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Research & Data

Driver Simulation

The National Advanced Driving Simulator (NADS)

The National Advanced Driving Simulator (NADS) is the most sophisticated research driving simulator in the world.

The NADS is located at the University of Iowa, Driving Safety Research Institute, Iowa City, IA. The university is responsible for the daily operational research, maintenance, and long term upgrading of the NADS. Additional information can be obtained by contacting their web site at the following web address:

The National Advanced Driving Simulator (NADS) And Intelligent Transportation System (ITS) Program

The National Advanced Driving Simulator (NADS) is a research tool that will be used to conduct fundamental research into the operation of the complex driver-vehicle-environment system. Of the three elements of this system, the driver is unique as the single element that is non-deterministic, i.e., driver behavior defies description or prediction by means of common physical laws.As a consequence, the only practical means of studying driver behavior is by means of direct observation. The most valid method of conducting such research is to make observations while the driver is engaged in the actual driving task, in a real vehicle, operating on a real highway.

However, many such experiments cannot be conducted without exposing the driver to unacceptable physical danger. Under these restrictions, the study of driver response during critical crash avoidance situations becomes a practical impossibility.

The NADS will offer the capability to study driver crash avoidance behavior and carry out related accident reconstructions. The complete control of highway environment and traffic scenarios provided by the NADS will allow researchers to set up hazardous situations and measure driver response. This same experimental control capability will allow conditions to be set up associated with real accident cases, so as to study the response options and limitations of drivers and involved vehicles.

The NADS provides the capability for safely evaluating advanced vehicle communication, navigation, and control technologies which are now being developed as part of the Intelligent Transportation System (ITS) program.

Important questions regarding the effect of these systems on driver workload, attention, behavior, and overall safety need to be addressed during the development phase. It is imperative to determine beforehand whether any of these advanced systems will have an unintended or detrimental impact on driver performance or highway safety.

The NADS provides the means by which such experimental data can be generated. A clear understanding of driver behavior under these circumstances will lead the way to developing effective strategies and countermeasures for improved crash avoidance and reduced injuries and fatalities.

The NADS also will provide a powerful and cost effective tool for conducting highway engineering and design research related to traffic safety. Since the driving scene and highway geometry are under the complete control of the simulator programmer, highway researchers will be able to evaluate alternative designs for intersections, entrances and exits, tunnel and bridge alignments, traffic control devices and highway signing without incurring the prohibitive expense of actual construction.

The NADS will be dedicated primarily to advancing the cause of improved highway safety and efficiency. As a national research facility, the simulator is accessible to the widest possible spectrum of researchers from both the public and private sectors. The Department of Transportation has located the NADS at the University of Iowa, who will be responsible for the daily operational research, maintenance, and long term upgrading of the NADS.

The NADS contains several subsystems which provide the driver with a direct presentation of the driving environment. These subsystems work in real time to provide a repeatable, natural and undistorted representation of the visual, motion, auditory and control feel sensory cues associated with the complete driving environment.

Visual System

The Visual System provides the driver a realistic fields of view, including the rear view mirror images. The driving scene has three dimensional perspective and is fully correlated with all of the other sensory stimulus. The Visual System database includes the full range of current and new highway traffic control devices (signs, signals and delineation), three dimensional objects that vehicles encounter (animals, potholes, concrete joints, pillars, etc.), high density, multiple lane traffic interacting with driver's vehicle, common intersection types (including railroad crossings, overpasses, bridge structures, tunnels, etc.) and roadway time of day and weather environment.

Motion System

The Motion System provides a combination of translational and angular motion that duplicates vehicle motion kinematics and dynamics within six degrees of freedom. The Motion System is coordinated with the Vehicle Cab System and its High Frequency Road Feel and Control Feel System to provide the driver with realistic motion and haptic cuing during normal driving and pre-crash scenarios. The motion system is configured and sized to correctly represent the specific forces and angular rates associated with actual vehicle motions for the full range of driving maneuvers.

Vehicle Cab System

The Vehicle Cab System consists of four actual vehicle cabs, configured to fit within the physical environment of the visual dome on the motion system and provides the driver with a realistic vehicle driving experiences. The cabs have defined interfaces and allow rapid interchangeability in order to meet the desired efficiency standards during NADS operations. The cabs have a full range of standard, optional and new design vehicle instrumentation interfaces. The cabs can be reconfigured to accommodate new technology when it becomes available.

Control Feel System

The Control Feel Systems for steering, brakes, clutch, transmission shift and throttle provide realistic control of feel feedback in response to driver inputs, vehicle motions and road/tire interactions over the vehicle maneuvering and operating ranges. The control feel systems is capable of representing automatic and manual control characteristics such as power steering, existing and experimental drive trains, Anti-lock Braking Systems and cruise control. The control feel cuing feedback has high bandwidth and no discernible delay or distortion associated with driver control actions or vehicle dynamics.

Auditory System

The Auditory System provides motion-correlated, directional sound sources. These sound sources are coordinated with the full range of the visual sensory systems database. The auditory database includes sounds emanating from current and new design highway surfaces, from contact with three dimensional objects that vehicles encounter (potholes, concrete/tar joints, pillars, etc.), from high density, multiple lane traffic, from the vehicle during operation and sounds which reflect roadway changes due to changes in the weather environments.

Vehicle Dynamics

The Vehicle Dynamics software properly represent vehicle motions and control feel conditions in response to driver control actions, road surface friction conditions and aerodynamic disturbances. All required vehicle responses are computed in real time for commanding the Visual, Motion, Cab, Control Feel and Auditory Systems. The vehicle dynamics models cover light passenger cars and trucks, and heavy trucks and buses. The models will encompass normal driving conditions and limit performance maneuvering that might be encountered during precrash avoidance situations, including spinout and incipient rollover.

The NADS contains several subsystems which provide the driver with a direct presentation of the driving environment.

Driving Maneuver

High Frequency Actuators

360 Degree Video/Audio Immersion

NADS dome and large x and y motion system

NADS dome and yaw turntable motion

NADS cab in dome and visual system

NADS front and rear high frequency Actuators

NADS front and rear instrumentation package

NADS cab in dome