SKEYEBALL: REAL-TIME VISION SYSTEM FOR AN
AUTONOMOUS MODEL AIRPLANE Danko Antolovic
Pervasive Technology Laboratory, Indiana University, Bloomington
Bryce Himebaugh
Steven D. Johnson
Department of Computer Science, Indiana University, Bloomington
Goals and Objectives of Skeyeball:
- Situated vision research:
- situational awareness => vehicle autonomy
- navigation
- target tracking
- collision avoidance (obstacles, terrain, other UAVs)
- Development of tools and methods for reliable embedded design:
- e.g. SPIDER avionics, under development at NASA/LRC
- Development of a platform for undergrad/graduate education
Situated computer vision
Why?
-Vision is an ill-posed problem
-Research has lead to a profusion of algorithms, many ill-suited for control and guidance applications
Situated application places stringent constraints on algorithms and hardware architecture. A situated vision system must be:
-Embedded, i.e. compact and mobile
-Real-time
-Integrated into the control loop(s)
The Vision Funnel
9.3 Mbytes/sec
YES/NO ?(~10 times/sec)
thresholding
edge detection
segmentation(logical analysis)
target identification
Data reduction by a factor of 10,000,000
Start with a gray-scale aerial shot …
… threshold it to B/W
… trace edges
… segment the edge map into connected components
… calculate moments of inertia for each component
Moments are invariant under rotations and translations.
Move the camera to bring the target in the center of the vision field.
15enable sigs.
4
addr
7
4
216
8
8
15
8
XC4010FPGA
back end
sampling clk.
digitized video
sync signals
LM1881
AD876
NTSCXC4010FPGA
front end
CY7C007AVDPRAM(32K)
Servos
Servo duty cycles
B/W threshold
MCF5307
Serial port
IRQ5
diagnosticsParallel port
8
duty cycles
servo motion
addr
data
data
video &threshold
servo data
PIC16F877
Servo position(analog)
4
2
controls
enable sigs.
Unified cache(DRAM only)
DRAM(8M)
Camera
To ground station (RF)
Architecture of the Vision Hardware
Measurement of the tracking speed
Maximum sweeping rate: 45 deg./sec, more than adequate for the airplane’s overflight speeds and a camera field of ca. 50 deg.
High-Priority Objectives …
- stable and unambiguous aerial tracking
- an orbiting mode, in which the aircraft autonomously circles above (or follows) an acquired target
- collision avoidance capability for stationary obstacles, to be extended in the future to avoidance of other UAVs
