| 1. |
- Alm, Håkan, et al.
(författare)
-
The use of car phones and changes in driver behaviour
- 2001
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Ingår i: International Journal of Vehicle Design. - 0143-3369 .- 1741-5314. ; 26:1, s. 4-11
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Tidskriftsartikel (refereegranskat)abstract
- The effects of mobile telephone use on traffic safety is discussed in the article. A number of empirical studies are reviewed and it is concluded that the use of a mobile telephone concurrently with car driving may have a negative impact upon traffic safety. The sub-tasks of entering a telephone number and having a demanding conversation are especially likely to increase the risk of an accident. To minimize the negative impact from telephoning on traffic safety a number of recommendations are suggested.
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| 2. |
- Ahlin, Kjell, et al.
(författare)
-
Comparing Road Profiles with Vehicle Perceived Roughness
- 2004
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Ingår i: International Journal of Vehicle Design. - Geneva, Switzerland : Inderscience Enterprises. - 0143-3369 .- 1741-5314. ; 36:2-3, s. 270-286
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Tidskriftsartikel (refereegranskat)abstract
- Accurate road profiles are useful in vehicle design, such as for simulation of durability and ride quality. Laser/inertial profilometers typically record I mm wide profiles. The question is how well such a profile matches perceived vehicle wheel roughness. The objective here was to create a more representative wheel track longitudinal profile. Simulated and measured wheel vibration was compared on a 6km long road. Simulations were made for several definitions of the profile. Results for single laser sensor profiles showed reasonable likeness to truck perceived roughness. By far the best likeness (14.5% better) was achieved when the profile was based on triangular 25%-50%-25% weighted data from three sensors in the wheel track. Clearly, vehicle engineers can benefit from using multiple laser profile sensors, instead of a single sensor. This will improve test accuracy, thus reducing vehicle design project lead times and costs.
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| 3. |
- Andrén, Peter, 1972-
(författare)
-
Power spectral density approximations of longitudinal road profiles
- 2006
-
Ingår i: International Journal of Vehicle Design. - : INDERSCIENCE ENTERPRISES LTD. - 0143-3369 .- 1741-5314. ; 40:1-3, s. 2-14
-
Tidskriftsartikel (refereegranskat)abstract
- The power spectral density (PSD) representation of road profiles can be used both to assess the road roughness, and as an input to vehicle dynamics. The PSD is often approximated with a simple function, using only a few parameters. The present paper presents a literature survey of such PSD approximations, and tests four approximations on longitudinal road profile data from the entire Swedish state road network.
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| 4. |
- Boere, Stijn, et al.
(författare)
-
Tyre/road interaction model for the prediction of road texture influence on rolling resistance
- 2014
-
Ingår i: International Journal of Vehicle Design. - 0143-3369 .- 1741-5314. ; 65:2-3, s. 202-221
-
Tidskriftsartikel (refereegranskat)abstract
- A novel modelling approach to predict the influence of road texture on the rolling resistance of car tyres is presented where the large static tyre deformations and the small texture induced tyre vibrations are treated separately. The energy dissipation due to the large continuous cyclic deformation of the tyre cross section for a treadless tyre subject to nominal load on a smooth road is determined in a non-linear steady-state rolling analysis on an FEM tyre model. The additional energy dissipation resulting from the con tact forces and tyre vibrations due to the combined effect of the tread profile and the road texture, are determined based on a modal representation of the deformed tyre. The predicted rolling resistance coefficients are compared to experimental data. Although an offset in the absolute rolling resistance levels can be observed, the model predicts the correct trend regarding the increase of rolling resistance with increasing texture depth.
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| 5. |
- Dahlberg, E., et al.
(författare)
-
The dynamic rollover threshold - a heavy truck sensitivity study
- 2006
-
Ingår i: International Journal of Vehicle Design. - 0143-3369 .- 1741-5314. ; 40:03-jan, s. 228-250
-
Tidskriftsartikel (refereegranskat)abstract
- Knowledge of rollover mechanics, which is required in heavy truck development, commonly relies on a static analysis, providing the steady-state rollover threshold, SSRT. In a rolling vehicle, kinetic energy is always present and that deteriorates the analysis of roll stability from SSRT and implies the need for a dynamic rollover threshold, DRT as a complement. A method to determine DRT is presented and a parameter sensitivity study The influences on SSRT and DRT, including interaction effects, from roll stiffnesses and roll centre heights, are calculated. Results show that a rigid truck and a tractor semitrailer combination are unequally sensitive to parameter changes. Design changes can hence affect SSRT and DRT differently, which indicates that two vehicles can be equally stable statically but differently dynamically. Therefore, if DRT is not analysed, a redesign of a vehicle can deteriorate roll stability even though it appears to improve it.
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| 6. |
- Davari, Mohammad Mehdi, et al.
