1. Computer and Information Science | Computer Systems Department
1st Seminar 28/2/2013
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 11st Seminar

2. • Team
– Ahmed Mohamed Emad
– Abdelrahman Ehab Soliman
– Muhammed Aly Huessin
– Anas Awad Ismail
• Academic Supervisors
– Prof. Hossam El-Din Fahem
– Dr. Wael S. El-Kilany
– TA. Agwad Hammad
Team Members
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 21st Seminar

3. • Area Exploration Problem:
– Problem definition.
– Previous Work.
• Cooperative Swarm:
– Swarm Robotics
– Why Swarm?!
– Goal.
– Frontier-Based Exploration.
– System Architecture.
• Robots Capabilities:
– Sensors, Brains, Cameras, … etc.
– Tools and Environment.
• Timeline:
– Our Status.
Outline Introduction Co-Swarm Timeline References
Outline
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 31st Seminar

4. Problem Definition
“In Robotics, the exploration problem deals with the use
of a robot to maximize the knowledge over a
particular area. The exploration problem arises in
mapping and search and rescue situations, where an
environment might be dangerous or inaccessible to
humans ”
Outline Introduction Co-Swarm Timeline References
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 41st Seminar
Introduction|Area Exploration

5. Problem Overview
– The exploration problems appeared when the humans think to use
robots to discover unknown areas that may be dangerous or
inaccessible for humans.
– Robot needs a map to operate in a particular environment.
– Autonomous Exploration : The ability of robots to autonomously
travel around an unknown environment gathering the necessary
information to obtain a useful map for navigation.
– Optimization Problem
Outline Introduction Co-Swarm Timeline References
Introduction|Area Exploration
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 51st Seminar

6. Previous Work
• In absence of global position information, (SLAM) techniques are
deployed to construct a map.
• State of the art:
– Classic non-coordinated strategies
– Classic coordinated strategies
– Integrated non-coordinated strategies
– Integrated coordinated strategies
Outline Introduction Co-Swarm Timeline Our Status
Introduction|Area Exploration
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 61st Seminar

7. Previous Work
• In absence of global position information, (SLAM) techniques are
deployed to construct a map.
• State of the art:
– Classic non-coordinated strategies
– Classic coordinated strategies
• Frontier-Based Exploration using Multiple Robots – Brain Yamuchi 1998
– Integrated non-coordinated strategies
– Integrated coordinated strategies
Outline Introduction Co-Swarm Timeline Our Status
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 71st Seminar
Introduction|Area Exploration

8. What’s Swarm ?!!
• New bio-inspired approach to control the coordination of (Multi-Robot
System)MRS, which consists of large numbers of mostly simple
physical robots.
• This collective behavior leads to the field of Artificial Swarm
Intelligence.
Outline Introduction Co-Swarm Timeline References
Co-Swarm | Swarm Robotics
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 81st Seminar

9. Why Swarm ?!!
• Simple and Elegant.
– Can be represented by State Machine.
• Scalable.
• Decentralized.
• Usage of local interactions.
Outline Introduction Co-Swarm Timeline References
Co-Swarm | Swarm Robotics
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 91st Seminar

11. Central Idea
• Gain the most new information about the world.
• Move to the boundary between open space and uncharted space.
Outline Introduction Co-Swarm Timeline References
Co-Swarm |Frontier-Based Exploration
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 111st Seminar

12. Evidence Grid
• Our Spatial Representation for the Environment.
• A Cartesian Grid containing cells and each cell contains its state
whether it is Open , Occupied or unknown.
Frontier Detection
• Frontiers are regions on the boundary between open space and
unexplored space.
• A process analogous to edge detection and region extraction in
computer vision is used to find the boundaries between open
space and unknown space.
Outline Introduction Co-Swarm Timeline References
Co-Swarm |Frontier-Based Exploration
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 121st Seminar

13. Navigate to Frontiers
• The robot attempts to navigate to the nearest accessible
unvisited frontier.
• Motion Planning with Obstacle Avoidance.
• Path Finding Algorithm  A*.
Outline Introduction Co-Swarm Timeline References
Co-Swarm |Frontier-Based Exploration
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 131st Seminar

14. Outline Introduction Co-Swarm Timeline References
Co-Swarm |Frontier-Based Exploration
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 141st Seminar

15. Multi-Robot Exploration
Outline Introduction Co-Swarm Timeline References
Co-Swarm |Frontier-Based Exploration
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 151st Seminar

16. Outline Introduction Co-Swarm Timeline References
Co-Swarm |System Architecture
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 161st Seminar

17. Outline Introduction Co-Swarm Timeline References
Co-Swarm |System Architecture
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 171st Seminar

18. Robocars
• 4-wheels car:
– with 4 DC motors and encoders
Outline Introduction Co-Swarm Timeline References
Co-Swarm |Capabilities
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 181st Seminar

19. Microcontroller
• ISP flash memory for 128 KB Internal Programming.
• 4 KB EEPROM.
• 4 KB Internal SRAM.
Outline Introduction Co-Swarm Timeline References
Co-Swarm |Capabilities
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 191st Seminar

