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Rosendahl, Sara
Publications (10 of 14) Show all publications
Casselgren, J., Rosendahl, S., Sjödahl, M. & Jonsson, P. (2016). Road condition analysis using NIR illumination and compensating for surrounding light (ed.). Paper presented at . Optics and lasers in engineering, 77, 175-182
Open this publication in new window or tab >>Road condition analysis using NIR illumination and compensating for surrounding light
2016 (English)In: Optics and lasers in engineering, ISSN 0143-8166, E-ISSN 1873-0302, Vol. 77, p. 175-182Article in journal (Refereed) Published
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.

National Category
Applied Mechanics
Research subject
Experimental Mechanics
Identifiers
urn:nbn:se:ltu:diva-3637 (URN)10.1016/j.optlaseng.2015.08.002 (DOI)000366617300021 ()2-s2.0-84941908610 (Scopus ID)1745f2b3-0568-4b59-9515-df224fe10d60 (Local ID)1745f2b3-0568-4b59-9515-df224fe10d60 (Archive number)1745f2b3-0568-4b59-9515-df224fe10d60 (OAI)
Note
Validerad; 2015; Nivå 2; 20150916 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Casselgren, J., Engström, N., Rosendahl, S. & Fransson, L. (2014). Investigation of ice surface change during vehicle testing (ed.). Paper presented at . International Journal of Vehicle Systems Modelling and Testing, 9(2), 137-150
Open this publication in new window or tab >>Investigation of ice surface change during vehicle testing
2014 (English)In: International Journal of Vehicle Systems Modelling and Testing, ISSN 1745-6436, E-ISSN 1745-6444, Vol. 9, no 2, p. 137-150Article in journal (Refereed) Published
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

National Category
Applied Mechanics Tribology (Interacting Surfaces including Friction, Lubrication and Wear) Infrastructure Engineering
Research subject
Experimental Mechanics; Machine Elements; Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-7501 (URN)10.1504/IJVSMT.2014.061435 (DOI)2-s2.0-84901634457 (Scopus ID)5e55df2a-1148-4308-bf6f-d8fde27fbe78 (Local ID)5e55df2a-1148-4308-bf6f-d8fde27fbe78 (Archive number)5e55df2a-1148-4308-bf6f-d8fde27fbe78 (OAI)
Projects
CASTT - Centre for Automotive Systems Technologies and Testing
Note
Validerad; 2014; 20131128 (sarros)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Casselgren, J., Rosendahl, S. & Eliasson, J. (2013). Road surface information system (ed.). In: (Ed.), (Ed.), Proceedings of the 16th SIRWEC conference: Helsinki, FInland (23-25th May 2012). Paper presented at SIRWEC 2012 : Standing International Road Weather Commission 23/05/2012 - 25/05/2012. : Standing International Road Weather Commission
Open this publication in new window or tab >>Road surface information system
2013 (English)In: Proceedings of the 16th SIRWEC conference: Helsinki, FInland (23-25th May 2012), Standing International Road Weather Commission , 2013Conference paper, Published paper (Other academic)
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.

