Tracking HMA Placement Using RFID TechnologyTracking HMA Placement Using RFID TechnologyCharles W. SchwartzCharles W. Schwartz
University of MarylandUniversity of Maryland
AASHTO Subcommittee on ConstructionAASHTO Subcommittee on ConstructionSan Antonio TX August 2008San Antonio TX August 2008
The ProblemThe Problem
Lot
AC
Lot
AC
Lot
ACMilepoint
Dis
tres
s
Pavement ConstructionPavement Construction Pavement ManagementPavement Management
Link??
The ProblemThe Problem
Lot
AC
Lot
AC
Lot
ACMilepoint
Dis
tres
s
Pavement ConstructionPavement Construction Pavement ManagementPavement Management
Link??
HMA from PlantHMA from Plant
PaverPaverHaul TruckHaul Truck
Tags scanned Tags scanned when convenient when convenient after constructionafter construction
Finished PavementFinished Pavement
Encapsulated Encapsulated RFID TagRFID Tag
Vehicle with RFID Vehicle with RFID Reader and GPSReader and GPS
CompactionCompaction
The Concept
Radio Frequency Identification (RFID)Radio Frequency Identification (RFID)
Tag IDTag IDPower to Power to
Transmitter Transmitter AntennaAntenna
Tag ID from Tag ID from Receiver Receiver AntennaAntenna
RF PowerRF Power
Tag IDTag ID
Tag Tag Activated by Activated by Transmitter Transmitter
RFRF
RFID ReaderRFID Reader
Passive Passive RFID TagRFID Tag
AntennaAntennaComputerComputer
Radio Frequency Identification (RFID)Radio Frequency Identification (RFID)
Tag IDTag IDPower to Power to
Transmitter Transmitter AntennaAntenna
Tag ID from Tag ID from Receiver Receiver AntennaAntenna
RF PowerRF Power
Tag IDTag ID
Tag Tag Activated by Activated by Transmitter Transmitter
RFRF
RFID ReaderRFID Reader
Passive Passive RFID TagRFID Tag
AntennaAntennaComputerComputer
Selected RFID TechnologySelected RFID Technology
Passive UHF (~900 MHz) TagsPassive UHF (~900 MHz) Tags
–– 2x2 inch Alien2x2 inch Alien
–– 1x1 inch Alien1x1 inch Alien
–– 1x2 inch UPM 1x2 inch UPM RaflatacRaflatac
Tag EncapsulationTag Encapsulation
CPVC pipes (11/16CPVC pipes (11/16””internal diameter)internal diameter)
Tags placed along Tags placed along inside of pipe wallinside of pipe wall
Pipe filled with highPipe filled with high--temperature epoxytemperature epoxy
Cost ~$1 eachCost ~$1 each
EpoxyEpoxy--filled filled CPVC pipeCPVC pipe
Hollow CPVC Hollow CPVC pipepipe
EpoxyEpoxyTag along inner Tag along inner
surface of pipe wallsurface of pipe wall
Laboratory EvaluationLaboratory Evaluation
Gyratory SpecimenGyratory Specimen
Encapsulated tags ovenEncapsulated tags oven--heated heated with HMA for 90 minutes at with HMA for 90 minutes at 165165ooC to simulate transport from C to simulate transport from plant to job siteplant to job site
Encapsulated tags compacted in Encapsulated tags compacted in gyratory with HMA to simulate gyratory with HMA to simulate field compactionfield compaction
Two RFID tags per gyratory Two RFID tags per gyratory specimenspecimen
Laboratory EvaluationLaboratory Evaluation
Transmitter
Receiver
Gyratory Plug Containing
Encapsulated Tags
Antenna
•• 67% survival rate67% survival rate•• Some degradation over timeSome degradation over time•• Read range: ~1 meterRead range: ~1 meter•• Encapsulation process later improvedEncapsulation process later improved