20. Sensors
• Position Sensitive Device (PSD)
– Range: 10 cm  80 cm
• Ultrasonic :
– Range: 10 cm  10 m
• Infra-red:
– For line tracking Applications
Outline Introduction Co-Swarm Timeline References
Co-Swarm |Capabilities
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 201st Seminar

21. Bluetooth Module
• Used in communication to exchange map information
Outline Introduction Co-Swarm Timeline References
Co-Swarm |Capabilities
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 211st Seminar

22. Camera
• Our system will not depend on vision system.
• Capturing the surroundings and pass the data to a base
station.
– 3D Area reconstruction.
Outline Introduction Co-Swarm Timeline References
Co-Swarm |Capabilities
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 221st Seminar

23. Brains
Outline Introduction Co-Swarm Timeline References
Co-Swarm |Capabilities
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 231st Seminar

24. Brains
Outline Introduction Co-Swarm Timeline References
Co-Swarm |Capabilities
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 241st Seminar

25. • AVR Studio
Outline Introduction Co-Swarm Timeline References
Co-Swarm |Tools and Environment
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 251st Seminar

26. Outline Introduction Co-Swarm Timeline References
Timeline
ID Task name start finish 11 12 1 2 3 4 5
1 problem characterization 1/11 15/11
2 literature survey on cooperative
mapping using multirobot systems
15/11 1/1
3 Testing robo-car capabilities 15/11 15/12
4 Developing a set of simple
behaviors to control the motion of
robo-car, obstacle avoidance
25/1 20/2
5 Developing a robo-car framework
to work with
20/2 6/3
6 Implementing exploration on one
robot
25/2 10/3
7 Developing a fusion technique for
combining local maps into global
map
10/3 5/4
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 261st Seminar

27. Outline Introduction Co-Swarm Timeline References
Timeline
ID Task name Start finis
h
11 12 1 2 3 4 5
8 Studying coordinated mobility
model mobility and anti-flocking
model mobility and their effect on
the mapping process
10/3 5/4
9 Implementation 15/11 1/5
10 Performance evaluation and
refinement
15/4 15/5
11 Final Report 1/12 30/5
12 Presentation and final delivery
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 271st Seminar

30. Framework
• Robot Motion:
– Description
– PID Control
Outline Introduction Co-Swarm Timeline References
Timeline| Our Status
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 301st Seminar

31. Outline Introduction Co-Swarm Timeline References
Timeline| Our Status
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 311st Seminar
D=2*∏*r
r= 42 mm
∅=D/R
R= 116 mm
VL /(R-L/2) = VR /(R+L/2)
L = 24 cm

32. Outline Introduction Co-Swarm Timeline References
Timeline| Our Status
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 321st Seminar
Framework
– Control Theory
• Systems (Velocity) : it is the component which describe what is the system doing now .
• System output (Rotations): is the result or the signals which generating from the system .
• Sensor(Encoder): it is the feedback system which can sense the output of the system .
• Reference(Target Velocity) : it is the target of the system or what we need the system
actually do.
• Controller(PWM) : the component which convert the Measured error to control signals.

33. Framework
• Motion Control : PID Control
Outline Introduction Co-Swarm Timeline References
Timeline| Our Status
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 331st Seminar

34. Framework
• Motion Control :
– PID Control effect
Outline Introduction Co-Swarm Timeline References
Timeline| Our Status
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 341st Seminar

35. Framework
• PID Control:
Outline Introduction Co-Swarm Timeline References
Timeline| Our Status
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 351st Seminar

36. Framework
• Communication:
– Sending and receiving data using Bluetooth
Outline Introduction Co-Swarm Timeline References
Timeline| Our Status
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 361st Seminar

38. Area Exploration
Outline Introduction Co-Swarm Timeline References
Timeline| Our Status
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 381st Seminar
Stop
Avoid
Obstacles
Rotate
Move
Gather Information &
Creating Local Grid
Explore
No Avail. Path
Avail. Path
Find obstacle
New path
New path

39. Area Exploration
• Now , We are working on the following :-
– Implementation of a mapping technique.
– Implementation path planning:
• Data Structure  Metric Mapping.
• Algorithm  A* for static environment .
Outline Introduction Co-Swarm Timeline References
Timeline| Our Status
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 391st Seminar

40. • Frontier-Based Exploration Using Multiple Robots – Brain
Yamauchi – 1998.
• A Frontier-Based Approach for Autonomous Exploration –
Brain Yamauchi – 1997.
• A comparison of path planning strategies for autonomous
exploration and mapping of unknown environments – Miguel
Juliá – 2012.
• Probabilistic Robotics – Sebastian Thrun.
• An Introduction to AI Robotics – Robin R. Murphy.
• Embedded Robotics – Thomas Braunl.
• Robocar user Manual.
Outline Introduction Co-Swarm Timeline References
References
Co-Swarm: Cooperative area exploration using a swarm of mobile robots February 2013 401st Seminar