(författare)
-
Extended Brush Tyre Model to Study Rolling Loss in Vehicle Dynamics Simulations
- 2017
-
Ingår i: International Journal of Vehicle Design. - : InderScience Publishers. - 0143-3369 .- 1741-5314. ; 73:4, s. 255-280
-
Tidskriftsartikel (refereegranskat)abstract
- This paper describes a semi-physical tyre model that enables studies of rolling loss in combination with vehicle dynamic simulations. The proposed model, named extended brush tyre model (EBM), takes the effects of driving conditions, wheel alignment, and tyre materials into account. Compared to the basic brush tyre model, EBM includes multiple numbers of lines and bristles as well as integrated rubber elements into the bristles. The force and moment characteristics of the model are shown to have a good correlation with the Magic Formula tyre model and experimental data. The numerically estimated rolling resistance coefficients under different conditions are compared to findings in the literature, FE-simulations and experiments. The model can capture some aspects that are not covered by the available literature and experimental observations such as camber effect on rolling loss. EBM can be used as a platform for future studies of rolling loss optimisation using active chassis control.
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| 7. |
- Englund, Cristofer, 1977-
(författare)
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Action intention recognition of cars and bicycles in intersections
- 2020
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Ingår i: International Journal of Vehicle Design. - : Inderscience Publishers. - 0143-3369 .- 1741-5314. ; 83:2-4, s. 103-121
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Tidskriftsartikel (refereegranskat)abstract
- Copyright © 2020 Inderscience Enterprises Ltd.Action intention recognition is becoming increasingly important in the road vehicle automation domain. Autonomous vehicles must be aware of their surroundings if we are to build safe and efficient transport systems. This paper presents a method for predicting the action intentions of road users based on sensors in the road infrastructure. The scenarios used for demonstration are recorded on two different public road sections. The first scenario includes bicyclists and the second includes cars that are driving in a road approaching an intersection where they are either leaving or continuing straight. A 3D camera-based data acquisition system is used to collect trajectories of the road users that are used as input for models trained to predict the action intention of the road users. The proposed system enables future connected and automated vehicles to receive collision warnings from an infrastructure-based sensor system well in advance to enable better planning.
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| 8. |
- Erséus, Andreas, et al.
(författare)
-
Characteristics of path tracking skill on a curving road
- 2015
-
Ingår i: International Journal of Vehicle Design. - : InderScience Publishers. - 0143-3369 .- 1741-5314. ; 67:1, s. 26-44
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this research work is to evaluate the relation of driver skill to measurements done when driving on a regular curving road, i.e., performing a primary driving task. A curving road scenario is designed using both clear sight and fog-limited sight distance. Measures are compared under equal conditions to identify the best separation of recruited driver types. A moving base simulator, VTI Simulator III, is used for the acquisition of driver metrics. Curves are found to be more reliable for identifying driver skill than straight road segments, and a number of measures show good performance in characterising driving skill under the tested conditions, both for clear sight and with the preview limited down to 30 m. The standard deviation proves to be very useful and qualifies for successful driver skill categorisation for commonly sampled data such as the lateral acceleration, yaw rate and steering wheel angle.
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| 9. |
- Favre, Tristan, et al.
(författare)
-
Static coupling between detached-eddy simulations and vehicle dynamic simulations of a generic road vehicle model with different rear configurations in unsteady crosswind
- 2016
-
Ingår i: International Journal of Vehicle Design. - : INDERSCIENCE ENTERPRISES LTD. - 0143-3369 .- 1741-5314. ; 72:4, s. 332-353
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, aerodynamic loads of a generic car model obtained from advanced computational fluid dynamics (CFD) simulations are coupled to a vehicle dynamics model to enable the assessment of the on-road response. The influence of four rear configurations is studied. The different configurations yield large differences in yaw moments and side forces, which in turn result in considerable discrepancies in lateral displacements as well as yaw rates. From the simulations, it is seen that through balancing the location of the centre of pressure, the stiffness of the suspension bushings and the cornering stiffness of the tyres, it is possible to obtain stable vehicles in strong crosswind conditions for all four rear designs. The results show that monitoring the location of the aerodynamic centre of pressure with respect to the centre of gravity and the neutral steer point is essential for the possibility of designing stable vehicles in transient crosswind.
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| 10. |
- Forsberg, Jimmy, et al.
(författare)
-
The optimisation process of an energy absorbing frontal underrun protection device
- 2008
-
Ingår i: International Journal of Vehicle Design. - 0143-3369 .- 1741-5314. ; 46:3, s. 271-293
-
Tidskriftsartikel (refereegranskat)abstract
- This paper describes the methodology used during the development of an energy absorbing Frontal Underrun Protection device (eaFUP). The aim of this study is to show how different optimisation methods can be used at different stages during the design process. It also shows one approach to derive an optimal design taking several different design alternatives into account, each of which consists of several different materials. The outcome of the optimisation process is three different designs of the eaFUP.
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| 11. |
- Fredricson, Harald
(författare)
-
Structural topology optimisation : an application review
- 2005
-
Ingår i: International Journal of Vehicle Design. - : InderScience Publishers. - 0143-3369 .- 1741-5314. ; 37:1, s. 67-80
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a survey of the literature on the use of structural topology optimisation in the vehicle industry. The focus is on some specific applications rather than on any specific optimisation discipline. The survey starts with a general historic resume and continues with a more detailed description of the status today. New applications and areas for optimisation are presented, with short summaries of the referred papers. The major focus is on applications for vehicle body structures. Trends and potential areas of research are also explored.
