Abstract
Real road tests are mostly too expensive, in some cases dangerous, difficult to vary and repeat. A fixed-based driving simulator for Automotive Research is designed and constructed at the Istanbul Technical University Faculty of Mechanical Engineering Automotive Division to investigate human driving behaviour, vehicle handling and performance and the environmental effects on these both issues in a virtual environment. The dynamics of a four-wheeled road vehicle is modelled according to the assumptions which were made. The sub-systems pneumatic tire, suspension, steering and brake systems, engine and transmission and body are expressed as equations and maps. Real road test measurement results are used to verify the vehicle model. The vehicle dynamics model must run in real-time because of the requirements of the real man-machine interface in the driving simulator. Another important necessity arises from the wide operation space of the simulator in which the driver can reach almost every operating point of every subsystem. An extra off-line operation mode of the vehicle model is also made ready to obtain a stand-alone vehicle simulation. The complete software is PC-based and runs on an Intel® PIV HT Processor. Based on a validated vehicle dynamics model of a passenger car with automatic transmission and programmed in C++, the simulator uses for image, sound and driver interface data processing the DirectX® SDK Libraries of Microsoft®. To achieve a high quality and real-like image objects like trees, traffic signs and road textures can be also added to the vision. The widely used CAD software AutoCAD® is used for the generation of tracks and the virtual environment structure. Virtual tracks are designed which agree with road design engineering aspects. Real tracks are also imported into the system such as "Istanbul Park" the new Formula 1 race track in Turkey. Engine noise is transmitted to the driver as a function of engine speed and throttle position. The fact that the constructed driving simulator (called SURTAK) is open to be developed and ready to investigate vehicle parameters and human factors is an achievement of this study. This driving simulator and others also may help to design and construct vehicles which will be elements of a safer vehicle traffic in the future.
Keywords - Vehicle Dynamics, Simulation, Driving Simulation, Driving Simulator, Virtual Environment