UWB Short Range (Radar) Sensors

Transcrição

UWB Short Range (Radar) Sensors
Reiner S. Thomä
Ilmenau
University of
Technology
Technische Universität
Ilmenau
FG Elektronische Meßtechnik
WCI 2008
Slide 1
UWB – An Idea Whose Time Has Come?
Communication – Localization – Sensors
Communication:
• “New frequencies”
q
for short range
g communication
FCC 2002: 3.1 - 10.6 GHz
Back to Marconi?
• Coexistence with other systems
• Simple systems and hardware
Localization:
• Unprecedented delay resolution (bandwidth!)
• Multipath resistance
Sensors:
• Material penetration (low frequencies!)
• More information on materials and shape of scanned media and bodies
Ilmenau
2008
Slide 2
UWB Spectrum Regulation - FCC
EIRP levvel [dBm
m/MHzz]
-30
-40
critical gap
for sensor
applications
-50
0,5 mW
- 3 dBm
-60
GPS
band
-70
indoor applications
pp
hand held devices, outdoor
-80
1
10
EIRP = -41,3
dBm/MHz
R
Rms
value
l off fi
field
ld
strength of 500
µV/m measured
at 3 m distance
and 1 MHz
bandwidth
frequency [GHz]
EIRP = effective isotropic radiated power
Ilmenau
2008
Slide 3
Basic UWB System Considerations
• Impulse radio, OFDM or direct sequence spread
spectrum?
• Integrated system design example
– Experimental system as used for all examples given
• Basic localization principles
• Radar imaging
Ilmenau
2008
Slide 4
System Characterization in the Time Domain
Impulse excitation:
y (t ) ~ h(t )
x(t ) ~ δ (t )
if
Excitation:
Impulse
x(t)
Ilmenau
reaction ~ IRF
LTI-System
h(t)
y(t)
2008
Slide 5
Correlation Processing
Excitation: noise
reaction
LTI-System
h(t)
x(t)
(t)
y(t)
y
correlator
l t
x
cyx(τ)
Cross-correlation ~ IRF
Ilmenau
2008
Slide 6
Maximum Length Binary Sequence (MLBS)
one period
T0 = N t c
VMSS
Ideal 4th order M-Sequence
time
tc = 1/fc
one chip
Auto correlation function
Number of chips:
Time-Bandwidth-Product:
Time
Bandwidth Product:
N = 2n-1
TB ≈ 2 n
1
Correlation
Gain!
10 lg(TB)
0
Ilmenau
2008
Slide 7
Single Chip Demonstrator System in SiGe
ADC
RF-clock
to DSP
Vee = 3 V
Rx
Tx
Rx
Trigger
Ilmenau
Sampling
li clock
l k
ADC
Courtesy M. Kmec,
TU Ilmenau
to DSP
2008
Slide
8 8
Experimental System (Baseband)
Transmit signal spectrum
(not calibrated)
Direct wave
Direct wave
C
Cross-talk
t lk
System impulse response
IR, not calibrated
35dB dynamic range
Ilmenau
Noise floor
IR calibrated
60dB dynamic range
2008
Slide 9
Demonstrator System 3.5…10.5 GHz
Modulated
MLBS
Digital
shift
hift register
it
RF-clock
MLBS
to sensor
7 GHz
Complex Impulse
Response Function
Binary
divider
1/2
00 900
LO
unit
Digital signal
processing
IRF
ADC
T&H
H
Sampling Clock
13.6 MHz
Base Band Processing
Ilmenau
from sensor
IF – Front - End
2008
Slide 10
Basic Radar Signal Processing
Port 1
Tx
reference
Target
a1
b2
Rx
IRF h(t)
Port 2
Radar echo depends on target
size shape,
size,
shape and material
composition
• desired target
g information:
ε = ε ( x, y , z , t , τ )
distance, location, orientation,
μ = μ ( x, y , z , t , τ )
speed, shape, material
composition,
iti recognition…
iti
σ = σ ( x, y , z , t , τ )
•
Ilmenau
ε
μ
σ
x,y,z
t
τ
permittivity
permeability
conductivity
space coordinates
observation time
delay time
2008
Slide 11
Spatial Processing and Radar Imaging
Focused data
Measured data
single scan
contribution
Cross range
Object
Focused data
Time delay
Measured data
Ilmenau
2008
Slide 12
UWB Localization and Sensor Applications
