Attachment_3_HDS_System_Description.pdf

693JJ318R000021

Attachment 3

FEDERAL HIGHWAY ADMINISTRATION'S

HIGHWAY DRIVING SIMULATOR

SYSTEM DESCRIPTION

SCOPE

The Federal Highway Administration's (FHWA) Highway Driving Simulator (HDS) was upgraded starting in 2004 to better meet the needs of Turner-Fairbank Highway Research Center’s (TFHRC) Human Centered Systems (HCS) safety research program. Additional upgrades were performed in 2012 to enhance the motion base and add an eye tracking capability. HDS is a fully interactive driving simulator used by HCS for human factors research in highway safety and highway operations. It provides a platform to study driver performance over a broad spectrum of driving situations as defined by varying highway designs and traffic control devices. One example of this is evaluating the effectiveness of various safety countermeasures developed as a result of identified driver performance problems or driver behavior (Figure 1.). The HDS is also being used for developing or testing new roadway designs. HDS’s capabilities need to be highly responsive to the increasing scope, complexity, and requirements of the FHWA's research program. Currently, rear view mirrors and traffic are being introduced into the HDS system to accommodate the requireents of the current research. This document describes the HDS system capabilities and its use for highway driving research.

Figure 1. A simulated two lane rural roadway scene with various safety related traffic control devices.

SYSTEM DESCRIPTION

The current upgrade configuration focused on increasing the capabilities of the system as well as lowering the life cycle support cost of the system. The major components that support the HDS are the Graphics Work Stations, HDS Interactive System and the Test/Preparation station. Figure 2.

shows the physical system layout. Note all major components including the TFHRC facility are tied together through a gigabit Local Area Network. Local area network controls exist to isolate or communicate with each of the major components including the TFHRC facility.

DEVELOPMENT WORK STATION

There are four Graphics Work Stations for Modeling, Software, Audio and Graphics development.

These Work Stations have an associated server for configuration management of archive data, software development, scenario models, and completed simulations. The Work Stations are equipped with essential application software for the development of software, modeling, configuration control and rendering. There is also a workbench and workstation area for the technician.

HDS INTERACTIVE SYSTEM

The HDS system includes the following subsystems; an operator’s control station, audio subsystem, scene projection subsystem, and the car cab control subsystem.

HDS SYSTEM – OPERATOR’S CONTROL STATION

The Operator's Control Station provides a central control point for running and monitoring an experiment. The experimenter and HDS staff can monitor simulator operations from the multiple displays at the console. The experimenter and staff can also verify that the experiment is progressing according to plan, observe the driver and the roadway scene, communicate with the driver and check to assure the experiment data are being properly collected and recorded. The station allows the experimenter to continuously monitor the participants performance. Power control and status indicators for major HDS components are located at the operator's control station.

Figure 1. HDS Physical System Plan The operators control station contains five CRT repeaters, one for each projector, a quad split camera CRT monitor, a Database Server PC, an Audio PC, a Vehicle Dynamics I/O control PC and Operator Control PC. The Operations Control PC provides system power control via commercial of the shelf digital I/O hardware and scenario management control. The audio PC provides aural cues for the driver. The Vehicle Dynamics PC provides motion equations and also provides the dynamic control of moving objects in the simulated environment (including the motion base). The Data Acquisition PC controls the interactive input/output signals for the Saturn vehicle.

HDS SYSTEM – SCENE PROJECTION SUBSYSTEM

The scene projection subsystem consists of five BARCO 909 projectors that are driven by five dual core graphics PC’s each containing two graphics cards. The PCs are mounted over the Saturn vehicle on a projector support structure that was custom designed and built for the HDS. The graphics cards operate using software retrace synchronization. Maximum useable resolution of these cards with the BARCO 909 projectors is 2048 X 1536. The multiple projectors allow the full use of the 240 degree cylindrical screen. Two side and one center rear view mirrors are to be simulated using seven inch liquid crystal dispay monitors.

HDS SYSTEM – SATURN VEHICLE CONTROL SUBSYSTEM

The central feature of HDS is the 1998 Saturn SL1 Sedan vehicle. Except for the engine and drive train, fuel tank and lines, the vehicle is complete and volunteer research participants in an experiment get in and "drive" an otherwise intact vehicle. Digital and Analog signals from the vehicle to the Dynamic I/O PC include steering wheel position, accelerator position, and the brake pedal position, etc. The steering, the accelerator pedal and the brakes provide realistic feedback to the driving participants.

Figure 1. View from Behind the 1998 Saturn Simulator Vehicle on 6DOF Motion Base

The HDS Saturn vehicle is mounted to an electronically actuated motion base that is state-sensed and controlled through the data in-out subsystem of the Dynamics in-out PC. The HDS motion base was upgraded from three to six degrees-of-freedom motion to obtain realistic motion effects and onset motion queues for human factors driving experiments. The motion base has six degrees-of-freedom (X, Y, Z, roll, pitch and yaw). The HDS vehicle dynamics software provides the calculated data to drive the motion base. Vehicle dynamics data comes from the driver’s interaction with the vehicle controls (accelerator, brake, steering, etc.) while reacting to the 3-dimensional visual scenes designed for a particular study. The motion base has the capability to move ±8 inches in the x, y or z axis or ±15˚ in roll, pitch or yaw. This system, under computer control, is used to generate car cab pitch under positive or negative acceleration, car body roll during cornering maneuvers and responds to roadway elevation and geometries.

HDS EYE TRACKING SYSTEM

An eye tracking system was recently integrated into the HDS to allow data to be collected about where participants are looking, primarily focuse on gaze bahavior outside of the vehicle. The eye tracker uses a quad SmartEye AB camera system and is integrated with the eyesDx MAPPS real time recording and analysis application for synchronization of the eye tracking data along with the visual environment.

The eye tracker consists of 4 cameras mounted on the simulation vehicle dash board and focused on the driver’s eyes. The tracker is fully calibrated and allows for approximately 1.5 degrees accuracy of tracking eye glances to viewed objects. While the driver experiences the simulated scene the eye tracker data is recorded by the MAPPS application for later analysis.

HDS SYSTEM – AUDIO SUBSYSTEM

The sound effects are provided by a six-channel system. Multiple speakers and subwoofer are used to simulate real time engine noise, road noise, wind noise, tire squeal, and other roadway vibrations.

TEST/PREPARATION STATION

The Test/Preparation station consists of multiple PCs and monitors to provide a means to continue HDS software development work and checkout while the HDS simulator is being used for experiments.

SOFTWARE ARCHITECTURE DESCRIPTION OF THE HDS

The HDS upgrade system is driven by a newly developed and evolving software engine which uses a PC cluster architecture to allow for multi-channel graphics rendering and distributed processing of real time dynamics and scene content control. The PC’s are interconnected through a Gigabit LAN. The distribution of PC’s within the system architecture optimizes the graphics and computational capability of each PC by distributing the software processing and to minimize LAN data traffic. This new software architecture allows for a scaleable system which can be configured as a single channel, single computer desk top system or to a larger multi-channel configuration which uses many computers to run each aspect of the simulation, thus allowing for much larger simulations with more dynamic scene content and additional projecters.