Developing a Low-Cost Robot Colony

Felix Duvallet, James Kong, Eugene Marinelli, Kevin Woo, Austin Buchan, Brian Coltin, Christopher Mar, Bradford Neuman

20 mins pres + 5 mins questions = 25 minutes

AAAI Fall Symposium 2007

November 10, 2007

Fix CMU logo – it looks out of place right now (probably move RC logo up or down)

Outline

Motivation and Goals Robots Sensors Infrastructure Behaviors Sustainability Future work

Motivation and Goals

Motivations– A low-cost experimental platform for multi-agent research– Tool for testing AI algorithms

Need capable robots

– Open-source software to promote similar research elsewhere

Goal: Develop a colony of robots– Low-cost robots– Homogeneous architecture– Distributed algorithms

Mot

ivat

ion

and

Goa

ls

Two hard things: experimental, and low-cost

Remove open-source software?

Colony Robot

BOM Dragonfly Board

Motors

ORBs

Range-Finders

XBee Module

Charging Contacts

Rob

ots

Cheap (~$350) but capable

Colony Brains

ATMega 128– 8MHz max– 128Kbytes program

memory

Programmed in C– arv-libc, avr-gcc– open-source, multi-

platform tools

Rob

ots

Sensors

Sharp IR rangefinders BOM

Also used:– Bump sensors– Pyroelectric sensors

Sen

sors

BOM – Bearing and Orientation Module

IR emitter/detector ring Emitter mode

– All emitters are powered simultaneously (beacon)

Detector mode– Detectors can be polled

individually for analog intensity readings

– Most excited sensor indicates bearing to emitting robot

Co-planarity assumption Must coordinate BOMs

Build connectivity graphs

1

20

Sen

sors

Wireless Infrastructure

Integrate BOM and wireless network– Beaconing robot sends wireless message– Receiving robots know when to poll BOM

Token-ring coordination scheme Share information about neighbors

– Propagate global connectivity graph

Infr

astr

uctu

re

Swarming

Local obstacle avoidance

Low coordination Highly scalable

Beh

avio

rs

Lemmings

Simple follow-the-leader

Medium Coordination

Variant:– Cooperative maze

solving

Beh

avio

rs

Towards Self-Sustainability

Goal is to develop a self-sustainable robot colony that can operate unassisted for long periods of time

Requirements– Autonomous recharging– Remote monitoring and

control

Fuel Cells

Obstacle

Warehouse

Charging Station

Factory

Sus

tain

abili

ty

Autonomous Recharging

Robots must request charging resources from a charging station

Additional sensor aids homing sequence Daughter-board controls battery charging process

Video?

Sus

tain

abili

ty

Bay Allocation

Maximize distance between occupied bays– Minimize likelihood of collisions

Can you really spend a whole slide explaining this? – perhaps if you make a very nice diagram

Sus

tain

abili

ty

ChargeRequest

ChargeAccept/Deny

Docking Bays

Wireless TokenRing

Charging Station

Bay Allocation Manager

Charge Board Dragonfly

I2C

Robot 0

ChargingAlgorithm

Scheduler:Task andCharging

FSMsBOM and Homing Signals

Robot 1

Robot 3Robot 2

Robot 4Autonomous Autonomous

Recharging SystemRecharging System

…

ChargeRequest

ChargeAccept/Deny

Docking Bays

Wireless TokenRing

Charging Station

Bay Allocation Manager

Charging Station

Bay Allocation Manager

Charge Board Dragonfly

I2C

Robot 0

ChargingAlgorithm

Scheduler:Task andCharging

FSMsBOM and Homing SignalsBOM and Homing Signals

Robot 1

Robot 3Robot 2

Robot 4

Robot 1

Robot 3Robot 2

Robot 4Autonomous Autonomous

Recharging SystemRecharging System

…

Sus

tain

abili

ty

Probably remove slide – diagram isn’t useful with time constraint

ColoNet

Towards Remote Monitoring

Autonomous recharging makes extended-duration tasks possible

Need tools to:– Monitor progress– Identify and resolve

problems Added bonus

– Useful debugging tool

User ServerTCP/IP

ServerWireless

R0

R1

Rn

Sus

tain

abili

ty

Web client

Future Work

Increase task complexity– Coordinated manipulation– Environment exploration

Increase trial duration– Days or weeks

Increase Colony scale

I don’t think you should put SLAM here, it’s very (very x 100) far away from working, and you don’t want to make promises you can’t keep

Fut

ure

Wor

k

Colony Members

Duncan Alexander Ben Berkowitz Austin Buchan Brian Coltin Felix Duvallet Siyuan Feng Aaron Johnson Jason Knichel James Kong

Christopher Mar Eugene Marinelli Brad Neuman Suresh Nidhiry Justin Scheiner Greg Tress Kevin Woo Cornell Wright

Prof. George Kantor

Questions?

www.robotcolony.org

Can we get an updated picture like this one?