observations from this initial study may be useful to understand the snow microstructure under applied stress.

  • 19.
    Eppanapelli, Lavan Kumar
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Friberg, Benjamin
    Casselgren, Johan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Sjödahl, Mikael
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Estimation of a low-order Legendre expanded phase function of snow2016Ingår i: Optics and lasers in engineering, ISSN 0143-8166, E-ISSN 1873-0302, Vol. 78, s. 174-181Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The purpose of this paper is to estimate the scattering phase function of snow from angularly resolved measurements of light intensity in the plane of incidence. A solver is implemented that solves the scattering function for a semi-infinite geometry based on the radiative transfer equation (RTE). Two types of phase functions are considered. The first type is the general phase function based on a low-order series expansion of Legendre polynomials and the other type is the Henyey-Greenstein (HG) phase function. The measurements were performed at a wavelength of 1310 nm and six different snow samples were analysed. It was found that a first order expansion provides sufficient approximation to the measurements. The fit from the first order phase function outperforms that of the HG phase function in terms of accuracy, ease of implementation and computation time. Furthermore, a correlation between the magnitude of the first order component and the age of the snow was found. We believe that these findings may complement present non-contact detection techniques used to determine snow properties.

  • 20.
    Jonsson, Patrik
    et al.
    Combitech AB, Mittuniversitetet.
    Casselgren, Johan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Thörnberg, Benny
    Mittuniversitetet.
    Road surface status classification using spectral analysis of NIR camera images2015Ingår i: IEEE Sensors Journal, ISSN 1530-437X, E-ISSN 1558-1748, Vol. 15, nr 3, s. 1641-1656Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    There is a need for an automated road status classification system considering the vast number of weather-related accidents that occur every winter. Previous research has shown that it is possible to detect hazardous road conditions, including, for example, icy pavements, using single point infrared illumination and infrared detectors. In this paper, we extend this research into camera surveillance of a road section allowing for classification of area segments of weather-related road surface conditions such as wet, snow covered, or icy. Infrared images have been obtained using an infrared camera equipped with a set of optical wavelength filters. The images have primarily been used to develop multivariate data models and also for the classification of road conditions in each pixel. This system is a vast improvement on existing single spot road status classification systems. The resulting imaging system can reliably distinguish between dry, wet, icy, or snow covered sections on road surfaces.

  • 21.
    Lundberg, Jan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik. Division of Operation and Maintenance, Luleå University of Technology.
    Rantatalo, Matti
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik. Division of Operation and Maintenance, Luleå University of Technology.
    Wanhainen, Christina
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geovetenskap och miljöteknik. Division of Geosciences and Environmental Engineering, Luleå University of Technology.
    Casselgren, Johan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik. Division of Fluid and Experimental Mechanics, Luleå University of Technology.
    Measurements of friction coefficients between rails lubricated with a friction modifier and the wheels of an IORE locomotive during real working conditions2015Ingår i: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 324-325, s. 109-117Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The real friction coefficients between the rails and the wheels on a 360. t and 10,800. kW IORE locomotive were measured using the locomotive[U+05F3]s in-built traction force measurement system. The locomotive consisted of two pair-connected locomotives had a CoCo+CoCo bogie configuration, and hauled a fully loaded set of 68 ore wagons (120. t/wagon). The measurements were performed both on rails in a dry condition and on rails lubricated with a water-based top-of-rail (ToR) friction modifier on the Iron Ore Line between the cities of Kiruna and Narvik in Northern Sweden and Norway, respectively. Since full-scale measurements like these are costly, the friction coefficients were also measured at the same time and place using a conventional hand-operated tribometer, with and without the ToR friction modifier. The most important results are that the real friction coefficient is definitely not constant and is surprisingly low (0.10-0.25) when the ToR friction modifier is used, and that it is also significantly dependent on the amount of ToR friction modifier. A large amount will reduce the friction coefficient. Furthermore, it is concluded that the real friction coefficients are in general lower than the friction coefficients measured with the hand-operated tribometer. A final remark is thus that the use of a water-based ToR friction modifier can give excessively low friction, which can result in unacceptably long braking distances.

