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  • 1.
    Andersson, Anders
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    A Framework for Credibility Assessment of a Powertrain Model in Driving Simulator Studies2016In: Proceedings of the 36th FISITA World Automotive Congress, 2016Conference paper (Refereed)
    Abstract [en]

    When performing a driving simulator study, validity of the vehicle model for the intended driving task is of key importance; otherwise, the reliability of the study results might be jeopardized. In this paper a framework for real-time credibility assessment of the simulated longitudinal dynamics by a powertrain model in a moving base driving simulator is presented. The framework consists of the physical system model and a quality model which run in parallel in real time. The developed framework has been evaluated by offline simulations, as well as in real-time in a moving base driving simulator. The evaluation results showed that the developed framework can accurately capture the validity of the powertrain model in different driving conditions and provide the credibility level of the simulation results to the simulator operator in real-time.

  • 2.
    Andersson, Anders
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Driving Simulation and Visualization.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Freight train model for real-time simulation2017In: Dynamics of Vehicles on Roads and Tracks Vol 2: Proceedings of the 25th International Symposium on Dynamics of Vehicles on Roads and Tracks (IAVSD 2017), 14-18 August 2017, Rockhampton, Queensland, Australia, 2017Conference paper (Refereed)
    Abstract [en]

    In an attempt to increse the freight transport capacity in Sweden, introduction of longer and heavier trains is investigated. To aid this investigation, a freight train simulator was designed and constructed. Here, the implemented freight train dynamics model is described, which includes slip control, a modular wagon model structrue and pneumatic brake system. Further, stable real-time performance of the implemented dynamics model is discussed.

  • 3.
    Andersson, Anders
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Driving Simulation and Visualization.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Vehicle model quality framework for moving base driving simulators, a powertrain model example2018In: International Journal of Vehicle Systems Modelling and Testing, ISSN 1745-6436, E-ISSN 1745-6444, Vol. 13, no 2, p. 93-108Article in journal (Refereed)
    Abstract [en]

    Moving base driving simulators, with an enclosed human driver, are often used to study driver-vehicle interaction or driver behaviour. Reliable results from such a driving simulator study strongly depend on the perceived realism by the driver in the performed driving task. Assuring sufficient fidelity for a vehicle dynamics model during a driving task is currently to a large degree a manual task. Focus here is to automate this process by employing a framework using collected driving data for detection of model quality for different driving tasks. Using this framework, a powertrain model credibility is predicted and assessed. Results show that chosen powertrain model is accurate enough for a driving scenario on rural roads/motorway, but need improvements for city driving. This was expected, considering the complexity of the vehicle dynamics model, and it was accurately captured by the proposed framework which includes real-time information to the simulator operator.

  • 4.
    Andersson, Anders
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Lind, Simon
    Myklebust, Andreas
    Linköpings Universitet.
    Parameterization procedure of a powertrain model for a driving simulator2016In: Advances in Transportation Studies, ISSN 1824-5463, Vol. 1, p. 99-112Article in journal (Refereed)
    Abstract [en]

    The automotive industry is facing a major challenge to reduce environmental impacts. As a consequence, the increasing diversity of powertrain configurations put a demand on testing and evaluation procedures. One of the key tools for this purpose is simulators. In this paper a powertrain model and a procedure for parameterizing it, using chassis dynamometers and a developed pedal robot are presented. The parameterizing procedure uses the on-board diagnostics of the car and does not require any additional invasive sensors.

    Thus, the developed powertrain model and parameterization procedure provide a rapid non- invasive way of modelling powertrains of test cars. The parameterizing procedure has been used to model a front wheel drive Golf V with a 1.4L multi-fuel engine and a manual gearbox. The achieved results show a good match between simulation results and test data. The powertrain model has also been tested in real-time in a driving simulator.

  • 5.
    Andersson, Anders
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Lind, Simon
    Myklebust, Andreas
    Parameterization Procedure of a Powertrain Model for a Driving Simulator2015In: Proceedings  of the 2015 Road Safety & Simulation International Conference, 2015Conference paper (Refereed)
    Abstract [en]

    The automotive industry is facing a major challenge to reduce environmental impacts. As a consequence, the increasing diversity of powertrain configurations put a demand on testing and evaluation procedures. One of the key tools for this purpose is simulations.

    In this paper a powertrain model and a procedure for parameterizing it, using chassis dynamometers and a developed pedal robot are presented. The parameterizing procedure uses the on-board diagnostics of the car and does not require any additional invasive sensors. Thus, the developed powertrain model and parameterization procedure provide a rapid non-invasive way of modelling powertrains of test cars. The parameterizing procedure has been used to model a front wheel drive Golf V with a 1.4L multi-fuel engine and a manual gearbox. The achieved results show a good match between simulation results and test data. The powertrain model has also been tested in real-time in a driving simulator.

  • 6.
    Atif, Yacine
    et al.
    University of Skövde.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Jianguo, Ding
    University of Skövde.
    Andler, Sten F.
    University of Skövde.
    Internet of Things data analytics for parking availability prediction and guidance2020In: Transactions on Emerging Telecommunications Technologies, ISSN 2161-5748, article id e3862Article in journal (Refereed)
    Abstract [en]

    Cutting-edge sensors and devices are increasingly deployed within urban areas to make-up the fabric of transmission control protocol/internet protocol connectivity driven by Internet of Things (IoT). This immersion into physical urban environments creates new data streams, which could be exploited to deliver novel cloud-based services. Connected vehicles and road-infrastructure data are leveraged in this article to build applications that alleviate notorious parking and induced traffic-congestion issues. To optimize the utility of parking lots, our proposed SmartPark algorithm employs a discrete Markov-chain model to demystify the future state of a parking lot, by the time a vehicle is expected to reach it. The algorithm features three modular sections. First, a search process is triggered to identify the expected arrival-time periods to all parking lots in the targeted central business district (CBD) area. This process utilizes smart-pole data streams reporting congestion rates across parking area junctions. Then, a predictive analytics phase uses consolidated historical data about past parking dynamics to infer a state-transition matrix, showing the transformation of available spots in a parking lot over short periods of time. Finally, this matrix is projected against similar future seasonal periods to figure out the actual vacancy-expectation of a lot. The performance evaluation over an actual busy CBD area in Stockholm (Sweden) shows increased scalability capabilities, when further parking resources are made available, compared to a baseline case algorithm. Using standard urban-mobility simulation packages, the traffic-congestion-aware SmartPark is also shown to minimize the journey duration to the selected parking lot while maximizing the chances to find an available spot at the selected lot.

