| 1. |
- Kianfar, Roozbeh, 1984, et al.
(författare)
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Design and Experimental Validation of a Cooperative Driving System in the Grand Cooperative Driving Challenge
- 2012
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Ingår i: IEEE Transactions on Intelligent Transportation Systems. - 1524-9050 .- 1558-0016. ; 13:3, s. 994-1007
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we present the Cooperative Adaptive Cruise Control (CACC) architecture, which was proposed and implemented by the team from Chalmers University of Technology, Göteborg, Sweden, that joined the Grand Cooperative Driving Challenge (GCDC) in 2011. The proposed CACC architecture consists of the following three main components, which are described in detail: 1) communication; 2) sensor fusion; and 3) control. Both simulation and experimental results are provided, demonstrating that the proposed CACC system can drive within a vehicle platoon while minimizing the inter-vehicle spacing within the allowed range of safety distances, tracking a desired speed profile, and attenuating acceleration shockwaves.
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| 2. |
- Augusto, Bruno, 1986-, et al.
(författare)
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Coupling forces in the B-triple and truck-B-double combinations : An extension of the 18868 ISO standard for D- and V-values and analysis of the normative case
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The forces in the couplings of articulated vehicle combinations, propel and fully determine the path of any towed unit thus playing a significant role in the vehicle behavior. A failure in the coupling could potentially have a devastating effect if it occurs while driving in traffic. To prevent this from happening, states and road authorities impose requirements in terms of tolerated forces on any coupling selection. The current legal requirement framework is based on an ISO standard, that stipulates minimum force levels that the couplings should stand. These forces have been derived under semi-empirical assumptions for a set of five vehicle combinations. The present report aims to extend the coupling requirements to two vehicle combinations that are candidates to become legal on the public road network. Due to the semi-empirical nature of the ISO standard, validation needed to be performed. The here presented requirements for the two new combinations were validated against simulation models and checked for reasonable requirements for some example weights of the combinations. The proposed requirements are aligned with the existing requirements derived from the ISO standard. This implies that they could be used to form the legal requirements on these vehicle combinations. However, further investigations on well-grounded deduced requirements should be performed to secure safety margins.
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| 3. |
- Augusto, Bruno, 1986-, et al.
(författare)
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Vehicle dynamics testing in driving simulators : a case study for heavy vehicles
- 2019
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- VDTestS set out to probe the potential of a driving simulator in the field of vehicle dynamics testing. For this purpose, a simulator test case was prepared embodying the nature of a vehicle dynamics test set-up. The goal was to figure out if the drivers in the simulator could identify the handling differences owed to changes in vehicle settings, while driving simulated trucks.A truck model was validated against the performance of a real vehicle under a predefined set of manoeuvres. This was coupled with the tuning of the simulator motion to improve the perception of the vehicle dynamics. These efforts were followed by definition of a group of four test cases, each corresponding to a set of alternate vehicle properties. These sets were selected based on their potential impact on the vehicle handling and correlation with changes that could occur in a real vehicle. Finally, experiments were conducted in VTI’s motion-based driving simulator, Sim IV in Gothenburg, with participation of ten engineers and mechanics from VGTT product development well familiar with truck mechanics and truck driving. The set-up made it possible to gather feedback, about the suitability of the driving simulator in these testing conditions, from professionals in the field. Data was collected subjectively via interviews and questionnaires as well as objectively from the logs comprising of driver inputs and vehicle motions generated during the simulator drives.
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| 4. |
- Bruzelius, Fredrik, 1974-, et al.
(författare)
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A Basic Vehicle Dynamics Model for Driving Simulators
- 2013
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Ingår i: International Journal of Vehicle Systems Modelling and Testing. - 1745-6436 .- 1745-6444. ; 8:4, s. 364-385
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Tidskriftsartikel (refereegranskat)abstract
- Driving simulators are a useful research tool in studies of vehicle and transport-related human machine interface. A vital part of the driving simulator is the vehicle dynamics model. In the present paper, such a model is developed. The model implements basic first order phenomena, but is yet complete in the terms of modelled parts of the vehicle. A major challenge is the trade-off between simplicity and accuracy imposed by the capabilities of the driving simulators motion platform. The modelling language Modelica was used for readability reasons. The model has been validated toward both measurements of a real car and subjectively in a driving simulator. It is shown that the model is well capable of fulfilling the imposed requirements, despite its simplicity. The model is open and available upon request.
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| 5. |
- Bruzelius, Fredrik, 1974-, et al.
(författare)
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Realism of overtaking situations in motion based driving simulators
- 2013
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Ingår i: Road Safety and Simulation International Conference RSS2012, October 23-25, 2013, Rome, Italy. ; , s. (1-12)
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Konferensbidrag (refereegranskat)abstract
- The credibility of the research results of driving simulator studies is highly dependent on the realism that the simulator is capable of producing. A key component is therefore how realistic the driving is perceived by the drivers (test subjects). Overtaking is a frequently occurring traffic situation (as well as one of the highest risk manoeuvres). The aim of the present study was to enhance the perceived realism of overtaking situations in a motion-based driving simulator by introduce aerodynamic forces and moments. An earlier developed real time model of the aerodynamic forces and moments was been implemented and tested in a study with test drivers.With an appropriate scaling of the forces and torques it was shown that the perceived realism can be enhanced by the introduction of these effects.
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| 6. |
- Bruzelius, Fredrik, 1974-, et al.