Place, publisher, year, edition, pages
Standing International Road Weather Commission, 2013
National Category
Applied Mechanics Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Experimental Mechanics; Industrial Electronics
Identifiers
urn:nbn:se:ltu:diva-29595 (URN)31db44be-d7b7-40e5-a1a6-16406f69e71b (Local ID)31db44be-d7b7-40e5-a1a6-16406f69e71b (Archive number)31db44be-d7b7-40e5-a1a6-16406f69e71b (OAI)
Conference
SIRWEC 2012 : Standing International Road Weather Commission 23/05/2012 - 25/05/2012
Projects
CASTT - Centre for Automotive Systems Technologies and Testing
Note
Godkänd; 2013; 20130211 (sarros)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Rosendahl, S. (2013). Shape and surface characterization using diffused light (ed.). (Doctoral dissertation). Paper presented at . Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>Shape and surface characterization using diffused light
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Diffuse reflection from various surfaces have been studied using several different methods in order to draw conclusions about the surfaces. First of all the aim was to perform fast and accurate shape measurements of molded steel objects on-line in a production system. Two measurement methods were used, stereoscopic imaging with projected fringes and dual wavelength digital holography. Information from the CAD model of the object was used to speed up the shape determination, mainly by enhancing the performance of the phase unwrapping. The uncertainty of the shape result was between 3.5 µm and 40 µm depending on the measurement method. The request on conformity between the object and the CAD model varied between 0.1 mm and 1.6 mm. To overcome the influence of speckles in the case of using interference fringes in the stereoscopic imaging an investigation of speckle reduction using a moving aperture was performed. The technique resulted in a decrease in the speckle contrast of about 60%.Secondly, diffuse reflections that come not only from the surface, but also from beneath it were studied. Measurements were done both on ice surfaces with the aim to identify changes in the surface structure and on glass spheres and sand grains with the aim to detect different moist content in granular material. The ice measurements showed an increase in the back reflection and a decrease in the specular reflection when the surface went from being smooth to being rough, a fact that can be useful when considering the roadgrip of icy roads. Depending on the water content in the granular materials the moist measurements when illuminating the surfaces with white light showed differences in the shape of the reflection distribution in the plane of incidence. Given these differences a simple model describing the water content was proposed.All experiments, except the ones on ice, have been performed in the laboratory. The results have been analyzed and compared to simulations, model estimations, and in the case of the shape measurements with the corresponding CAD models, all with relatively good outcome.In this thesis the work is presented in six papers. One about the speckle reduction method, three about the shape measurements and two about the ice surface structure and the moist in granular material, respectively.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2013
Series
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544
National Category
Applied Mechanics
Research subject
Experimental Mechanics
Identifiers
urn:nbn:se:ltu:diva-18083 (URN)6c36694c-55c4-4be3-a7e4-b4406207f03f (Local ID)978-91-7439-566-2 (ISBN)6c36694c-55c4-4be3-a7e4-b4406207f03f (Archive number)6c36694c-55c4-4be3-a7e4-b4406207f03f (OAI)
Note
Godkänd; 2013; 20130207 (sarros); Tillkännagivande disputation 2013-03-15 Nedanstående person kommer att disputera för avläggande av teknologie doktorsexamen. Namn: Sara Rosendahl Ämne: Experimentell mekanik/Experimental Mechanics Avhandling: Shape and Surface Characterization Using Diffused Light Opponent: Senior Lecturer Pablo Ruiz, Wolfson School, Loughborough University, Leicestershire, UK Ordförande: Professor Mikael Sjödahl, Institutionen för teknikvetenskap och matematik, Luleå tekniska universitet Tid: Fredag den 5 april 2013, kl 10.00 Plats: E246, Luleå tekniska universitetAvailable from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved
Rosendahl, S., Casselgren, J. & Sjödahl, M. (2013). Simplified model for light scattering from granular materials with varying moisture content (ed.). Paper presented at . Applied Optics, 52(17), 4006-4012
Open this publication in new window or tab >>Simplified model for light scattering from granular materials with varying moisture content
2013 (English)In: Applied Optics, ISSN 1559-128X, E-ISSN 2155-3165, Vol. 52, no 17, p. 4006-4012Article in journal (Refereed) Published
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.

National Category
Applied Mechanics
Research subject
Experimental Mechanics
Identifiers
urn:nbn:se:ltu:diva-14725 (URN)10.1364/AO.52.004006 (DOI)000320110900014 ()23759849 (PubMedID)2-s2.0-84879229237 (Scopus ID)e245e565-c5d7-460e-9416-e0af00c518b4 (Local ID)e245e565-c5d7-460e-9416-e0af00c518b4 (Archive number)e245e565-c5d7-460e-9416-e0af00c518b4 (OAI)
Projects
CASTT - Centre for Automotive Systems Technologies and Testing
Note
Validerad; 2013; 20130704 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Rosendahl, S., Bergström, P., Gren, P. & Sjödahl, M. (2011). Dual-wavelength holographic shape measurement with iterative phase unwrapping (ed.). In: (Ed.), Peter H. Lehmann; Wolfgang Osten; Kay Gastinger (Ed.), Optical Measurement Systems for Industrial Inspection VII: . Paper presented at Optical Measurement Systems for Industrial Inspection : 23/05/2011 - 26/05/2011 (pp. 80820B). Bellingham, Wash.: SPIE - International Society for Optical Engineering
Open this publication in new window or tab >>Dual-wavelength holographic shape measurement with iterative phase unwrapping
2011 (English)In: Optical Measurement Systems for Industrial Inspection VII / [ed] Peter H. Lehmann; Wolfgang Osten; Kay Gastinger, Bellingham, Wash.: SPIE - International Society for Optical Engineering, 2011, p. 80820B-Conference paper, Published paper (Refereed)
Abstract [en]

In order to measure the shape of a large number of identical components in a manufacturing industry we propose a method where digital holography is used to capture an image of the object and then the shape of the object is achieved by using information from the CAD-model. The holographic recording of the object is done using dual wavelengths giving a synthetic wavelength of about 400 μm. This gives a phase map where the phase intervals represent a depth distance on the object of about 0.2 mm. To find the shape of the object the phase map has to be unwrapped. Since the surface contains discontinuities we use information from the CAD-model of the measured object and unwrap the phase iteratively. The result becomes a digital point representation of the measured surface that can either be used just as a description of the object shape or as a way to describe how well the object has been manufactured compared to the CAD-model. The measurement process that is proposed is adapted for on-line purposes; hence it is fast and reliable.