  • 7.
    Augusto, Bruno
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Driving Simulation and Visualization.
    Bruzelius, Fredrik
    Swedish National Road and Transport Research Institute, Traffic and road users, Driving Simulation and Visualization. Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Svensson, Bolennarth
    EMA-QC.
    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 case2020Report (Other academic)
    Abstract [en]

    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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  • 8.
    Augusto, Bruno
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Driving Simulation and Visualization.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Fröjd, Niklas
    Volvo Group Trucks Technology, VGTT.
    Vehicle dynamics testing in driving simulators: a case study for heavy vehicles2019Report (Other academic)
    Abstract [en]

    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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  • 9.
    Behera, Abhijeet
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation.. Department of Electrical Engineering, Linköping University, Sweden.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation.. Department of Electrical Engineering, Linköping University, Sweden.
    Frisk, Erik
    Department of Electrical Engineering, Linköping University, Sweden.
    Performance analysis of an A-double in roundabouts using naturalistic driving data2024In: Technology Convergence 2023: Setting the Wheels In Motion: Reimagining the future of heavy vehicles, roads and freight, International Forum for Heavy Vehicle Transport & Technology; The International Society for Weigh-In-Motion , 2024, article id 4565Conference paper (Other academic)
    Abstract [en]

    The focus of this paper is to use Naturalistic Driving Data to understand how the drivers manoeuvre an A-double combination in the roundabouts and evaluate performance in the roundabouts using measures like Low-Speed Swept Path (LSSP) and Tail Swing (TS). The analyses of the steering patterns and speed variations depict that the standard deviations of the responses of the drivers for a given travel direction in a roundabout are within 35o (17 % of the baseline) for the steering wheel angle and 8 km/h (40 % of the baseline) for the speed. It is also found that the cognitive workload of the drivers due to the steering pattern is higher in right turns compared to straight crossings through the roundabout. The performance analyses show a dependency of LSSP on the instantaneous radius obtained from the vehicle's path, and the vehicle's travel direction in the roundabout. LSSP ranges from 7.7 m for a left turn in a roundabout with an inner radius of 12 m to 3.1 m for a straight crossing in a roundabout with a 30 m inner radius. TS is observed in only one roundabout and its magnitude goes up to 0.4 m in a roundabout of 30 m inner radius.

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  • 10.
    Bruzelius, Fredrik
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation..
    Low speed performance based standards for the Nordic countries2021In: International Journal of Vehicle Design. Heavy Vehicle Design, ISSN 1744-232X, E-ISSN 1741-5152, Vol. 28, no 1, p. 110-124Article in journal (Refereed)
    Abstract [en]

    Performance based standards (PBS) is an effective regulator policy which can address variation complexity in vehicle combinations. This paper investigates aspects of using computer simulation and mathematical models to assess the performance of vehicle combinations in low speed manoeuvring, and in particular roundabouts. A set of 22 vehicle combinations, including existing conventional heavy vehicles as well as prospective high capacity vehicles, is used to study the effects of turn angle and road surface conditions on the friction demand and swept path measures. Simulation results suggest that the friction demand measure is dependent on the available grip. This makes it hard to interpret and may not be suitable in the PBS framework. The swept path measure is relatively unaffected by friction levels, and can hence be calculated with simple and robust expressions not considering the road interaction. However, turn angle affects the swept path measure considerably, and should be addressed when designing the PBS scheme implementation into the legislations.

  • 11.
    Bruzelius, Fredrik
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation..
    Hjort, Mattias
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation..
    Augusto, Bruno
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation..
    The influence of tractor lengths on traffic safety and efficiency: a simulation study2022Report (Other academic)
    Abstract [en]

    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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  • 12.
    Bruzelius, Fredrik
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Körsimulering och visualisering, SIM.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Förare och fordon, FOF.
    Pettersson, Emil
    Volvo GTT.
    Model and Road Surface Sensitivity of Longitudinal Performance Based Standards2016Conference paper (Refereed)
    Abstract [en]

    Performance-based standards (PBS) is a regulation policy to address the complexity of variations in vehicle combinations. It enables a direct way of addressing certain requirements associated with the safety, environment and road network and their implications to the vehicle specific quantities without stipulating vehicle properties.

    Computer-based simulations may be an efficient tool to assess the performance measures. However, using simulations through models in a legislation raise questions of model accuracy and model complexity. What is a required level of modelling details to be used to assess a PBS measure?

    We investigate three level of complexity of models and the impact this have on three longitudinal performance measures; Startability, Gradeablity and Acceleration Capability. Simulations for 10 vehicle combinations are compared with two different engine alternatives. For Nordic countries, slippery road conditions are common during winter conditions. Hence, low friction is included in the comparison.

    The comparison suggested that the complexity could potentially be kept really low, without major loss of accuracy. However, for slippery conditions, a higher levels of complexity might be required.

  • 13.
    De Saxe, Christopher
    et al.
    WITS - University of the Witwatersrand.
    Kural, Karel
    HAN University of Applied Sciences.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle. Linköpings Universitet.
    Schmidt, Franziska
    IFSTTAR/MAST/EMGCU.
    Van Geem, Carl
    Belgian Road Research Centre.
    Robert, Berman
    WITS - University of the Witwatersrand.
    Woodrooffe, John
    University of Michigan.
    Cebon, David
    CAM - University of Cambridge.
    FALCON III: Defining a performance-based standards framework for high capacity vehicles in Europe2018Conference paper (Refereed)
    Abstract [en]

    The FALCON project (“Freight and Logistics in a Multimodal Context”) is a collaborative effort funded by the Conference of European Directors of Roads (CEDR), and has set out to address ambitious carbon emission reduction targets set by the European Commission. A primary goal of the project is to define a potential Performance-Based Standards (PBS) framework for cross-border road freight transport in Europe. First, a representative fleet of heavy vehicle combinations carrying modular loading units was formulated in collaboration with industry. The fleet was then simulated against a wide range of potential performance standards sourced from various countries. These findings together with expert opinion were then used to draft recommendations for a PBS framework for Europe.

  • 14.
    Eek, Magnus
    et al.
    Saab Aeronautics.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Gavel, Hampus
    Saab Aeronautics.
    Ölvander, Johan
    Linköpings Universitet.
    Study of industrially applied methods for verification, validation and uncertainty quantification of simulator models2015In: International Journal of Modeling, Simulation, and Scientific Computing, ISSN 1793-9623, E-ISSN 1793-9615, Vol. 6, no 2, article id 1550014Article in journal (Refereed)
    Abstract [en]

    To better utilize the potential of system simulation models and simulators, industrially applicable methods for Verification, Validation and Uncertainty Quantification (VV&UQ) are crucial. This paper presents an exploratory case study of VV&UQ techniques applied on models integrated in aircraft system simulators at Saab Aeronautics and in driving simulators at the Swedish National Road and Transport Research Institute (VTI). Results show that a large number of Verification and Validation (V&V) techniques are applied, some of which are promising for further development and use in simulator credibility assessment. Regarding the application of UQ, a large gap between academia and this part of industry has been identified, and simplified methods are needed. The applicability of the NASA Credibility Assessment Scale (CAS) at the studied organizations is also evaluated and it can be concluded that the CAS is considered to be a usable tool for achieving a uniform level of V&V for all models included in a simulator, although its implementation at the studied organizations requires tailoring and coordination.