•Localization of active devices (tags)
•Localization
Localization and recognition of passive objects
•Imaging of structures and environments
•Material characterization
•Non destructive testing
•Civil engineering and mining
•Short
Sh t range navigation
i ti
•Industrial sensing
•Safety and security
•Automotive
•Biomedical engineering
•Law enforcement,, militaryy
•Search and rescue
Ilmenau
2008
Slide 13
Humanitarian Demining (GPR)
3 x 3 UWB array and metal detector
9 channel M-Sequence UWB Radar
Courtesy QinetiQ
Courtesy MEODAT and QinetiQ
Ilmenau
2008
Slide 14
Humanitarian Demining (GPR)
APL and UXO Detection
“Wave penetration” into the soil
APL
3 cm
R2M2 -Mine
Courtesy Vrije Universiteit Brussels
(Demonstrating video)
Ground surface profile
gained by the radar
Ilmenau
2008
Slide 15
Non-Destructive Testing in Civil Engineering
Experimental Set-up
Arrangement of 5 by 3 bricks
Ilmenau
2008
Slide 16
Non-Destructive Testing in Civil Engineering
Detection of wall structures, artefacts, moisture
antenna polarisation
all bricks are dry
y
y
x
y
the central brick was
exposed to water
y
x
Ilmenau
x
x
2008
Slide 17
Radar Sewer Tube Crawler
Antenna unit
Test field in preparation
g objects
j
with foreign
Ilmenau
• radar unit
• operation
p
control
• angle sensor
• data interface
2008
Slide 18
Radar Sewer Tube Crawler: Measurement example
Ilmenau
2008
Slide 19
Detection of human body activities: cardiac & respiratory
heart beat rate: 83
Measurement data with
background subtraction
Ilmenau
breathing
stop breathing
2008
Slide 20
MRI Image Enhancement
Tracking of heart and lunge movement
Ilmenau
2008
Slide 21
Cancer Detection
In vitro measurement of
a human lung during
NaCl-Perfusion
Watwer co
ontent [%]
Variation of water content
b approaching
by
hi the
h cancer
88
86
84
82
80
78
76
Ilmenau
2008
Slide 22
Active Location Approach
• cm (sub-cm) precision
Measured Example
2.5
measured
track
Y directtion [m]
2
circular wave front
detected wave front
actual
t l track
t k
R l antenna
Real
t
1.5
time [ns]
?
ϕ = 90°
1
0.5
ϕ = 0°
0
-1
1
moved
transmit antenna
(bi-cone)
Ilmenau
ϕ = 45°
ϕ = - 45°
-0.5
05
0
05
0.5
1
X direction [m]
receive array
(Vivaldi antennas)
2008
Slide 23
23
Active Location Approach
Measured example: 3D-positioning
sandbox
Demonstrating video
Vivaldi-Array
Ilmenau
2008
Slide 24
Passive Approach
Example
moving
target
2.5
Y directtion [m]
(box 0,5 x 0,1 x 0,5 m)
2
1.5
actual track
1
measured track
05
0.5
0
-1
transmit antenna
(bi cone)
(bi-cone)
Ilmenau
-0.5
0
0.5
X direction [m]
1
receive array
(Vivaldi antennas)
2008
Slide 25
25
Search and Rescue Applications
Detection of people
buried by an avalanche
Detection of people
buried by earthquake
Rescue personnel, injured
persons in static environments
• detection respiratory activity
• detection cardiac activity
g persons
• moving
Ilmenau
Tracking of people
behind the wall
Recognition of building structures
• hidden rooms and cavities
• wall structures
• blocked entrance
2008
Slide 26
Tx/Rx node
y[m]
[x3,y3]
Tx node
[xm100,ym100]
Rx node
[[0,0]
, ]
[xm1,ym1]
[x2,0]
x[m]
Ilmenau
2008
Slide 27
Imaging of Environments: Measured Example
• Rx1 and Rx 2: anchor nodes
• Tx: roaming illuminator node
• Direct and scattered wave separated
• Tx position track estimated from direct wave
• Image of environment calculated from scattered wave
Measurement environment
Direct wave
