Date post: | 15-Jun-2015 |
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Technology |
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UAV Image RecognitionTechnology and Applications
The UT UAV GroupCockrell School of EngineeringThe University of Texas at Austin
Harmony Mones‐MurphyChockalingam Viswanathan
Tejas Kulkarni
What is a UAV?
• The Department of Defense Dictionarydefines a UAV as:A powered, aerial vehicle that does not carry a human operator, uses aerodynamic forces to provide vehicle lift, can fly autonomously or be piloted remotely, can be expendable or recoverable, and can carry a lethal or nonlethal payload.
Driving Technology• Powered heavier than air flight• Radio control (R/C)• Autopilots• GPS• Imagery systems• High density power batteries• Long range and low‐power micro radio devices• Miniaturized parts• Wireless networks• Powerful micro‐processors
HISTORICAL FIRSTS
1898 1933
1903
1912
1918 1959
1960
1898: First demonstration of radio‐control
Nikola Tesla’s “Teleautomaton,” a radio‐control boat
Electrical Exposition at Madison Square Garden
1912: First autopilot
Elmer and Lawrence Sperry
• A gyrostabilizer hydraulically operated the elevators and rudder.
• Allowed the aircraft to fly straight and level without pilot input.
Curtiss B‐2
1918: First radio‐controlled unmanned flight
Curtiss‐Sperry Aerial Torpedo
• Forerunner of the modern cruise missile.
1959: First unmanned reconnaissance aircraft
Northrop Radioplane SD‐1 Falconer/Observer
TYPES OF UAVS
Fixed‐Wing
Northrop Grumman RQ‐4 Global Hawk
Rotorcraft
Helicopter: Northrop Grumman MQ‐8 Fire Scout
Quadcopter Tiltrotor: Bell Eagle Eye
PAYLOADS
Electro‐optic Payload Systems
• Optical Cameras• Low‐light‐level
(LLL) Cameras• Thermal Imagers
Radar Imaging Payloads
• Synthetic Aperture Radar(SAR)
Dispensable Payloads
• Civil ‐ Pesticides
• Military – Missiles
UT UAV
Our Team
• Undergraduate• Interdisciplinary• Student leadership
AUVSI Competition
• Student UAS Competition in Maryland
• Reconnaissance mission
• Fourth year of participation
• 1st in Autonomous Target Recognition in 2010
Phoenix II
Imagery
AvionicsAirframe
UT UAV Overview• Our Implementation
– Target Detection– Target Analysis– Position Determination
Target Characteristics
• Position (LLA) • Background Shape• Background Color• Alphanumeric
Character• Alphanumeric Color• Orientation
4 to 8 feet
4 to 8 feet
Target Detection
• Color‐based approach– Outlier image
• Exploit target attributes– Size, aspect ratio
• Implemented on DSP– Texas Instruments C6748
Background Image
• Represent image in 3‐D color space– ,
• Image contains background and foreground
Foreground Image
• Average RGB pixels in frame
• Compute distance from mean• Distance threshold determines potential targets
0 50 100 150 200 2550
0.02
0.04
0.06Red Plane
Per
cent
0 50 100 150 200 2550
0.02
0.04Green Plane
Per
cent
0 50 100 150 200 2550
0.02
0.04
Pixel Intensty
Blue Plane
Per
cent
Outlier Image
• Potential targets highlighted in oultlierimage
Original Image Outlier Image
Binary Image
• Remove noise ‐ windowed median filter• Label objects ‐ connected component
Binary Image Label Image
Target Analysis
CroppedImage
Segmentation Skeleton BoundingRectangle Rotate Compare
Target Detection Performance• Tested on scaled airfield and recorded video– Robust to trees, runways– Poor at detecting some colorsSpecification Performance
Speed 10 frames per second
Detection Accuracy* 85%
False Positive Rate 10%
* Accuracy = ratio of targets detected to total number of targets
Results
Legend: Correct Incorrect Marginally Incorrect
Target Position Determination
• Convert image coordinates to absolute position
• Position Accuracy– Maximum allowable error – 150 feet– Desired error – less than 50 feet
• Monte Carlo Error Analysis– Sweep camera 60 degrees in all directions from the vertical
– Estimate standard deviation of error
Monte Carlo Error Analysis
-750 -500 -250 0 250 500 750 1000-1000
-750
-500
-250
0
250
500
750
1000Error Analysis (500 feet altitude)
feet
feet
Standard Deviation (feet)
15
20
25
30
35
40
45
System Overview
Triangle J Purple
Yellow NW Lat Lon
Sony FCB EX‐980S
TexasInstruments
C6748
Target AnalysisLabVIEW
Plans for 2012
• Communication– Switch to Wifi (802.11N)
• Digital camera (DSLR)
• Weight reduction
Why UAVs?
• UAVs are suited for doing the “dull, dirty and dangerous” tasks of everyday life.
Applications of UAVs in Texas
• Oil & gas• Wildfires• Ranching
Oil & Gas
Use as a method to collect and transmit data between rigs
Use to check pipelines for leaks
Wildfires
Bastrop County Wildfire
Aid Firefighters with real time information and firefighting
capability.
Ranching
Check fences for holes
Use to track cattle/deer
Spraying crops with pesticide and fertilizer, monitoring crops, soil, moisture, and pest conditions, and insect sampling
Safety
• Due to safety concerns there are strict regulations regarding the use of UAV’s in unrestricted airspace throughout the world.
Air Systems Lab
• All the work done in the Air systems lab are undergraduate student projects, for various competitions.
Q&A