Place, publisher, year, edition, pages
Bellingham, Wash.: SPIE - International Society for Optical Engineering, 2011
Series
Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X ; 8082
National Category
Applied Mechanics Computational Mathematics
Research subject
Experimental Mechanics; Scientific Computing
Identifiers
urn:nbn:se:ltu:diva-32846 (URN)10.1117/12.889424 (DOI)000295076900011 ()84861059715 (Scopus ID)7771828a-1842-469d-815b-51c84b901bdf (Local ID)9780819486783 (ISBN)7771828a-1842-469d-815b-51c84b901bdf (Archive number)7771828a-1842-469d-815b-51c84b901bdf (OAI)
Conference
Optical Measurement Systems for Industrial Inspection : 23/05/2011 - 26/05/2011
Note
Validerad; 2011; 20110816 (ysko)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-07-10Bibliographically approved
Bergström, P., Rosendahl, S. & Sjödahl, M. (2011). Shape verification aimed for manufacturing process control (ed.). Paper presented at . Optics and lasers in engineering, 49(3), 403-409
Open this publication in new window or tab >>Shape verification aimed for manufacturing process control
2011 (English)In: Optics and lasers in engineering, ISSN 0143-8166, E-ISSN 1873-0302, Vol. 49, no 3, p. 403-409Article in journal (Refereed) Published
Abstract [en]

We describe a method to verify the shape of manufactured objects by using their design model. A non-contact measuring method that consists of a stereo-camera system and a single projected fringe pattern is used. The method acquires one image from each camera. Additional shape information from the design model is also used. This surface-measurement method gives an accuracy of about 45 µm. Deviations from the design model within ±1.6 mm can be correctly detected. The measured surface representation is matched to the design model using the ICP-method. Fast performance has been considered adapting the method for on-line use.

Keywords
Manufacturing engineering and work sciences - Manufacturing engineering, Produktion och arbetsvetenskap - Produktionsteknik
National Category
Computational Mathematics Applied Mechanics
Research subject
Scientific Computing; Experimental Mechanics
Identifiers
urn:nbn:se:ltu:diva-14894 (URN)10.1016/j.optlaseng.2010.11.009 (DOI)000286720400016 ()2-s2.0-78650825619 (Scopus ID)e53f91b0-fe0e-11df-8b95-000ea68e967b (Local ID)e53f91b0-fe0e-11df-8b95-000ea68e967b (Archive number)e53f91b0-fe0e-11df-8b95-000ea68e967b (OAI)
Note
Validerad; 2011; 20101202 (berper)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Bergström, P., Rosendahl, S., Gren, P. & Sjödahl, M. (2011). Shape verification using dual-wavelength holographic interferometry (ed.). Paper presented at . Optical Engineering: The Journal of SPIE, 50(10), Article ID 101503.
Open this publication in new window or tab >>Shape verification using dual-wavelength holographic interferometry
2011 (English)In: Optical Engineering: The Journal of SPIE, ISSN 0091-3286, E-ISSN 1560-2303, Vol. 50, no 10, article id 101503Article in journal (Refereed) Published
Abstract [en]

In automotive industry there is an interest of controlling the shape of a large number of identical components on-line in the manufacturing process. We propose a method to do this by capturing a digital hologram of the object and then using information from its computer aided design (CAD) model to calculate the shape and determine the agreement between the manufactured object and the CAD-model. The holographic recording of the object is done using dual wavelengths with a synthetic wavelength of approximately 400 μm. The optical measurement results in a wrapped phase map with the phase values in the interval [−π, π]. Each phase interval represents a depth distance on the object of about 0.2 mm. The phase unwrapping is done iteratively using information from the CADmodel. This implies that it is possible to measure large discontinuities on the surface of the measured object. The method also gives a point-to-point correspondence between the measurement and the CAD-model which is vital for tolerance control.