  • 22.
    Odelius, Johan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Famurewa, Stephen Mayowa
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Forslöf, Lars
    Roadroid AB Ljusdal .
    Casselgren, Johan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Konttaniemi, Heikki
    Arctic Power RDI-team, Lapland University of Applied Sciences Rovaniemi .
    Industrial internet applications for efficient road winter maintenance2017Ingår i: Journal of Quality in Maintenance Engineering, ISSN 1355-2511, E-ISSN 1758-7832, Vol. 23, nr 3, s. 355-367Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: For the expected increase in the capacity of existing transportation systems and efficient energy utilisation, smart maintenance solutions that are supported by online and integrated condition monitoring systems are required. Industrial Internet is one of the smart maintenance solutions, which enables real-time acquisition and analysis of asset condition by linking intelligent devices with different stakeholdersᅵ applications and databases. This paper presents some aspects of Industrial Internet application as required for integrating weather information and floating road condition data from vehicle mounted sensors to enhance effective and efficient winter maintenance.

    Design/methodology/approach: The concept of real-time road condition assessment using in-vehicle sensors is demonstrated in a case study of a 3.5 km road section located in northern Sweden. The main floating data sources were acceleration and position sensors from a smartphone positioned on the dash board of a truck. Features extracted from the acceleration signal were two road roughness estimations. To extract targeted information and knowledge, the floating data were further processed to produce time series data of the road condition using Kalman filtering. The time series data were thereafter combined with weather data to assess the condition of the road.

    Findings: In the case study, examples of visualisation and analytics to support winter maintenance planning, execution, and resource allocation were presented. Reasonable correlation was shown between estimated road roughness and annual road survey data to validate and prove the presented results wider applicability.

    Originality/value: The paper describes a concept of floating data for an industrial internet application for efficient road maintenance. The resulting improvement in winter maintenance will promote dependable, safe and sustainable transportation of goods and people, especially in northern Nordic region with harsh and sometimes unpredictable weather conditions.

  • 23.
    Olofsson, Ulf
    et al.
    Machine Design, KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden.
    Zhu, Yi
    Machine Design, KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden.
    Casselgren, Johan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Löfving, Sten
    Optical sensors.
    Meyer, L
    Stockholm Public Transport.
    Nilsson, Rickard N.
    Stockholm Public Transport.
    An optical sensor for the identification of low adhesion in the wheel rail contact2012Ingår i: 9th International Conference on Contact Mechanics and Wear of Rail/Wheel Systems: CM2012, 27-30 August 2012, Chengdu, China : proceedings, Chengdu: State Key Laboratory of Traction Power (TPL), Southwest Jiaotong University , 2012, s. 318-323Konferensbidrag (Refereegranskat)
    Abstract [en]

    Low adhesion between railway wheel and rail, which is usually induced by contaminants such as water, oil, leaves etc., affects railway operation in terms of performance and safety. This study uses an optical sensor to identify different surface layers which cause low adhesion. A laboratory set up and field tests under various conditions were subject to the surface layer identification by the optical sensor. In addition, the friction coefficient was measured on the same surface layers. The results show that the sensor can distinguish between different surface layers. This information further linked to the levels of the friction coefficient, which can be used in the prediction system for the railway operator.

  • 24.
    Rosendahl, Sara
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Casselgren, Johan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Sjödahl, Mikael
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Simplified model for light scattering from granular materials with varying moisture content2013Ingår i: Applied Optics, ISSN 1559-128X, E-ISSN 2155-3165, Vol. 52, nr 17, s. 4006-4012Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Reflection measurements were performed on dry and moistened sand grains and glass spheres, respectively. A simple model for determining the water content is proposed from looking at the reflection distribution in the plane of incidence. The model is a combination of two sheared cosine-functions and consists of only two parameters. One parameter controls whether the reflection is mainly in the forward or backward direction. The former is true when the water content is high and the latter is true when the material is dry. The other parameter gives an idea of the homogeneity of the material.

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