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| 12. |
- Gil Gómez, Gaspar, et al.
(författare)
-
Correlations of subjective assessments and objective metrics for vehicle handling and steering : A walk through history
- 2016
-
Ingår i: International Journal of Vehicle Design. - : Inderscience Enterprises. - 0143-3369 .- 1741-5314. ; 72:1, s. 17-67
-
Tidskriftsartikel (refereegranskat)abstract
- Achieving customer satisfaction concerning steering feel and vehicle handling requires subjective assessments and tuning of vehicle components by expert test drivers and engineers. Extensive subjective testing is expensive, time consuming and requires physical vehicles, which is in conflict with reduction of development time and cost. Objective testing and model-based development are constantly increasing but translating subjective requirements into objective ones is non-trivial. This paper summarises, discusses and classifies the methods, strategies and findings in previously published research regarding correlations of subjective assessments and objective metrics for vehicle handling and steering. The aim is twofold: (i) to identify key parameters of steering, handling and their preferred values and (ii) to compile and discuss the fundamental issues to deal with in the continued search for correlations between objective metrics and subjective assessments. The paper gives a comprehensive overview and insight of different aspects to take into account when conducting research in this field.
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| 13. |
|
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| 14. |
- Hanson, Lars, et al.
(författare)
-
Effects of stature, age and vehicle motion on ingress movement
- 2009
-
Ingår i: International Journal of Vehicle Design. - 0143-3369 .- 1741-5314. ; 51:3/4, s. 292-305
-
Tidskriftsartikel (refereegranskat)abstract
- Vehicle ingress is an important automotive industry issue. End-users and production line assemblers perform similar ingress tasks. In this study, comparisons were made of the car ingress motion in 40 subjects of different statures, acting both as assemblers and end-users. Half of the subjects were under 28 years of age and the remaining were over 60. Results show no significant differences in motion patterns between assemblers and end-users, i.e., slow forward motion of the car on the assembly line had no effect on ingress patterns. This suggests that ergonomic departments working either with end-users or assemblers may instead cooperate or even be fully integrated. Stature significantly affected joint angle distribution and joint angle velocity distribution. No stature effect was found on time to perform ingress movements or on ingress technique. Age significantly affected all test parameters and is thus an issue for developers to consider along with anthropometric variables like stature. To facilitate age analysis, manikins in digital human modelling tools should be able to replicate the physical characteristics of different age groups and the movement behaviour of older people.
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| 15. |
- Hanson, Lars, et al.
(författare)
-
Preferred car driving posture using 3-D information
- 2006
-
Ingår i: International Journal of Vehicle Design. - : InderScience Publishers. - 0143-3369 .- 1741-5314. ; 42:1/2, s. 154-169
-
Tidskriftsartikel (refereegranskat)abstract
- Few studies have presented three-dimensional car-driving postural information. This laboratory study investigated drivers' preferred postures, preferred interior dimensions and how they characterise their postures. The minimum-maximum intervals of preferred angles corresponded well with other experimental studies and were larger than intervals for comfort, strength and alertness defined on the basis of theoretical reasoning. No preferred posture differences were found between females and males; nor were differences found when comparing posture after five and twenty minutes of driving. Preferred posture was not symmetric: significant differences were found between the left and right side. Subjects characterised their posture as comfortable, relaxing and restful.
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| 16. |
- Hoffenson, S., et al.
(författare)
-
Quantification of the design relationship between ground vehicle weight and occupant safety under blast loading
- 2013
-
Ingår i: International Journal of Vehicle Design. - 0143-3369 .- 1741-5314. ; 61:1/2/3/4, s. 204-218
-
Tidskriftsartikel (refereegranskat)abstract
- Military ground vehicle design must consider the threat posed by underbody blasts to new vehicles and their occupants, while also accounting for weight reduction goals for improving fuel economy and mobility. A two-stage process is presented to model the blast event, using LS-DYNA for simulating vehicle response and MADYMO for the occupant's response. Issues including computational expense, objective function formulation and multi-objective seating system design optimisation are addressed in detail, and three different blastworthiness optimisation formulations are presented and evaluated
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| 17. |
- Högberg, Dan
(författare)
-
Digital human modelling for user-centred vehicle design and anthropometric analysis
- 2009
-
Ingår i: International Journal of Vehicle Design. - : InderScience Publishers. - 0143-3369 .- 1741-5314. ; 51:3/4, s. 306-323
-
Tidskriftsartikel (refereegranskat)abstract
- Digital human modelling (DHM) is discussed as a design tool in the context of user-centred design, with a focus on DHM usage for anthropometric analysis in occupant packaging tasks in the vehicle interior design process. References are made to concepts of inclusive design, user-centred design, design cognition and design methodology. Examples are presented to illustrate how DHM can be of great use to the vehicle designer, but also to show some of the difficulties involved. This includes the complexity in considering anthropometric variation of the targeted product users in multivariate design problems, such as the design of vehicle interiors and suggestions on how to deal with this difficulty in an industrial design setting. Overall, the paper takes a designer's view of DHM tools and illustrates how the tool can be of value in the design process, but also considers what implications this has on the functionality and usability of the tools.
