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Källgren, Laban
Publications (6 of 6) Show all publications
Hjort, M., Andersson, A., Blissing, B., Källgren, L., Karlsson, L., Rydell, M. & Dahlhielm, M. (2022). Smarta gator: VR-simulering av framtida stadsmiljöer. Linköping: Statens väg- och transportforskningsinstitut
Open this publication in new window or tab >>Smarta gator: VR-simulering av framtida stadsmiljöer
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2022 (Swedish)Report (Other academic)
Alternative title[en]
Smart streets : VR simulation of future city environments
Abstract [sv]

Denna rapport beskriver arbetet av arbetspaket 6 och 8 i det Vinnova-finansierade projektet Smarta gator. Utifrån arkitektoniska beskrivningar har tre olika VR-miljöer skapats – så kallade ”digitala tvillingar” av en idag existerande gatumiljö i Stockholm, samt två olika tänkbara framtida versioner av gatumiljön. Den simulerade miljön kan upplevas av fotgängare i VTI:s fotgängarsimulator, och alternativt också av bilist genom co-simulering med annan körsimulator. De två tänkbara framtidsvisionerna utvärderades från ett fotgängarperspektiv genom en workshop med 30 försökspersoner i VTI:s fotgängarsimulator i Linköping. Deltagarnas svar visar tydligt att upplevelsen av trygghet, prioritet samt trevlighet/trivsel ökade i de smarta miljöerna jämfört med den ursprungliga miljön. 

Läsbarheten av gaturummet upplevdes i de smarta miljöerna dock något sämre än i ursprungsmiljön. En förklaring kan vara att många känner igen ursprungsmiljön eftersom det är en relativt vanlig gatutyp – breda körfält för bil, kantstensparkering och trottoarer, medan de smarta miljöerna är uppbyggda på ett annorlunda sätt vilket kan innebära en omställning för att förstå en ”ny typ” av gata. 

Sammantaget visar studien på hur man kan skapa gaturum som upplevs trevligare och tryggare genom att prioritera gång- och cykeltrafik genom en större yta tillägnat gång, cykel och vistelse än för motortrafik. Även skapandet av vistelseytor och sociala funktioner längs gatan hade en positiv effekt på upplevelsen av gaturummet. Att placera träd och grönska längs gatan är utöver de ekologiska fördelarna också viktigt för trivseln och upplevelsen av gaturummet. 

Vi konstaterar att VR-simulering kan vara ett användbart verktyg för att på ett tidigt stadium bedöma olika designlösningar. VTI:s fotgängarsimulator har ett state-of-the-art bildsystem, men dess fria yta om 3x6 meter är för liten för att på ett smidigt sätt kunna promenera runt i stadsmiljön. Autonoma fotgängare, styrda av spelmotorn Unreal Engine, upplevdes av de flesta försökspersoner som väldigt verklighetstrogna, och de bidrog till illusionen om att vara på plats i miljön.

Abstract [en]

This report describes the work of work packages 6 and 8 in the Vinnova-funded Smarta gator project. Based on architectural descriptions, three different VR environments have been created – so-called “digital twins” of a currently existing street environment in Stockholm, as well as two different possible future versions of the street environment. The simulated environment can be experienced by pedestrians in VTI’s pedestrian simulator, and alternatively also by motorists through co-simulation with another driving simulator. The two possible visions for the future were evaluated from a pedestrian perspective through a workshop with 30 subjects in VTI’s pedestrian simulator in Linköping. The participants’ answers clearly show that the experience of security, priority and well-being increased in the smart environments compared with the original environment. 

However, the readability of the street space was experienced in the smart environments somewhat degraded compared to the original environment. One explanation may be that many people recognize the original environment because it is a relatively common type of street – wide lanes for cars, curbside parking and sidewalks, while the smart environments are structured in a different way, which may need additional experience to understand this “new type” of street. 

Overall, the study demonstrates how street spaces can be created that are experienced as more pleasant and safer by prioritising pedestrian and bicycle traffic through a larger area dedicated to walking, cycling and accommodation than for motor traffic. The creation of living spaces and social functions along the street also had a positive effect on the experience of the street space. Placing trees and greenery along the street is in addition to the ecological benefits also important for the well-being and experience of the street space. 

It is concluded that VR simulation can be a useful tool for assessing various design solutions at an early stage. VTI’s pedestrian simulator is equipped with a state-of-the-art image system, but the restricted area of 3x6 meters is too small to allow for a person to easily walk around the urban environment. Autonomous pedestrians, controlled by the game engine Unreal Engine, were perceived by most subjects as very realistic, and they contributed to the illusion of being in place in the environment.

