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  • 1. Bucca, Giuseppe
    et al.
    Carnevale, Marco
    Collina, Andrea
    Facchinetti, Alan
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Jönsson, Per-Anders
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Stichel, Sebastian
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Adoption of different pantographs' preloads to improve multiple collection and speed up existing lines2012In: Vehicle System Dynamics, ISSN 0042-3114, E-ISSN 1744-5159, Vol. 50, no SUPPL. 1, p. 403-418Article in journal (Refereed)
    Abstract [en]

    The current collection using more than one pantograph is needed in railway operation to provide power to non-electrically connected traction units and, in some cases, to reduce current density on the collector strips that heavily influences the wear on the contacting bodies. The multiple current collection may become a critical condition due to the mechanical disturbances produced on the trailing pantographs by the interaction between the first pantograph and the catenary. The present-day evolution of pantograph preload regulating systems, exploiting pressure-controlled servo-valves driven by electronic units, allows a diversification of the preloads of front and rear pantographs. In this work, a suitable solution to improve multiple pantograph collection quality is analysed by the use of a lower mean force on the leading pantograph aimed at reducing the oscillations of contact wire the trailing pantograph is subjected to. This would improve the current collection quality of the trailing pantograph, and could be pursued even admitting a slight worsening of front pantograph's performances.

  • 2. Bucca, Guiseppe
    et al.
    Carnevale, Marco
    Collina, Andrea
    Facchinetti, Alan
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Jönsson, Per-Anders
    Stichel, Sebastian
    KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group. KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Differentiation of pantographs’ preloads as a mean to improve multiple collection and speed upexisting lines2011In: Proceedings of 22nd Symposium of the International Association for Vehicle System Dynamics / [ed] Simon Iwnicki, 2011Conference paper (Refereed)
  • 3.
    Cocron, Peter
    et al.
    TU Chemnitz.
    Neumann, Isabel
    TU Chemnitz.
    Kreußlein, Maria
    TU Chemnitz.
    Pereira Cocron, Maria
    TU Chemnitz.
    Wanner, Daniel
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Bierbach, Maxim
    Federal Highway Research Institute (BAST).
    Augusto, Bruno
    VTI.
    Driver and vehicle behaviour to power train failures in electric vehicles – experimental results of field and simulator studies.2014Report (Refereed)
    Abstract [en]

    see fulltext

  • 4.
    Daniel, Wanner
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Nybacka, Mikael
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Wallmark, Oskar
    KTH, School of Electrical Engineering (EES), Electrical Energy Conversion.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Stensson Trigell, Annika
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Experimental implementation of a fault handling strategy for electric vehicles with individual-wheel drives2016In: The Dynamics of Vehicles on Roads and Tracks - Proceedings of the 24th Symposium of the International Association for Vehicle System Dynamics, IAVSD 2015, CRC Press, 2016, p. 147-152Conference paper (Refereed)
    Abstract [en]

    This paper presents a fault handling strategy for electric vehicles with four individual-wheel drives, which are based on wheel hub motors. The control strategy to handle the faults is based on the principle of control allocation and is implemented in an experimental vehicle. Experimental tests has been performed with the experimental vehicle and with simulation. The results show that the directional stability of such a vehicle can be improved for the analysed manoeuvre and failure mode, and the tendencies of the experimental results correspond with the simulation results. It has been found that the lateral and yaw motion could be strongly improved. 

  • 5.
    Davari, Mohammad Mehdi
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Jerrelind, Jenny
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Stensson Trigell, Annika
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    A Multi-Line Brush Based Tyre Model to Study the Rolling Resistance and Energy Loss2015In: Proceedings of 4th International Tyre Colloquium: Tyre Models for Vehicle Dynamics Analysis, Guildford, UK (2015), 2015Conference paper (Refereed)
    Abstract [en]

    This study aim to develop a three dimensional multi-line brush based tyre model for investigating the rolling resistance and energy loss in tyres. The losses in the model are characterised by the external losses originated from the sliding phenomenon in the tyre contact patch, and the internal losses due to the tyre viscoelastic nature which is employed by a rubber model. The Extended Brush tyre Model (EBM) proposed in this work can be used to estimate the dissipated energy and the rolling resistance under different driving manoeuvres and wheel conditions. This paper focuses on the estimation of energy loss and in-plane rolling resistance.

  • 6.
    Davari, Mohammad Mehdi
    et al.
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design. KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Jerrelind, Jenny
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design. KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Stensson Trigell, Annika
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design. KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design. KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Extended Brush Tyre Model to Study Rolling Loss in Vehicle Dynamics Simulations2017In: International Journal of Vehicle Design, ISSN 0143-3369, E-ISSN 1741-5314, Vol. 73, no 4, p. 255-280Article in journal (Refereed)
    Abstract [en]

    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.

  • 7.
    Davari, Mohammad Mehdi
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Jonasson, Mats
    KTH.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Jerrelind, Jenny
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Stensson Trigell, Annika
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Rolling Loss Optimisation of an Over-actuated Vehicle using Predictive Control of Steering and Camber ActuatorsArticle in journal (Refereed)
  • 8.
    Davari, Mohammad Mehdi
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Jonasson, Mats
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Jerrelind, Jenny
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Stensson Trigell, Annika
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Rolling loss analysis of combined camber and slip angle control2016Conference paper (Refereed)
    Abstract [en]

    The objective of this work is to present a new functionality of over-actuated systems, such as Wheel Corner Modules, to reduce the rolling loss in vehicles. The findings are based on numerical simulations using a bicycle model coupled with a newly proposed tyre model which is capable of simulating the tyre losses during vehicle motions. The results show that for the considered vehicle in the considered manoeuvre the rolling loss can be reduced about 25–40% by proper control of camber and slip angle combinations, while still maintaining the vehicle performance.

