my co-supervisor Lena Buffoni who has been very helpful throughout my whole progress and I am thankful for the numerously valuable discussions

Simulation is often used as a technique to test and evaluate systems, as it provides a cost-efficient and safe alternative for testing and evaluation. A combination of simulators can be used to create high-fidelity and realistic test scenarios, especially when the systems-under-test are complex. An example of such complex systems is Cooperative Intelligent Transport Systems (C-ITS), which include many actors that are connected to each other via wireless communication in order to interact and cooperate. The majority of the actors in the systems are vehicles equipped with wireless communication modules, which can range from fully autonomous vehicles to manually driven vehicles. In order to test and evaluate C-ITS, this paper presents a distributed simulation framework that consists of (a) a moving base driving simulator; (b) a real-time vehicle simulator; and (c) network and traffic simulators. We present our approach for connecting and co-simulating the simulators. We report on limitation and performance that this simulation framework can achieve. Lastly, we discuss potential benefits and feasibility of using the simulation framework for testing of C-ITS. (C) 2019 Elsevier Ltd. All rights reserved.

For assessing whether a system model is a good candidate for a particular simulation scenario or choosing the best system model between multiple design alternatives it is important to be able to evaluate the suitability of the system model.In this paper we present a methodology based on finite state machine requirements verifying system behaviour in a Modelica environment where the intended system model usage is within a moving base driving simulator.A use case illustrate the methodology with a Modelica powertrain system model using replaceable components and measured data from a Golf V.The achieved results show the importance of context of requirements and how users are assisted in finding system model issues.

When performing a driving simulator study, validity of the vehicle model for the intended driving task is of key importance; otherwise, the reliability of the study results might be jeopardized. In ...

Using induced unintentional lane departure (ULD) in an advanced driving simulator, we investigated car drivers' acceptance of rumble strips and lane departure warning system (LDW), respectively, and driving performance with each of these warning types. Twenty-four participants drove with simulated rumble strips in one trial and with a simulated LDW in another trial. A forced yaw motion of the vehicle induced ULDs while the driver attended jammed music coming from a CD-player. Each drive took about 25 min to complete and was set up to include 13 events of ULD coupled with jammed music in which the driver had to immediately change point of gaze from the road to take care of the CD-player. The results show the drivers were more satisfied with the LDW, trusted the rumble strips more, and overall preferred the warning types about equally. All drivers considered it valuable to have assistance in ULD, either by the rumble strips or the LDW, and several (i.e. 25%) chose to have both types of warning in parallel. Response completion was faster with the rumble strips warning, but no difference was found in time to back in lane and lane exceedence area, respectively. Thus, although differences in driver acceptance and performance were found between using the LDW and the rumble strips there were no major overall differences. The clear preference for having a warning function further strengthens the positive opinion on the need for assistance systems in ULDs.

To evaluate driver perception of a vehicle powertrain a moving base simulator is a well- established technique. We are connecting the moving base simulator Sim III, at the Swedish National Road and Transport Research Institute with a newly built chassis dynamometer at Vehicular Systems, Linkping University.The purpose of the effort is to enhance fidelity of moving base simulators by letting drivers experience an actual powertrain. At the same time technicians are given a new tool for evaluating powertrain solutions in a controlled environment.As a first step the vehicle model from the chassis dynamometer system has been implemented in Sim III. Interfacing software was developed and an optical fiber covering the physical distance of 500 m between the facilities is used to connect the systems. Further, a pedal robot has been developed that uses two linear actuators pressing the accelerator and brake pedals. The pedal robot uses feedback loops on accelerator position or brake cylinder pressure and is controlled via an UDP interface.Results from running the complete setup showed expected functionality and we are successful in performing a driving mission based on real road topography data. Vehicle acceleration and general driving feel was perceived as realistic by the test subjects while braking still needs improvements. The pedal robot construction enables use of a large set of cars available on the market and except for mounting the brake pressure sensor the time to switch vehicle is approximately 30 minutes.