Keywords
Manufacturing engineering and work sciences - Manufacturing engineering, Produktion och arbetsvetenskap - Produktionsteknik
National Category
Computational Mathematics Applied Mechanics
Research subject
Scientific Computing; Experimental Mechanics
Identifiers
urn:nbn:se:ltu:diva-2402 (URN)10.1117/1.3572182 (DOI)000296559700008 ()2-s2.0-79959390403 (Scopus ID)0051dd1e-3031-4492-a817-faa2657f141a (Local ID)0051dd1e-3031-4492-a817-faa2657f141a (Archive number)0051dd1e-3031-4492-a817-faa2657f141a (OAI)
Note
Validerad; 2011; 20110708 (berper)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Rosendahl, S., Hällstig, E., Gren, P. & Sjödahl, M. (2010). Phase errors due to speckles in laser fringe projection (ed.). Paper presented at . Applied Optics, 49(11), 2047-2053
Open this publication in new window or tab >>Phase errors due to speckles in laser fringe projection
2010 (English)In: Applied Optics, ISSN 1559-128X, E-ISSN 2155-3165, Vol. 49, no 11, p. 2047-2053Article in journal (Refereed) Published
Abstract [en]

When measuring a three-dimensional shape with triangulation and projected interference fringes it is of interest to reduce speckle contrast without destroying the coherence of the projected light. A moving aperture is used to suppress the speckles and thereby reduce the phase error in the fringe image. It is shown that the phase error depends linearly on the ratio between the speckle contrast and the modulation of the fringes. In this investigation the spatial carrier method was used to extract the phase, where the phase error also depends on filtering the Fourier spectrum. An analytical expression for the phase error is derived. Both the speckle reduction and the theoretical expressions for the phase error are verified by simulations and experiments. It was concluded that a movement of the aperture by three aperture diameters during exposure of the image reduces the speckle contrast and hence the phase error by 60%. In the experiments, a phase error of 0.2 rad was obtained.

National Category
Applied Mechanics
Research subject
Experimental Mechanics
Identifiers
urn:nbn:se:ltu:diva-4951 (URN)10.1364/AO.49.002047 (DOI)000276612200007 ()20390003 (PubMedID)2f52d150-3d57-11df-a0f4-000ea68e967b (Local ID)2f52d150-3d57-11df-a0f4-000ea68e967b (Archive number)2f52d150-3d57-11df-a0f4-000ea68e967b (OAI)
Note
Validerad; 2010; 20100401 (sarros)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Rosendahl, S., Hällstig, E., Gren, P. & Sjödahl, M. (2010). Phase errors in speckle reduced laser fringe projection (ed.). In: (Ed.), Armando Albertazzi Gonçalves (Ed.), Speckle 2010: optical metrology : 13 - 15 September 2010, Florianópolis, Brazil. Paper presented at International Conference on Correlation Optics : 13/09/2010 - 15/10/2010 (pp. 73871E). Bellingham, Wash: SPIE - International Society for Optical Engineering
Open this publication in new window or tab >>Phase errors in speckle reduced laser fringe projection
2010 (English)In: Speckle 2010: optical metrology : 13 - 15 September 2010, Florianópolis, Brazil / [ed] Armando Albertazzi Gonçalves, Bellingham, Wash: SPIE - International Society for Optical Engineering, 2010, p. 73871E-Conference paper, Published paper (Refereed)
Abstract [en]

When measuring 3D-shape with triangulation and projected interference fringes it is of interest to reduce the phase error in the fringe pattern. A study has been carried out concerning parameters that will affect the phase error and an analytical expression has been derived. It is concluded that the phase error depends on the speckle contrast, C, and the modulation, M, of the fringes and since the phase in this investigation is determined using the spatial carrier method the phase error also depends on the filtering of the Fourier spectrum. To reduce the phase error this work has been focusing on suppressing the speckle contrast. For this the method with a moving aperture is used; a disk with several apertures is rotated in the aperture plane of the camera lens. To verify the derived expression for the phase error and the method to suppress speckles both numerical simulations and experiments have been performed. In the measurements made it was concluded that after an aperture movement of three aperture diameters the speckle contrast and hence the phase error was reduced by 60 %. A phase error of 0.15 radians was obtained in the experiments, thus approximately 1/40 of a fringe period

Place, publisher, year, edition, pages
Bellingham, Wash: SPIE - International Society for Optical Engineering, 2010
Series
Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X ; 7387
National Category
Applied Mechanics
Research subject
Experimental Mechanics
Identifiers
urn:nbn:se:ltu:diva-28482 (URN)10.1117/12.869659 (DOI)000287657900050 ()2-s2.0-78049385535 (Scopus ID)24c9ee40-f08e-11df-8b36-000ea68e967b (Local ID)978-0-8194-7670-8 (ISBN)24c9ee40-f08e-11df-8b36-000ea68e967b (Archive number)24c9ee40-f08e-11df-8b36-000ea68e967b (OAI)
Conference
International Conference on Correlation Optics : 13/09/2010 - 15/10/2010
Note
Validerad; 2010; 20101115 (andbra)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-07-10Bibliographically approved
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