  • 9.
    Drugge, Lars
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Juhlin, Magnus
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Aerodynamic loads on buses due to crosswind gusts: extended analysis2010In: Vehicle System Dynamics, ISSN 0042-3114, E-ISSN 1744-5159, Vol. 48, p. 287-297Article in journal (Refereed)
    Abstract [en]

    The objective of this work is to use inverse simulations on measured vehicle data in order to estimate the aerodynamic loads on a bus when exposed to crosswind situations. Tyre forces, driver input, wind velocity and vehicle response were measured on a typical coach when subjected to natural crosswind gusts. Based on these measurements and a detailed MBS vehicle model, the aerodynamic loads were estimated through inverse simulations. In order to estimate the lift force, roll and pitch moments in addition to the lateral force and yaw moment, the simulation model was extended by also incorporating the estimation of the vertical road disturbances. The proposed method enables the estimation of aerodynamic loads due to crosswind gusts without using a full scale wind tunnel adapted for crosswind excitation.

  • 10.
    Drugge, Lars
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Larsson, Tobias
    Luleå University of Technology.
    Stensson, Annika
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Modelling and simulation of catenary-pantograph interaction2000In: Vehicle System Dynamics, ISSN 0042-3114, E-ISSN 1744-5159, Vol. 33, p. 202-213Article in journal (Refereed)
  • 11.
    Drugge, Lars
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Lennartsson, Anders
    Stensson Trigell, Annika
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    A laboratory model study of a railway current collection system2008In: Proceedings of the ASME Design Engineering Technical Conferences and Computers and Information in Engineering Conference, Vol 5, PTS A-C,, NEW YORK: AMER SOC MECHANICAL ENGINEERS , 2008, p. 1805-1810Conference paper (Refereed)
    Abstract [en]

    A vital system on modem high-speed electric trains is the overhead catenary system and the pantograph current collector. As speed limits are increased, train operators and railway engineers need measures of system performance in a number of situations. In this work a laboratory model is built to study the pantograph behaviour on curved track running on a catenary system with large stiffness variation. The model is designed to be simple, yet exhibit the most characteristic dynamic properties of the real system. Another objective is the possibility to run the pantograph at speeds near the wave propagation velocity of the contact wire. The situation of several trailing pantographs, with even spacing, which excites the system to steady state, is considered. Effects of changes in design features such as tension in the contact wire and torsion and translation stiffness of components in the pantograph are studied for different speeds. The interaction is complex and the performance depends on the dynamic properties of both the catenary system and the pantograph. The results show that the pantograph configuration mainly affects the size of amplitudes in the system while the contact wire tension influences at which velocities large amplitudes and contact losses occur.

  • 12.
    Edrén, Johannes
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Jerrelind, Jenny
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Stensson Trigell, Annika
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Implementation and evaluation of force allocation control of a down-scaled prototype vehicle with wheel corner modules2013In: International Journal of Vehicle Systems Modelling and Testing, ISSN 1745-6436, Vol. 8, no 4, p. 335-363Article in journal (Refereed)
    Abstract [en]

    The implementation of wheel corner modules on vehicles creates new possibilities of controlling wheel forces through the utilisation of multiple actuators and wheel motors. Thereby new solutions for improved handling and safety can be developed. In this paper, the control architecture and the implementation of wheel slip and chassis controllers on a down-scaled prototype vehicle are presented and analysed. A simple, cost-effective force allocation algorithm is described, implemented and evaluated in simulations and experiments. Straight line braking tests were performed for the three different controller settings individual anti-lock brakes (ABS), yaw-torque-compensated ABS and force allocation using both wheel torque and steering angle control at each wheel. The results show that force allocation is possible to use in a real vehicle, and will enhance the performance and stability even at a very basic level, utilising very few sensors with only the actual braking forces as feedback to the chassis controller.

  • 13.
    Edrén, Johannes
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Jonasson, Mats
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Jerrelind, Jenny
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Stensson Trigell, Annika
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Energy efficient cornering using over-actuationManuscript (preprint) (Other academic)
    Abstract [en]

    This work deals with utilisation of active steering and propulsion on individual wheels in order to improve a vehicle’s energy efficiency during a double lane change manoeuvre at moderate speeds. Through numerical optimization, solutions have been found for how wheel steering angles and propulsion torques should be used in order to minimise the energy consumed by the vehicle travelling through the manoeuvre. The results show that, for the studied vehicle, the cornering resistance can be reduced by 10% compared to a standard vehicle configuration. Based on the optimization study, simplified algorithms to control wheel steering angles and propulsion torques that are more energy efficient are proposed. These algorithms are evaluated in a simulation study that includes a path tracking driver model and an energy efficiency improvement of 6-9% based on a combined rear axle steering and torque vectoring control during cornering is found. The results indicate that in order to improve energy efficiency for a vehicle driving in a non-safety-critical situation the force distribution should be shifted towards the front wheels.