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| 18. |
- Jarlmark, Jonas
(författare)
-
Steering system forces due to local camber in ruts
- 2006
-
Ingår i: International Journal of Vehicle Design. - 0143-3369 .- 1741-5314. ; 40:1-3, s. 93-105
-
Tidskriftsartikel (refereegranskat)abstract
- A driver related area that is difficult to simulate and to reproduce in a driving simulator is the steering feel, especially the sense of longitudinal ruts and the self-steering of the vehicle. The hypothesis that the major contribution to the steering feel is due to the lateral movement of the vertical force due to local camber changes is stated. A tyre measurement rig is original hypothesis is proven to be false by computer simulations using the measurements from the rig. Instead the aligning moment created by the tare belt stiffness for a cambered tyre is shown to have the largest significance on a steering system of modern layout.
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| 19. |
- Johannesson, Pär, 1969, et al.
(författare)
-
Modelling of road profiles using roughness indicators
- 2014
-
Ingår i: International Journal of Vehicle Design. - 0143-3369 .- 1741-5314. ; 66:4, s. 317-346
-
Tidskriftsartikel (refereegranskat)abstract
- The vertical road input is the most important load for durabilityassessments of vehicles. We focus on stochastic modelling of the road profilewith the aim to find a simple but still useful model. The proposed nonstationaryLaplace model with ISO spectrum has only two parameters, andcan be efficiently estimated from a sequence of roughness indicators, such asIRI or ISO roughness coefficient. Thus, a road profile can be stochasticallyreconstructed from roughness indicators. Further, explicit approximations forthe fatigue damage due to Laplace roads are developed. The usefulness of theproposed Laplace-ISO model is validated for eight measured road profiles.
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| 20. |
- Johannesson, Pär, 1969, et al.
(författare)
-
Modelling roughness of road profiles on parallel tracks using roughness indicators
- 2016
-
Ingår i: International Journal of Vehicle Design. - : Inderscience Enterprises Ltd.. - 0143-3369 .- 1741-5314. ; 70:2, s. 183-210
-
Tidskriftsartikel (refereegranskat)abstract
- The vertical road input is the most important load for durability assessments of vehicles. We focus on stochastic modelling of the parallel road profiles with the aim to find a simple but still accurate model for such bivariate records. A model is proposed that is locally Gaussian with randomly gamma distributed variances leading to a generalised Laplace distribution of the road profile. This Laplace model is paired with the ISO spectrum and is specified by only three parameters. Two of them can be estimated directly from a sequence of roughness indicators, such as IRI or ISO roughness coefficients. The third parameter, needed to define the cross-spectrum between the left and right road profiles, is estimated from the sample correlation. Explicit approximations for the expected fatigue damage for the proposed Laplace-ISO model are developed. The usefulness of the methods is validated using measured road profiles.
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| 21. |
- Kanchwala, Husain, et al.
(författare)
-
Vehicle handling control of an electric vehicle using active torque distribution and rear wheel steering
- 2017
-
Ingår i: International Journal of Vehicle Design. - 0143-3369 .- 1741-5314. ; 74:4, s. 319-345
-
Tidskriftsartikel (refereegranskat)abstract
- There are two objectives of this work. First is to develop a detailed mathematical model of a vehicle. The second is to develop a controller which makes the vehicle follow desired dynamic characteristics. Suspension kinematics and compliance characteristics have been obtained from the complex suspension models developed in Adams Car (R). Vehicle roll-pitch interactions and variations of roll and pitch centres with respect to wheel travel are considered. The controller is developed as a combination of force allocation control and active rear wheel steering control. Reference trajectories of vehicle velocity, path geometry and vehicle slip angle are the inputs. The controller transforms these user inputs and generates wheel torques and steering commands. A desired value of yaw rate is maintained by generating a restoring yaw moment from unequal torque distribution, and side slip is substantially reduced by active rear wheel steering controller. Finally simulation results illustrate the suitability of the controller.
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| 22. |
- Kim, H.M., et al.
(författare)
-
Target cascading in vehicle redesign : A class VI truck study
- 2002
-
Ingår i: International Journal of Vehicle Design. - 0143-3369 .- 1741-5314. ; 29:3, s. 199-225
-
Tidskriftsartikel (refereegranskat)abstract
- The analytical target cascading process is applied to the redesign of a U.S. class VI truck. Necessary simulation and analysis models for predicting vehicle dynamics, powertrain, and suspension behaviour are developed. Vehicle design targets that include improved fuel economy, ride quality, driveability, and performance metrics are translated into system design specifications, and a consistent final design is obtained. Trade-offs between conflicting targets are identified. The study illustrates how the analytical target cascading process can reduce vehicle design cycle time while ensuring physical prototype matching, and how costly design iterations late in the development process can be avoided
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| 23. |
- Kokkolaras, Michael, et al.
