M E T ROVER MSCD Engineering Technology Critical Design Review Metropolitan State College of Denver April 2004.

M E T ROVER

MSCD Engineering Technology

Critical Design Review

Metropolitan State College of Denver

April 2004

Mission Description

Deploy rover from the payloadcarrier upon landing.

Image flight and landing site autonomously.

Accomplish mission under strictmass limitations.

Mission GoalsDesign and build an autonomous roverand its carrier under strict mass limitation of 1.8 kg.Incorporate imaging system on the rover to video entire fight and the landing site.Carrier & Rover must survive: high altitude extreme cold temperatures impact forces during landing

Include additional Windsat mission into Rover package

NASA Benefits

Prototype development which maybe used during future missions toMars or the moon.

Test existing paradigms of rover design.

Explore new methods of rover design, construction, and deployment.

Project Requirements

Carrier and Rover combined must meet 1.8 kg mass limitation.

Rover must image the landing site.

Rover must deploy at the landing site.

Rover must have a drive systemallowing it to maneuver on the groundat the landing site.

Mass Budget

Carrier 400g

Camera (w/out battery) 166g

Drive motor/gearbox assembly 200g

Chassis & Electronics 400g

Wheels 400g

WindSat addition 234g

Total 1800g

Rover Design

Must operate in either orientation.

Drive arms move to raise chassis height.

Each wheel has independent motor.

Chassis made of carbon fiber composite.

Electronics will be insulated inside chassis.

Rover Design

Rover Design

Wheel Design

Rover Drive System

Drive the Rover out of the carrier and around the landing site.

One electric motor per wheel to get four wheel drive and steering.

Operate the rover in either of twopossible carrier landing orientations.

Incorporate obstacle avoidance system.

Drive Components

Orientation sensor.

Drive motors inside each wheel.

Movable side arms to raise chassis height.

Obstacle avoidance system.

Drive wheels.

Drive System InterfacesOrientation

SensorObstacleSensor

Controller

DriveArms

Motors

Drive System Prototyping

Aluminum wheels:Machined from solid 4.25 inch diameter

aluminum bar stock.Goal weight (mass) of 100 grams per

wheel.Drive arms machined from ¼” x ¾” stock.

Carrier System

Securely carry the Rover payload to high altitude and back.

Constructed foam and carbon fiber composite.

Open to allow the deployment of the Rover upon landing in correct orientation.

Carrier Components

Air piston system to open carrier

Foam-core with carbon fiber Carrier.

Rover door latching mechanism.

Rover opening mechanism.

Carrier Design

Imaging System

Digital video system will be employed to document entire flight plus image landing site.

Mounted to the Rover so multipleviews of the landing site will be recorded upon deployment.

Imaging Components

Panasonic SD mini digital video camera.

MPEG4 video compression.

Over 2 hr. 20 Min. of recording time.

320x240 dot/ 420 Kbps.

512 MB memory card.

Solar power unit to power video camera.

Electrical Requirements

Control and operate the Imaging & Drive Systems.

Open the Rover carrier upon landing.

Orientate the Rover and chassis.

Direct rover around obstacles.

Process and store in flight data.

Electrical Systems

Embedded Computer

SensorsSubsystem

ActuatorsSubsystem

USBSubsystem

GPSSubsystem

Subsystem - Stamp (Sensors)

Purpose: Read data from sensors, communicate with embedded computer

Interface: SPI (Serial Peripheral Interface)

Subsystem - Stamp (Sensors)

Altimeters

Temp Sensors

Tilt Sensors

Digital Compass

Wheel Encoders

Arm Angle Encoders

BASICSTAMP IIControllers

SPIInterfaceEmbedded

Computer

Subsystem - Stamp (Actuators)

Purpose: Control actuators, communicate with embedded computer

Interface: SPI (Serial Peripheral Interface)

Subsystem - Stamp (Actuators)

BASICSTAMP IIControllers

SPIInterfaceEmbedded

Computer

ParallaxServo

Controller

PololuMotor

Controllers

Relays

LCD

Motors

Servos

Subsystem – USB

Purpose: Provide communication between embedded computer and USB Devices

Interface: System Bus

Subsystem – USB

TD OT243USBHost

Controller

System BusInterfaceEmbedded

Computer

Flash Memory

Hub

HubCamera 3

Camera 2

Camera 1

Subsystem – GPS

Purpose: receive GPS signals and communicate coordinates to embedded computer

Interface: RS232 Serial

Subsystem – GPS

GaminGPSOEM

RS232 SerialInterfaceEmbedded

ComputerAntenna

Power Budget (incomplete)Component Voltage Current Power Time Total Power

Coldfire 3.3v ~250mA ~850mW 3hr 2550mWhStamps 5v 16mA 80mW 3hr 240mWhLaser 5v 65mA 325mW 0.1hr 33mWhTD243 USB 3.3v 12mA 40mW 3hr 120mWhGPS 5v 85mA 425mW 3hr 1275mWhMotorsServosUSB Cams

Total

Budget (Electronics/Software)Item(s) Status Price

Arcturus Networks Coldfire 5272 uCdimm dev kit Have it 1200Parallax Stamp BS2's and dev kits Have it 2451mW Laser, single line head, bandpass filter Have it 424Lynxmotion servo pan/tilt kit Have it 60Parallax servo contoller Have it 39Stamp AppMod Digital Compass Have it 59TrendNet TV-PC301 USB Cams (OV511+, OV7620) Ordered 132DS1620 Digital Thermometers Have it NCMemsic 2125 accelerometer/tilt sensor Have it NCPololu micro dual motor controllers Have it NCReed relays, switching transistors, resistors Have it NCLCD 2x16 Serial 50Garmin OEM GPS, Antenna ~175Transdimension EVB243, host controller software ~500USB Compact Flash Reader, 128Mb Compact Flash, USB Hubs ~165

Prototyping (Electronics/Software)

Set up development computer with compiler, dev tools, NFS. Ran simple program on embedded computer to flash LED's

Tested various USB cams and software

Experiences/Hardware from last year

Electronics Components

Altitude sensor.

Rover orientation sensor.

Obstacle avoidance sensor.

Micro-controller.

Wiring to/from sensors, camera and drive motors.

Carrier door latch servo.

Onboard programming.

Project OrganizationProfessor

KeithNorwood

Don GrissomTeam Lead

Power OscarMatt

LukeNathanChris

Amparo

ImagingBrianDon

Chris

CarrierOscarLeah

WalterJohn

Electronics Luke

NathanAmparo

Chassis John WalterMattLeahBrianDon

BudgetExpenses to date:

Beginning total $4000Carbon fiber materials $ 150Camera $ 800Motors/gearbox assy. $ 40Wheel material $ 100Machining tools $ 50Carrier material $ 30Misc. Material and Electronics $1800subtotal $2970

Remaining Balance $1030

Schedule

Construction Completed June 15

Operational testing Completed July 20

Final Construction Completed July 30

Mission Readiness Review July 30

Launch Readiness Review Aug 6

Launch Aug 7