  • 14.
    Edrén, Johannes
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Jonasson, Mats
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Jerrelind, Jenny
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Stensson Trigell, Annika
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Energy efficient cornering using over-actuation2019In: Mechatronics (Oxford), ISSN 0957-4158, E-ISSN 1873-4006, Vol. 59, p. 69-81Article in journal (Refereed)
    Abstract [en]

    This work deals with utilisation of active steering and propulsion on individual wheels in order to improve a vehicle's energy efficiency during a double lane change manoeuvre at moderate speeds. Through numerical optimisation, solutions have been found for how wheel steering angles and propulsion torques should be used in order to minimise the energy consumed by the vehicle travelling through the manoeuvre. The results show that, for the studied vehicle, the energy consumption due to cornering resistance can be reduced by approximately 10% compared to a standard vehicle configuration. Based on the optimisation study, simplified algorithms to control wheel steering angles and propulsion torques that results in more energy efficient cornering are proposed. These algorithms are evaluated in a simulation study that includes a path tracking driver model. Based on a combined rear axle steering and torque vectoring control an improvement of 6–8% of the energy consumption due to cornering was found. The results indicate that in order to improve energy efficiency for a vehicle driving in a non-safety-critical cornering situation the force distribution should be shifted towards the front wheels.

  • 15.
    Edrén, Johannes
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Jonasson, Mats
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Jerrelind, Jenny
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Stensson Trigell, Annika
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Utilization of optimization solutions to control active suspension for decreased braking distanceManuscript (preprint) (Other academic)
    Abstract [en]

    This work deals with how to utilize active suspension on individual vehicle wheels in order to improve the vehicle performance during straight-line braking. Through numerical optimization, solutions have been found to how active suspension should be controlled and coordinated with friction brakes to shorten the braking distance. The results show that, for the studied vehicle, the braking distance can be shortened by more than 1 m when braking from 100 km/h. The applicability of these results is studied by investigating the approach for different vehicle speeds and actuator stroke limitations. It is shown that substantial improvements in the braking distance can also be found for lower velocities, and that the actuator strokes are an important parameter. To investigate the potential of implementing these findings in a real vehicle, a validated detailed vehicle model equipped with active struts is analysed. Simplified control laws, appropriate for on-board implementation and based on knowledge of the optimized solution, are proposed and evaluated. The results show that substantial improvements of the braking ability, and thus safety, can be made using this simplified approach. Particle model simulations have been made to explain the underlying physics and limitations of the approach. These results provide valuable guidance on how active suspension can be used to achieve significant improvements in vehicle performance with reasonable complexity and energy consumption.

  • 16.
    Edrén, Johannes
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Jonasson, Mats
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering. Volvo Car Corporation, Sweden .
    Jerrelind, Jenny
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Trigell, Annika Stensson
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Utilisation of optimisation solutions to control active suspension for decreased braking distance2015In: Vehicle System Dynamics, ISSN 0042-3114, E-ISSN 1744-5159, Vol. 53, no 2, p. 256-273Article in journal (Refereed)
    Abstract [en]

    This work deals with how to utilise active suspension on individual vehicle wheels in order to improve the vehicle performance during straight-line braking. Through numerical optimisation, solutions have been found as regards how active suspension should be controlled and coordinated with friction brakes to shorten the braking distance. The results show that, for the studied vehicle, the braking distance can be shortened by more than 1 m when braking from 100 km/h. The applicability of these results is studied by investigating the approach for different vehicle speeds and actuator stroke limitations. It is shown that substantial improvements in the braking distance can also be found for lower velocities, and that the actuator strokes are an important parameter. To investigate the potential of implementing these findings in a real vehicle, a validated detailed vehicle model equipped with active struts is analysed. Simplified control laws, appropriate for on-board implementation and based on knowledge of the optimised solution, are proposed and evaluated. The results show that substantial improvements of the braking ability, and thus safety, can be made using this simplified approach. Particle model simulations have been made to explain the underlying physical mechanisms and limitations of the approach. These results provide valuable guidance on how active suspension can be used to achieve significant improvements in vehicle performance with reasonable complexity and energy consumption.

  • 17.
    Edrén, Johannes
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Jonasson, Mats
    Vehicle Dynamics and Active Safety, Volvo Car Corporation, Göteborg, Sverige.
    Stensson Trigell, Annika
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Jerrelind, Jenny
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    The developement of a down-scaled over-actuated vehicle equipped with autonomous corner module functionality2010In: FISITA Proceedings 2010, paper F2010B056, 2010Conference paper (Refereed)
    Abstract [en]

    This paper presents the development of a functional down-scaled prototype of a passenger car with capability to control steering, wheel torques, wheel loads and camber individually. The adopted chassis technology is based on a modularised platform, referred to as Autonomous corner modules (ACM), which simplifies the re-use of components at the four corners of the vehicle and between different vehicles.

    This work gives an insight in the design of the vehicle and the selection of electrical actuators and sensors to provide all ACM functions. Since a part of the implemented chassis components do not admit to be scaled down at the same level, necessary design modifications are suggested. The problems of scaling, meaning that a down-scaled prototype cannot fully emulate a full-scaled vehicle’s all functions simultaneously, are a great disadvantage of down scaling. For example is gravity one desired parameter that is hard to physically scale down.

    In order to evaluate the behaviour of the down-scaled prototype, it is of high importance to establish the characteristics of the developed vehicle and its subsystems. In particular, tyre design is considered as complex. For this reason, different ideas of methods to confirm tyre characteristics are proposed.

    Also the paper presents the initial process of developing the prototype vehicle that is later to be used in vehicle dynamics research.

