440 likes | 640 Views
Automatic Pavement Cracking Distress Measurement System. Bugao Xu and Yaxiong Huang University of Texas at Austin bxu@mail.utexas.edu (512) 471-7226 December 2004. Automated Pavement Distress Measurement Vehicle. Digital Line Scan Camera. System Specifications.
E N D
Automatic Pavement Cracking Distress Measurement System Bugao Xu and Yaxiong Huang University of Texas at Austin bxu@mail.utexas.edu (512) 471-7226 December 2004
Automated Pavement Distress Measurement Vehicle Digital Line Scan Camera
System Specifications One linescan camera: 2k pixel, 37k scan/sec One frame grabber: 4 taps, 40MB each GSP: position and speed LED or halogen linear lighting device (patent pending) Imaging Resolution: min 1.786 mm per pixel Image capturing and processing: Real-time Network support
System Capabilities • Real-time inspection • Distance coverage: 100% • Lane coverage: Up to 12 feet (3.65 m) • Vehicle speed: 3-70 mile/hour (5 to 112 km/hour) • Pavement type :flexible and rigid pavements • Weather tolerance: cloudy or sunny • Night operation: same as in daytime
System Output • Format: PMIS and ASSHTO protocols • Summary data: at a given interval • Crack map: continuous • Snapshot: at an interval • AVI images: saved up to one km • Compressed images: continuous
System Performance • Repeatable over multiple runs: R2>0.8, CV 5.0~14% • Repeatable over testing speeds • Repeatable under different cloud conditions • Reproducible (vehicle to vehicle) • Output data directly up-loadable input PMIS • Measurements correlate well with manual ratings for flexible pavements
System Benefits • Safety (removing raters for roadway) • Low cost compared to visual rating • High data Quality • Multiple data types with one pass of vehicle • Easy data management
Continuous Crack Maps (40ft) Unsealed Crack Sealed Crack
120 2 R = 0.9519 100 80 60 40 20 0 0 20 40 60 80 100 120 Asphalt PavementCorrelation of Multiple Scans 2nd Scan 1st Scan Longitudinal Crack on SL360 R1 432 to 436.
Longitudinal Cracks on SL360 R1 432 to 436 300 #1 250 #2 #3 200 Feet/station 150 100 50 0 1 51 101 151 201 TransverseCracks on SL360 R1 432 to 436 stations 6.0 #1 #2 #3 4.0 Count/station 2.0 0.0 1 51 101 151 201 stations Multiple Scans
May 8 (heavily cloudy) May 9 (sunny) May 20 (cloudy) Transverse Cracks on SL360 R1 432 to 436 6.0 4.0 Count\Station 2.0 0.0 1 51 101 151 201 Stations Weather Conditions Longitudinal Crack on SL360 R1 432 to 436 300 250 200 Feet\Station 150 100 50 0 1 51 101 151 201 Stations
35 mph 200 45 mph 55 mph 160 120 80 40 0 0 500 1000 1500 2000 2500 3000 Vehicle Speeds Longitudinal Crack on SL360 R1 432 to 432+0.5 Feet\Station 0 500 1000 1500 2000 2500 3000 Scanned Section (ft) Transverse Cracks on SL360 R1 432 to 436 3.0 2.0 Count\Station 1.0 0.0 Scanned Section (ft)
200 150 100 50 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 0 200 150 100 50 200 0 16.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0 15.0 150 100 50 0 16.0 17.0 18.0 19.0 20.0 21.0 22.0 23.0 24.0 Long Distance Data (24 miles) longitudinal crack Miles
Concrete PavementTransverse Cracks Correlations of Different Runs (Transverse) Scan
Concrete PavementTransverse Cracks (V1 and V2) Correlations
Concrete: Spalled (1) Spalled crack