  • 15.
    Hjort, Mattias
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation..
    Arvidsson, Anna K
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Sandin, Jesper
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation..
    Nyberg, Jonna
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Utredning av regler för vinterdäck till tunga fordon: Ett regeringsuppdrag2023Report (Other academic)
    Abstract [en]

    VTI, together with the Swedish Transport Agency, has been commissioned by the government to analyse the current regulations for winter tyres for heavy vehicles and to investigate the need for changed requirements for winter tyres or tyre equipment in order to reduce accessibility and safety problems in road traffic when winter road conditions prevail. If necessary, the Swedish Transport Agency will propose changes to the regulations. The assignment also included following up on compliance with the stricter requirements for winter tyres for heavy vehicles that were decided in 2018, and became active on 1 June 2019, and assessing the effect these regulatory changes have had on accessibility and road safety. In this investigation, we have conducted focus groups and interviews, collected statistics and carried out accident risk analyses, as well as carried out a couple of field studies of the condition of the tyres for trucks and buses in traffic. The existing regulations have been reviewed in detail and compared with the regulations in Norway and Finland, where winter conditions are similar to those in Sweden. Based on these analyses, we see no reason for changes to the existing regulations for winter tyres for heavy vehicles. The statistical analysis did not show any improvement in slippery conditions related to accessibility or road safety effects after the stricter winter tyre regulations in 2019.

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  • 16.
    Hjort, Mattias
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Bruzelius, Fredrik
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Andersson, Håkan
    Swedish National Road and Transport Research Institute, Infrastructure, Crash safety.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Towards a method for determining maximum oversteer in slippery conditions2013In: Proceedings of 23rd International Symposium on Dynamics of Vehicles on Roads and Tracks (IAVSD'13). Qingdao, China, 19-23 August, 2013., 2013Conference paper (Refereed)
    Abstract [en]

    Fatal accidents during winter time in Sweden are to a large extent due to vehicle spinning. Therefore, it is crucial to analyse and compare vehicle/tyre performance on slippery roads with respect to oversteering. In this study, a new test method for evaluation of vehicle's stability during oversteering on icy roadways is developed and evaluated using a series of tests with a rear wheel driven car, equipped with ESC, and six different tyres on ice test tracks in northern Sweden. The test method consists of an asymmetric sine-with-dwell manoeuvre and a measure forquantifying the level of oversteering based on the relation between yaw rate and lateral acceleration. The test results show good robustness of the method, and that it can successfully rate the various tyres performance on polished ice. However, to have a fair comparison, the proposed method should be modified to take into account the steering ability of the tyres and the consequent difference in the manoeuvre severity when tested with tyres with different side grip.

  • 17.
    Hjort, Mattias
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation..
    Bruzelius, Fredrik
    Chalmers tekniska högskola, Sverige.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation..
    Ydenius, Anders
    Folksam, Sverige.
    Test av åretruntdäck: Väggrepp på is och snö samt barmark2023Report (Other academic)
    Abstract [en]

    All-season tyres have previously not been approved for use as winter tyres in Sweden but are now allowed after a change of regulations in 2019. To compare the grip of this type of tyre with regular winter and summer tires, brake tests were conducted for 14 different all-season tyres on packed snow and ice, as well as on dry and wet asphalt. The tyres were selected to be representative of the available all-season tyres on the Swedish market. The results show large differences in braking grip between different all-season tires. Some tyres perform more like European non-studded winter tyres, and others more like summer tyres, which seems to be a conscious choice by the various manufacturers. On average, the braking distance of all-season tyres on snow is clearly longer than that of both Nordic and European non-studded winter tyres, and although there are all-season tyres that are similar to European winter tyres on snow, others perform significantly worse. On ice, the braking grip of all-season tyres is much worse compared to the Nordic non-studded reference tyre.

    Our assessment is that the ice grip is generally too poor to constitute a safe alternative on Swedish winter roads, and that one of the winter-approved all-season tyres performed just as bad as one of the summer tyres on ice is remarkable. There is a correlation between low rolling resistance and poor ice grip, which indicates that measures to reduce rolling resistance can have a negative impact on the ice grip of this type of tyre. Braking performance on dry and wet asphalt for all-season tyres are widespread, with the best all-season tyres performing equally with summer tyres, and the worst being about the same level as the best of the Nordic winter tyres. We can therefore not recommend all-season tyres as an alternative to winter and summer tyres.

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  • 18.
    Hjort, Mattias
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Eriksson, Olle
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Hjälmdahl, Magnus
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Limit handling in a driving simulator2015Report (Other academic)
    Abstract [en]

    The purpose of this work has been to investigate how the driving simulator performs at the handling limit of a vehicle and improve its function so that the simulator feels and behaves more like a real vehicle when driving on the limit. Tests were performed with a Volvo S40, the same vehicle model for which the driving simulator vehicle dynamics model is based upon. Based on these test results the vehicle model that is currently used in VTI’s driving simulator III was modified in order to better simulate vehicle characteristics when driving on the handling limit. A method for validation of handling characteristics was developed. The method is based on the double lane change manoeuvre, and comprise a subjective and an objective part. The method was regarded to work well, and the validation tests showed that the modified vehicle model closer captures the understeer and time lag properties of a real Volvo S40 compared to the original model. Still, additional improvements need to be made before the model can be regarded as fully useful for on-the-limit driving situations.

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  • 19.
    Hjort, Mattias
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Eriksson, Olle
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Hjälmdahl, Magnus
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Andersson Hultgren, Jonas
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Validating on-the-limit properties of a driving simulator2014In: New development in driving simulation design and experiments: Driving simulation conference Europe 2014 proceedings, 2014Conference paper (Refereed)
    Abstract [en]

    The paper describes a validation model for both subjective and objective comparison of on-the-limit properties of a driving simulator. VTI moving base driving simulator, SIM III, has been used with three different versions of VTI’s vehicle model, for validation toward field tests involving double lane change manoeuvres. Methods for handling evaluation suggested in the literature were adapted to our circumstances. The results are encouraging, although we found some limitations with respect to the objective evaluations that need to be addressed in future studies.

  • 20.
    Hjort, Mattias
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation..
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation..
    Fröjd, Niklas
    AB Volvo.
    Siltanen, Teppo
    Nokian Heavy Tyres Ltd, Finland.
    Tyre modelling for high capacity vehicle simulations2021In: 16th International Symposium on Heavy Vehicle Transportation Technology: China – 2021, International Forum for Heavy Vehicle Transport & Technology , 2021Conference paper (Other academic)
    Abstract [en]

    Tyre friction properties of 21 different heavy vehicle tyres have been measured on smooth ice and dry asphalt using a dedicated flat-bed machine. The purpose of the measurements was to study characteristics of typical heavy vehicle tyres, and to provide representative models for heavy vehicle dynamic simulations for both high and low friction conditions, with focus on lateral friction forces. The results reveal large differences of the cornering stiffness between new and worn tyres, where lower tread depth results in substantially higher stiffness. Cornering stiffness values on smooth ice and asphalt are very similar, suggesting that rubber and carcass stiffness rather than the friction level determines this property. Also, peak friction level on asphalt and relaxation length exhibits higher values for worn tyres compared to new. The measured data is currently being analysed in more detail with the purpose of creating standardized tyre models that can be used for PBS simulations.