  • 18.
    Eriksson, Johan
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics.
    Nordmark, Arne B.
    KTH, School of Engineering Sciences (SCI), Mechanics.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    An Experimental and Numerical Study of Pantograph Dynamics, with the Application of Dimension Estimation.Manuscript (preprint) (Other academic)
  • 19.
    Erséus, Andreas
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Stensson Trigell, Annika
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    A path tracking driver model with representation of driving skill2011In: International Journal of Vehicle Systems Modelling and Testing, ISSN 1745-6436, Vol. 6, no 2, p. 145-186Article in journal (Refereed)
    Abstract [en]

    A flexible and intuitive non-linear driver model is proposed, which allows setting of physically relevant parameters for representation of both typical high and typical low skill drivers in a path tracking scenario with constant speed. The model is equipped with a relatively simple internal vehicle model and is divided into three levels of driving skill: perceptual, anticipatory and interpretational skill; decisional skill; and execution skill. Validation of the model is performed using the results from moving base driving simulator tests with the double lane change scenario described in ISO 3888-1:1999. The parameter sets used for the model configuration are selected based on physical relevance to the model and optimisation is carried out with a Nelder-Mead implementation, showing that the model is able to resemble the characteristics of the driver types in the scenario for 70 km/h, and with adjustments being able to represent drivers at other speeds.

  • 20.
    Erséus, Andreas
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Stensson Trigell, Annika
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Characteristics of path tracking skill on a curving road2015In: International Journal of Vehicle Design, ISSN 0143-3369, E-ISSN 1741-5314, Vol. 67, no 1, p. 26-44Article in journal (Refereed)
    Abstract [en]

    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.

  • 21.
    Erséus, Andreas
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Stensson Trigell, Annika
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Methodology for finding parameters related to path tracking skill applied on a DLC-test in a moving base driving simulator2013In: International Journal of Vehicle Autonomous Systems, ISSN 1471-0226, E-ISSN 1741-5306, Vol. 11, no 1, p. 1-21Article in journal (Refereed)
    Abstract [en]

    The objective of this research is to develop and assess a method that can evaluate the relation of the driver's path tracking skill to a large number of vehicle parameters. The proposed methodology for comparison of measures under equal conditions is applied on test data from a double lane change test in a moving base simulator. Several measures are found to separate the recruited high and low skill driver groups, with the best results for the second part of the manoeuvre. Standard deviation qualifies for successful driver skill categorisation using commonly sampled data, e.g., steering wheel rate and angular acceleration.

  • 22.
    Gil Gómez, Gaspar
    et al.
    Volvo Cars.
    Nybacka, Mikael
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Bakker, Egbert
    Volvo Cars.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Analysing vehicle dynamics objective and subjective testing in winter conditions2016In: The Dynamics of Vehicles on Roads and Tracks: Proceedings of the 24th Symposium of the International Association for Vehicle System Dynamics, IAVSD 2015, Taylor & Francis Group, 2016, p. 759-768Conference paper (Refereed)
    Abstract [en]

    This paper presents a test procedure developed to gather good quality data from objective and subjective testing on winter conditions. As the final goal of this test is to analyse the correlation between objective metrics and subjective assessments on winter for steering and handling, this procedure has to ensure a minimum change of the surface properties, which has a major influence on vehicle performance, during the whole test campaign. Therefore, the method presented keeps the total test time very low and allows similar vehicle configurations to be test- ed, objectively and subjectively, very close in time. Moreover, continuous maintenance work on the ice is performed. Reference vehicles are also used to monitor the changes on vehicle per- formance caused by weather conditions, which are inevitable. The method showed to be very effective. Initial results on objective metrics and subjective assessments are also presented. 

  • 23.
    Gil Gómez, Gaspar
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics. Volvo Cars.
    Nybacka, Mikael
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Bakker, Egbert
    Volvo Cars.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Correlations of subjective assessments and objective metrics for vehicle handling and steering: A walk through history2016In: International Journal of Vehicle Design, ISSN 0143-3369, E-ISSN 1741-5314, Vol. 72, no 1, p. 17-67Article in journal (Refereed)
    Abstract [en]

    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.

  • 24.
    Gil Gómez, Gaspar
    et al.
    Volvo Cars.
    Nybacka, Mikael
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Bakker, Egbert
    Volvo Cars.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Findings from subjective evaluations and driver ratings of vehicle dynamics: steering and handling2015In: Vehicle System Dynamics, ISSN 0042-3114, E-ISSN 1744-5159, Vol. 53, no 10, p. 1416-1438Article in journal (Refereed)
    Abstract [en]

    This paper investigates subjective assessments (SA) of vehicle handling and steering feel tests, both numerical and verbal, to understand drivers’ use of judgement scales, rating tendencies and spread. Two different test methods are compared: a short multi-vehicle first-impression test with predefined-driving vs the standard extensive single-vehicle free-driving tests, both offering very similar results but with the former saving substantial testing time. Rating repeatability is evaluated by means of a blind test. Key SA questions are identified by numerical subjective assessment autocorrelations and by generating word clouds from the most used terms in verbal assessments, with both methods leading to similar key parameters. The results exposed in this paper enable better understanding of SA, allowing improving the overall subjective testing and evaluation process, and improving the data collection and analysis process needed before identifying correlations between SA and objective metrics.

