| 1. |
- Andersson, Anders, 1983-, et al.
(författare)
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Co-simulation architecture with pedestrian, vehicle, and traffic simulators
- 2021
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Ingår i: Actes (IFSTTAR). - : Driving Simulation Association. ; , s. 181-184
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Konferensbidrag (refereegranskat)abstract
- Automated and connected traffic systems with cooperative functionality need effective testing. One way to enable such testing is to represent the current traffic environment by co-simulating different simulators using a communication layer between the simulators for cooperative functionality. With this approach, this paper presents a platform with its included simulators (vehicle, pedestrian, and traffic simulators), the used run-time infrastructure (RTI) for co-simulation, and the connection to the Unreal Engine based visual system for the simulators. The architecture was tested with two vehicle simulators (one autonomous bus and a truck), one pedestrian simulator, and one traffic simulator connected using a cloud-based service for the RTI.
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| 2. |
- Bolling, Anne, et al.
(författare)
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SHAKE - an approach for realistic simulation of rough roads in a moving base driving simulator
- 2010
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Ingår i: Trends in driving simulation design and experiments. - Arcueil : Institut national de recherche sur les transports et leur securite, INRETS. - 9782857826859 ; , s. 135-143
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Konferensbidrag (refereegranskat)abstract
- With today’s advanced measurement equipment for measuring roads, it is possible to measure road geometry at high precision within a large span of wavelengths. Detailed information about the roads longitudinal and lateral profile, including macro texture, would in theory be sufficient for a realistic reproduction of road induced vibration and noise in a driving simulator. Especially, it would be possible to create a direct connection between the visual information of the road condition and the ride experience, which would increase the level of realism in the simulation. VTI has during three years performed an internal project called SHAKE with the aim to develop and implement models in VTI driving simulator III that use measured road data for generating realistic vibrations and audible road noise connected to the visual impression presented on the projection screen. This has indeed resulted in an more realistic driving experience, and a validation study with test persons driving both in the simulator and in the field has been undertaken. The OpenDRIVE standard is used as a framework for describing the road properties (e.g. visual, vibrations and noise). For this purpose some augumentations to the OpenDRIVE standard had to be made. This paper describes the technical implementations in the driving simulator, along with results from test drives on the implemented road sections
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| 3. |
- Eriksson, Louise, et al.
(författare)
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Tema miljörisker : miljörisker och trafikanters beteenden
- 2011
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report compiles the results from the project Theme Environmental risks. More specifically, the project concerned how different transport related environmental risks influence different road users and how their behaviour influence the environment. The project aimed at preparing for interdisciplinary research about environmental risks at VTI. The project was divided into three parts. The first subproject aimed at compiling literature about transport related environmental risks from psychological and economic perspectives, and in the second subproject a willingness to pay study was outlined where both economic and psychological principles were considered. In the third subproject, a simulator study was outlined. The focus was to study environmental effects of driving under controlled circumstances in the driving simulator. The report is divided into two parts. In part 1, the results from the literature review and the proposal for a willingness to pay study are described (subproject 1 and 2). This part is written in English. Part 2 contains a project outline for a simulator study in the form of an research project application (project 3). This part is written in Swedish.
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| 4. |
- Hjort, Mattias, et al.
(författare)
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A test method for evaluating safety aspects of ESC equipped passenger cars : a prototype proposal
- 2009
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Active safety systems are becoming increasingly common in today's vehicles. Electronic Stability Control (ESC) systems were introduced during the end of the 1990s, and accident statistics show that they have had a huge impact on traffic safety. In the USA, a new legislation has recently been adopted which demands on every new light vehicle that is sold to be equipped with ESC, beginning 2011. New systems require new testing methods, and there is a need expressed by the New Car Assessment Program (NCAP), which at present time only evaluates the passive safety of cars, also to include tests for active safety systems. In a previous VTI work, a literature review regarding methods for the evaluation of traffic safety effects of Antilock Braking Systems (ABS) and ESC was performed. Based on the findings of that review, we have proceeded with defining a test method for evaluating safety aspects of ESC equipped passenger cars. The objective has been to suggest a (prototype) test method that can be used for a more holistic evaluation of the safety effect of ESC in cars, including the driver behaviour perspective. From discussions with leading experts on traffic safety and ESC, possible benefits of ESC systems on traffic safety were identified. In addition to increasing the yaw stability of the vehicle, the following ESC benefit effects were identified: - A warning system for slippery roads. ESC activation indication may act as a warning system to the driver about slippery road conditions. - Reduced collision speed. In a critical situation, ESC activation may reduce the collision speed, which will mitigate the outcome of the collision. - Improved vehicle roll stability. The ESC system may also stabilise the vehicle with respect to untripped rollovers. Most rollovers are however tripped rollovers, which can occur when a vehicle, with some lateral slip, strikes an object or slides off the road. These rollovers also benefit from the ESC system as it aids in keeping the vehicle on the road.
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| 5. |
- Hjort, Mattias, 1972-, et al.
