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Cartel: Cartography (mapmaking) + Intel (intelligence)

Preliminary Design ReviewECE4007 L01 – Senior Design – Fall 2007School of Electrical and Computer EngineeringGeorgia Institute of Technology

Project Advisor: Dr. Hamblen

Autonomous Multi-robot Mapping System

Brandon Chong - Team LeaderDavid EsiobuJonathan KingMark NfodzoChristopher Pau - Webmaster

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Autonomous Multi-Robot Mapping System• Develop two prototypes of mapping

robot• Map urban warfare areas for U.S.

Military • Improve on expensive and complex

military robots • Design our system cheaper,

specialized, and expandable • Focus on cost, expandability, and

autonomy

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Design Objectives• Lowering cost allows more systems• Using cheaper parts, software over

hardware• Designing expandability increases

accuracy and speed• Allowing easy and fast addition of

robots• Designing autonomy reduces human

element• Coordinating between robots

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Hardware Connection Diagram

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Mounting Diagram

Source: Microsoft

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iRobot Create

Source: iRobot.com

• Small wheeled profile• Cargo bay for additional hardware• Serial command interface• Rechargeable battery

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eBox 2300• 200 Mhz Vortex86 System-On-Chip • Fanless, compact design• Ultra Low Power• Wireless LAN, USB / Ethernet / RS-232

ports

Source: EmbeddedPC.net

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IR Sensor - GP2D12 • Sharp GP2D12 IR Sensor• Used to gather obstacle data• Distances from 10 cm to 70 cm• Analog Output Voltage from 0 to 2.5V

Source: Phidgets.com

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Ultrasonic Sonar Sensor• 42kHz Ultrasonic

sensor• Used to

determine robot movement

• Detects objects from 0 to 6.45 m

• Multiple Outputs• Analog Output -

10mV/inc• 2.5V-5.5V, < 3mA

supply current• Small, light

weight module Source: LV MaxSonar EZ1 Datasheet

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Compass Sensor• Used to coordinate

robot data• Power - 5-volts DC @

19 ma.• Outputs - Dual

analog channels • Weight - 2.25 grams• Size - 12.7 mm

diameter, 16 mm tall• Pins - 3 pins on 2

sides on .050 centers• Temp - 20 to +85

degrees C

Source : dinsmoresensors datasheet

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Phidgets Interfacekit 8/8/8• Used to interface sensors to the eBox• 8 Analog Input / 8 Digital Input / 8

Digital Output• Output to USB (drivers provided for

Win CE)• Analog to Digital converter

Source: Phidgets.com

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Phidgets Servo• Used to rotate IR sensor to make

multiple readings• HiTec HS-322HD Servo• 0.19sec/60 degrees at 4.8V • USB controller (drivers provided for

Win CE)

Source: Phidgets.com

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Software Overview• Operating System: Windows CE 6.0• Cartel Application: Microsoft Visual C#• Development environment: Microsoft Visual Studio

2005

Source: Microsoft

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Microsoft Visual C#Advantages

• Rapid software development (Managed Code)

• .NET Platform compatibility

• Pre-built drivers and projects (Phidgets)

Disadvantages• Windows-only - no

support on Linux (Mono = .NET alternative)

• Microsoft licensing fees

• .NET Code Performance Overhead (speed of sonar?)

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Cartel ControllerCartel Controller

Monitors and handles all requests

Sensor ControllerSensor data and Servo controls

Robot ControlleriRobot commands

Wireless Controller802.11b/g Network Communications

Intelligence ControllerGenerates movement operations

Runs on startup

Stores

Initial position

Map Data

Starts deployment procedure

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Robot Deployment Procedure

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Robot Deployment Procedure (2)

1) Leader (Robot 1) is in initialization2) Robot 2 gets position and starts exploration3) Robot 3 gets position and starts exploration4) No more robots after 3 minutes5) Leader starts exploration

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• Implements UDP/IP

• Opens Socket for receiving data

• Opens Socket for sending data

• Sends Broadcast Packets

Wireless Controller

Source: http://bit.kuas.edu.tw/~csshieh/

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Sensor Controller• Initialize interfaces to sensors and

servo• Process periodic readings from sonar

sensors• Take IR readings from a specified

angle• Generate events for Intelligence

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Robot Controller• Initialize and configure the Create• Translate commands to the Create’s

Open Interface• Process periodic readings from robot

sensors• Generate events for Intelligence

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Intelligence Controller• Process events generated by other

controllers• Make decisions about motion based

on gathered data• Share findings with other robots at

regular intervals

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Intelligence Controller - Exploration• Discretize the space • Track the explored

and occupied cells• Avoid explored areas

and probe occupied ones

• Sonar data will offer longer range, “soft” feedback

• IR readings will give hard numbers at closer range

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Advantages/Disadvantages of Controller Design• Divides work up• Shortens development time• Easily changeable for different robots• Increases complexity

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Mapping Software• Receives UDP

broadcast packets from the robots

• Plots unexplored area as grey squares

• Plots unoccupied area as white squares

• Plots occupied area as blue squares

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Timeline

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Future Work• Finish interfacing sensors• Finish Cartel Controllers• Establish communications between

robots• Establish communications between

robots and the Mapping Software• Perform mapping test runs• Debug problems encountered in test

runs

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Questions?

More information: please visit our website

http://cartel.shorturl.com

OR

http://www.ece.gatech.edu/academic/courses/ece4007/07fall/ece4007l01/group01/