  • 25.
    Gil Gómez, Gaspar
    et al.
    Volvo Cars.
    Nybacka, Mikael
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Bakker, Egbert
    Volvo Cars.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Objective metrics for vehicle handling and steering and their correlations with subjective assessments2016In: International Journal of Automotive Technology, ISSN 1229-9138, E-ISSN 1976-3832, Vol. 17, no 5, p. 777-794Article in journal (Refereed)
    Abstract [en]

    This paper focuses on increasing the available knowledge about correlations between objective metrics and subjective assessments in steering feel and vehicle handling. Linear and non-linear correlations have been searched for by means of linear regression and neural network training, complemented by different statistical tools. For example, descriptive statistics, the t-distribution and the normal distribution have been used to define the 95% confidence interval for expected subjective assessments and their mean, which makes it possible to predict the subjective rating related to a given objective metric and its area of confidence. Single- and multi-driver correlations have been investigated, as well as how the use of different databases and different vehicle classes affects the results. A method for automatizing the search for correlations when using the driver-by-driver strategy is also explained and evaluated. Ranges of preferred objective metrics for vehicle dynamics have been defined. Vehicles with characteristics within these ranges of values are expected to receive a higher subjective rating when evaluated. Finally, linear correlations between objective metrics have been studied, linear dependency between objective metrics has been identified and its consequences have been presented.

  • 26.
    Gurov, Alexey
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Sengupta, Abhinav
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Jonasson, Mats
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Collision avoidance driver assistance system using combined active braking and steering2014In: Proceedings of AVEC’14, 12th symposium on Advanced Vehicle Control, Sept 22-26, Tokyo, Japan., 2014Conference paper (Refereed)
  • 27. Harell, P.
    et al.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Reijm, M.
    Study of critical sections in catenary systems during multiple pantograph operation2005In: Proceedings of the Institution of mechanical engineers. Part F, journal of rail and rapid transit, ISSN 0954-4097, E-ISSN 2041-3017, Vol. 219, no 4, p. 203-211Article in journal (Refereed)
    Abstract [en]

    To improve the dynamic behaviour of a catenary system, the sections that limit the speed have to be found. A survey was made to gather information about critical sections of the catenary-pantograph system. Interviews with personnel at the Swedish National Rail Administration were performed and problem areas that need consideration were found and are presented. The purpose of this study was to find out how much of these critical sections affect the system and to suggest improvements to the design. Section overlaps and section insulators, both in combination with the usage of multiple pantographs, were modelled, and simulations have been performed at different speeds and for different catenary systems. As a result of this research, a better base could be built on how to ease the operation with multiple pantographs.

  • 28.
    Harell, Pia
    et al.
    KTH, Superseded Departments, Vehicle Engineering.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Reijm, Marten
    Multiple pantograph operation: effects of section overlaps2004In: Vehicle System Dynamics, ISSN 0042-3114, E-ISSN 1744-5159, Vol. 41, p. 687-696Article in journal (Refereed)
    Abstract [en]

    The traffic situation of the future goes towards flexibility of train configurations and increasing speed. There is a need for the ability to adjust the number of passenger cars as well as the energy consumption for trains to run efficiently, leading to multiple pantographs and short pantograph distances. Limitations due to this were studied on an existing catenary system. A model of the pantograph catenary system was developed in a finite element program. To verify the correctness of the model, comparison with full scale experiments was done. Results from the simulations indicates that trailing pantographs suffers from high dynamic effects within the section overlap. Effects of changes in design of the section overlap was studied. The results show that it is possible to get lower dynamic effects in the section overlap, even lower than within an ordinary span.

  • 29.
    Harell Poznic, Pia
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Jerrelind, Jenny
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Experimental evaluation of nonlinear dynamics and coupled motions in a pantograph2010In: Proceedings of the ASME Design Engineering Technical Conferences and Computers and Information in Engineering Conference, Vol 1, Pts A and B, NEW YORK: AMER SOC MECHANICAL ENGINEERS , 2010, Vol. 1, p. 619-626Conference paper (Refereed)
    Abstract [en]

    Continuous electric power supply, which is transferred from the contact wire to the train through a pantograph mechanism, is a necessity for a train to function satisfactory. Since various sources of nonlinearities are present, such as friction in the pantograph suspensions and impacts in the subsystems and at the excitation, there is a possibility of nonlinear dynamic behaviour. The aim of this work is to experimentally investigate the dynamic behaviour of a commercial pantograph to verify if nonlinear behaviour and coupling effects can occur. A test rig has been built that has the ability to simulate both the horizontal and vertical excitation generated by the contact wire. Measurements have been performed for sinusoidal input signals both in horizontal and vertical directions. Harmonic and subharmonic motions as well as irregular behaviour are shown to exist in the system. The results show that the pantograph's rotational degree of freedom, friction in the suspension systems and the nonlinear stiffness play an important role for the dynamic behaviour of the system and are therefore crucial to include when creating mathematical models of the system.

  • 30.
    Jerrelind, Jenny
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Stensson Trigell, Annika
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Nybacka, Mikael
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Simulation of Vehicle-Overhead Power System Interaction on Electric Roads2012Conference paper (Refereed)
    Abstract [en]

    Due to the upcoming lack of oil and the environmental problems that conventional internal combustion engines are causing, electric vehicles have gained a growing interest during recent years. One solution to improve the efficiency of the existing road network is to make use of electric roads equipped with an overhead power system, thereby allowing also long-distance truck and bus transports to be powered by electricity without the need of heavy, bulky and expansive batteries.

    Providing electric power using an overhead power system has primarily been used in railway applications and only to some extent in road applications, for example in the case of trolley buses in urban areas. In this study, an overhead catenary system providing electric power to a long-distance truck by means of a pantograph mechanism that collects power through sliding contact with the overhead wire is analysed through simulation.

    A model of a truck equipped with a pantograph is developed and its interaction with an overhead catenary system model is simulated using the finite element method. The current collection quality is evaluated by analysing the pantograph-catenary contact force variation during the influence of different disturbances such as road irregularities and contact wire vibrations due to multiple pantographs.

