Post on 30-Jul-2020
July 13th 2012 Indian Institute of Technology Madras, India UMCSP 2012
Sheik Mohammed Ali S, Boby George and Lelitha Vanajakshi
Indian Institute of Technology Madras, India
July 13th 2012 UMCSP 2012
Intelligent Transportation System
Traffic Control Room
E-Message
Sends
Information
Traffic Signal
Control
Traffic
Detector
2
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Homogeneous and Heterogeneous Traffic
Homogeneous Heterogeneous
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Traffic Detector
•Detect various vehicles reliably
•Categorize as bus, car, motor cycle, bicycle, etc.
•Count
•Measure the speed of the vehicle
•Direction of movement
•Keep the power dissipation low
Heterogeneous
July 13th 2012 UMCSP 2012
Traffic Flow Sensors
Tape switch-US 4568937, US 4472706 Video Image-US 7646890, US5535314
Inductive Loop Detectors-US4472706, US3571789 Microwave radar-US5266954,
US7439876
5
In-roadway Sensors Over-roadway Sensors
July 13th 2012 UMCSP 2012
Inductive loops
Inductive loops are placed inside a Saw cut made in the road
Detector System
Existing Inductive Loop Detector
suitable only for
lane disciplined and homogeneous traffic
6
Detector System
July 13th 2012 UMCSP 2012
The Proposed Inductive Loop Detector
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July 13th 2012 UMCSP 2012
Magnetically Coupled Inductive loops
8
N
1
N
2
N
n3
N N
n-1
N
Measurement
Unit
a b
Mutually coupled inductive loop detector with the multiple inner loop (1, 2, …n)
and a single outer loop. All the inner loops are identical and a pictorial view of the
loop employed is shown right side.
July 13th 2012 UMCSP 2012
Electrical equivalent circuit
9
ZS
L1
C1
L2
C2
L n -1
Cn-1
vin
L n
Cn
M1
M2 M3
M4
L
vo
Magnetically-coupled inductive loop system
July 13th 2012 UMCSP 2012
The Measurement Scheme Employed for the
Magnetically Coupled Inductive Loops
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ZS
ADCvo
varb
Programmable Synchronous demodulator
+
x2
y2
LPF
LPF90o
x
y
√x
2+
y2
x/ytan-1vo1
vr
1
2
n
φφφφ
varb = vm(sin2πfp1t + sin2πfp2t +, ….+ sin2πfpnt).
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Multiple Inner loops
Single Outer loop
Inductive Loops Switched with the carpet
Experimental Setup and Results
Measurement
System
Measurement
System
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Multiple Inner loops
Single Outer loop
Inductive Loops Switched with the carpet
Experimental Setup and Results
Measurement
System
Measurement
System
July 13th 2012 UMCSP 2012
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fp1fp2
fp3
Results of the Sensitivity and Resonance
Frequency shift Test
Sen
siti
vit
y
(Norm
ali
zed
)
Sensitivity testThe parallel resonance frequency shift in the
presence of a conductive/metallic object
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Front Wheel Rear Wheel
Front AxleRotating
Shaft
Front Wheel Rear Wheel
Measurement unit
BUS
L1
L2
L3
L4
L5
Results from the Mutually Coupled Multiple
Loop Detector
Signature of a bus obtained from multi-
loop vehicle detector
July 13th 2012 UMCSP 2012
Results from the Mutually Coupled Multiple
Loop Detector
Right side
wheels
Left side
wheels
Entire lower
body
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Measurement unit
L1
L2
L3
L4
L5
CAR
Signature of a car obtained from multi-
loop vehicle detector
July 13th 2012 UMCSP 2012
BicycleBicycle
Bicycle
Bicycle
Motorbike
Motorbike
Scooter
Scooter
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Measurement unit
L1
L2
L3
L4
L5
Results from the Mutually Coupled Multiple
Loop Detector
Signature obtained from all the three loops
when there was continuous movement of vehicles
July 13th 2012 UMCSP 2012
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Results from the Mutually Coupled Multiple
Loop Detector with Outer-loop resonating
Signature of a bus obtained from single
outer loop and multiple inner loop
ZS
L1
C1
L2
C2
L n -1
Cn-1
vin
L n
Cn
M1
M2 M3
M4
L
vo
C
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Results from the Mutually Coupled Multiple
Loop Detector with Outer-loop resonating
Signature of a car obtained from single
outer loop and multiple inner loop
Signature obtained for the continuous
movement of vehicles from single outer
loop and multiple inner loop
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Thank you
ACKNOWLEDGMENT
�The support provided by Ministry of Urban Development through
project No. K-14011/28/2007-UT (Centre of Excellence for Urban
Transportation )