Place, publisher, year, edition, pages
Linköping: Statens väg- och transportforskningsinstitut, 2022
Series
VTI rapport, ISSN 0347-6030 ; 1141
National Category
Architectural Engineering Infrastructure Engineering
Identifiers
urn:nbn:se:vti:diva-19083 (URN)
Available from: 2022-10-18 Created: 2022-10-18 Last updated: 2022-10-19Bibliographically approved
Nåbo, A., Börjesson, C., Källgren, L., Nyman, J. & Stave, C. (2018). Laddsträcka i Lund: En studie av busslinje i körsimulator. Linköping: Statens väg- och transportforskningsinstitut
Open this publication in new window or tab >>Laddsträcka i Lund: En studie av busslinje i körsimulator
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2018 (Swedish)Report (Other academic)
Alternative title[en]
Electric road in Lund : A study of a bus line using a driving simulator
Abstract [sv]

År 2018 träder klimatlagen i kraft. Till år 2030 ska klimatpåverkan i transportsektorn ha minskat med 70 procent jämfört med år 2010 och år 2045 ska Sveriges klimatpåverkan vara netto noll. Det innebär en fundamental omställning av energiförsörjningen av vägtransporter och fordonsflottan. För bussar i stadstrafik ser man gärna en elektrifiering då elbussar både är avgasfria och tysta, vilket ger en mindre miljöpåverkan på gaturummet och det då finns möjlighet att även skapa attraktiva busslinjer.

För att exemplifiera hur en elektrifiering av buss kan göras gjordes en studie i körsimulator där en möjlig elbusslinje i Lund som använder elväg studerades. Elektrifieringens mål var att nå en hög användarvänlighet och uppfylla framtidens krav på miljö- och energianpassning. Med hjälp av olika informationskällor om elbussar, elvägsteknik och Lunds stadsmiljö skapades virtuella modeller av dessa som sedan installerades i körsimulatorn.

För att utvärdera om bussen och elektrifieringen uppfyllde kraven på användarvänlighet genomfördes försök med bussförare i en dynamisk körsimulator, SIM II på VTI i Linköping. Resultaten visade att förarna inte hade några större svårigheter att framföra bussen så att elektrifieringen fungerade. Tyvärr drabbades några av förarna av illamående under körningen (”simulatorsjuka”) och fick avbryta.

En utvärdering av körsimulatorn som ett verktyg för opinionsbildning gjordes genom att tillhandahålla ett informationsblad om elväg för bussar samt att demonstrera elektrifieringen för anställda i Lunds kommun med hjälp av en mindre, flyttbar körsimulator. Intervjuer om elbussar och elektrifiering gjordes före och efter demonstrationen för att se effekter på inställningen till och förståelsen av elbuss och elväg. Resultaten visade att simulatorkörningen gav ett mervärde utöver informationsbladet, 2/3 av deltagarna svarade att förståelsen blev större och 1/3 att den inte förändrades. Inställningen till elbuss och elväg förändrades inte. Majoriteten av deltagarna ansåg att simulatorn kan vara en hjälp i beslutsfattande.

En analys av energiåtgången för bussen visade att batterinivån var lägre i slutet av körningen än i början, det vill säga batterinivån sjönk. Detta hade kunnat undvikas om elektrifieringen lagts ut på ett mer fördelaktigt sätt, och behöver således inte vara en begränsande faktor vid en framtida implementering.

Vidare gjordes en jämförelse med några andra energiförsörjningsalternativ såsom depåladdning och ändhållplatsladdning. För- och nackdelar för dessa alternativ diskuterades utifrån ekonomiska och bussoperativa perspektiv.

Abstract [en]

By the year 2018, the Climate Act will come into force. By 2030, climate impact in the transport sector should have fallen by 70 percent compared with 2010 and by 2045 Sweden’s climate impact will be net zero. This means a fundamental transformation of the energy supply of vehicles in road transport. For buses in city traffic, electrification is favorable because electric buses are both exhaustfree and quiet, giving a lesser environmental impact in the street environment, and by that the possibility of creating attractive bus lines.

To exemplify how a bus electrification can be done, a driving simulator study was conducted on a possible electric bus line in the city of Lund using an electric road system. The goal of electrification was to achieve a high user acceptance and to meet the targets for the future environment and energy use.

With the help of various sources of information about electric buses, electric road systems and the urban environment of Lund, virtual models were created, which were then installed in the driving simulator.

To evaluate whether the bus and electrification complied with the user acceptance requirements, bus drivers participated in a test in a dynamic driving simulator, SIM II at VTI in Linköping. The results showed that the drivers had no major difficulties in driving the bus so that the electrification worked. Unfortunately, some of the drivers suffered from sickness while driving (“simulator sickness”) and had to stop driving.