    The study is an assessment of the possibility of using a conventional overhead power system developed for trains in a new context by providing power to long-distance road transports. The results show that the investigated disturbances influence the dynamics of the studied truck-pantograph-catenary system, nevertheless the contact force variation is within the allowed range according to the technical specifications for interoperability (TSI) for trains. It can be concluded that an overhead power system is a promising solution for a more environmentally friendly energy supply for trucks and buses at specific road sections.

  • 31.
    Jerrelind, Jenny
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Edrén, Johannes
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Li, Shiruo
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Davari, Mohammad Mehdi
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Stensson Trigell, Annika
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Exploring active camber to enhance vehicle performance and safety2013Conference paper (Refereed)
    Abstract [en]

    The aim of this study is to evaluate optimal active camber strategies for improvement of vehicle performance and safety during limit handling. Numerical optimisation is used to find solutions on how the active camber should be controlled and coordinated in cooperation with individual braking and front axle steering. Based on the characteristics of a multi-line brush tyre model, a Simple Magic Formula description is developed where camber dependency, load sensitivity and first order speed dependent relaxation dynamics are included. The vehicle is analysed during an evasive manoeuvre when the vehicle is running at the limit. It is evident from the results that active camber control can improve safety and performance during an avoidance manoeuvre.

  • 32.
    Jerrelind, Jenny
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Lopez Arteaga, Ines
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Kari, Leif
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Effects of non-linear wheel suspension bushing on vehicle response2012In: Proceedings of the ASME Design Engineering Technical Conferences And Computers And Information In Engineering Conference, Vol 6, ASME Press, 2012, p. 615-622Conference paper (Refereed)
    Abstract [en]

    This work presents an analysis of the effects of non-linear characteristics of a top mount bushing in the wheel suspension of a vehicle when evaluating vehicle characteristics such as comfort and handling. The investigation is performed by comparing simulation results from a quarter car model when using a non-linear bushing model and an approximated linear bushing model. It is revealed when analysing the results that there are differences in the response when comparing measures such as sprung mass acceleration, rattle space ratio and tyre-ground contact force. The conclusion is that the more detailed bushing model mainly affects the acceleration levels especially at high frequencies where the linear model underestimates the acceleration. The rattle space ratio and tyre-ground contact force are also affected but not to the same extent.

  • 33.
    Lesser, Martin
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics.
    Karlsson, Lennart
    Luleå Tekniska Universitet .
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    An interactive model of a pantograph-catenary system1996In: Vehicle System Dynamics, ISSN 0042-3114, E-ISSN 1744-5159, Vol. 25, p. 397-412Article in journal (Refereed)
  • 34.
    Mårtensson, Jonas
    et al.
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Nybacka, Mikael
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Jerrelind, Jenny
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Evaluation of Safety Distance in Vehicle Platoons by Combined Braking and Steering2012In: Proceedings of 11th International Symposium on Advanced Vehicle Control, Sept 9-12, 2012, Seoul, Korea, Japan Society of Mechanical Engineers (JSAE) , 2012Conference paper (Other academic)
    Abstract [en]

    Platooning is a way to increase the traffic flow and capacity on roads to handle the upcoming problems of traffic congestion and exhaust emissions. The aim with this work is to evaluate if the safety distance of platooning vehicles can be further reduced when both lateral and longitudinal control is implemented. The idea is that when the vehicle in front suddenly brakes the vehicle behind, if needed, is steered aside while braking and stops beside the preceding vehicle. The analysis is performed using a game theoretical approach and different detailed vehicle models. Results show that the safety distance can be reduced.

  • 35.
    Nilsson, Andreas
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Stensson Trigell, Annika
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    A path tracking scenario without preview for analysis of driver characteristics2008In: Proceedings of the 9th International Symposium on Advanced Vehicle Control, 2008Conference paper (Refereed)
  • 36.
    Nilsson, Andreas
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Stensson Trigell, Annika
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Methodology to find parameters characteristic to path tracking skill: DLC-test in a moving base simulator2009In: Proceedings of the 21st International Symposium: Dynamics of Vehicles on Roads and Tracks, 2009Conference paper (Refereed)
    Abstract [en]

    The objective of this work is to evaluate the driver skill relation to a large number of objective vehicle parameters, all measured in a moving base simulator used in the test. Recruitment of High skill and Low skill drivers is done based on self evaluations by the drivers in relation to driver type descriptions. A moving base simulator with a double lane change (DLC) scenario is used both for recruitment verification and measurement of parameter metrics. Here, a suggested method that is used for the comparison of measures under equal conditions is described, and the best separation between the two recruited driver types is found for the highest velocity with all drivers participating, 70 km/h, in the second part of the manoeuvre, e.g. by using standard deviation of steering wheel rate or angular acceleration.

