Figure 1: Overview of Hardware Setup
In a driving simulator, the seamless inclusion of the driver behavior into the computer is important. To process this continuous driver behavior in real-time, the data acquisition system should be capable of sampling and updating the data with reasonable accuracy and speed. A Pentium PC is dedicated to acquire driver behavior and update the auditory display device as shown in Figure 1. Vehicle dynamics and scene graphics are processed on SGI Onyx2 to generate real-time vehicle response and driving scenes. The two computers are capable of full-duplex communication via TCP/IP, which is discussed in the next section. The simulator hardware provides visual cues, audio cues, and Driving stimuli to the driver who controls the simulation model in the simulator software. Simulation software is coded in Labview on the PC and is coded in C on the Onyx2. Software subsystems are designed to work independently and they include vehicle dynamics, scene generation, communication, and auditory cue generation.
Figure 1: Overview of
Hardware Setup
The virtual environment of the driving simulator is created by assembling the nodes into a hierarchical scene graph. Each node contains either structural element such as road, building, and tree or geometry, light, fog, and position information. The details of manipulating these nodes to create a scene graph is beyond the scope of this report. However, it is necessary and important task in order to maintain the realistic driving environment as well as the acceptable frame rate of simulation. The scene graph of the driving simulator includes trees, buildings, sky, a mountain with a closed loop road track. Also a dashboard is included as a moving object with the scene graph on a display screen. The driving scene of the driving simulator is shown in driving scene and movies.
The driving console and audio device are connected to the Personal Computer. The Labview program is used to activate these devices as a development software. Onyx2 computer is used for vehicle dynamics, scene graphs, and communications, which creates a separate module in the software. In Figure 2, the actions module is the core of the simulation which calls these modules. The C programming with WTK library functions is used to create each module. Each module is intended to work individually for faster development of the entire system. Architecture and Data flow of the software used in the driving simulator is shown in Figure 2.
Figure 2: Architecture of Software