(författare)
-
Towards a comprehensive framework for simulation-based vehicle systems design validation
- 2013
-
Ingår i: International Journal of Vehicle Design. - 0143-3369 .- 1741-5314. ; 61:.1/2/3/4, s. 233-248
-
Tidskriftsartikel (refereegranskat)abstract
- We present an overview of our most recent and ongoing research efforts to develop a comprehensive framework for simulation-based design validation of vehicle systems. Specifically, we present the three major building blocks of our framework: (1) the introduction of an appropriate validation metric for dealing with the multivariate functional data that are the output of dynamic vehicle systems; (2) the robust implementation of a Bayesian interval-based hypothesis testing technique for quantifying the confidence in simulation models used for design under uncertainty; (3) the development of a sequential design optimisation and calibration-based validation methodology that addresses the inadequacy of current validation practices in simulation-based design optimisation. We present a simple yet illustrative example and discuss the techniques being developed currently that will complete the proposed framework
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| 24. |
- Maghsood, Roza, 1980, et al.
(författare)
-
Detection of steering events based on vehicle logging data using hidden Markov models
- 2016
-
Ingår i: International Journal of Vehicle Design. - : Inderscience Publishers. - 0143-3369 .- 1741-5314. ; 70:3, s. 278-295
-
Tidskriftsartikel (refereegranskat)abstract
- In vehicle design it is desirable to model the loads by describing load environment, customer usage and vehicle dynamics. In this study a method will be proposed for detection of steering events such as curves and manoeuvring using on-board logging signals available on trucks. The method is based on hidden Markov models (HMMs), which are probabilistic models that can be used to recognise patterns in time series data. In an HMM, 'hidden' refers to a Markov chain where the states are not observable. However, observations depending on the hidden Markov chain can be observed. The idea here is to consider the current driving event as the hidden state, while the on-board logging signals generate the observed sequence. Examples of curve detection are presented for both simulated and measured data on a truck. The classification results indicate that the method can recognise left and right turns with small misclassification errors.
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| 25. |
- Maghsood, Roza, et al.
(författare)
-
Detection of steering events based on vehicle logging data using hidden Markov models
- 2016
-
Ingår i: International Journal of Vehicle Design. - : Inderscience Enterprises Ltd. - 0143-3369 .- 1741-5314. ; 70:3, s. 278-295
-
Tidskriftsartikel (refereegranskat)abstract
- In vehicle design it is desirable to model the loads by describing load environment, customer usage and vehicle dynamics. In this study a method will be proposed for detection of steering events such as curves and manoeuvring using on-board logging signals available on trucks. The method is based on hidden Markov models (HMMs), which are probabilistic models that can be used to recognise patterns in time series data. In an HMM, 'hidden' refers to a Markov chain where the states are not observable. However, observations depending on the hidden Markov chain can be observed. The idea here is to consider the current driving event as the hidden state, while the on-board logging signals generate the observed sequence. Examples of curve detection are presented for both simulated and measured data on a truck. The classification results indicate that the method can recognise left and right turns with small misclassification errors.
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| 26. |
- Magnusson, Thomas, 1970-, et al.
(författare)
-
Environmental innovation in auto development : managing technological uncertainty within strict time limits
- 2001
-
Ingår i: International Journal of Vehicle Design. - 0143-3369 .- 1741-5314. ; 26:2-3, s. 101-115
-
Tidskriftsartikel (refereegranskat)abstract
- Manufacturing industry is facing increasingly stringent demands on environmental compliance and the auto industry is particularly exposed to pressure from public and authorities in this area. The purpose of this article is to provide an empirical analysis on how the application of new technologies in order to comply with environmental demands may change the product development process within the auto industry. Experiences from the development of Toyota Prius, the worlds first mass-produced car based on a hybrid power train, are presented and analysed. The analysis shows that technological uncertainty made it necessary to move beyond the prevailing lean product development approach. The article concludes by suggesting a strategy consisting of three fundamental elements in order to control technological uncertainty in innovative and time-focused product development projects up-front testing, intense horizontal communication, and clear and challenging objectives.
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| 27. |
- Nilsson, Håkan O.
(författare)
-
Local evaluation of thermal comfort
- 2006
-
Ingår i: International Journal of Vehicle Design. - 0143-3369 .- 1741-5314. ; 42:1-2, s. 8-21
-
Tidskriftsartikel (refereegranskat)abstract
- Increasing demand for a comfortable cabin environment makes it necessary, as early as the construction phase, to estimate what effect different factors will have on the driver and passenger. Full-scale measurements and numerical simulations have been carried out in order to investigate how well computational fluid dynamics (CFD) and thermal manikins are able to predict the perceived thermal climate. The heat loss from real or virtual manikins interacts with the environment around the body, as well as thermal interaction with windows; ventilation and seat are influencing the manikins. When manikin heat loss is linked to human thermal sensations in new comfort zone diagrams, the local as well as total thermal situation can be clearly presented. Simulations of this type will enable engineers to make better decisions and early predictions in the design and construction process, improving the thermal comfort in the vehicle environment.
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| 28. |
- Shetty, Sandeep, et al.