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  • 21.
    Islam, Md Manjurul
    et al.
    Chalmers Tekniska Högskola.
    Fröjd, Niklas
    Volvo Group Trucks Technology.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Jacobson, Bengt
    Chalmers Tekniska Högskola.
    How well a single-track linear model captures the lateral dynamics of long combination vehicles2019In: Vehicle System Dynamics, ISSN 0042-3114, E-ISSN 1744-5159Article in journal (Refereed)
    Abstract [en]

    The effect of centre-of-gravity heights on the high-speed performance measures of long combination vehicles including truck with double centre-axle trailers, Nordic, and A-double combination vehicles is investigated. The high fidelity three-dimensional models, used in this research, are validated against physical test data. These models are often accurate in terms of the actual dynamic behaviours of the vehicle. On the other hand, the simple yaw-plane single-track models with linear tires require less number of vehicle parameters. In this paper, it is investigated how accurate the estimations of performance measures are at high forward speeds by such single-track linear (STL) models. The influence of load height is especially studied. The high-speed performance-based standard or PBS measures considered are rearward amplifications of both lateral acceleration and yaw velocity; lateral load transfer; yaw damping and high-speed transient offtracking. The results show that tire relaxation has a large effect and it is rather easy to add to an STL model, so it is assumed to be modelled in STL. With realistically high payload and a required accuracy of PBS measures of approximately 10%, only the accuracy of rearward amplification of yaw velocity calculated by the frequency response is fulfilled by the STL. With low payload, the same statement is valid, but with around 5% in required accuracy. The roll dynamics effects are more important than the tire non-linearities.

  • 22.
    Jacobson, Bengt J H
    et al.
    Chalmers.
    Sundström, Peter
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Fröjd, Niklas
    Islam, Manjurul
    Chalmers.
    An Open Assessment Tool for Performance Based Standards of Long Combination Vehicles2017Report (Other academic)
    Abstract [en]

    The project “Performance Based Standards for High Capacity Transports in Sweden” (Performance Based Standards for High Capacity Transports in Sweden, 2013-2017) have generated a first version of an open PBS assessment tool, OpenPBS. The tool uses models and computations to calculate Performance Based Standards (PBS) measures for combination vehicles. The tool targets Long Combination Vehicles (LCVs, typically 25-35 m) but it can also calculate PBSes for shorter combinations and solo units. This report describes the tool. The report explains the concepts selected for the tool. Future developments are proposed.

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  • 23.
    Jacobson, Bengt
    et al.
    Vehicle Engineering and Autonomous Systems Division, Department of Mechanics and Maritime Sciences, Chalmers University of Technology, Gothenburg, Sweden.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation.. Department of Electrical Engineering, Linköping University, Sweden.
    Fröjd, Niklas
    Volvo Group Trucks Technology, Gothenburg, Sweden.
    Ghandriz, Toheed
    Volvo Group Trucks Technology, Gothenburg, Sweden; Department of Mechanics and Maritime Sciences, Chalmers University of Technology, Gothenburg, Sweden.
    Bagdadi, Omar
    Swedish Transport Administration, Borlänge, Sweden.
    An open assessment tool for standardized performance measures of long combination vehicles2024In: Technology Convergence 2023: Setting the Wheels In Motion: Reimagining the future of heavy vehicles, roads and freight, International Forum for Heavy Vehicle Transport & Technology; The International Society for Weigh-In-Motion , 2024, article id 5256Conference paper (Other academic)
    Abstract [en]

    Long Combination Vehicles (LCV) are transport efficient. However, allowing any combination of, individually legal, loaded vehicle units which when connected become LCV, can lead to traffic risks. Therefore, ways to assess LCVs are developed. The paper proposes an open tool which can assess a certain LCV for a certain load distribution. The tool could be a base for a digital service for such assessment. The assessment is done with Performance-Based Standards (PBS). PBS measures, computed through dynamic models and simulations, can be compared to numerical requirements. The vehicle parameters are selected to be as easy as possible to find values on, e.g., from available data in a vehicle unit registry. Also, the loading is defined by giving the static vertical force for each axle and the load height for each vehicle unit. A PBS based assessment method, as opposed to simply prescribing certain vehicle design parameters, would encourage novel combination vehicle designs. That would continuously drive the development towards even better transport efficiency, including energy efficiency.

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  • 24.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Assessing dynamics of heavy vehicles in a driving simulator2018In: Proceedings of DSC 2018 EUROPE 17th Driving Simulation & Virtual Reality Conference & Exhibition September 2018, Antibes, France, 2018Conference paper (Refereed)
  • 25.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation..
    Performance based standards II2022Report (Other academic)
    Abstract [en]

    High Capacity Transport (HCT) is part of Sweden’s attempts towards a more efficient transport system. HCT vehicles are heavier and/or longer than conventional heavy vehicles and can carry more load per vehicle, resulting in less fuel consumption and emissions. In Sweden the legal length and weight limits for heavy vehicles are 25.25 m and 64 t. Also, from April 2018, heavier vehicles up to 74 t have been allowed on parts of the road network with a new bearing capacity named BK4. Introduction of vehicles longer than 25.25m is currently under consideration. In the neighboring country, Finland, the weight limit for heavy vehicles was increased to 76 t in 2013, and longer HCT vehicles up to 34.5 m are allowed on most of the road network since 2019. After allowing HCT vehicles in Sweden, regulations concerning heavy vehicles access to road network have been modified and a PBS based regulation for 74 t vehicles have been introduced. PBS stands for performance based standards, under which the required performance from the vehicles is regulated, instead of limiting their length or weight. The purpose of the PBS II project has been to contribute to further development of the PBS scheme in Sweden and to support its implementation. One important aspect which required further investigation was the effect of tire characteristics on the performance of the HCT vehicles. Also, the assessment procedure of the HCT vehicles and a corresponding tool for it, demanded further developments. These issues have been addressed in the PBS II project, resulting in standard tire models for assessment of HCT vehicles, as well as an improved open access PBS tool.

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  • 26.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Performance Based Standards Project In Sweden2018Conference paper (Refereed)
    Abstract [en]

    There is a great interest in increasing the efficiency of the transport system in Sweden, which makes the High Capacity Transports (HCT) an attractive solution. To gain more knowledge about HCT vehicles and their effects on traffic safety, infrastructure and environment, the Swedish government is undertaking a large research program focused on HCT vehicles in Sweden. One of the projects in the HCT program was “Performance based standards for high capacity transport in Sweden”. This project started at the end of 2013 to investigate the applicability of a regulatory framework based on performance based standards in Sweden, taking into consideration the winter road conditions. This paper presents a summary of the main outcomes of the project, which ended in 2017.

  • 27.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Förare och fordon, FOF.
    Performance of High Capacity Vehicles, Winter Versus Summer2016Conference paper (Refereed)
    Abstract [en]

    The transport sector is facing a major challenge to reduce energy consumption and limit environmental impact; therefore, there is a great interest in increasing the efficiency of the transport system in Sweden, which makes the High Capacity Vehicles (HCVs) an attractive solution. In order to introduce HCVs in Sweden, the existing regulations should be modified; one approach is to use performance based standards (PBS) as in e.g. Australia and Canada. However, it is very important that the winter road conditions in Sweden is considered and a PBS system suitable for Swedish condition is developed. In this paper performance of a selection of HCVs are compared for both summer and winter condition, which shows a strong correlation between the two.

