TxDOT 3-D Pavement Survey Technology
Dr. Yaxiong (Robin) Huang, [email protected] Texas Department of Transportation, Construction Division
New Technologies for Pavement Evaluation
For 86th Annual Transportation Short Course at Texas A&M University, 2012
What is High Speed Pavement Evaluation A combination of following pavement condition measurement 1. Ride quality IRI by longitudinal profiler
2. Rutting by five-point rut measurement device
3. Surface distress (cracking) by downward surface image
4. Surface texture by high speed laser sensor
New Technology for 3-D pavement structure A combination of surface image and surface elevation data 1. Rutting by high speed continuous transverse profile
2. Surface distress (cracking) by downward surface image and depth imformation
3. Surface texture by high resolution surface 3-D structure
4. Cross slope, faulting, marking thickness, pothole, and other features
TxDOT 3D Rutting system, VRUT
• Based on high speed 3D technology
• Samples 1536 points of profile for every 1 inch of travel
• Covers 14’ (4.26m) wide surface
• .025” (0.65 mm) rut resolution
• .093” (2.38 mm) transverse resolution
• Works on any type of pavement
• 0 to 70 mph (112 km/h) speed
• Straight edge, string line, and 5 point rut measurement methods
14 feet laser line, 1500/2300 data points
Image capability
Surface (intensity) image:
Range (elevation) image:
Surface Intensity Image and Elevation Image capable
Rut Measurement
String Line Rut Measurement
Six feet Straight Edge Rut Measurement
Based on continuous transverse profile Lane width detection for correct rut locations String line and straight edge rut algorithms
Rut Location and Spacing
US0183 major highway FM2239 county road
Only measured rut deeper than 1/8” are shown on maps
Rut spacing is calculated only when left and right rut is measured
Rut trace changes with distance
Rut space changes with different traffic patterns
Accuracy: Manual vs. 3D Rut Data Comparison
Manda Rd Left Wheelpath Rut R²=0.939
0
0.5
1
1.5
2
1 11 21 31 41 51 61 71 81 91 101Measurement (Count)
Rut
val
ue in
Inch
Manual 3D Rut
Manda Rd Right Wheelpath Rut R²=0.948
0
0.5
1
1.5
2
1 11 21 31 41 51 61 71 81 91 101Measurement (Count)
Rut
Val
ue in
Inch
Manual 3D RUT
ACP S
mooth
FM165 Left Wheelpath Rut R²=0.423
0.0
0.5
1.0
1.5
2.0
1 21 41 61 81 101 121 141
Measurement (count)
Rut
(in
inch
)
Manual 3D Rut
FM165 Right Wheelpath Rut R²=0.910
0.0
0.5
1.0
1.5
2.0
1 21 41 61 81 101 121 141
Measurement (Count)
Rut
in in
ches
Manual 3D Rut
Seal coat G
3 rough
Repeatability Test, Multiple Runs
Each test was conducted:
On same test section
At posted speed
Three trial runs
left and right rut on ever 10 ft
VRUT Repeatability Test, FM165, Right Wheelpath
0
0.2
0.4
0.6
0.8
1
1.2
1 21 41 61 81 101 121 141Measurement Count
Rut V
alue in
inch
RUN#1RUN#2RUN#3
VRUT Repeatability Test, FM967, Right Wheelpath
0
0.2
0.4
0.6
0.8
1
1.2
1 11 21 31 41 51 61 71 81 91 101Measurement count
Rut V
alue in
inch
RUN#1RUN#2RUN#3
Excellent correlation between different runs.
TxDOT 3D Texture system Technology for texture survey has moved to 3D for reliable data!
TxDOT 3D Texture System • Based on high speed 3D technology
• Samples 2048 points for every 2 inches of travel
• Covers 12” (304 mm) wide surface, 100%
• 10 µm texture resolution
• .007” (0.2 mm) spatial (x, y) resolution
• Works on any type of pavement
• Very high resolution 3D texture image for project level test
• Speed independent data.
Longitudinal Scanning Unit
Network level
Survey
Transverse Scanning Unit
Project level
Survey
Accurate, Repeatable, Speed Independent
1. Scan on test targets with known depth at different speed from 0 to 70 mph.
2. Reproduce each target profile accurately 3. Speed independent MPD data
VTexture Errors in %
VTexture errors in % at 0 to 70 mph
-10.0
10.0
30.0
50.0
0 10 20 30 40 50 60 70
Speed in MPH
Erro
r in
%
2.5 mm Target 3 mm Target 5.5 mm Target 8 mm Target
VTexture system errors in %
Targets 2.5 mm 3 mm 5.5 mm 8 mm
Travel Speed (mph)
0 -0.1 1.0 2.2 0.8
10 3.0 2.1 2.0 0.1
20 4.3 2.9 2.1 1.1
30 6.6 0.7 1.5 1.0
40 6.6 2.1 2.4 1.4
50 9.6 3.0 2.3 1.2
60 9.8 2.6 2.5 1.8
70 9.2 4.1 0.5 -2.1
1. Produce high accurate MPD data on different targets
2. Very low error on large target
3. Acceptable accuracy on small target
Comparison to other Texture Methods 3D vs Sand Patch in MPD R2 = 0.9907
0.000
0.500
1.000
1.500
2.000
2.500
3.000
0.00 0.50 1.00 1.50 2.00 2.50 3.00
Section Sand Patch CTM 3D
A 1.31 1.28 1.284
B 1.26 1.40 1.367
C 1.71 1.91 1.936
D 1.23 1.18 1.380
E 0.51 0.48 0.570
F 0.65 0.77 0.779
G 2.56 2.81 2.883
H 0.42 0.46 0.455
I 0.94 1.17 1.078
J 1.19 1.50 1.371
K 1.02 1.37 1.181
3D vs CTM in MPD R2 = 0.9742
0.000
0.500
1.000
1.500
2.000
2.500
3.000
0.00 0.50 1.00 1.50 2.00 2.50 3.00
1. Tested on 11 different pavement surface
2. VTexture shows very high correlations to sand patch and CTM data
3. VTexture works on concrete surface
Network Level Data
1. During network level survey, VTexture gives am MPD for every 2” of travel
2. Statistical summary reported every 0.1 mile, includes average, minimum, maximum MPD values and standard deviation.
3. Fully automated, no operator assistance is needed.
Texture MPD Mopac N.
0
1
2
3
4
5
1 2001 4001 6001 8001 10001 12001 14001
Bridge joints on ACP
Bridge joints on concrete
ACP on MoPac Smooth Street
Texture profile on ACP Texture Profile on tined concrete
Project Level Application 1. Three scan direction at Longitudinal, transverse, and 45 degree mount 2. 5 to 10 mph speed, continuous data collection. 3. High density data at 256 profile per foot of travel 4. Different display images for better analysis
Asphalt Intensity Range Image Concrete Intensity Range Image
3-D Display
TxDOT 3-D Cracking System
Built on true 3-D technology High speed 0 to 70 mph Fully automated Works on different pavement 2350 Data point 10000 scan/sec 8.11 profiles/inch 3.13 x 1.81 mm resolution
Surface and Depth Image Capable
Intensity and range Images 3-D Display
Automated Image Processing
Intensity Image Processed Range Image
Crack Detection Result
Pavement Image in 3D Display
Cracks Displayed in Range Image
Crack map
Crack Map
Thank You!
All systems were developed by TxDOT 3-D development team: Dr. Robin Huang, Todd Copenhaver, Phillip Hempel, P.E. and others from Construction Division, Pavement and Material Branch under the leadership of branch manager Dr. Magdy Mikhail, P.E.