  • 37.
    Nybacka, Mikael
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    He, Xuxin
    Gil Gómez, Gaspar
    Volvo Car Corporation.
    Bakker, Egbert
    Volvo Car Corporation.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Links between subjective assessments and objective metrics for steering2014In: International Journal of Automotive Technology, ISSN 1229-9138, E-ISSN 1976-3832, Vol. 15, no 6, p. 893-907Article in journal (Refereed)
    Abstract [en]

    The characteristics of steering perception are decisive factors for overall driver preference and for vehicle safety. Car manufacturers are continuously required to tune the characteristics of the vehicle and have a strong need to be more effective in the design and evaluation of cars. Using only objective metrics (OM) can result in unwanted steering feel and using only subjective assessments (SA) is time-consuming, costly and non-repetitive. Before a tool can be built to predict the steering feel in front-end development and to improve design knowledge from the full vehicle level to the component level, links between subjective assessments and objective metrics must be found and analysed. The data collected for the study presented in this paper include subjective ratings from expert drivers and objective measurements made with steering robots, involving twelve expert drivers and over twenty vehicles across four different vehicle classes. Linear regression and neural network analysis (NN) have been used to explore reliable subjective-objective links. The tools and methods used in this research showed promising results. Most of the links found concern response and torque feedback. The preferred ranges of some crucial objective metrics leading to more desirable steering feel have been defined and presented. The results indicate that it would be possible for car manufacturers to develop new vehicles more effectively with a steering feel in line with the design criteria by using the tools and methods investigated in this paper. 

  • 38.
    Nybacka, Mikael
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    He, Xuxin
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Su, Zhicheng
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Bakker, Egbert
    Volvo Car Corporation.
    LINKS BETWEEN SUBJECTIVE ASSESSMENTS AND OBJECTIVE METRICS FOR STEERING AND DRIVER RATING EVALUATION2013Conference paper (Refereed)
    Abstract [en]

    During development of new vehicles finding correlation links between subjective assessments and objective metrics is an important part in the vehicle evaluation process. Studying different correlation links is of importance in order to make use of the gained knowledge in the front end of development, during testing and for new systems. Both subjective assessments using the rating scale of 1-10 from expert drivers and objective metrics from different tests measured by a steering robot were collected by standard testing protocols at an automotive manufacturer. This paper evaluates driver ratings and analyse correlations by using Regression Analysis and Neural Networks through a case study approach. Links have been identified and are compared to related research.

  • 39.
    Nybacka, Mikael
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    He, Xuxin
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Su, Zhicheng
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Bakker, Egbert
    Volvo Car Corporation, Gothenburg, Sweden.
    Links between subjective assessments and objective metrics for steering, and evaluation of driver ratings2014In: Vehicle System Dynamics, ISSN 0042-3114, E-ISSN 1744-5159, Vol. 52, p. 31-50Article in journal (Refereed)
    Abstract [en]

    During the development of new vehicles, finding correlation links between subjective assessments (SA) and objective metrics (OM) is an important part of the vehicle evaluation process. Studying different correlation links is important in that the knowledge gained can be used at the front end of development, during testing and when creating new systems. Both SA from expert drivers using a rating scale of 1-10 and OM from different tests measured by a steering robot were collected using standard testing protocols at an automotive manufacturer. The driver ratings were evaluated and the correlations were analysed using regression analysis and neural networks through a case study approach. Links were identified and were compared with related research.

  • 40.
    Rehnberg, Adam
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Influence of tyre properties on the ride dynamics of heavy off-road vehicles2011Conference paper (Other academic)
    Abstract [en]

    Wheeled earthmoving machines are a class of off-road vehicles that are typically equipped withlarge and soft tyres to obtain sufficient traction and flotation on unpaved surfaces. Theunsuspended mass is typically larger than for road vehicles. This indicates that the tyreproperties will affect not only the dynamics of the wheels and axles, but may also have asubstantial effect on the ride dynamics of the vehicle. This paper investigates how the tyrecharacteristics influence the optimal design of a wheel suspension for an off-road constructionmachine. Frequency domain analysis of a pitch and bounce model show that overallacceleration levels are significantly affected by tyre stiffness and damping, but that the tradeoffbetween pitch and bounce is unaffected by tyre properties although the main ride frequenciesare offset. Also, optimal suspension damping is fairly independent of the tyres. It is alsoinvestigated if a locked front axle suspension may be used in the loaded case, to simplifysuspension system design by using tyres as sole suspension elements. It is found that thisconfiguration leads to decreased ride quality, mainly due to the increased suspension stiffnessand lack of damping.

  • 41.
    Rehnberg, Adam
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Pitch comfort optimisation of a front end loader using a hydropneumatic suspension2007In: SAE technical paper series, ISSN 0148-7191, no 2146, p. 67-76Article in journal (Refereed)
    Abstract [en]

    Front end loader vehicles are prone to excessive pitching when travelling at high speed, partly due to the absence of axle suspension. This paper studies the fundamental design of a hydropneumatic suspension for a medium wheel loader. The vehicle is analysed using an analytical frequency response model as well as multibody simulations. Results show that favourable pitching response can be achieved by increasing the rear axle stiffness, but also that a similar effect is achieved with higher front axle stiffness. For the loaded vehicle, it is also found that the benefits of an optimal stiffness distribution are offset to some extent by the reduction in relative damping as the vehicle mass and inertia increases. Thus, it is desirable to increase suspension damping under load to maintain a suitable level of relative damping.

  • 42.
    Rehnberg, Adam
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Ride comfort simulation of a wheel loader with suspended axles2008In: International Journal of Vehicle Systems Modelling and Testing, ISSN 1745-6436, Vol. 3, no 3, p. 168-188Article in journal (Refereed)
    Abstract [en]

    Wheel loaders are used in a variety of tasks. The traditional design of the vehicle is unfavourable from a ride comfort standpoint, as the unsuspended axles lead to high vibration levels. This study investigates the possibility to reduce driver vibrations by introducing suspended wheel axles. A multibody simulation model is used to study vibration levels with and without suspension. Results show that vertical and longitudinal vibrations are reduced significantly when comparing with the unsuspended vehicle. Less reduction is attained in the lateral direction, mainly because of high roll stiffness and the high placement of the driver seat.