(författare)
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The influence of tractor lengths on traffic safety and efficiency : a simulation study
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Several different heavy vehicle combinations are allowed on the Swedish road network. A commonly seen combination is the tractor and semi-trailer combination with a maximum total length of 16.5 meters. The legal limitation on the total length of the combination has led to the use of a short tractor to make space for more goods on the trailer. There is a concern that the shortness of the tractors will have a negative consequence on traffic safety and the ability to negotiate uphills. The short wheelbase of the tractor and the weight imbalance between the tractor and the semitrailer could be an issue when braking and negotiating turns. This study was ordered by the Swedish Transport Agency to investigate the traffic safety aspects and hill-climbing problems of certain heavy vehicle combinations. The concerns raised should be investigated from a vehicle dynamical point of view for the vehicle combinations in question and compare them with other common vehicle combinations through a simulation study. A set of tractor and semitrailer combinations have been simulated in severe conditions and maneuvers to investigate the vehicle response and its dependencies with respect to the wheelbase of the tractor, coupling length, fifth wheel lubrication, and road surface conditions. Whenever meaningful, a comparison was made with a Nordic combination (truck and full trailer) as well as a B-double combination (tractor, link trailer, and trailer). The overall result of the simulation study is that the tractor and semitrailer combination is a stable combination, which outperforms the longer and heavier Nordic and B-double combinations in all the measured situations and maneuvers where comparison is meaningful. Furthermore, the wheelbase of the tractor seems to have a very minor effect on the performance of the vehicle combinations.
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| 7. |
- Bärgman, Jonas, et al.
(författare)
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Quantitative Driver Behavior Modelling forActive Safety Assessment Expansion (QUADRAE)
- 2021
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In-vehicle technologies are essential for vehicle safety. This project, Quantitative Driver Behavior Modeling for Active Safety Assessment Expansion (QUADRAE), addresses two crucial components of the technology development process: driver models and simulation methodology. Together, they have provided the industrial partners with state-of-the-art tools for system development and testing, facilitating the development of innovative technologies to improve traffic safety. The main objectives of the project were to:develop and validate models of driver behavior needed in current and future simulation tools for virtual testing of active safety and automationcarry out prioritized virtual tests to estimate the safety benefit of a system, tune system parameters, and explore potential outcomes in scenarios when the system is activelearn more about the best methods for performing virtual testing using driver modelsAs a result of the project, the partners now have an established virtual simulation framework using Predictive Processing (PP) as a general paradigm for modeling driver behavior. The modeling, based on the latest knowledge and ideas about human behavior in driving, draws on extensive research using volunteer drivers as study participants. Data from both controlled experiments and naturalistic driving were used to develop and validate the models. These models are already being used by the industry partners as part of their virtual safety assessment toolchain, to develop advanced driver support systems. The data will continue to be used by the project partners in industry and academia to develop future driver models (which will, in turn, foster improved driver support systems).
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| 8. |
- Cocron, Peter, et al.
(författare)
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Driver and vehicle behaviour to power train failures in electric vehicles : experimental results of field and simulator studies
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- New electric power trains can be subject to different failures when compared to those arising in conventional vehicles. The objectives for active safety investigations within the EVERSAFE project were to address vehicle stability under these failure conditions and the driver response to relevant types of failures. Failure conditions that affect the vehicle stability are believed to be significantly different from today’s conventional internal combustion engine cars, and may potentially be a substantial safety problem if not treated in a correct manner. To study these effects, two examples of system failures and their consequences on the driver response and vehicle stability were investigated with the help of three studies.The first two studies investigated a failure of wheel hub motors (WHMs), an emerging technology among the future generation of electric vehicles (EV). The main benefits of a WHM are its controllability, high efficiency, high power density and low weight. However, the direct connection to the wheel comes along with the potential disadvantage in case a failure occurs in the system.The third study conducted within the active safety focus of the EVERSAFE project examined a failure of the regenerative braking (RB) system. The latter is a system designed to convert kinetic energy to chemical energy stored in the energy storage system (i.e. battery) while the vehicle decelerates.
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| 9. |
- Eriksson, Alexander, et al.
(författare)
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Drivers’ recovery performance in a critical run-off-road scenario : A driving simulator study
- 2018
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Ingår i: Proceedings of the 6th Humanist Conference, The Hague, Netherlands, 13-14 June 2018. ; , s. 7-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Single vehicle accidents are commonly caused by fatigue and distractionand resulting in severe casualties and high economic costs. In order to evaluate driver recovery from run-off-road accidents, comprising of 80% of fatal crashes on rural roads, a simulator study in an advanced full-motion driving simulator was carried out. Drivers were given a secondary task to perform at six positions down the road (to simulate distraction), and an artificial yaw deviation was added to the vehicle to induce a run-off-road accident whilst the driver was distracted. The results show that the severity of the recovery manoeuvre was larger than similar events caused by the failure of automated lane keeping systems, leading to lane departures. Furthermore, significant learning effects was found, providing recommendations for further studies into run-off-road experiments.
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| 10. |
- Hansson, Patrik, et al.
(författare)
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Prepositioning of driving simulator motion systems
- 2015
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Ingår i: International Journal of Vehicle Systems Modelling and Testing. - 1745-6444 .- 1745-6436. ; 10:3, s. 288-304
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Tidskriftsartikel (refereegranskat)abstract
- Motion base driving simulators have limited space in which to recreate the motions of the simulated road vehicle. Conventional motion cueing algorithms strive to centre the cabin in the simulator motion envelope to accommodate accelerations in a worst case scenario while respecting the physical boundaries. Using information about the road ahead one can preposition the cabin to an off-centre point, virtually increasing the available space so that larger motions are made possible. The prepositioning algorithm presented here was developed as an addition to a classical motion cueing algorithm and makes use of road data and vehicle speed to adjust the simulator displacement. Simulations show that the amount of acceleration presented by an x, y-sled system can, with prepositioning, be increased by up to 25% in longitudinal and 53% in lateral direction for an example road. A comparative study including 12 test subjects indicates that the perceived realism is rated higher with prepositioning.
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