Transcript SmartSat - University of Colorado Boulder

M E T ROVER
MSCD Engineering Technology
Critical Design Review
Metropolitan State College of Denver
April 2004
Mission Description
Deploy rover from the payload
carrier upon landing.
Image flight and landing site
autonomously.
Accomplish mission under strict
mass limitations.
Mission Goals
Design and build an autonomous rover
and 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 may
be used during future missions to
Mars 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 system
allowing it to maneuver on the ground
at the landing site.
Mass Budget
Carrier
Camera (w/out battery)
Drive motor/gearbox assembly
Chassis & Electronics
Wheels
WindSat addition
Total
400g
166g
200g
400g
400g
234g
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 two
possible 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 Interfaces
Orientation
Sensor
Obstacle
Sensor
Controller
Drive
Arms
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 multiple
views 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
Sensors
Subsystem
Actuators
Subsystem
USB
Subsystem
GPS
Subsystem
Subsystem - Stamp
(Sensors)
Purpose: Read data from sensors,
communicate with embedded computer
Interface: SPI (Serial Peripheral Interface)
Subsystem - Stamp
(Sensors)
Altimeters
Temp Sensors
Embedded
Computer
SPI
Interface
BASIC
STAMP II
Controllers
Tilt Sensors
Digital Compass
Wheel Encoders
Arm Angle Encoders
Subsystem - Stamp
(Actuators)
Purpose: Control actuators, communicate
with embedded computer
Interface: SPI (Serial Peripheral Interface)
Subsystem - Stamp
(Actuators)
Embedded
Computer
SPI
Interface
BASIC
STAMP II
Controllers
Parallax
Servo
Controller
Servos
Pololu
Motor
Controllers
Motors
Relays
LCD
Subsystem – USB
Purpose: Provide communication between
embedded computer and USB Devices
Interface: System Bus
Subsystem – USB
Camera 1
Hub
Embedded
Computer
System
Bus
Interface
Camera 2
TD OT243
USB
Host
Controller
Camera 3
Hub
Flash Memory
Subsystem – GPS
Purpose: receive GPS signals and
communicate coordinates to embedded
computer
Interface: RS232 Serial
Subsystem – GPS
Embedded
Computer
RS232
Serial
Interface
Gamin
GPS
OEM
Antenna
Power Budget (incomplete)
Component Voltage
Current
Power
Time
Total Power
Coldfire
Stamps
Laser
TD243 USB
GPS
Motors
Servos
USB Cams
~250mA
16mA
65mA
12mA
85mA
~850mW
80mW
325mW
40mW
425mW
3hr
3hr
0.1hr
3hr
3hr
2550mWh
240mWh
33mWh
120mWh
1275mWh
3.3v
5v
5v
3.3v
5v
Total
Budget
(Electronics/Software)
Item(s)
Status
Price
Arcturus Networks Coldfire 5272 uCdimm dev kit
Parallax Stamp BS2's and dev kits
1mW Laser, single line head, bandpass filter
Lynxmotion servo pan/tilt kit
Parallax servo contoller
Stamp AppMod Digital Compass
TrendNet TV-PC301 USB Cams (OV511+, OV7620)
DS1620 Digital Thermometers
Memsic 2125 accelerometer/tilt sensor
Pololu micro dual motor controllers
Reed relays, switching transistors, resistors
LCD 2x16 Serial
Garmin OEM GPS, Antenna
Transdimension EVB243, host controller software
USB Compact Flash Reader, 128Mb Compact Flash, USB Hubs
Have it
Have it
Have it
Have it
Have it
Have it
Ordered
Have it
Have it
Have it
Have it
1200
245
424
60
39
59
132
NC
NC
NC
NC
50
~175
~500
~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 Organization
Professor
Keith
Norwood
Don Grissom
Team Lead
Chassis
Imaging
Brian
Don
Chris
Carrier
Oscar
Leah
Walter
John
John
Walter
Matt
Leah
Brian
Don
Power
Oscar
Matt
Luke
Nathan
Chris
Amparo
Electronics
Luke
Nathan
Amparo
Budget
Expenses to date:
Beginning total
Carbon fiber materials
Camera
Motors/gearbox assy.
Wheel material
Machining tools
Carrier material
Misc. Material and Electronics
subtotal
Remaining Balance
$4000
$ 150
$ 800
$ 40
$ 100
$ 50
$ 30
$1800
$2970
$1030
Schedule
Construction Completed
Operational testing Completed
Final Construction Completed
Mission Readiness Review
Launch Readiness Review
Launch
June 15
July 20
July 30
July 30
Aug 6
Aug 7