RFID Automated Navigation of a Mobile Platform

Tommy Brant, Charles Harper, Patrick Smith, Eni Ofong, Caleb Howell

Georgia Institute of TechnologySchool of Electrical and Computer Engineering

December 8, 2008

Project Overview• The Mobile Platform (MP) is a robot-based

system that uses an embedded system and RFID tags to communicate wirelessly with a remote GUI to navigate itself to a final destination

• Prototype Dimensions:– 5” x 5” x 5”

Business Aspect

• Intended for use in warehouses as a subsystem of automated storage (AS) and retrieval systems (RS)

• Appeals to AS/RS developers for use in easily expandable retrieval systems

• Costs $41,600 includes the product and labor for the on-site setup of the network of checkpoints

Project Goals• Wireless communication between the GUI and the robot

control systems• RFID tagged areas to identify the location of the robot• Motor control to travel on a point to point basis• Overall objective is for the MP to arrive at the user-

determined destination by following the shortest path through a network of RFID checkpoints

RFID Automated MP

Design Approach

• Program components separately to ensure the correct output

• Once desired outputs are achieved, attach hardware components together and modify code if needed for components to communicate properly

RFID MP System

System Logic

Is at RFID?

No

Yes

Transmit via serial

CPU decides direction for

robot

Gumstix console-vx

Gumstix Verdex

Stop robot

Transmit via serial

Gumstix console-vx

Turn robot in needed

direction

Robot Movement

Determine Direction

Is at RFID?

No

Yes

Transmit via serial

CPU decides direction for

robot

Gumstix console-vx

Gumstix Verdex

Stop robot

Transmit via serial

Gumstix console-vx

Turn robot in needed

direction

Robot Movement

Wireless Transmission

Is at RFID?

No

Yes

Transmit via serial

CPU decides direction for

robot

Gumstix console-vx

Gumstix Verdex

Stop robot

Transmit via serial

Gumstix console-vx

Turn robot in needed

direction

Robot Movement

Network Card

Is at RFID?

No

Yes

Transmit via serial

CPU decides direction for

robot

Gumstix console-vx

Gumstix Verdex

Stop robot

Transmit via serial

Gumstix console-vx

Turn robot in needed

direction

Robot Movement

Motherboard

Is at RFID?

No

Yes

Transmit via serial

CPU decides direction for

robot

Gumstix console-vx

Gumstix Verdex

Stop robot

Transmit via serial

Gumstix console-vx

Turn robot in needed

direction

Robot Movement

Update Direction

Is at RFID?

No

Yes

Transmit via serial

CPU decides direction for

robot

Gumstix console-vx

Gumstix Verdex

Stop robot

Transmit via serial

Gumstix console-vx

Turn robot in needed

direction

Robot Movement

Movement

Is at RFID?

No

Yes

Transmit via serial

CPU decides direction for

robot

Gumstix console-vx

Gumstix Verdex

Stop robot

Transmit via serial

Gumstix console-vx

Turn robot in needed

direction

Robot Movement

RFID Search LoopTransmit via

serial

CPU decides direction for

robot

Gumstix console-vx

Gumstix console-vx

Stop robot

Transmit via serial

Gumstix console-vx

Turn robot in needed

direction

Robot MovementIs at RFID?

No

Yes

(Delay)

Checkpoint

Is at RFID?

No

Yes

Transmit via serial

CPU decides direction for

robot

Gumstix console-vx

Gumstix console-vx

Stop robot

Transmit via serial

Gumstix console-vx

Turn robot in needed

direction

Robot Movement

Back To Network Card

Is at RFID?

No

Yes

Transmit via serial

CPU decides direction for

robot

Gumstix console-vx

Gumstix console-vx

Stop robot

Transmit via serial

Gumstix console-vx

Turn robot in needed

direction

Robot Movement

Return Info.

Is at RFID?

No

Yes

Transmit via serial

CPU decides direction for

robot

Gumstix console-vx

Gumstix Verdex

Stop robot

Transmit via serial

Gumstix console-vx

Turn robot in needed

direction

Robot Movement

Wait for Next Action

Is at RFID?

No

Yes

Transmit via serial

CPU decides direction for

robot

Gumstix console-vx

Gumstix Verdex

Stop robot

Transmit via serial

Gumstix console-vx

Turn robot in needed

direction

Robot Movement

Current Problems

• While cross-compiling, Linux OS crashed– More control in Linux– Can modify system files easily– Also destroyed easily

• Unable to integrate and test components• Due to the delay in receiving parts,

unforeseen problems with cross-compiling C-code, and OS crash, we are significantly behind schedule

Potential Problems

• Proper communication between different hardware components

• Straight-line travel• Developing algorithms for shortest path• Power supply to the robot components• Heat dissipation from the Gumstix

modules

Project Schedule Re-cap

Task Duration Start Date End Date Milestone?Assigned Member

Troubleshoot Robot Movement

36 days 8-Oct 12-Nov N BRANT/OFONG, then GROUP

Troubleshoot RFID Readings 42 days 8-Oct 18-Nov N HARPER, then GROUP

Troubleshoot Serial/WiFi Communication Path

28 days 22-Oct 18-Nov N SMITH/HOWELL, then GROUP

Integrate/Troubleshoot Gumstix

21 days 18-Nov 7-Dec Y GROUP

Prepare Final Demo/Presentation

7 days 1-Dec 7-Dec Y GROUP

Cost Analysis

Working Components

Peripheral components are individually working properly

– RFID reader recognizes RFIDs and writes tag ID to file

– Motor controller properly receives input from RFID reader

Current Status

• Operating system is operable• Cross-compilation success• OS, source code, phidgets libraries on

Gumstix but execution results in error• With more time, troubleshooting problems

could be accomplished and produce working prototype

In Hindsight• Proposed project required more time than was

available– Parts delayed– Cross-compilation toolchain setup caused multiple

crashes• Cross-compilation could have been design

project in itself• Still feasible tasks given more time• With more funds, better equipment could have

been acquired