(författare)
-
Multiobjective reliability-based and robust design optimisation for crashworthiness of a vehicle side impact
- 2015
-
Ingår i: International Journal of Vehicle Design. - : InderScience Publishers. - 0143-3369 .- 1741-5314. ; 67:4, s. 347-367
-
Tidskriftsartikel (refereegranskat)abstract
- Optimisation of vehicle design is necessary to meet increased safety requirements, new emission regulations, and to deal with competition in the global market, etc. However, optimised design using classical optimisation techniques with deterministic models might not meet the desired performance level or might fail in extreme events in real life owing to uncertainties in the design parameters and loading conditions. Consequently, it is essential to account for uncertainties in a systematic manner to generate a robust and reliable design. In this paper, an approach to perform multiobjective, reliability-based, and robust design optimisation is presented using a vehicle side impact crashworthiness application. Metamodels have been used in the optimisation process to decrease computational effort. Variations in material properties, thicknesses, loading conditions, and B-pillar heat-affected zone material strength have been considered for the stochastic optimisation. A comparative study of deterministic, reliability-based, and robust optimisation approaches is performed.
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| 29. |
- Ydrefors, Lisa, et al.
(författare)
-
Parametrisation of a rolling resistance model for extending the brush tyre model
- 2024
-
Ingår i: International Journal of Vehicle Design. - : Inderscience Publishers. - 0143-3369 .- 1741-5314. ; 94:1-2, s. 38-56
-
Tidskriftsartikel (refereegranskat)abstract
- A rolling resistance model (RRM) has been created and parametrised with the purpose of modelling tyre rolling resistance within complete vehicle dynamics simulations. The RRM is based on a combination of the Masing and Zener models to simulate the Payne effect and the viscoelastic properties of rubber. The parametrised model is able to recreate the relationship between the rolling resistance and the tyre deformation well and it has a low computational power requirement. Today the model is limited to simulation of free-rolling tyres on a flat surface, but it can be extended to also include the effects of changes in operating conditions such as wheel angles or road surface.
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| 30. |
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| 31. |
|
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| 32. |
- Hanson, Lars, et al.
(författare)
-
Preferred car driving posture using 3-D information
- 2006
-
Ingår i: International Journal of Vehicle Design. - 1741-5314. ; 42:1-2, s. 154-169
-
Tidskriftsartikel (refereegranskat)abstract
- Few studies have presented three-dimensional car-driving postural information. This laboratory study investigated drivers' preferred postures, preferred interior dimensions and how they characterise their postures. The minimum-maximum intervals of preferred angles corresponded well with other experimental studies and were larger than intervals for comfort, strength and alertness defined on the basis of theoretical reasoning. No preferred posture differences were found between females and males; nor were differences found when comparing posture after five and twenty minutes of driving. Preferred posture was not symmetric: significant differences were found between the left and right side. Subjects characterised their posture as comfortable, relaxing and restful.
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| 33. |
- Holen, Peter, et al.
(författare)
-
Aspects on damper-attachment compliance
- 2006
-
Ingår i: Int. J. of Vehicle Design. - 0143-3369. ; 40:1/2/3, s. 77-92
-
Tidskriftsartikel (refereegranskat)abstract
- This paper investigates how attachment compliance coming from mounting bushings or brackets affects damper efficiency. Analyses with a simple mass-spring-damper system show that compliance in damper-attachment points reduces the damper efficiency. If however vibration isolation of the mass is considered, it may be seen that compliance increases low frequency vibrations but reduces high frequency vibrations. Through analyses of this system, the relative damping ratio is studied as a function of excitation frequency and attachment stiffness. furthermore obtained from both static finite element (FE) analysis of the chassis frame and from dynamic FE analysis of a tractor. The effect damper-attachment compliance has on vehicle behaviour is finally quantified with MBS simulations of a tractor semi trailer combination. It is found that attachment stiffness should be considered when simulating load cases containing high frequency inputs.
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| 34. |
- Huang, Sunan, 1979, et al.
(författare)
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A Reversible Bumper System for Protecting Pedestrian Lower Limbs from Car Collisions
- 2010
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Ingår i: International Journal of Vehicle Design. - 1741-5314. ; 53:4, s. 288-299
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated the performance of a Reversible Bumper System (RBS) for protecting pedestrian lower limbs from car collisions. The Finite Element (FE) model of the RBS was developed based on a validated car front FE model. The FE models of a lower legform impactor and a pedestrian lower limb were used to investigate the performance of the RBS model at different impact conditions. It was finally determined that the RBS performance can be improved by reducing bumper stiffness; however, this performance is impaired in the bumper deploying process by the speed of 2.5 m/s or greater.
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| 35. |
- Jacobson, Bengt J H, 1962, et al.
(författare)
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Gearshift Sequence Optimisation for Vehicles with Automated Non-Powershifting Transmissions
- 2003
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Ingår i: International Journal of Vehicle Design. - 0143-3369. ; 32:3/4, s. 187-207
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Tidskriftsartikel (refereegranskat)abstract
- Vehicle powertrains are increasingly automated. The gearshift strategy that is built into an automated manual (non-powershifting) transmission (AMT) has to determine when to shift and to which gear. AMT has the potential to reduce environmental impact and improve vehicle performance. However, the gearshift strategy is far from obvious, especially for heavy-duty trucks with many gears. This paper presents an analytic tool for finding the ultimate gearshift sequence for any given vehicle and driving situation. The paper includes some case studies that show credible results. These studies addressuphill acceleration and engine torque down control. The optimisation criterion used is minimum acceleration time. The tool is based on a trajectory optimisation method called dynamic programming. The cost function is formulated using simulations results from a dynamic system model, which can be implemented in Simulink. Comparisons with measurements secure a reasonably good practical relevance.
