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Virtual Proving Ground Terrain Validation
by Dr. David Lamb, Dr. Alex Reid, Nancy Truong, John Weller(IVSS-2003-MAS-1)
Virtual Proving Ground Terrain Validation
by Dr. David Lamb, Dr. Alex Reid, Nancy Truong, John Weller(IVSS-2003-MAS-1)
3rd Annual Intelligent Vehicle Systems SymposiumNational Defense Industrial Association
10 June 2003
Presented by: Nancy TruongUS Army TACOM-TARDEC
National Automotive Center (NAC)Ground Vehicle Simulation Laboratory (GVSL)
OutlineOutline
• Background Information about Lab
• Visual
• Churchville
• Virtual Profilometer
• Validation Process/Methodology
• NURBS
• Conclusions
• Background Information about Lab
• Visual
• Churchville
• Virtual Profilometer
• Validation Process/Methodology
• NURBS
• Conclusions
RMSRMS
• Capable of reproducing the ride of most ground vehicles • Realistic environment• The Evans and Sutherland ESIG
HD/3000 and Harmony Image Generators.
• Real-time warfighter/hardware-in-the-loopsimulation
• Aberdeen Proving Ground’s (APG) Churchville
Why Do We Need More Resolution?
• To aid in the application of high-fidelity modeling and simulation techniques to the development/testing of new vehicle systems and emerging technologies.
• To include:– motion-based, human- and hardware-in-the-
loop simulations.– high-resolution virtual testing of systems.
Terrain Limitations
• High-resolution dynamic model requires very small terrain resolution
• Higher resolution terrains cannot be rendered in real-time.
3.55
3.6
3.65
x 105
-5.68-5.66
-5.64-5.62
-5.6-5.58
-5.56
x 105
3000
3500
4000
4500• Typical terrain grids come no smaller than 30m x 30m and most areas typically are even lower resolution.
• Use of terrain for primarily off-road simulations
Visual Correlation Questions
• How does the low-resolution IG database correlate to the high-resolution dynamic database?
• Does it need to?
• Why?
Visual Correlation
• Needed to mitigate simulator sickness
• Creates a more realistic virtual environment
• Use Bump-Map Texturing
GVSLGVSL
• Human Factors
• Vehicle performance
• Motion Sickness
• Comparison of head-mounted display (HMD) vs flat panel
• Human Factors
• Vehicle performance
• Motion Sickness
• Comparison of head-mounted display (HMD) vs flat panel
Components of a Real-Time Simulation
Components of a Real-Time Simulation
Mathematical ModelVirtual Environment
Real-Time Computer
Experimental Environment
Churchville Churchville
• Visual- what we see • Terrain- what we feel
• Visual- what we see • Terrain- what we feel
Validate the TerrainValidate the Terrain
• Acquired the data for the virtual terrain,
• Obtained the x & y coordinates
• Input data into the virtual profilometer
• Acquired the data for the virtual terrain,
• Obtained the x & y coordinates
• Input data into the virtual profilometer
Virtual ProfilometerVirtual Profilometer
• Acts the same way a profilometer acts over a read proving ground
• Simulates a trailer
• Reports other terrain properties stored in the database
• Acts the same way a profilometer acts over a read proving ground
• Simulates a trailer
• Reports other terrain properties stored in the database
Equal distance spacingEqual distance spacing
Input-Constant time delta, but at a variable speed
Output- Constant space delta
Interpolation of pointsInterpolation of pointsOnce the arc length (distance) down the course to each point in the input series is computed, then interpolate to get points the desired distance apart.
212121 1,1,1 zzyyxx
This is the new point, where the interpolation parameter is
12
1
ss
ss
The desired distance is s, other distances are for the two points
111 ,, zyx 222 ,, zyx
Other FeaturesOther Features
• A rough Power Spectral Density (PSD) of the course
• Various input and output formats are supported
• Options for track offset (left and right) or single track (centerline) available
• A rough Power Spectral Density (PSD) of the course
• Various input and output formats are supported
• Options for track offset (left and right) or single track (centerline) available
Profile DataProfile Data
• MATLAB • Linear interpolation • Two curves start and stop
at the same point • Virtual proving ground
correlated well with large terrain changes
• MATLAB • Linear interpolation • Two curves start and stop
at the same point • Virtual proving ground
correlated well with large terrain changes
RMS ValuesRMS Values
• Removed wavelengths greater than 18m
• Real-terrain is 4.95 cm.
• Virtual terrain is 4.57 cm.
• A difference of 8%.
• Removed wavelengths greater than 18m
• Real-terrain is 4.95 cm.
• Virtual terrain is 4.57 cm.
• A difference of 8%.
PSDPSD
• Virtual terrain is much lower than the real terrain
• Construction of polygons
• Virtual terrain is much lower than the real terrain
• Construction of polygons
ConclusionConclusion
• Need to validate models• Real and virtual terrain
comparisons• NURBS• Work on other APG databases
• Need to validate models• Real and virtual terrain
comparisons• NURBS• Work on other APG databases
QuestionsQuestions
For further information on this presentation, contact:
Dr. David Lamb LambD@tacom.army.mil (586)-574-5209Dr. Alex Reid, ReidA@tacom.army.mil (586)-753-2212Nancy Truong, TruongN@tacom.army.mil (586)-574-8633John Weller, WellerJ@tacom.army.mil (586)-574-8633
Motion Base Technologies TeamTACOM-TARDEC6501 E. Eleven Mile RoadWarren, MI 48397AMSTA-TR-NMS: 157, Bldg 215
For further information on this presentation, contact:
Dr. David Lamb LambD@tacom.army.mil (586)-574-5209Dr. Alex Reid, ReidA@tacom.army.mil (586)-753-2212Nancy Truong, TruongN@tacom.army.mil (586)-574-8633John Weller, WellerJ@tacom.army.mil (586)-574-8633
Motion Base Technologies TeamTACOM-TARDEC6501 E. Eleven Mile RoadWarren, MI 48397AMSTA-TR-NMS: 157, Bldg 215
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