Abstract—Software equipment of interactive vehicle simulators consists of two main parts; a generator of virtual reality (generating 3D graphics and surrounding sound) and a mathematical model of vehicle dynamics. The basic elements of mathematical dynamics model of the vehicle consists first of a physics of an engine and a set of parameterization files that define the current values of the parameters of the vehicle, second of the world which with each particular vehicle can interact. The paper describes the development, implementation and testing of such a mathematical software model, which was subsequently used in the latest driving simulator in the laboratories at the Faculty of Transportation Sciences of the Czech Technical University in Prague. Keywords— car dynamics, driving simulator, mathematical model I. INTRODUCTION OFTWARE equipment of a driving simulator consists of two basic parts, a generator of virtual reality (generating 3D graphics and spatial sound) and the physical model. In 2010 at the Faculty of Transportation Sciences, we have developed mathematical-physical model, which was subsequently fully utilized in 2011 in the newly realized chassis simulator (Octavia II 3D). This model was developed as a universal module, which is expected to be used in future interactive simulators of ground vehicles. Our driving simulators are successfully used for analyzing problem of HMI, reliability in transportation ([4]) or ITS applications ([5], [6], [7]). II. CONSTRUCTION AND FUNCTIONAL DESIGN OF DRIVING SIMULATOR An overall system of ‘living’ simulator (equipped with tools enabling its modifications respecting the actual needs of each particular experiment) can be described as a multilayer model [1]. The next figure (Fig. 1) introduces the functional structure of our equipment from the simulator point of view. The whole system can be divided into four layers (they are separated by green lines on the picture). P. Bouchner, e-mail: bouchner@lss.fd.cvut.cz, S. Novotný, e-mail: novotny@lss.fd.cvut.cz The authors participate in Driving Simulation Research Group, Joint Laboratory of System Reliability, Department of Transporting Technology, Faculty of Transportation Sciences, Czech Technical University in Prague, Konviktská 20, 110 00 Prague, Czech Republic. Fig. 1: Functional structure of the simulator The first layer represents the simulator device itself. It consists of software and hardware parts. As the hardware of our “light” simulator, we consider the cockpit that is composed of parts of a real car and PCs connected to a network. I/O cards (like CAN bus to PC interface) are also included in this layer. Software of the simulator consists of Virtual Reality Engine (for generation of 3D graphics and spatial sound) and mathematical model of the car and environment. The physical engine is always a compromise between a very accurate physical behavior and a very fast (real-time) response. The next layer represents a database of testing tracks (sometimes called scenarios) and cars. Each experiment requires a more or less different scenario. To get objective results, it is necessary to have precisely defined the difficulty of each scenario. Sometimes we need a curveted road to study driver’s ability to keep the car on the road while he/she is forced to fulfill an additional task. On the other hand, a scenario for investigation of driver’s drowsiness and fatigue is recommended to have a very boring (almost straight) highway road which cannot divert him/her but it lets the driver get into relaxed state [2], [3]. By the same way, we should treat the database of cars. Strong engine with automatic gearbox is suitable for measurement of drowsiness while a car with Car Dynamics Model - Design for Interactive Driving Simulation Use Petr Bouchner and Stanislav Novotný S Recent Researches ιn Applied Informatics ISBN: 978-1-61804-034-3 285