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| 36. |
- Johansson, Bengt
(författare)
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Homogeneous charge compression ignition: the future of IC engines?
- 2007
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Ingår i: International Journal of Vehicle Design. - 1741-5314. ; 44:1-2, s. 1-19
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Tidskriftsartikel (refereegranskat)abstract
- The Homogeneous Charge Compression Ignition Engine, HCCI has the potential to combine the best of the Spark Ignition and Compression Ignition Engines. With high octane number fuel, the engine operates with high compression ratio and lean mixtures giving Cl engine equivalent fuel consumption or better. Owing to pre-mixed charge without rich or stoichiometric zones, the production of soot and NO, can be avoided. This paper presents some results from advanced laser diagnostics showing the fundamental behaviour of the process from a close to homogeneous combustion onset towards a very stratified process at around 20-50% heat released. The need for active combustion control is shown and possible means of control are discussed. Results with multi-cylinder engines using negative valve overlap, variable compression ratio, fast inlet temperature control as well as dual fuel are given.
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| 37. |
- Klomp, Matthijs, 1976, et al.
(författare)
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Influence of front/rear drive force distribution on the lateral grip and understeer of all-wheel drive vehicles
- 2011
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Ingår i: International Journal of Vehicle Design. - 0143-3369. ; 56:1/2/3/4, s. 34-48
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, the combined longitudinal and lateral road holding capability for All-Wheel Drive (AWD) vehicles with equal left/right longitudinal forces is analysed using a simple single-track model and assuming quasi-steady state conditions. To facilitate an improved correlation of the single-track model to more complex models, closed-form expressions that better describe critical axle performance parameters than currently used approximations are necessary. New expressions for the lateral grip limits and the vehicle understeer are therefore developed to account for general cases of front/rear drive force distributions. In order to visualise the effect of an arbitrary front/rear drive force distribution on the lateral grip, a contour plot, called the dynamic square, is used. The developed single-track model is applied to four particular driveline configurations (including an optimal front/rear distribution) and visualised in the dynamic square diagram, thereby demonstrating the application of these methods for analysis of modern driveline systems.
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| 38. |
- Laine, Leo, 1972, et al.
(författare)
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Traction and braking of hybrid electric vehicles using control allocation
- 2008
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Ingår i: International Journal of Vehicle Design. - 0143-3369. ; 48:3/4, s. 271-298
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Tidskriftsartikel (refereegranskat)abstract
- This paper considers how a reusable motion control system can be designed to handle Hybrid Electric Vehicle (HEV) systems. The design considers simultaneously energy management and vehicle stability control, by distributing the task among available actuators. The suggested controlsystem includes a control law for longitudinal, lateral, and yaw motion and a control distributor which distributes the desired control signals on the available actuators. The distribution among available actuators is designed by using constrained control allocation with mixed optimisation formulation, which gives a smooth blending among the available actuators. Simulations confirm that the proposed motion control system not only works as a traction, braking, and steering controller, it also works well as a vehicle stability controller.
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| 39. |
- Manente, Vittorio, et al.
(författare)
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Gasoline partially premixed combustion: high efficiency, low NOx and low soot by using an advanced combustion strategy and a compression ignition engine
- 2012
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Ingår i: International Journal of Vehicle Design. - 1741-5314. ; 59:2-3, s. 108-128
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Tidskriftsartikel (refereegranskat)abstract
- A light-duty engine Volvo D5 was run with gasoline to demonstrate that high-octane number fuels, in compression ignition engines, are able to achieve high efficiency, low NOx and soot simultaneously. An advanced three stage injection strategy was developed. A load sweep was performed between 6 and 17 bar IMEP and 2000 rpm. Gross indicated efficiency stays fairly constant at 47% with very low NOx and soot. In the second section of the paper, diesel was compared with gasoline, while in the final part the commercial 140 degrees UA nozzle was compared with the narrower one, 120 degrees, used in the above-mentioned experiments.
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| 40. |
- Pettersson, Pär, 1985, et al.
(författare)
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Comparison of dual and single clutch transmission based on Global Transport Application mission profiles
- 2018
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Ingår i: International Journal of Vehicle Design. - 0143-3369. ; 77:1-2, s. 22-42
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Tidskriftsartikel (refereegranskat)abstract
- Global Transport Application (GTA) is a common language to define transport missions for development, sales and aftermarket processes. To achieve a light weight and low-cost powershifting transmission for the targeted heavy vehicle applications, GTA was used in the development of the I-Shift Dual Clutch (I-Shift DC). Using a well-defined transport mission enables relevant modelling and simulation for performance assessment. This paper outlines the methods and shows some examples of technical implications. Firstly, the results from real world measurements in one specific scenario are presented. This shows the difference between a single clutch (SC) and dual clutch (DC) transmission for heavy-duty vehicles. Secondly, a full vehicle simulation model is built to extend the results to longer transport missions. The measurement results are used to parametrise and calibrate the model. Finally, the calibrated model is used to evaluate the performance in detail by using GTA to select appropriate transport missions for simulation.
