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

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1.0 1.2 1.4 1.6 1.8 2.0

MilepointR

ut D

epth

(in)

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AC

(%)

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MilepointR

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epth

(in)

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(%)

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MilepointR

ut D

epth

(in)

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Milepoint

AC

(%)

Pavement Management

Construction