  • 28.
    Kharrazi, Sogol
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Almen, Marcus
    SAAB.
    Frisk, Erik
    Linköpings Universitet.
    Nielsen, Lars
    Linköpings Universitet.
    Extending behavioral models to generate mission-based driving cycles for data-driven vehicle development2018In: IEEE Transactions on Vehicular Technology, ISSN 0018-9545, E-ISSN 1939-9359, Vol. 68, no 2, p. 1222-1230Article in journal (Refereed)
    Abstract [en]

    Driving cycles are nowadays to an increasing extent used as input to model-based vehicle design and as training data for development of vehicles models and functions with machine learning algorithms. Recorded real driving data may underrepresent or even lack important characteristics, and therefore there is a need to complement driving cycles obtained from real driving data with synthetic data that exhibit various desired characteristics. In this paper, an efficient method for generation of mission-based driving cycles is developed for this purpose. It is based on available effective methods for traffic simulation and available maps to define driving missions. By comparing the traffic simulation results with real driving data, insufficiencies in the existing behavioral model in the utilized traffic simulation tool are identified. Based on these findings, four extensions to the behavioral model are suggested, staying within the same class of computational complexity so that it can still be used in large scale. The evaluation results show significant improvements in the match between the data measured on the road and the outputs of the traffic simulation with the suggested extensions of the behavioral model. The achieved improvements can be observed with both visual inspection and objective measures. For instance, the 40% difference in the relative positive acceleration (RPA) of the originally simulated driving cycle compared to real driving data was eliminated using the suggested model.

  • 29.
    Kharrazi, Sogol
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Atif, Yacine
    Högskolan i Skövde.
    Sustainable smart-parking management for connected and autonomous vehicles2020Report (Other academic)
    Abstract [en]

    Traffic induced by parking-spot seekers is a growing challenge and constitutes a considerable portion of the traffic in city centers. New opportunities to solve this problem are emerging by connected vehicles and infrastructure. For instance, ultrasonic and magnetic sensors are already mounted on the ceiling of many parking lots to detect the availability of a parking spot. These sensors can provide parking spot availability information in real-time. Further, traffic-aware smart sensors which can detect the movement of individual vehicles are also available in many city and highway areas. This report suggests an algorithm for a cloud-based parking service that exploits these streams of data to choose the best parking lot in a given parking area.

    The parking seeking problem is subject to a range of criteria that may include user, municipality and parking operator preferences. Users may have some preferences with respect to walking distance to destination. Municipalities prefer to spread the traffic to reduce congestion in the urban core. Parking operators seek to maximize parking lot utilization in order to increase the revenue on real-estate investments. To solve this problem, an optimization algorithm based on multicriteria decision making process is used.

    The proposed SmartPark algorithm employs a discrete Markov-chain model to demystify the future state of a parking lot. The algorithm features three modular sections:

    • First, a search process is triggered to identify the expected arrival time periods to all parking lots in the targeted parking area. This process utilizes smart pole data streams reporting congestion rates across the targeted parking area.

    • Then, a predictive analytics phase uses consolidated historical data about past parking dynamics to infer a state transition matrix, showing the transformation of available spots in a parking lot over short periods of time.

    • Finally, this matrix is projected against similar future seasonal periods to predict the actual vacancy of a parking lot at the arrival time.

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  • 30.
    Kharrazi, Sogol
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Augusto, Bruno
    Swedish National Road and Transport Research Institute, Traffic and road users, Driving Simulation and Visualization.
    Fröjd, Niklas
    Volvo Group Technology.
    Assessing dynamics of heavy vehicles in a driving simulator2019In: Transportation Research Part F: Traffic Psychology and Behaviour, ISSN 1369-8478, E-ISSN 1873-5517, Vol. 65, p. 306-315Article in journal (Refereed)
    Abstract [en]

    This article investigates the potential of a motion based driving simulator in assessing and comparing dynamic performance of different heavy vehicles. A driving simulator study with 55 professional truck drivers is performed and the achieved results show a strong correlation between the objective and subjective measures of the different vehicles performance. The motion based driving simulator is used to compare the performance and controllability of high capacity transport vehicles with conventional heavy vehicles.

  • 31.
    Kharrazi, Sogol
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Augusto, Bruno
    Swedish National Road and Transport Research Institute, Traffic and road users, Driving Simulation and Visualization.
    Fröjd, Niklas
    Volvo.
    Vehicle dynamics testing in motion based driving simulators2019In: Vehicle System Dynamics, ISSN 0042-3114, E-ISSN 1744-5159Article in journal (Refereed)
    Abstract [en]

    This article investigates the potential of a motion-based driving simulator in the field of vehicle dynamics testing, specifically for heavy vehicles. For this purpose, a case study was prepared embodying the nature of a truck dynamics test setup. The goal was to investigate if the drivers in the simulator could identify the handling differences owed to changes in vehicle parameters, while driving the simulated trucks. Results show that the drivers could clearly identify the differences in vehicle behaviour for most of the performed tests, which motivates further investigative work in this area and exposes the feasibility of heavy vehicle dynamics testing in simulators.

  • 32.
    Kharrazi, Sogol
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Aurell, John
    Chalmers Tekniska Högskola.
    Sadeghi Kati, Maliheh
    Chalmers Tekniska Högskola.
    Jacobson, Bengt
    Chalmers Tekniska Högskola.
    Fröjd, Niklas
    Volvo Group Trucks Technology.
    Asp, Thomas
    Trafikverket.
    Towards performance based standards in Sweden2014Conference paper (Refereed)
    Abstract [en]

    The large increase in the goods transport demands, the growing congestion problem and the environmental concerns over transportation emissions and fuel consumption, make High Capacity Transport (HCT) vehicles an attractive alternative to the conventional heavy vehicle combinations on the roads in Sweden; an alternative which would also result in significant economic benefits. In order to introduce HCT vehicles in Sweden, the existing regulations should be modified and a proper way of regulating HCT vehicles and their access to the road network should be developed to ensure that a certified HCT vehicle would not have negative effects on traffic safety, infrastructure and environment. One possible solution is application of performance based standards (PBS); this paper presents a project called "Performance Based Standards for High Capacity Transports in Sweden" which investigates applicability of PBS to Swedish conditions.

