Software-Hardware mapping

in a Robot Design

Software-Hardware mapping

in a Robot DesignPavol Jusko, David Obdrzalek, Tomas Petrusek

Charles University, PraguePavol Jusko, David Obdrzalek, Tomas Petrusek

Charles University, Prague

MART Robotic Team, http://mart.matfyz.cz, petrusek@gmail.com

Introduction

• MART Robotic Team

• How we improved the design and the implementation of our robot

• Built from scratch, then improved

• PC based

• Software - Hardware mapping

MART Robotic Team, http://mart.matfyz.cz, petrusek@gmail.com

Agenda

• Original design• Hardware• Software• Pros and Cons

• New design• Hardware changes• Hardware modules• Software changes

• Conclusion

MART Robotic Team, http://mart.matfyz.cz, petrusek@gmail.com

First idea

• One MCU controlling all peripherals

• RS-232 – Serial Port

• Packet oriented protocol

MART Robotic Team, http://mart.matfyz.cz, petrusek@gmail.com

Software design

• What we wanted

• universal software

• for universal robot

• with any kind of hardware

• Layered design

• Communication layer

• Hardware abstraction layer

• Smart layer

MART Robotic Team, http://mart.matfyz.cz, petrusek@gmail.com

Com

mun

icat

ion

laye

r

Group“Bios”

- Packets- Bridge between HW and SW...

Sm

art l

ayer

Other inputs(camera, user)

Output to screen

GroupBrain

- Objectives- Decisions- Driving and guiding the robot...

HW

abs

trac

tion

laye

rGroupDriver

- Motors- LEDs...

GroupLocalizer

- Encoders- Compass- Calculate position...

Rea

l har

dwar

e

a11

a223

a34

a4

b1b2b3b4

5678

a11

a223

a34

a4

b1b2b3b4

5678

RS-232

MART Robotic Team, http://mart.matfyz.cz, petrusek@gmail.com

Pros and Cons• Pros

• Easy to create

• Worked well on two contests

• Eurobot 2007

• Robotour 2007

MART Robotic Team, http://mart.matfyz.cz, petrusek@gmail.com

Pros and Cons

• Cons

• “Hardcoded” solution

• Packet handling is not maintainable

• Hard to extend

• MCU limitations

RS-232

MCU 1

Motor 1

SW Panel

Motor 2

Encoder 1

MCU 2

Encoder 2

I2C - Compass

A/D - Battery meter

LED Panel

Splitter

Computer(with COM port)

MART Robotic Team, http://mart.matfyz.cz, petrusek@gmail.com

Hardware changes

• Removed one-to-one concept

• Bus topology

• I2C high speed bus with SMBus

• USB to I2C bridge

• Independent modules on the bus

USB I2C bus

Motor 1Encoder 1

Control panelButtons & LEDs

Motor 2Encoder 2

CompassMotor 3

...USB to I2Cbridge

New modulesComputer

(with USB port)

MART Robotic Team, http://mart.matfyz.cz, petrusek@gmail.com

HBmotor board

• MCU (Atmel AVR)

• H-Bridge

• Encoders

• Switches

MART Robotic Team, http://mart.matfyz.cz, petrusek@gmail.com

Hardware comparison

MART Robotic Team, http://mart.matfyz.cz, petrusek@gmail.com

Sm

art l

ayer

Other inputs(camera, user)

Output to screen

GroupBrain

- Objectives- Decisions- Driving and guiding the robot...

HW

abs

trac

tion

laye

r

...Other modules

GroupRangeFinder

- Moving average- Value correction

GroupDriver

- Motors- LEDs...

GroupLocalizer

- Encoders- Compass- Calculate position...

Com

mun

icat

ion

laye

r

...Other modulesGroupRangeFinder

- Request and read distance

GroupCompass

- Heading

GroupMotorLeft

- Motor 1- Encoder 1- Bumper 1

GroupMotorRight

- Motor 2- Encoder 2- Bumper 2

Scheduler

Ker

nel

Files created by Linux Kernel modules for I2C devices

Device 1 Device 2 ... Device N

Rea

l har

dwar

e USB to I2C

Individual I2C modules

...1 2 N

MART Robotic Team, http://mart.matfyz.cz, petrusek@gmail.com

Conclusion

• More universal design

• Better maintainability

• Better extendibility

• Easier changes

• More possibilities for the future

Thank you for your timeQuestions?

Thank you for your timeQuestions?

Pavol Jusko, David Obdrzalek, Tomas PetrusekCharles University, Prague

Pavol Jusko, David Obdrzalek, Tomas PetrusekCharles University, Prague

http://mart.matfyz.cz, petrusek@gmail.comhttp://mart.matfyz.cz, petrusek@gmail.com