Simulator overview

In the following we give a short presentation of the PC-cluster based driving simulator. The first section is a description of the software system, ASim, and the second part will give an overview of the simulator site.

ASim description

The basic purpose of the simulator was to allow for implementation of user-made applications/prototypes. For production of these applications commercial prototyping tools should be used. Also environmental models should be produced by the users using commercial tools. This ambition led to the principle simulator design presented in Figure 3.

Figure 3. Schematic view of ASim. Presented with permission from ACE Simulation AB, 2005.

The driver environment consists mainly of physical hardware, video projectors, data screens, loudspeakers, physical cockpit with steering wheel and pedals etc. The prototyping facility is a dynamic set of software-based modules that handles specific tasks in the simulation. Most of the devices in the driver environment have a direct mapping to one of these modules in the prototyping environment. This means that the entire driver environment is fully accessible for software-based prototyping and thereby for simulator-based design and interaction activities.

Figure 4. ASim communication architecture. Presented with permission from ACE Simulation AB

All modules in the prototyping facility communicate with each other through the communication functions provided by the ASim simulator kernel. Two critical issues are solved by this approach. First, every module has access to all information in the simulation. Second, every module is synchronized and can be logged with the rest of the simulation data. With this approach a user can add its own IVS logic for future in-vehicle system designs. Since all simulation information is accessible through the RT communications layer this module can listen to the data provided by the standard driving control module (steering, gas, brake). This data can then be manipulated together with other simulation data to implement an adaptive cruise control for example. The new data is then provided to the standard dynamics module. The performance of this new IVS-function then can be logged and evaluated.

Site and hardware description

The VR-lab has four main facilities, the prototyping and modeling workshop, a meeting area, the simulator hall, and the experimenter station. The workshop has five PC workstations, where students and researchers have access to advanced tools for design and prototyping activities. The basic idea is to use these off-line resources and thereby avoid occupation of the simulator facility for other purposes than implementation and experimental sessions. See fig 5.

Figure 5. Workshop.

In the simulator hall we have projectors and screens for environment presentation. For the moment we use five screens and projectors covering 200º field of view. Depending on the projects demands we can also add solutions for rear view mirrors on momentary bases. Another important equipment is the sound system. This system can produce environment sounds very realistically, e.g., the sound of passing cars and horn signals.

We have two different cockpits, one sedan model (SAAB See fig 6) and one truck cockpit (SCANIA See fig 7), which are used alternately depending on the character of the project.

Figure 6. SAAB Cockpit.

Figure 7. SCANIA Cockpit.

Both are rebuilt in order to meet the glass cockpit demands, which mean that for example the main instrument hardware is replaced with configurable screens (LCD’s) and the central consoles are replaced with touch screens. See fig 8.

Figure 8. LCD and Touch screen monitors.

This makes it possible to implement new interface prototypes and we also believe that the screen solutions mirror a possible future in real cars. Programmable force feedback electrical motors replace the ordinary steering systems. See fig 9.

Figure 9. SAAB - Replacement of the ordinary steering systems.

This gives us not only the possibility to give the right feeling in driving the specific vehicle but also opens for more advanced concepts, which will be available in future steer-by-wire systems. Examples could include over-laid haptic warning signals, automated procedures for parking etc. The ordinary speakers are kept and included in the sound system of the complete simulator facility.

Depending on the purpose of the simulation we bring in various measurement systems but we also have a stationary IR/video camera for supervising the driver activities.

In the control room (See fig 10) we have complete control of all displays in the driver environment and also overview information of the driving scenario including the traffic situation beyond what is seen on the environmental screens. Normally we also follow some key measures on-line. These could be various log data from ASim or other measurements like for example eye-tracking data. From the control room we can communicate with the driver by speech.

Figure 10. Control Room.

As mentioned above, the simulator is running on a PC cluster. Since the basic software principle is modularization the number of PC computers could change depending on the number of IVS prototypes or specific measurement systems. If we for instance like to implement a night vision display this application will run on a additional computer and will have its specific visualization resources. See fig 11.

Figure 11. Simulator - PC cluster.