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DriveSafety CDS-250 Driving Simulator (Neurology)
In 2010, as a result of collaborative work between the UF's College of Medicine, Department of Neurology and the Institute for Mobility, Activity, and Participation, we obtained a DriveSafety CDS-250. This simulator was the first of its kind to be designed on a mobile platform for portable use in a hospital setting.
- Our DriveSafety CDS-250 simulator on a mobile platform for portable use in a hospital setting.
- A five-point harness and race seat keeps the driver secure.
The CDS-250 console and controls are based on Ford Focus sedan. The simulator provides an automotive control environment with standard driver controls and computerized information systems. "Live" controls include a steering wheel with active force feedback, automatic transmission, turn signals, and gas and brake pedals. A high-fidelity sound system creates digital audio simulation of the sounds of driving.
Simulator Operating System
- Overhead shot of the driving environment or "world".
The host computer is based on real-time Linux operating system on an off-the-shelf, Intel-based computer. It provides the simulator's vehicle dynamics, instrumentation input/output processing, scenario control, and data collection. Real-time driving and traffic simulation is provided by DriveSafety's Vection™ runtime simulation software. Vection™ is a deterministic real-time simulation system. This run-time software package includes advanced vehicle dynamics, scenario control with both scripted and autonomous traffic simulation, flexible data collection, audio and visual subsystems, and integrated support for cab instrumentation and control loading. Vection™ provides an extremely powerful environment to provide realistic driving simulation experiences and measure the desired results. The simulator utilizes high-speed (2400Hz) multi-body vehicle dynamics to represent real world vehicle performance and handling characteristics. Drives are created with a combination of ambient and scripted traffic. Traffic interacts realistically with other vehicles based on human behavior/decision models and real-time physics-based vehicle dynamics calculations. If specific behavior is desired, such as collision avoidance, vehicles and other entities can be issued script commands through the use of triggers (e.g., car pulls in front of driver at a certain point in the drive), or other scenario tools including timers, or routes (e.g., incorporating unprotected left turns).
The simulator utilizes high resolution textured graphics to deliver high visual quality without sacrificing performance. All geometry is designed to run efficiently in real-time, maintaining a 60 Hz update rate in most situations and with 48 msec measured system latency. The simulators' virtual drives utilize user-definable databases created with the HyperDrive™ Authoring Suite's library of over 400 driving environment tiles or the pre-programmed Simetrx™ drives. Roadways and traffic control devices are geometrically correct and modeled to highway design standards. The host computer controls three graphics channel computers running high performance graphics accelerators that are responsible for the scene rendering. The driving scene is presented on a triple-screen display using three 20-inch panels for a 65 degree field of view (FOV). FOV compression allows the rendered scene to easily accommodate a 110 degree horizontal view. Scene rendering also includes real-time views for a head-up display rearview mirror and sideview mirrors.
- Graphical representation of a drive created in HyperDrive™ Authoring Suite
The simulator has real-time data collection capabilities and collects a wide range of data at rates up to 60 Hz. Over 80 standard performance measures are provided via output files. These include speed, lane position, reaction time, steering, and use of brake or accelerator.
Performance Measure Examples
- Lane Position - The lane offset in meters within the current lane.
- Steering - The steering input value in degrees.
- Velocity - The speed of the subject vehicle in meters per second.
- Collision variables - Object the vehicle is colliding with, angle of collision and collision velocity.
Several acclimation drives were designed to train drivers on aspects of simulator operation and help them adjust to driving in a simulator. The simulator drives address lane keeping on straight and curved roads, changing lanes, use of side and rearview mirrors, and stopping.
- Driving the acclimation scenarios to become familiar with simulator controls and responsiveness.
In addition to standard acclimation drives, DriveSafety created a drive of 25 km and approximately 35 minutes in length for the purposes of this study. The drive transitions from a two lane road in a rural area to suburban and urban areas including a long expressway section. There is both ambient (free-roaming) and scripted traffic in the drive, and traffic level was adjusted for the desired level of driving challenge in each area. For example, traffic is low in the rural area, but increases in the suburban and urban areas and on the expressway. The drive also features pedestrians, bicyclists and animals. Three challenges were scripted for the drive: (1) the driver must stop for a railroad crossing, (2) a vehicle pulls into the driver's lane of travel in the urban area and the driver must brake and/or swerve to avoid a collision, (3) in the neighborhood, a car pulls out from behind parked cars requiring the driver to stop.
- Picture of challenge 1 - Railroad crossing.
- Picture of challenge 2 - Vehicle pulls into the driver's lane of travel.
- Picture of challenge 3 - In the neighborhood, a car pulls out from behind parked cars.