Mars RoverMars Rover

By: Colin SheaDan Dunn

Eric Spiller

Advisors: Dr. Huggins, Dr. Malinowski

OutlineOutline

• Project Summary• Review of Previous Work• Division of Labor• Project Description• Data Sheet• Equipment and Parts• Design Changes• Schedule• Progress Update• Results• Future Revisions

Project SummaryProject Summary• The main objective is to design the Rover for long battery life

that must last 7 days without recharging.

• The Rover will use a PC104 computer to control the interface between the user and the Rover.

• It will also use the MicroPac 535 microprocessor to control low level software such as the motors, the sonar system, and the battery level.

• The user will be able to enter a specific distance, move the Rover using the keypad, or rotate the Rover to get a preferred direction.

Previous WorkPrevious Work

• 2002• Rob Shockency and Randall Satterthwaite• Robotic Platform Design • EMAC 8051 and a CPLD• Design Goals• 1. Create Cheaper version of Telerobotics 2001• 2. Upgradeable and expandable in the future

Division of LaborDivision of Labor

Dan Dunn Colin Shea Eric Spiller

Assembly Code Java/Server Hardware

- Motor Control - Image Capture - DC Motors

- Wheel Sensors - Rover Controls - Platform Construction

- Battery Charge Level - Serial Communication - H-bridge/Motor Driver

- Serial Communication - Battery Charger

- Acoustic Sensors

Functional DescriptionFunctional Description

Wait

Charge

Low BatterySleep

User

Low Battery

Tim

eout

Connect

Disconnect

Activity

Man

ual

Full Charge

Low Battery

Low Battery

Functional DescriptionFunctional Description

• Wait mode – • All systems are powered, except the motors.• The CPU monitors the wireless card for network activity• The last image captured from the camera is displayed to the

user.• Web page accessible to user• Battery Status is monitored

• Sleep mode – • The sub-systems are powered down except for the CPU and

the wireless network card. • CPU runs in a reduced power mode. • Web page accessible• Battery Status is monitored. • Rover remains in sleep mode until signaled by the user.

Functional DescriptionFunctional Description

• Low battery mode –

• Battery drops below 10% of charge Distance and Direction Control

• Email sent to Dr. Malinowski requesting a charge

• Rover shuts down all components, except Micropac 535.

• User mode –

• All Systems powered

• Distance and Direction Control

• Web Page accessible to user

• Image capture and display

• Charge mode –

• Rover continues to charge until power button is pressed

• Stays in this mode until battery level reaches 100%

Functional DescriptionFunctional Description

Wait

Charge

Low BatterySleep

User

Low Battery

Tim

eout

Connect

Disconnect

Activity

Man

ual

Full Charge

Low Battery

Low Battery

System Block DiagramSystem Block DiagramUser

Computer Internet

MicroPac 535Embedded System

Motor

Wheel Sensors

Battery ChargeLevel

Camera

Voltage

Control TCP/IP

Bi t

Str

eam Acoustic

Sensors

PC104Upper level software

WirelessNetwork

card

802.11bRF signal digital bit stream

Tra

nsm

it pu

lse

TTL Signal

Object

USB Protocol

PWM Signal

Java Applet

Image

Com

mands

Sta

tus

Ech

o p

uls

e

H-Bridge

Software Flow ChartSoftware Flow Chart

• High Level Software • Rover Control

Software Flow ChartSoftware Flow Chart

• High Level Software • Image Retrieval/Display

Software Flow ChartSoftware Flow Chart

• Low Level Software• Motor Control

Software Flow ChartSoftware Flow Chart

• Low Level Software• Object Detection

Software Flow ChartSoftware Flow Chart

• Low Level Software• Battery Voltage Level

Micropac 535 A/D converter

Battery terminalvoltage

Compare to DataTable

User present

Display to userapproximate battery

charge levelCharge too low

Stop rover and switchto low charge mode

Charge G

ood

Continue operatingrover

User not present, charge good

Data SheetData SheetSpecifications

Turning accuracy - ± 5° for an individual turn commandTurning resolution - 15° Driving accuracy - ± 5cm and ± 2° for a 100cm commandCamera capture speed – 5 frames/sec @ 324x288 resolution for a 10BaseT connectionWeight – ~33lbsBattery life – 7 days without a rechargeTop speed – 10cm/sBattery charge level accuracy - ± 5%Acoustic sensors –