New simulator models concerning vibration, noise and graphics have been designed and implemented in the VTI Simulator III. The objective of this study is to validate this simulator in terms of road surface realism. Twenty-four drivers participated in the study and drove the same route both in the simulator and on real roads. Three road sections ranging from very smooth to rather uneven were incorporated in the design. The comparison included the objective driving parameter speed as well as subjective parameters from questionnaires and rating scales (evenness, quietness and comfort level). A road section with five speed limit changes was of particular interest in the analyses. No statistically significant difference could be found between the simulator and the car, neither in the parameter speed (in sections with no speed limit changes) nor in the ratings evenness and quietness. Despite similar speed profiles surrounding the speed limit signs, there was a statistically significant difference between the speed in the car and in the simulator, with more rapid accelerations and decelerations in the simulator. The comfort rating was shown to be higher in the car compared to the simulator, but in both cases the general trend showed higher comfort on smoother roads. These results indicate absolute validity for the ratings evenness and quietness, and for the measure speed, and relative validity for comfort and speed surrounding speed limit signs.

Additional sound capabilities in visually advanced simulators may offer researchers and practitioners better resources to evaluate in-vehicle auditory signals and advanced auditory displays. In the first part of the present report, the implementation of a new audio system in the Scania truck cabin for the VTI driving simulator 2 and 3 at the Swedish National Road and Transport Research Institute (VTI) is described. The new system is designed to make it easier to use the advanced driving simulator to study the effects of in-vehicle auditory signals on drivers and traffic safety. The system includes both new software and hardware. The new audio software is based on the Open Audio Library (OpenAL) implementation for the Macintosh Operating System OS X. It communicates with the existing simulator software using the Open Sound Control (OSC) standard. The remaining program code is open, which offers the possibility of adapting the system for the future demands and specific needs of members within Virtual Prototyping and Assessment by Simulation (ViP). The new audio software contains a simple visual interface that can be used to set up, test and calibrate auditory cues inside the cabin at an early stage of a project. In terms of hardware, six new loudspeakers have been installed in the truck cabin. This speaker setup can be used to simulate sound sources in various spatial positions around the driver. Special consideration was taken regarding the placement of the loudspeakers inside the cabin in order not to make them disturbing to the drivers. Additionally, even though the system was especially designed for the simulation of ADASs, the functionality was implemented to prepare the system for presentation of other sound sources in the driver environment. Another aim for the present project was to investigate the potential of urgent alarms to raise annoyance and negatively affect drivers’ subsequent responses to unrelated, critical events on the road. While performing a simulated driving task, truck drivers received two types of warnings that were designed to significantly differ in perceived urgency. Several times in the trial, an unexpected event occurred just seconds after drivers were presented with an unrelated warning, and the drivers had to brake immediately to avoid a collision. The results indicate that acoustic characteristics and semantic meaning may impact the perceived annoyance of in-vehicle warnings. Furthermore, the participants who received the high-urgency warning braked significantly harder and tended to brake later than the drivers who received a low-urgency warning. The simulator study was also used to validate the reliability of the new audio system. In summary, the new audio system worked reliably during all 24 trials. However, more extended validations should be carried out in the future to investigate the exact accuracy of the system in representing signals in specific spatial directions.

The main objective of this study was to investigate how an electronic stability control (ESC) system may aid the driver in a critical sideswipe accident. Another objective was to investigate the possibility of having a realistic simulation of a sideswipe accident in a large moving base simulator. The experiment can be divided into two parts. In part one, the driver is unaware of the sudden side impact and in part two, the side impact was repeated six times. The experiment was driven by 18 persons. With the ESC system active no driver lost control, while with the system inactive there were five drivers that lost control in part one. In part two, the ESC system showed to stabilize the vehicle faster, and the improvement in stabilization time was between 40% and 62%. It was also seen that 2% loss of control occurred with an ESC system active and 45% without.