Container
Engine 2
Tx
moving
Rx1
Data measured
by anchor node
Rx1
Rx2
Engine 1
Ilmenau
Wall
Multipath components
2008
Slide 28
Imaging of Environments: Measured Example
Container
Engine 2
Tx
Rx1 contribution to
the focused image
- single snapshot
Rx1
Focused image
from Rx1 and Rx2 contribution
Engine 1
Container
Engine 2
Tx
moving
Rx1
Estimated track of
the Tx movement
Rx2
Engine
g 1
Ilmenau
Wall
2008
Slide 29
R
Rx1
Tx Rx22
Imaging by “Bat-type” Sensors
„Bat-type“ sensors are equipped with
one Tx and two Rx antennas
No coherent cooperation of
distributed sensors required
Object 2
Sensor p
positioning
g maybe
y self
contained
Object
j
1
Additional positioning (inertial sensors
or by
y anchor nodes)) may
y help
p
Resulting image
Rx1 Tx
Rx2
Correlation of single
snapshots
Object 1
Object 2
Ilmenau
2008
Slide 30
Imaging of Objects: Resolution
24
Ilmenau
2008
Slide 31
Localizing of people – through the wall
Measurement scenario
1st part of
the track
500cm
2nd part of
the track
3rd part of
the track
500cm
4th part of
the track
Table
Test object
Furniture
30cm
Wooden door
Rx1 Tx1
Ilmenau
Rx2 Tx2
Rx3 Tx3
200cm
200cm
2008
Slide 32
Localizing of people – through the wall
Antenna arrangement
Demonstrating video
Measurement scenario in reality
Ilmenau
2008
Slide 33
Through Wall Detection of Breathing Activity
Tx antenna Rx antenna
Wooden door
40cm
200cm
Brick wall
5 times deep breath
slow
5 times deep breath fast
4 times flat breathing
Test object
Ilmenau
2008
Slide 34
Detection of Breathing and heart beat
Propag
gation Time
e, ns
Detection of buried people
20
Radar data after removing static
scatterer
22
24
26
28
30
Backscattered signal modulated by
rhythmic variations of the breast due to
breathing
32
110
120
130
140
Observation Time, s
Propagatio
on Time [ns]
Breathing person
10
20
30
40
50
Ilmenau
Radar data after enhancement
of breathing activity
0.2
0.4
0.6
0.8
1
Breathing rate [Hz]
1.2
2008
Slide 35
35
Through-Wall Measurements
Wooden wall
Light concrete
wallll
Bricks
Timber
Hand held
device
Tile
Til
Tile
Floor
Ilmenau
2008
Slide 36
Courtesy RADIOTECT project
Larvae detection
Hylotrupes bajulus
Measurement set-up
Bi-static radar
Wood with larva
Ilmenau
2008
Slide 37
Larvae detection
ROI ((region
g
of interest))
Movement of the larva
16
18
20
22
24
26
0
20
normallised enerrgy of RO
OI
round trrip time [n
ns]
Radargram after Background removal
Ilmenau
1
Movement of the operator
0.8
(far away from the test object)
06
0.6
40
60
0.4
80
100
120
observation time [s]
140
160
180
0.2
0
0
20
40
60
80
100
120
140
160
180
observation time [s]
2008
Slide 38
38
Conclusions
• UWB sensor application offers clear advantage over
other radar, optical and ultrasound sensors.
• Frequency regulation not optimal for sensor
application.
li ti
• Low power, high clock rate integrated circuit
technolog required
technology
req ired (SiGe)
(SiGe).
• Huge absolute and relative bandwidth requires
paradigm shifts from narrowband to wideband
principles.
• Sensor cooperation and spatial distributed
processing (sensor networks).
Ilmenau
2008
Slide 39
Acknowledgement
Contributions by Dr. Sachs, Dr. Zetik, Dr. Hirsch, Dr. Helbig
Ultra-Wideband Radio Technologies
g
for
Communications, Localization and
Sensor Applications
Ilmenau
2008
Slide 40

UWB Short Range (Radar) Sensors

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