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| 41. |
- Pipkorn, Bengt, 1963, et al.
(författare)
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Evaluation of Adaptive Carbon Fiber Reinforced Door Beams
- 2017
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Ingår i: International Journal of Vehicle Design. - 0143-3369. ; 74:2
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Tidskriftsartikel (refereegranskat)abstract
- An expandable, carbon fibre reinforced polymer (CFRP) door beam was designed, built and experimentally evaluated to improve side impact performance and reduce mass in passenger vehicles. Pressurisation and expansion of the beam was achieved using gas generator technology. The impact performance of the beam was evaluated by means of a sub system test method, mimicking vehicle-to-pole side impact. The sub system test method comprised a 3-point, bending load case, with a spring loaded sliding boundary condition at one end of the beam, while the other end was rigidly fixed. The beam was impacted by a 60 kg cylindrical impactor at 6 m/s. For the expanded and pressurised beam peak deflection was 193 mm. For the folded unpressurised beam peak deflection was 216 mm. To achieve the same impact performance with the expandable CFRP beam, as with a state of the art aluminium door beam, mass reductions seem plausible.
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| 42. |
- Warell, Anders, et al.
(författare)
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Interior aesthetics: an experience-focused approach for the design of brand-specific automotive identity
- 2011
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Ingår i: International Journal of Vehicle Design. - 1741-5314. ; 55:2-4, s. 278-303
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Tidskriftsartikel (refereegranskat)abstract
- In this research, two objectives were pursued. Firstly, to develop an experience-focused approach to design, based on a framework for perceptual product experience, and, secondly, to test and verify the proposed methodology through an interior design study of the Hulme.F1 supercar. In the process, experience design criteria were developed, which served creative and evaluative purposes. The final design proposal was assessed by an external lead user group through a subjective qualitative-quantitative survey study. The evaluation suggested that targeted design intentions were successfully met with respect to visual product brand identity as well as visual-aesthetic coherence between interior and exterior design.
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| 43. |
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| 44. |
- Yao, Jianfeng, 1977, et al.
(författare)
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Development and Validation of a Pedestrian Dummy FE Model for the Design of Pedestrian Friendly Vehicles
- 2011
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Ingår i: International Journal of Vehicle Design. - 0143-3369. ; 57:2/3, s. 254-274
-
Tidskriftsartikel (refereegranskat)abstract
- A Finite Element (FE) model of the Chalmers-Autoliv pedestriandummy was developed and validated. The dummy model was used to• investigate the difference in the assessment of head injury risks by thedummy model and by an EEVC adult headform model• to develop and optimise a pedestrian airbag system.The study showed that the head impact conditions and the calculated headinjury parameters of the dummy model were different from those of the EEVCheadform model. A properly designed airbag system can effectively reducehead injury risks in a pedestrian accident.
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| 45. |
- Zhang, Lin, et al.
(författare)
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Characteristics of pressure waves along high-speed Maglev trains in railway tunnels and comparison of fatigue strength requirements according to different standards
- 2023
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Ingår i: International Journal of Vehicle Design. - 0143-3369. ; 93:4, s. 293-309
-
Tidskriftsartikel (refereegranskat)abstract
- The aerodynamics of railway trains and tunnels were studied by using N-S equations and SST k-ω turbulence model. The results indicate that the train surface pressure amplitudes when high-speed trains are travelling at 500-800 km/h in a tunnel show a tendency to increase along the train, while the amplitudes intersecting in a tunnel were relatively close at the front and rear of the train, with fluctuations in the uniform section. When a train passed through the tunnel, the negative peak value and amplitude of the pressure wave acting on the train body exhibited linear relationship with the train speed, whereas when two trains met in the tunnel, the positive peak value, negative peak value, and amplitude were proportional to the 2.8, 2.5, and 2.6 power of the train speed. Finally, the characteristics of the International Union of Railways (UIC) and Japanese Industrial Standards (JIS) were compared and studied.
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| 46. |
- Åhman, Max
(författare)
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Assessing the future competitiveness of alternative powertrains
- 2003
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Ingår i: International Journal of Vehicle Design. - 1741-5314. ; 33:4, s. 309-331
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Tidskriftsartikel (refereegranskat)abstract
- Vehicle technology is currently facing a transition period in which vehicles equipped with alternative powertrains, such as battery powered electric vehicles, hybrid vehicles or fuel cell vehicles, are being developed for future markets. An assessment of the competitiveness of vehicles using alternative powertrains has been made here. Previous studies estimating future costs and the technical performance of crucial powertrain components have been analyzed regarding both the results and the methods used. Contradictory results concerning future costs and performance in previous studies stem from the fact that they have used different methods and assumptions that answer different questions and reflect different levels of technical optimism. This assessment indicates that it is possible for all alternatives to attain both technical and economic competitiveness. However, the uncertainty and time scale associated with the alternatives differ substantially. Policy makers need not attempt to 'pick winners' from the alternative powertrains since demand-pull policy can be designed to benefit all alternatives and to be sensitive to the varying development status of key technologies.
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