An evaluation of the driving simulator used as a tool for public relation purposes was made by providing an information sheet and demonstrating the electrification to employees in Lund municipality by using a small, moveable driving simulator. Interviews about electric buses and electrification were made before and after the demonstration to see effects on the opinion and understanding of electric buses and electric road systems. The results showed that the simulator drive gave added value in addition to the information sheet only, 2/3 of the participants answered that their understanding was increased by the simulator drive and 1/3 answered that it was not changed. The attitude to the electric bus and the electric road system did not change. Most people considered that the simulator could be a helpful tool in decision making.

An analysis of the energy consumption of the bus showed that the battery level was lower at the end of the test drive than in the beginning, i.e. the battery level dropped. This would not have been the case if the electrification had been made more advantageously, and thus would not need to be a limiting factor in future implementation.

In addition, the studied electric road system was compared with some other power supply options such as charging at bus depot and at bus end stop. The pros and cons of these alternatives were discussed based on economic and bus operational perspectives.

Place, publisher, year, edition, pages
Linköping: Statens väg- och transportforskningsinstitut, 2018. p. 52
Series
VTI notat ; 8-2018
National Category
Vehicle Engineering
Identifiers
urn:nbn:se:vti:diva-13146 (URN)
Available from: 2018-07-05 Created: 2018-07-05 Last updated: 2021-09-14Bibliographically approved
Hjort, M. & Källgren, L. (2016). A method for road description based on map data and road measurements: White Paper. Linköping: ViP - Virtual Prototyping and Assessment by Simulation
Open this publication in new window or tab >>A method for road description based on map data and road measurements: White Paper
2016 (English)Report (Other academic)
Abstract [en]

Simulation has become a useful tool for vehicle manufacturers in the design and assessment of new vehicles. Using an advanced driving simulator in early design phases may reveal defects in the construction, which otherwise would not be noticed until full scale prototyping, and thereby reduce development time and costs. In most driving simulator studies the road design does not have to conform to an existing road. But for some purposes it may be crucial that the virtual road describes the real road as close as technically possible. Examples are vehicle vibration studies, fuel consumption evaluation with respect to driver behaviour, and comparisons between driving on the virtual and real road. The required level of detail of different road features varies between applications (projects). Parameters like road curvature, inclination, elevation and crossfall, the surrounding terrain as well as road imperfections and unevenness may be of more or less importance and therefore have to be modelled with high or lower accuracy. In the Known Roads project, a real road, the “Gothenburg triangle” (Gothenburg-Borås-Alingsås- Gothenburg), was modelled as realistically as possible. Road curvature, inclination and crossfall as well as the surrounding terrain were considered important. This White Paper is complementary to other deliverables from the Known Roads project. It presents in more detail the method of recreating existing roads in a simulation environment, developed by VTI in the project. The White Paper concerns specifically the difficulties of merging different data sources into a road representation, and describes the problems that were encountered and the solutions that were developed for implementing an existing road in the driving simulator.

Place, publisher, year, edition, pages
Linköping: ViP - Virtual Prototyping and Assessment by Simulation, 2016. p. 54
Series
ViP PM ; 2015-2
National Category
Vehicle Engineering
Identifiers
urn:nbn:se:vti:diva-15564 (URN)
Available from: 2020-09-21 Created: 2020-09-21 Last updated: 2020-09-21
Nåbo, A., Andhill, C. J., Blissing, B., Hjort, M. & Källgren, L. (2016). Known Roads: real roads in simulated environments for the virtual testing of new vehicle systems. Linköping: Statens väg- och transportforskningsinstitut
Open this publication in new window or tab >>Known Roads: real roads in simulated environments for the virtual testing of new vehicle systems
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2016 (English)Report (Other academic)
Abstract [en]

This publication presents a project aiming to develop virtual representations of real roads for use in driving simulators. The development was done in order to enable assessments of new systems on existing and well known roads in a driving simulator, and will increase the external validity of virtual testing. Furthermore, the usage of the virtual model of such roads makes the simulator results better comparable to earlier performed or later following road tests. The roads connecting Göteborg-Borås-Alingsås-Göteborg were selected. The purpose for this is due to their proximity to the vehicle industry in west Sweden and to the test tracks “Hällered” and “AstaZero”. However, the tools and methods developed can be used to build a virtual representation of any other road through a surrounding landscape and/or more urban environment. The project was carried out in steps, starting with data collection (investigation and assessment of available data from different sources as well as measurement of road properties) followed by data treatment (remove irrelevant data and errors, filtering, etc.), modelling (mathematical description of road properties) and simulation (selection of data formats for real time simulation).

