Wireless Networks for Multi-Robot Communications

Creating a Sensor Network of Robots.

Project Purpose

Create a sensor network of robots that, together, achieve a shared goal.

What is a Sensor Network? A sensor network contains multiple

devices. Each device has devices on it that

can sense conditions of the outside world, or sensors.

Each device communicates to other devices in order to achieve a shared goal.

Advantages of Sensor Networks Jobs can be complete with large

numbers of units in parallel Redundancy: Each unit of the

network can be destroyed with little to no damage to the network as a whole

Jobs of Sensor Network Surveillance: Sensor network can

cover a large are, and collate the data before it reaches the user

Search: Sensor networks can cover multiple parts simultaneously for quicker results.

Remote Monitoring and Control

Design Problem Develop a wireless

communication network for multi-robot teams. This network, preferably made with radio frequency transceivers, plus the on board sensors of the robots themselves, will form a sensor network, in order to locate a light source.

Existing ImplementationsDARPA has

sponsored a project for “smart dust”: a sensor network of thousands all small enough to float in the wind, to be used for surveillance.

TinyOS and TinyDB Part of the DARPA

project is the creation of an embedded operating system to run units on the sensor network, called TinyOS, and a data gathering utility, TinyDB

RFID TagsThese tags are

small devices that transmit an ID number when hit with a radio frequency.

Design ConstraintsThe project must… Maneuver around objects. Search for target. Realize it has found target. Signal other robots. Search for robot that signals. Wait for turn to communicate. Not interfere or be interfered with in

terms of RF communications.

Design ConstraintsThe project should… Be easy to modify system behavior. Be easy to interface. Use parts and tools readily available. Sense obstacles to avoid contact. Use small enough area to ensure the RF

transmitters can reach all distances.

Feasibility StudyShow the project is physically, technically, and

economically feasible in the time available. Similar projects have been successfully

completed. Can use past projects for guidelines and

ideas. Budget is within reason. Using mature technologies such as RF and

photocells. Easy to interface with robots.

Timeline

3 4 5 6 7 8 9 10 11 12 13 14 15 16

Presentation

Testing

Integrate

RF Software

Integrate

Searching Software

Initial movement of Bots

Build Bots

Parts List

Proposal

Week

Survey of Products AmigoBot (ActiveMedia) Khepera (K-Team) Trilobot (Arrick Electronics) Hexapod (LynxMotion) Boebot (Parallax)

AmigoBot Comes with battery

and battery charger Comes with

AmigoOS and AmigoBot User Guide

Great Indoor/Outdoor range

Comes with various packages (e.g. Wirefree)

Too Expensive

Khepera Not Enough

Payload to add on RF products

Shorter whiskers than Boebot

Light, compact design

Limited kits available

Trilobot Heaviest of all robots 8 whiskers around

base 4 light level sensors Digital tempature

sensor Engineered for easy

expansion Once again…

Hexapod Never specified

payload Lacking

Documentation and manuals

Affordable Price

Boebot Comes with

BasicStamp2 Get Full Kit with

each robot purchase

Extensive Documentation and very adaptable

Price is right!

BudgetProduct Quantity PriceBoebot Full Kit 5 1145.00(w/shipping) 1157.28Transmitter (TWS-434) 5 38.25 Receiver (RWS-434) 5 38.25433 MHz Antenna 5 45.00(w/shipping) 130.84Alkaline Batteries (AA) 100.00Total Cost 1388.12

Design Validation Test servos, whiskers,

photoresistors, and IR subsystem individually as outlined in Boe-Bot manual

Integrate and test servos, whiskers, photoresistors, and IR subsystem

Search and Communicate Implement and test

random search for light using single Boe-Bot

Implement and test patterned search for light using single Boe-Bot

Implement and test RF communication between two Boe-Bots

Develop, implement, and test a communication protocol for multiple Boe-Bots

Putting it all Together Combine communication protocol with

individual Boe-Bot random and pattern searches

Begin stepwise refinement Determine which search is best Determine how close Boe-Bots should get to

each other before moving away from each other

Enhance communication protocol

Proposal Choose parts

Order parts

Connect servos to robots

Build robots

Get robots moving

Connect whiskers

Write and implement obstacle avoidance software

Connect photocells

Write and implement light sensing software

Connect RF transmitter and receiver

Write and implement RF software

Write and implement networking protocol

Connect IR

Write and implement IR

Write and implement object searching

Write and implement object tracking

Create team

(Optional – if time permits) Search and rescue lost robots

Complications Test with various objects blocking

the search Test with Boe-Bots being

dynamically added and removed from the search