(författare)
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Handling of buses on slippery roads during the influence of side wind : A study of the effects of different tyres
- 2010
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Ingår i: Accident Analysis and Prevention. - : Elsevier. - 0001-4575 .- 1879-2057. ; 42:3, s. 972-977
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Tidskriftsartikel (refereegranskat)abstract
- Accident statistics assembled by the Swedish National Road and Transport Research Institute (VTI) have shown that buses are overrepresented when it comes to accidents on icy and snowy roads. For a better understanding of the problem, the performance of modern summer and winter tyres on winter road conditions had to be assessed. The objective of this work has been to go beyond standard road grip studies, and instead investigate how the driver's possibility to deal with one challenging situation depends on the tyres and tyre configuration. This paper describes a novel methodology where measurements with different tyres on ice in VTI's tyre test facility, enabled a simulator study for evaluating the impact of different tyre characteristics when driving in conditions with strong side wind on a slippery road.The main results of the study are: to deal with strong side wind, good front wheel grip is most important, and while non-studded winter tyres provided little or no improvement over summer tyres, studded winter tyres significantly reduced the risk to run off the road. Furthermore, it is very difficult for the drivers to judge, beforehand, whether a vehicle with a particular tyre configuration will perform good or bad.
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| 6. |
- Jansson, Andreas, et al.
(författare)
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Developing of a Driver Model for Vehicle Testing
- 2014
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Ingår i: Proceedings of the 14th International Symposium on Advanced Vehicle Control (AVEC), Tokyo, September 2014..
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Konferensbidrag (refereegranskat)abstract
- There is today no established automated method for testing vehicles or tyres, and the most common option is using professional drivers for this purpose. The tests are supposed to be fair and repeatable, which means using human drivers for these kinds of vehicle testing is not an option. Using a steering robot modelled to drive as a human is therefore preferable. The approach described in this paper shows how a driver model can be created by using a control algorithm based on gathered data from human drivers performing double lane change (DLC) manoeuvres in a simulator. The implemented controller shows how human drivers’ behaviors can be captured using control theory.
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| 7. |
- Jansson, Jonas, 1973-, et al.
(författare)
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Driver reactions to horn and headlight warnings in critical situations : A simulator study
- 2013
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Ingår i: Proceedings of the 16th International Conference Road Safety on Four Continents. - Linköping : Statens väg- och transportforskningsinstitut.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents a driving simulator study on driving behavior in a critical head-on collision scenario. The study aims at providing basic understanding of driver responses to headlight and horn warning coming from another vehicle a time critical situation. In total, 48 participants drove 30 km. During the drive participants performed a secondary task, announced by a vibration in the seat. At the time of the secondary task the own vehicle was directed into the opposing lane where oncoming simulated vehicles issued a light and/or sound warnings to get the drivers attention. An additional purpose of the study was to examine if the warning coming from the other vehicle has a different effect on persons with a hearing loss. A possible application for this type of warnings is the implementation of a system for automatic activation. Systems for automatic activation of brakes and steering are currently entering the market. These systems use proximity sensors to monitor the state of surrounding road users. Depending on the specific situation the effort/possibility to avoid or mitigate an accident may differ significantly between the principle road users of a pending collision, e.g. one road user (1) may easily avoid a collision while another (2) may not be able to do so. The only possibility for the second road user (2) to avoid a collision in such a situation is to issue a warning to the first (1), so that he/she may take evasive actions. Connecting the horn and the headlight to already existing sensor system, for automatic warning activation, is a cost effective means to provide such a warning. The warnings, could of course, also be triggered manually by the driver.The results indicate that a driver who receives a warning from the oncoming vehicle responds faster to avoid the pending frontal collision. The most effective warning was the combination of horn and headlight. A majority of the participants where positive to the notion of an automated system to provide this type of warning (n=41). No significant difference in the behavior between the groups with and without hearing loss was found in this study.
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| 8. |
- Thorslund, Birgitta, 1976-, et al.
(författare)
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Principle Other Vehicle Warning
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The only possibility for a driver to avoid a collision may sometimes be to issue a warning to another driver. Connecting the horn and the headlight to an already existing sensor system could be a cost effective solution. This report covers the implementation and evaluation of such an automated warning system in a driving simulator at VTI. In this test 24 drivers with normal hearing and 24 with moderate hearing loss experienced five critical events in which four different warning signals were evaluated; sound, light, and a combination of sound and light, and no warning (as reference). A visual distraction task was used to distract the drivers and create critical situations. The results were consistent. A combined sound and light warning significantly increased cautious driving behaviour and also lead to the highest perceived criticality of the situations. With the combined warning the driver’s attention was effectively drawn from the visual distraction task. Drivers were generally positive towards the warning system, and most positive towards the combined warning presenting light and sound signals. Drivers were able to distinguish between warnings (at critical events) and greetings (at non-critical events) suggesting that the tested additional use of horn and headlight would not affect reactions to non-critical warnings or greetings. Hearing loss was associated with worse performance on the visual distraction task and less perceived realism of the driving simulator. But it was not associated with effects on any driving behaviour measures or of warning modalities. This result suggests that the evaluated system should work also for drivers with moderate hearing loss.
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| 9. |
- Ydrefors, Lisa, et al.
(författare)
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Parametrisation of a rolling resistance model for extending the brush tyre model
- 2024
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Ingår i: International Journal of Vehicle Design. - : Inderscience Publishers. - 0143-3369 .- 1741-5314. ; 94:1-2, s. 38-56
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Tidskriftsartikel (refereegranskat)abstract
- A rolling resistance model (RRM) has been created and parametrised with the purpose of modelling tyre rolling resistance within complete vehicle dynamics simulations. The RRM is based on a combination of the Masing and Zener models to simulate the Payne effect and the viscoelastic properties of rubber. The parametrised model is able to recreate the relationship between the rolling resistance and the tyre deformation well and it has a low computational power requirement. Today the model is limited to simulation of free-rolling tyres on a flat surface, but it can be extended to also include the effects of changes in operating conditions such as wheel angles or road surface.
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