Place, publisher, year, edition, pages
Linköping: Statens väg- och transportforskningsinstitut, 2016. p. 40
Series
ViP publication: ViP - Virtual Prototyping and Assessment by Simulation ; 2015-2
Keywords
Simulator (driving), Simulation, Road, Geometric design, Landscape, Method, Software
National Category
Vehicle Engineering
Research subject
90 Road: Vehicles and vehicle technology
Identifiers
urn:nbn:se:vti:diva-11556 (URN)
Available from: 2017-02-06 Created: 2017-02-06 Last updated: 2022-10-19Bibliographically approved
Jansson, J., Sandin, J., Augusto, B., Fischer, M., Blissing, B. & Källgren, L. (2014). Design and performance of the VTI Sim IV. In: Andras Kemeny (Ed.), New development in driving simulation design and experiments: Driving simulation conference Europe 2014 proceedings. Paper presented at Driving simulation conference 2014 (pp. 4.1-4.7). Paris
Open this publication in new window or tab >>Design and performance of the VTI Sim IV
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2014 (English)In: New development in driving simulation design and experiments: Driving simulation conference Europe 2014 proceedings / [ed] Andras Kemeny, Paris, 2014, p. 4.1-4.7Conference paper, Published paper (Refereed)
Abstract [en]

The VTI simulator IV (Sim IV) is the fourth advanced driving simulator designed and built at The Swedish National Road and Transport Research Institute (VTI). The simulator, taken into operation 2011, has an 8 degrees of freedom (DoF) moving base, a field of view (FoV) of 180 degrees and features a system for rapid cabin exchange. With a budget of roughly 2,4 M euro; Sim IV was developed to provide VTI’s newly established Gothenburg office with advanced driving simulation capability, and to be a cost efficient complement to the Sim II and Sim III facilities in VTI’s Linköping office. This paper describes the design and technical performance of the facility. A brief summary of results and experience from validation studies for the first three years of operation is also presented.

Place, publisher, year, edition, pages
Paris: , 2014
Keywords
Simulator (driving), Design (overall design), Characteristics
National Category
Vehicle Engineering
Research subject
90 Road: Vehicles and vehicle technology, 91 Road: Vehicle design and construction
Identifiers
urn:nbn:se:vti:diva-7062 (URN)
Conference
Driving simulation conference 2014
Funder
VINNOVA
Available from: 2014-09-16 Created: 2014-09-16 Last updated: 2022-10-19Bibliographically approved
Ljung Aust, M., Engström, J., Viström, M., Nåbo, A., Bolling, A., Hjort, M. & Källgren, L. (2011). Effects of forward collision warning, initial time headway and repeated scenario exposure on driver response in emergency lead vehicle braking scenarios. Linköping: Statens väg- och transportforskningsinstitut
Open this publication in new window or tab >>Effects of forward collision warning, initial time headway and repeated scenario exposure on driver response in emergency lead vehicle braking scenarios
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2011 (Swedish)Report (Other academic)
Abstract [en]

To address the research questions, acritical lead vehicle braking scenario and anFCW system was developed and pilot tested in Saab’s fixed based driving simulator in Trollhättan. After piloting, the scenario was implemented in VTI’s moving base simulatorin Linköping, and the effects,of FCW presence, two different initial time headways at visual distraction task onset and repeated scenario exposure, on driver response timeswere examined.The study showed significant effects of FCW and repeated scenario exposure on response times. Moreover, these effects were not additivei.e. a significant interaction between the two was found. There was also a significant effect on responsetimes ofinitial time headway at onset of the visual distraction task. In addition, an interaction between initial time headway and repeated scenario exposure was found for drivers with FCW, but not for drivers without FCW. A second objective of the project was to compare the extent to which the VTI moving base simulator with motion cues generates similar driver responses(quantitatively and qualitatively)as the static simulator set-up at Saab. In general, theresults from this project have important implications for the interpretation of driver performance in experimental settings, particularlywhen aiming toevaluate safety-related in-vehicle information and warning technologies. For onething,they pose a general question markaround the generalizabilityof results to real world events. Second, a future prerequisite for FCW studies should probably be that test drivers have a previous level of system exposure level which matchesthat of real world drivers encountering typical critical events. Also, tuning the initialtime headwayat distraction task onsetin the experimentalsetting to real world conditions is of critical importance.

Place, publisher, year, edition, pages
Linköping: Statens väg- och transportforskningsinstitut, 2011. p. 45
Series
ViP publication: ViP - Virtual Prototyping and Assessment by Simulation ; 2011-5
Keywords
Collision avoidance system, Driver, Behaviour, Reaction time, Braking, Steering (process), Simulator (driving), Test, Kollisionsvarningssystem, Förare, Beteende, Reaktionstid, Bromsning, Styrning, Körsimulatorer, Test
National Category
Vehicle Engineering
Research subject
90 Road: Vehicles and vehicle technology, 911 Road: Components of the vehicle; 80 Road: Traffic safety and accidents, 841 Road: Road user behaviour
Identifiers
urn:nbn:se:vti:diva-5285 (URN)
Available from: 2013-12-03 Created: 2013-12-03 Last updated: 2016-02-25Bibliographically approved
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