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  • 33.
    Kharrazi, Sogol
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation..
    Bruzelius, Fredrik
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Augusto, Bruno
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation..
    Hjort, Mattias
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation..
    Wheelbase Influence on Performance of Tractor-Semitrailer Combinations2022In: Lecture Notes in Mechanical Engineering: 27th Symposium of the International Association of Vehicle System Dynamics, IAVSD 2021, Springer Science and Business Media Deutschland GmbH , 2022, p. 713-725Conference paper (Refereed)
    Abstract [en]

    A commonly seen vehicle combination on the European road network is the tractor-semitrailer with a maximum legal length of 16.5 m. In Nordic countries longer tractor-semitrailers are allowed, which makes tractors with larger wheelbase an appealing option. Concerns have been raised that shorter tractors have poorer performance and are involved in more accidents than the Nordic equivalents, especially in winter conditions. To answer the raised questions and concerns, this paper investigates the effects of a tractor wheelbase length on performance of a vehicle combination, as well as other influencing factors such as lubrication of the fifth when, loading condition and road friction level. Six tractor-semitrailer combinations with different wheelbases and axle configurations are modeled and compared. Nordic (truck-dolly-semitrailer) and B-double (tractor-link trailer-semitrailer) combinations, which are common in Nordic countries, are also used as reference vehicles in the comparison. Three maneuvers are simulated to provoke dangerous situations, namely braking with all wheels in a curve, engine braking in a curve and a fast single lane change. The results show that wheelbase alone does not have a major role in the outcome of the simulations, but a combined influence of axle configuration, wheelbase, fifth wheel position and axle loads determines the vehicle performance. Factors such as existence of a working anti-lock braking system or lubrication of the fifth wheel have a large effect on the vehicle performance, under the tested conditions.

  • 34.
    Kharrazi, Sogol
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Bruzelius, Fredrik
    Swedish National Road and Transport Research Institute, Traffic and road users, Driving Simulation and Visualization.
    Sandberg, Ulf
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Performance based standards for high capacity transports in Sweden: FIFFI project 2013-03881: final report2017Report (Other academic)
    Abstract [en]

    Project “Performance Based Standards for High Capacity Transports in Sweden” started at the end of 2013 to investigate applicability of PBS in Sweden, and ended in Autumn 2017. The purpose of the project was to propose a performance based regulation of HCT vehicles and their access to the road network; under a PBS approach to regulation, standards would specify the performance required from the vehicle, rather than mandating prescriptive length and weight limits. In this project, all the three domains of safety, infrastructure and environment were addressed, but the focus has been on safety for which extensive testing, simulations and analysis were performed. This report gathers the outcomes of the project.

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  • 35.
    Kharrazi, Sogol
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle. Linköping University, Sweden.
    Frisk, Erik
    Linköping University, Sweden.
    Nielsen, Lars
    Linköping University, Sweden.
    Driving Behavior Categorization and Models for Generation of Mission-based Driving Cycles2019In: 2019 IEEE Intelligent Transportation Systems Conference, ITSC 2019, Institute of Electrical and Electronics Engineers Inc. , 2019, p. 1349-1354Conference paper (Refereed)
    Abstract [en]

    The concept of mission-based driving cycles has been introduced as an efficient way of generating driving cycles with desired characteristics for data-driven development of vehicle powertrains. Mission-based driving cycles can be generated using traffic simulation tools with improved behavioral models that match simulation outputs and naturalistic driving data. Here, driving behavior categorization and how it can be used to create a set of differently parameterized behavioral models corresponding to various types of drivers, are studied. The focus is on curvy road driving, and two different categorization features are used, speed through the curves and the braking behavior. © 2019 IEEE.

  • 36.
    Kharrazi, Sogol
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Hjort, Mattias
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Bruzelius, Fredrik
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Andersson, Håkan
    Testing Vehicle Performance on Snow Using Sine with Dwell2014In: Proceedings of the 14th International Symposium on Advanced Vehicle Control (AVEC), Tokyo, September 2014., 2014Conference paper (Refereed)
    Abstract [en]

    Measuring and evaluating vehicle and tire performance in winter conditions are highly motivated by accident statistics. The present paper investigates use of the sine with dwell maneuver in this context. Various aspects of winter testing is discussed and illustrated with test track measurements, such as test repeatability and trade-off between stability and maneuverability. An evaluation procedure is presented and demonstrated with the classical issue of which axle to choose for the worst set of tires.

  • 37.
    Kharrazi, Sogol
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Karlsson, Robert
    Trafikverket.
    Performance based standards for vehicle combinations with weight and/or dimensions exceeding the specified limits in the Directive 96/53/EC: a pre-study for CEDR2015Report (Other academic)
    Abstract [en]

    This report includes the gathered information in a CEDR pre-study, with the objective to list the relevant safety, manoeuvrability, infrastructure and environment related criteria for longer and/or heavier vehicles. Furthermore, research areas that should be further investigated for development of a harmonized performance based standards for assessing longer and/or heavier vehicles access to a road network, are identified.

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  • 38.
    Kharrazi, Sogol
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Karlsson, Robert
    Swedish National Road and Transport Research Institute, Infrastructure.
    Sandin, Jesper
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Aurell, John
    John Aurell consulting.
    Performance based standards for high capacity transports in Sweden: FIFFI project 2013-03881: Report 1: Review of existing regulations and literature2015Report (Other academic)
    Abstract [en]

    Project Performance Based Standards (PBS) for High Capacity Transports (HCT) in Sweden started at the end of 2013 to investigate applicability of PBS in Sweden. The purpose of the project is to propose a performance based regulation of HCT vehicles and their access to the road network; under a PBS approach to regulation, standards would specify the performance required from vehicle, rather than mandating how this level of performance should be achieved by putting limits on the vehicle length or weight. In this project, all the three domains of safety, infrastructure and environment will be addressed, but the focus is on safety for which extensive testing, simulations and analysis are planned. This report gathers the outcome of work packages 1 and 2 of the project, which is a review of the existing regulation in Sweden, PBS approaches in other countries and relevant literature and regulations.

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  • 39.
    Kharrazi, Sogol
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation.. Department of Electrical Engineering, Linköping University, Sweden.
    Laine, Leo
    Department of Mechanics and Maritime Sciences, Chalmers University of Technology, Gothenburg, Sweden; Volvo Group Trucks Technology, Gothenburg, Sweden.
    Larsson, Lena
    Volvo Group Trucks Technology, Gothenburg, Sweden.
    Sandin, Jesper
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Jacobson, Bengt
    Vehicle Engineering and Autonomous Systems Division, Department of Mechanics and Maritime Sciences, Chalmers University of Technology, Gothenburg, Sweden.
    Asp, Thomas
    Swedish Transport Administration, Gothenburg, Sweden.
    Bagdadi, Omar
    Swedish Transport Administration, Borlänge, Sweden.
    A review of more than a decade of research and field tests on longer vehicle combinations in Sweden that supported road approval2024In: Technology Convergence 2023: Setting the Wheels In Motion: Reimagining the future of heavy vehicles, roads and freight, International Forum for Heavy Vehicle Transport & Technology; The International Society for Weigh-In-Motion , 2024, article id 7891Conference paper (Other academic)
    Abstract [en]

    For more than a decade, Longer Vehicle Combinations (LVCs) have been tested in Sweden on roads and test tracks and studied in simulations. Based on the outcomes of this research, the government in Sweden has decided to open part of the road network for LVCs with a length up to 34.5 m. Necessary regulatory framework should be in place before this change can be applied. Thus, the LVCs are not expected on the roads before winter 2023-2024. This article reviews outcomes of the extensive research which has been performed on High Capacity Transport (HCT) to support introduction of LVCs in Sweden. Summary of studies on various aspects of HCT, such as regulation, safety, maneuverability, electrification, and emissions, are presented.