  • 43.
    Rehnberg, Adam
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Stensson Trigell, Annika
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Snaking stability of articulated frame steer vehicles with axle suspension2010In: International Journal of Heavy Vehicle Systems, ISSN 1744-232X, Vol. 17, no 2, p. 119-138Article in journal (Refereed)
    Abstract [en]

    A known problem of articulated vehicles is that snaking oscillations may occur at high speed. For ride comfort reasons, it is desirable to introduce suspended axles on articulated vehicles such as wheel loaders which are traditionally built without wheel suspension. This paper investigates how this may affect the snaking stability, by studying the vehicle dynamic behaviour of a multibody simulation model with and without suspension. Results show that an axle suspension may have a slightly destabilising effect, although the difference is small and can be offset by a stiffer or more damped steering system.

  • 44.
    Rehnberg, Adam
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Edrén, Johannes
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Eriksson, Magnus
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Stensson Trigell, Annika
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Scale model investigation of the snaking and folding stability of an articulated frame steer vehicle2011In: International Journal of Vehicle Systems Modelling and Testing, ISSN 1745-6436, Vol. 6, no 2, p. 126-144Article in journal (Refereed)
    Abstract [en]

    This paper describes the development and evaluation of an articulated frame steer testvehicle on a model-scale. Vehicles with articulated steering are known to exhibit unstable behaviour in the form of snaking or folding instabilities when operated at high speed, as previously studied using analytical models, simulations and full vehicle tests. The aim ofthis study is to design a scaled test vehicle that is able to reproduce unstable modes found in articulated vehicles. The model vehicle may provide greater insight than simulations, while avoiding the costs and hazards associated with full vehicle tests. The objective is also to investigate how well a linearised planar model and eigenvalue analysis can predict vehicle stability properties. Experimental and theoretical results have been critically analysed, and found to exhibit typical full vehicle behaviour. The linear mathematical model exhibited similar trends when compared to the scale model test results.

  • 45.
    Rothhämel, Malte
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    IJkema, Jolle
    Scania AB.
    Finding correlation between handling values and the drivers’ performance using a moving base driving simulator2011In: Proceedings of the 22st International Symposium: Dynamics of Vehicles on Roads and Tracks, 2011Conference paper (Refereed)
    Abstract [en]

    This work presents the evaluation of an experiment on the relationship between driver performance and vehicle handling quantities. Both of them are instrumental quantities, however, the former are driver dependent, the latter are only vehicle dependent. A moving base driving simulator was used to examine 16 truck-trailer-combinations. The driving of 28 test drivers in a special developed manoeuvre resulted in characteristic driver performance values evaluated of vehicle system quantities measured while driving. Stationary and dynamical ISO-handling tests resulted in handling quantities. The correlation by means of regression analysis between these driver performance values and the quantities of the ISO-handling tests are presented here as a step towards the mapping of steering feel.

  • 46.
    Rothhämel, Malte
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    IJkema, Jolle
    Scania CV AB.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    A method to find correlations between steering feel and vehicle handling properties using a moving base driving simulator2011In: Vehicle System Dynamics, ISSN 0042-3114, E-ISSN 1744-5159, Vol. 49, no 12, p. 1837-1854Article in journal (Refereed)
    Abstract [en]

    There have been several investigations to find out how drivers experience a change in vehicle-handling behaviour. However, the hypothesis that there is a correlation between what the driver perceives and vehicle-handling properties remains to be verified. To define what people feel, the human feeling of steering systems was divided into dimensions of perception. Then 28 test drivers rated different steering system characteristics of a semi-trailer tractor combination in a moving base-driving simulator. Characteristics of the steering system differed in friction, damping, inertia and stiffness. The same steering system characteristics were also tested in accordance with international standards of vehicle-handling tests resulting in characteristic quantities. The instrumental measurements and the non-instrumental ratings were analysed with respect to correlation between each other with the help of regression analysis and neural networks. Results show that there are correlations between measurements and ratings. Moreover, it is shown that which one of the handling variables influence the different dimensions of the steering feel.

  • 47.
    Rothhämel, Malte
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Ijkema, Jolle
    Scania.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Artificial understeer by means of active steering: an investigation of proper handling test methods2013In: Proceedings of the 23rd Symposium of the International Association for Vehicle System Dynamics, 2013Conference paper (Refereed)
    Abstract [en]

    This paper shows for a heavy truck simulation model the advantages of an artificial understeering functionality realised by a PID controlled active front steering system based on linear calculated yaw rate error. The yaw rate error results from the difference between measured vehicle yaw rate and a linear calculated yaw rate based on steering wheel angle and vehicle speed. The integrated controlled system shows increased performances: The more linear-like behaviour together with a higher understeer gradient over a wide lateral acceleration range which increases safety especially in emergency conditions.

  • 48.
    Rothhämel, Malte
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    IJkema, Jolle
    Scania AB.
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Finding correlation between steering feel assessments and the driver’s performance using a moving base driving simulator2011In: FAST-zero’11, Society of Automotive Engineers, 2011Conference paper (Refereed)
    Abstract [en]

    There is not yet a standardised method to find mutual corresponding subjective and objective measurements. This paper describes how non-instrumental measurements (made by human measurement gauges) and instrumental measurements (made by measuring instruments) can be distinguished in quantities that are dependent of the vehicle, the driver's skills or the driver's individual preferences. Moreover, this paper shows the correlation between instrumental and non-instrumental measurements.

  • 49.
    Rothhämel, Malte
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.