Time between transmit signals – 1 secondFarthest object detection – 200cmClosest object detection – 5cm

Data SheetData SheetPC104 –

Max Current, during boot – 1.5ANormal operating current – .8ASleep mode current – .026A Processor – National Semiconductor Geode Processor @ 300MHzRAM – 128MBVideo – Onboard Video card

PCMCIA module –Current - .07A

Wireless Card – Linksys WPC11Max Current - .3ACurrent in Sleep mode - .02A

Hard Drive – IBM Travelstar 2.5 inch IDE hard drive, 10GBMax Current - .94A (Spin-up Current)Current in Sleep Mode - .02A

Camera –Logitech USB WebcamMax Current - .1A

Motors – Model number – GM9236Gearing – 1:65.5Voltage – 12V

Power CalculationsPower CalculationsPower Consumption for Sleep Mode:

PC104 computer .026APC104 PCMCIA module .07AIDE Laptop Hard drive .015APCMCIA Wireless Card .009AEMAC .045A

+ _____Total .165A

24hrs * 7days = 168hrs168hrs * .165A = 27.72 Ah @ 5V27.72Ah * 5V = 138.6Wh

Using 3 - 12 Volt, 7.2Ah batteries:12V * 7.2Ah * 3 = 259.2 Wh available

Power CalculationsPower Calculations

Power Consumption for User Mode:PC104 computer .800APC104 PCMCIA module .070AIDE Laptop Hard drive .400APCMCIA Wireless Card .285AEMAC .045ACamera .100A2 DevanTech SRF04 .060A

+ ______Total 1.760A

Power CalculationsPower Calculations• Motors with a load draw 0.5 - 0.8 A.

• Total Amps with motors: 1.76A + (0.4A * 2) = 2.56A

• [(0.8A * 12V + 1.76A * 5V) * 4.1% + (.165A * 5V) * 95.9%] * 168hrs = 259.2Wh

• If the Rover is in User Mode for 4.1%, then168 hrs * 4.1% = 6.88hrs of battery life dedicated to User

Mode

Parts and Price ListParts and Price List

Part Manufacturer Price10 Gb IBM $80.00

128 Mb RAM Infineon $14.20

PC/MCIA Wireless Card Logictech $69.00

USB Webcam Logictech $16.00

PC104 300MHz w/ USB National Semi $399.00

Dual PC/MCIA Adapter National Semi

$94.00

Pittman DC Motor #9236 Pittman

Total $672.20

Design ChangesDesign Changes

• Replaced Linux based operating system with Windows based operating system• Video Card was incompatible with Linux although manufacturer

stated the card was compatible• Linux operating system was not stable on PC-104 board

Design ChangesDesign Changes

• Flash Memory Card and PCMCIA Hard drive replaced by Laptop Hard drive• Flash Memory Card was not capable of booting the PC-104 at

start-up• PCMCIA Hard drive was not visible by computer until system

completed start-up sequence• Laptop Hard drive booted easier and still remained low power• Flash Memory Card was used as secondary drive to limit usage

of Laptop Hard drive• Contained component software for Web Server (Apache and Java)

ScheduleScheduleTime Frame Accomplishment

1/19/03 – 2/8/03 Operating System

2/9/03 – 2/22/03 Serial Comm, H-Bridge, Camera

2/23/03 – 3/1/03 PWM, Java Program, Wheel Sensor Program

3/2/03 – 3/8/03 Movement Routines, Command Coding

3/9/03 – 3/15/03 User Interface

3/23/03 – 4/12/03 Tested Mobility

4/13/03 – 4/22/03 Acoustic Sensors, Battery Voltage Testing

Progress Flow ChartProgress Flow ChartUser

Computer Internet

MicroPac 535Embedded System

Motor

Wheel Sensors

Battery ChargeLevel

Camera

Voltage

Control TCP/IP

Bit

Str

eam Acoustic

Sensors

PC104Upper level software

WirelessNetwork

card

802.11bRF signal digital bit stream

Transm

it pulse

TTL Signal

Object

USB Protocol

PWM Signal

Java Applet

Image

Com

mands

Sta

tus

Ech

o pu

lse

H-Bridge

Green = Developed

ResultsResults

• H-bridges introduced noise to the system

Future RevisionsFuture Revisions

• Replace H-Bridge with Power Amp / Switching Circuit

Mars RoverMars Rover

Mars RoverMars Rover

Questions and AnswersQuestions and Answers