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  • 40.
    Kharrazi, Sogol
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Nielsen, Lars
    Linköpings Universitet.
    Frisk, Erik
    Linköpings Universitet.
    Design cycles for a given driving mission2018In: Dynamics of Vehicles on Roads and Tracks Vol 1: Proceedings of the 25th International Symposium on Dynamics of Vehicles on Roads and Tracks (IAVSD 2017), 14-18 August 2017, Rockhampton, Queensland, Australia / [ed] Maksym Spiryagin, Timothy Gordon, Colin Cole, Tim McSweeney, London: CRC Press, 2018, Vol. 1, p. 323-328Conference paper (Refereed)
    Abstract [en]

    Representative driving cycles are of key importance for design and dimensioning of powertrains. One approach for generation of representatives driving cycles is to define relevant driving missions which include different street types, obstacles and traffic conditions, and simulate them in a traffic simulation tool. Such a simulation approach will also require representative driver models to generate the speed profiles for the defined driving missions. Feasibility of this approach is investigated in this paper.

  • 41.
    Kharrazi, Sogol
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation..
    Nielsen, Lars
    Vehicular Systems, Department of Elec, Linköping University, Sweden.
    Frisk, Erik
    Vehicular Systems, Department of Elec, Linköping University, Sweden.
    Generation of Mission-Based Driving Cycles Using Behavioral Models Parameterized for Different Driver Categories2023In: SAE technical paper series, ISSN 0148-7191, article id 2023-01-5033Article in journal (Refereed)
    Abstract [en]

    A methodology for the generation of representative driving cycles is proposed and evaluated. The proposed method combines traffic simulation and driving behavior modeling to generate mission-based driving cycles. Extensions to the existing behavioral model in a traffic simulation tool are suggested and parameterized for different driver categories to capture the effects of road geometry and variances between drivers. The evaluation results illustrate that the developed extensions significantly improve the match between driving data and the driving cycles generated by traffic simulation. Using model extensions parameterized for different driver categories, instead of only one average driver, provides the possibility to represent different driving behaviors and further improve the realism of the resulting driving cycles.

  • 42.
    Kural, Karel
    et al.
    HAN University of Applied Sciences.
    de Saxe, Christopher C
    University of Cambridge.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Asp, Thomas
    Trafikverket.
    Kraaijenhagen, Ben
    MAN Truck & Bus AG.
    Pauwelussen, Joop
    Council for Scientific and Insustrial Research, South Africa.
    Smart infrastructure access policy: a highway towards more efficient road transport2018In: Proceedings of the 7th Transport Research Arena (TRA), Vienna, Austria, 16-19 April 2018, 2018Conference paper (Refereed)
    Abstract [en]

    This paper describes interim results of the ongoing CEDR-funded "FALCON" project, which aims to introduce a step improvement in transport efficiency in Europe through the definition of a new performance-oriented legislative framework for road freight transport, thus ensuring a proper match between vehicles and the infrastructure. A Smart Infrastructure Access Policy (SIAP) is being developed as the primary method of regulation, in which policy explicitly specifies the performance level required from the road freight vehicle with respect to safety, manoeuvrability, infrastructure loading, and environmental impact, while giving consideration to national topologies and operational conditions. This method is fundamentally different to the prescriptive approach which mandates only mass and dimension limits of vehicles. The prescriptive approach only indirectly and often ineffectively ensures acceptable vehicle performance, as is the case of current prescriptive European legislation (96/53/EC).

  • 43.
    Rahman, Mohammad Shafiqur
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation.. Department of Electrical Engineering, Linköping University, Sweden.
    Erlingsson, Sigurdur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    High-capacity transport in cities and the impact on the roads2024In: Technology Convergence 2023: Setting the Wheels In Motion: Reimagining the future of heavy vehicles, roads and freight, International Forum for Heavy Vehicle Transport & Technology; The International Society for Weigh-In-Motion , 2024, article id 8555Conference paper (Other academic)
    Abstract [en]

    This paper presents the evaluation of the relative pavement damage caused by a high-capacity transport (HCT) 5 axle truck with respect to three other reference trucks consisting of 4, 3 and 2 axles. The analysis was conducted by simulating the responses of three pavement structures using the pavement analysis tool ERAPave. Two damage criteria of the pavement structures were evaluated: fatigue cracking of the asphalt concrete (AC) layer and permanent deformation of the subgrade. The relative damage caused by the different vehicles were estimated by calculating a damage factor (Dr) following the Asphalt Institute Method. Three loading scenarios of the trucks were analyzed: (a) one way trip with fully loaded trucks, (b) round trip where the return trip consisted of the empty vehicles with lifted axles and (c) round trip where the return trip consisted of the empty vehicles without lifting any axles. The damage factors were calculated for per ton of carried load and were normalized with respect to the 2-axle truck. Results indicate that the relative impacts of the vehicles depend on the structure type and seasons. Generally, the 4-axle truck appeared to be the least damaging one. The HCT 5-axle truck is more damaging than the 4-axle truck, but less damaging than the other two.

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  • 44.
    Sandberg, Ulf
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Mioduszewski, Piotr
    Gdansk University of Technology.
    Comparison Of Noise Emission Of HCT And Classic Vehicle Combinations For Timber Transportation In Sweden2018Conference paper (Refereed)
    Abstract [en]

    By means of a special simulation tool, the noise emission of a high-capacity heavy vehicle (11 axles) was compared to that of a classic heavy vehicle (a truck-dolly-semitrailer with 8 axles). The two cases are designated “Extended vehicle” versus “Classic vehicle” in this study, having total lengths of 34 and 25 m, respectively. The Classic vehicle represents the most common articulated heavy vehicle configuration for transport of timber and other goods in Sweden. Tyres were assumed to be typical of each axle and their noise emission values were taken from a recent study. Noise from the propulsion unit were assumed to just meet the present maximum legal levels. It was found that noise emission from the Extended vehicle is approx. 1.5 dB higher than for Classic vehicle, as max. A-weighted level per vehicle passage, but as the number of vehicles in traffic is lower for a certain transportation volume, the resulting road traffic noise exposure in terms of A-weighted equivalent level LAeq is similar. Consequently, noise emission is not a factor that gives either vehicle type a clear advantage over the other.

