The WolfBot:
Swarm Robotics Platform with Image
Processing Applications
Jimit Patel
Dr. Edgar Lobaton
Department of Electrical and Computer Engineering
North Carolina State University
What is Swarm Robotics?

Multi-robot system inspired from social
insects

Ability to work co-operatively to achieve a
common goal

“Swarm Intelligence”: simple set of rules for
individuals, sophisticated collective behavior
for the group.
Research in Swarm Robotics
Communications
 Control Approach
 Mapping and localization
 Learning and task allocation
 Reconfigurable Robotics
 Object transportation and manipulation

Applications

Reconnaissance scenarios such as a
natural disaster, search and rescue
missions, surveillance, security purposes,
mapping unknown terrain or distributed
sensing …

Gathering information about environment
◦ Computer Vision
Existing Swarm Robots

Trade-off between cost, size and features

Very few swarm robots have camera
◦ From those which have cameras, ability to
take images at good resolution is rare
 Those which do take images at good resolution,
often lack ability to process images
 Finally, those which have ability to process images, aren’t fast
enough! (or are very expensive)
Comparison with different swarm
robots
Name(s)
Cost per unit
Camera
Kilobot, R-one, Elisa III, Alice, Libot,
Robomote, I-swarm, Jasmine, i-robot, …
< $350
NA
E-puck
MM-robot[1]
Khepera III
Corobot
$730
NA
$3,500
$4,000
40x40 @ 4 FPS
VGA @ 20 FPS max
HD, logitech
VGA
The WolfBot
•
•
•
•
•
•
Low Cost
High Performance
Designed for swarm robotics
Ability for on-board image processing
Easily replaceable camera and
communication modules
Omnidirectional drive
Processor

Beaglebone - TI AM3359
◦ ARM Cortex A8, 720 MHz, 256 MB DDR2
RAM




C
- Ubuntu 12.10 armhf
- OpenCV 2.4.2

Sensors
Accelerometer, Magnetometer
Ambient Light sensors
IR Distance Measurement sensors

Camera
MS LifeCam HD3000

Communication
IR (Robot-to-Robot)
Zigbee
Wifi (video stream/ftp)
Sensors

LSM303DLHC 3D Accelerometer and digital
compass

Ambient Light Sensors

IR Distance Measurement sensors (~10cm
to 100cm)

Microsoft LifeCam HD-3000
◦ 720p HD, 50 FPS
Communications

Nano wi-fi adaptor used for WLAN. Used
for video stream/ftp

IR Transceiver Beacon for short range,
line of sight communication (range upto
15 ft)

Zigbee communication for mesh network
in the swarm
Battery and Power Management

7.4V Lithium Ion 5200mAh Battery

Two TPS5420 DC-DC Converters to step
down the voltage to 5V and 3.3V
Experimental Results

Currently, the Wolfbot is programmed to
receive its co-ordinates from OptiTrack
(local positioning system) and move in
random directions till it detects an object.

Peak current draw of ~1.5A and upto 2.5
hrs of continuous operation (motion,
sensing and video stream at 720p
resolution)

Edge Detection
◦ Used cvCanny() from OpenCV on 512x512
pixels image
◦ Execution time : 0.05 sec (at 500MHz)*
* For comparison, the execution time is 0.34sec for CITRIC platform which used IPP
canny edge detection at 520MHz for 512x512 pixel images. Same program on intel
core-i5 laptop takes 0.008 sec at 2.6 GHz

Face Detection
◦ Used Haar-Cascades for face detection from
OpenCV on 512x512 pixels image
Summary
•
Introduction of image processing
capabilities in swarm robotics research
•
Low cost design (approx $500)
•
Facilitates experiments on different
research domains in swarm intelligence
References
1)
Haverinen, J., Parpala, M., & Roning, J. (2005). A Miniature Mobile Robot With a Color Stereo Camera System
for Swarm Robotics Research. IEEE International Conference on Robotics and Automation (ICRA 2005), (April 1822), 2494–2497.
2)
Rubenstein, M., Ahler, C., & Nagpal, R. (2012). Kilobot: A low cost scalable robot system for collective
behaviors. 2012 IEEE International Conference on Robotics and Automation, 3293–3298.
3)
Zahugi, E. M. H., Shabani, A. M., & Prasad, T. V. (2012). Libot : Design of a Low Cost Mobile Robot for Outdoor
Swarm Robotics. IEEE International Conference on Cyber Technology in Automation, Control and Intelligent Systems,
(May 27-31), 342–347.
4)
Sibley, G. T., Rahimi, M. H., & Sukhatme, G. S. (2002). Robomote : A Tiny Mobile Robot Platform for Large-scale
Ad-hoc Sensor Networks ’. IEEE International Conference on Robotics and Automation, (May), 1143–1148.
5)
Mondada, F., Bonani, M., Raemy, X., Pugh, J., Cianci, C., Klaptocz, A., Zufferey, J., et al. (2006). The e-puck , a
Robot Designed for Education in Engineering.
6)
Blazovics, L.,Varga, C., Csorba, K., Feher, M., Forstner, B., & Charaf, H. (2011). Vision Based Area Discovery
with Swarm Robots. 2011 Second Eastern European Regional Conference on the Engineering of Computer Based
Systems, 149–150. doi:10.1109/ECBS-EERC.2011.32