1x1 tag1x1 tag2x2 tag2x2 tag
Field Trials: UMD Lot XX1Field Trials: UMD Lot XX1
50 mm thick surface layer of 12.5 mm HMA mixture50 mm thick surface layer of 12.5 mm HMA mixturew/ prew/ pre--positioned RFID tagspositioned RFID tags
PrePre--Positioned TagsPositioned Tags ThroughThrough--Paver TagsPaver Tags
Field Trials: UMD Lot EEField Trials: UMD Lot EE
12.5 mm HMA surface, 50 mm thick19 mm HMA base, 100 mm thick
1x1 tag (20 total)1x1 tag (20 total)2x2 tag (10 total)2x2 tag (10 total)
2x2 tag (20 total)2x2 tag (20 total)1x1 tag (10 total)1x1 tag (10 total)
UMD Field Trial ResultsUMD Field Trial Results
1x1 Base
1x1 Surface
1x1 All
2x2 Base
2x2 Surface
2x2 All
All
0%
20%
40%
60%
80%
100%
Detection on basis of Layer/Course
Rea
d Su
cces
s R
ate
1x1 Base
1x1 Surface
1x1 All
2x2 Base
2x2 Surface
2x2 All
All
0%
20%
40%
60%
80%
100%
Detection on basis of Layer/Course
Rea
d Su
cces
s R
ate
Lot EE1010”” antenna heightantenna height
UMD Field Trial ResultsUMD Field Trial Results
Lot EE
1x1Paver,
AC Surface
1x1Paver,
AC Base1x1
Paver, All courses
2x2Paver,
AC surface 2x2Paver,
AC Base
2x2Paver,
All Courses
1x1Placed,
AC Base
2x2Placed,
AC Base
All tagsPlaced,
All Courses
All tagsPaver,
All Courses
0%
20%
40%
60%
80%
100%
Detection on basis of placing method
Perc
enta
ge R
eads
1x1Paver,
AC Surface
1x1Paver,
AC Base1x1
Paver, All courses
2x2Paver,
AC surface 2x2Paver,
AC Base
2x2Paver,
All Courses
1x1Placed,
AC Base
2x2Placed,
AC Base
All tagsPlaced,
All Courses
All tagsPaver,
All Courses
0%
20%
40%
60%
80%
100%
Detection on basis of placing method
Perc
enta
ge R
eads
2x2 Tag2x2 Tag
1x1 Tag
Tag SurfacingTag Surfacing
Tag surfacing in Lot EE:Tag surfacing in Lot EE:•• 1x1 tags: 20%1x1 tags: 20%•• 2x2 tags: 40%2x2 tags: 40%(Surface lift tags only)(Surface lift tags only)
Hampstead Bypass Field Trial• MD 30 NW of Baltimore• New alignment: 4.4 miles, 2 lanes• 2” surface lift over two 4” base lifts (19 mm)• Staged construction
Hampstead Bypass Field TrialNovember 2007
• Lower 4” base lift (19 mm)• 40 UPM Raflatac 1x2 tags, 60 Alien 2x2 tags (10/truck)• No MTV
C.J. Miller PavingC.J. Miller Paving
•• Vehicle speed: < 5 mphVehicle speed: < 5 mph•• Antenna height: 3Antenna height: 3”” and 12and 12””•• Future tests to vary:Future tests to vary:
-- Vehicle speedVehicle speed-- Antenna heightAntenna height-- Antenna configurationAntenna configuration
Read Success RateRead Success Rate
3in12in
1x2
2x2
56.7%66.7%
17.5%17.5%
0%
20%
40%
60%
80%
100%
Perc
enta
ge o
f Tag
s R
ead
Antenna Height
Tag Dimension
Hampstead Bypass
TruckB1-10 TruckB11-
20 TruckB21-30 TruckB31-
40
3 inch
12 inch
(3" U 12")
30%
40%
20%
10%
20%
30%
10%10%
20%20%
20%
10%0%
10%
20%
30%
40%
50%
Tags percentage Read
Trucks
Height of Antenna
Precentage of 1x2Tags Read in each Truck Vs Height of Antenna
Truc
k1-1
0
Truc
k11-
20
Truc
k21-
30
Truc
k31-
40
Truc
k41-
50
Truc
k51-
60
3 inch
12 inch
(3" U 12")
80%80%
100%
80%
60%60%
80%
70%80%
60%
50%60%
50%60%90%
70%
40%
30%
0%20%40%
60%
80%
100%
Tags Percentage Read
Trucks
Height of Antenna