  • 45.
    Sandin, Jesper
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Bálint, András
    Chalmers Tekniska Högskola.
    Fagerlind, Helen
    Chalmers Tekniska Högskola.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Traffic safety of Heavy Goods Vehicles and implications for High Capacity Transport vehicles2014In: Transport Research Arena 2014, Paris, 2014Conference paper (Refereed)
    Abstract [en]

    The paper summarizes the results of the programme "Traffic safety effects of High Capacity Transport (HCT) vehicles and suggestions for compensatory measures" this far. An analysis of ten years of Swedish accident data shows that "long" combinations (18.76m to 25.25m) had lower rate of fatal or severe accidents per billion vehicle kilometres travelled compared to medium and short vehicles. It is argued in the literature that HCT vehicles would, on average, reduce the number of Heavy Goods Vehicles (HGV) accidents because fewer vehicles would be needed to transport a given amount of goods. However, further investigation is required of the causal relationship between crash risk and a HGVs’ weight, length, number of units, links and axles in certain traffic situations. One way to ensure the safety performance of HCT vehicles, and HGVs, is to assess them by Performance Based Standards. The paper describes the plans to adapt PBS to Swedish conditions, and to monitor Swedish HCT vehicles under trial with the surveillance system Intelligent Access Programme (IAP).

  • 46.
    Schmidt, Franziska
    et al.
    Ifsttar .
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Erlingsson, Sigurdur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology. University of Iceland.
    Van Geem, Carl
    Belgian Road Research Centre.
    Cocu, Xavier
    Belgian Road Research Centre.
    Jacob, Bernard
    IFFSTAR.
    FALCON II: Input For A European PBS Definition: Review Of Vehicle Legislations And Infrastructure Design Criteria2018Conference paper (Refereed)
    Abstract [en]

    In Europe, the regulation on weights and dimensions of trucks are complex : European rules are given by EC Directive 96/53/EC as modified by Directive (EU) 2015/719 [1]. These rules apply for international traffic, but countries can decide to add specific national rules. Moreover, these rules are often different from one country to another, due to policy choices and local history. More specifically, the impact of trucks on infrastructure has not always been the primary fact for defining these rules. But in other countries or other research domains, performance based standards (PBS) are used to determine what is allowed, in terms of performance. For example, vehicles may be allowed in terms of their induced damage on bridges (Bridge Formula, see [2]) or dynamic behavior (PBS as in Australia for example). In another context, materials and structures are now often defined in calls for tender in terms of performance (durability, resistance for example). In this context, the work package (WP) C (Fit for purpose road vehicles to influence modal choice) of CEDR project FALCON (Freight And Logistics in a multimodal CONtext) aims at developing Performance Based Standards [3]. For that, the first step is to create a state-of-the art of the European situation concerning vehicle policy and infrastructure. This paper summarizes this work: the first section gives insight on the European vehicle policy. The second section presents the infrastructure catalogue developed within the FALCON project. Finally, these infrastructure elements are characterized in terms of design criteria in Section 3.

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  • 47.
    Sedran, Stefano
    et al.
    Politecnico di Torino.
    Bruzelius, Fredrik
    Swedish National Road and Transport Research Institute, Traffic and road users, Driving Simulation and Visualization.
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Jacobson, Bengt
    Chalmers University of Technology.
    Amati, Nicola
    Politecnico di Torino.
    A Heavy Vehicle Dynamics Model for Driving Simulators2016Conference paper (Refereed)
    Abstract [en]

    The aim of the present paper was to develop and validate a heavy vehicle dynamics model for driving simulators. The model was thought to be open, with a high level of readability and flexibility for future understanding, modification and use. A stepwise increment of the model complexity was utilized to understand the most contributing factors and to obtain a model capable of running in real-time. The model has been validated objectively using a previously validated model and through subjective evaluation in a driving simulator.

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  • 48.
    Ydrefors, Lisa
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation.. KTH, Fordonsdynamik.
    Hjort, Mattias
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation..
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation.. KTH, Sweden.
    Jerrelind, Jenny
    KTH, Sweden.
    Stensson Trigell, Annika
    KTH, Sweden.
    Development of a method for measuring rolling resistance at different tyre temperatures2022In: Lecture Notes in Mechanical Engineering: 27th IAVSD Symposium, 2021, digital from St Petersburg, 17-19 august, 2021, 2022, p. 1026-1039Conference paper (Refereed)
    Abstract [en]

    Measurement methods to determine the rolling resistance of tyres during different operation conditions are essential in the work towards more energy efficient vehicles. One of the influential parameters is the tyre temperature distribution, which has a large impact on the rolling resistance. Today, the standardised test procedure to measure rolling resistance is steady-state measurement on drums. However, the steady-state temperature on a drum is not the same as the temperature during ordinary driving conditions. The aim of this work is to develop a measuring method that enables to set a desired measurement temperature, which would create the possibility to study the relationship between tyre temperature and rolling resistance in more detail. The measurement method was developed by the use of a flat track equipment but should be applicable to other rolling resistance measurement equipment such as drums. The resulting method gives a repeatable tyre temperature and rolling resistance and can be used for measurements on tyres heated to a chosen measurement temperature. 

  • 49.
    Ydrefors, Lisa
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation.. KTH, Fordonsdynamik.
    Hjort, Mattias
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation..
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation.. KTH, VinnExcellence Center for ECO2 Vehicle design.
    Jerrelind, Jenny
    KTH, Fordonsdynamik.
    Stensson Trigell, Annika
    KTH, Teknisk mekanik.
    Development of rolling resistance measurement set-up in order to enable energy optimisation of vehicle-road interaction taking into account safety and performance2021In: Proceedings of the Resource Efficient Vehicles Conference - 2021 / [ed] O'Reilly, Ciarán J. et al., 2021, p. 116-122Conference paper (Other academic)
    Abstract [en]

    Reducing the rolling resistance for future vehicle designs creates a possibility to reduce the fuel consumption and make the future vehicles more economical and ecological. For electric vehicles it is also an enabler to increase their driving range per charge. When optimising for reduced rolling resistance, contradictory requirements such as force generation for maintaining safety and performance need to be considered. Furthermore, it is important to include both the effects of road surface and vehicle, to avoid sub-optimisation regarding only the tyres. A cross-functional conflict on the component level is well known, in form of energy consumption versus wet grip (traffic safety). On the system level, different wheel settings to optimise energy consumption conflicts with vehicle dynamical properties related to traffic safety, such as stability or steer response. The long term vision of the work presented is to create tools for more energy efficient vehicles by reducing the rolling resistance during driving. The first part is to establish a credible measurement method for rolling resistance on road under controlled conditions (lab environment). Today’s existing measurement methods on rolling resistance under laboratory conditions commonly utilise a rotating drum, whose curved surface affects the results. Therefore, rolling resistance influence of vehicle settings such as camber or toe angles is difficult to assess using standard methods, and there is a need for measurements using a more realistic contact patch, which would need a flat surface. The existing unique tyre testing facility at the Swedish National Road and Transport Research Institute, VTI, is used as a base for developing the new rolling resistance set-up. The tyre test facility is today used to determine tyre characteristics such as brake and steering forces. The method to measure rolling resistance with this equipment under highly controlled conditions is under development, and some preliminary results are presented.

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  • 50.
    Ydrefors, Lisa
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation..
    Hjort, Mattias
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation..
    Kharrazi, Sogol
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation..
    Jerrelind, Jenny
    KTH, Sweden.
    Stensson Trigell, Annika
    KTH, Sweden.
    Measurement and evaluation of rolling resistance of car tyres at low operating temperatures2023Conference paper (Other academic)
12 1 - 50 of 52
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