Precentage of 2x2Tags Read in each Truck Vs Height of Antenna
Tag Surfacing Rates:Tag Surfacing Rates:
•• 1x2: 0%1x2: 0%
•• 2x2: 15%2x2: 15%
Hampstead Bypass Field TrialApril 2008
• Upper 4” base lift (19 mm)• 32 Alien 2x2 tags (8/truck)• MTV
Tag Spatial SequenceTag Spatial Sequence
Station:
Delivery Location:
Read Location:
89-96 97-104 105-112
105,107,108, 109
90,101,103, 105 112
326
85,86 84,88,92,93, 94,95,98 99,100,102 81 ,106,110,
111
81-88
327321 322320 323 324 325
•• Variable (unknown) spatial lagVariable (unknown) spatial lag•• Mixing in MTV surge hopperMixing in MTV surge hopper
Antenna Configuration InfluenceAntenna Configuration Influence
0%
10%
20%
30%
40%
50%
60%
70%
80%
R Outboard R Inboard
Antenna Configuration
Rea
d Su
cces
s R
ate
0%
10%
20%
30%
40%
50%
60%
70%
80%
R Outboard R Inboard
Antenna Configuration
Rea
d Su
cces
s R
ate
Read Success vs. SpeedRead Success vs. Speed
0%
20%
40%
60%
80%
100%
0 10 20 30 40 50
Vehicle Speed (mph)
Rea
d Su
cces
s (R
elat
ive
to 0
mph
)
0%
20%
40%
60%
80%
100%
0 10 20 30 40 50
Vehicle Speed (mph)
Rea
d Su
cces
s (R
elat
ive
to 0
mph
)
Tag LongevityTag Longevity2x2 Tags - Lower Base Lift (November 2007)
0%
20%
40%
60%
80%
100%
Nov 07 - 3" Nov 07 - 12" Apr 08 - 3"
Read Date and Antenna Height
Rea
d Su
cces
s R
ate
2x2 Tags - Lower Base Lift (November 2007)
0%
20%
40%
60%
80%
100%
Nov 07 - 3" Nov 07 - 12" Apr 08 - 3"
Read Date and Antenna Height
Rea
d Su
cces
s R
ate
ConclusionsConclusionsHMA production tracked successfully in field HMA production tracked successfully in field using RFID technologyusing RFID technology–– Minimal interference with paving operationsMinimal interference with paving operations–– No projection of 2x2 tags above mat surfaceNo projection of 2x2 tags above mat surface–– Surfacing of tags needs further investigationSurfacing of tags needs further investigation
Adequate to good read success rateAdequate to good read success rate–– Range sufficient for bumperRange sufficient for bumper--mounted antenna arraymounted antenna array–– 2x2 tags: 602x2 tags: 60--80% read success rate or higher80% read success rate or higher–– Need improvement for smaller tagsNeed improvement for smaller tags
Ongoing WorkOngoing Work
Evaluation of surfaced tagsEvaluation of surfaced tags
Evaluation of SAW RFID technologyEvaluation of SAW RFID technology–– Smaller format ID tagsSmaller format ID tags–– Interface for sensors (temperature, strain, Interface for sensors (temperature, strain,
cracking, moisture, others)cracking, moisture, others)
Tracking of PCC placementTracking of PCC placement
Guidance on data integrationGuidance on data integration
Benefit:Benefit:
AddedAddedValue Value
totoDataData
0.00
0.05
0.10
0.15
0.20
1.0 1.2 1.4 1.6 1.8 2.0
MilepointR
ut D
epth
(in)
3.0
4.0
5.0
6.0
7.0
1.0 1.2 1.4 1.6 1.8 2.0
Milepoint
AC
(%)
0.00
0.05
0.10
0.15
0.20
1.0 1.2 1.4 1.6 1.8 2.0
MilepointR
ut D
epth
(in)
3.0
4.0
5.0
6.0
7.0
1.0 1.2 1.4 1.6 1.8 2.0
Milepoint
AC
(%)
0.00
0.05
0.10
0.15
0.20
1.0 1.2 1.4 1.6 1.8 2.0
MilepointR
ut D
epth
(in)
3.0
4.0
5.0
6.0
7.0
1.0 1.2 1.4 1.6 1.8 2.0
Milepoint
AC
(%)
Pavement Management
Construction