Mars Rover

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Mars Rover

• By
• Colin Shea
• Dan Dunn
• Eric Spiller

Advisors Dr. Huggins, Dr. Malinowski
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Outline

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

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Project 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.

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Previous 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

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Division 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

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Functional Description
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Functional 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.

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Functional 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

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Functional Description
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System Block Diagram
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Software Flow Chart

• High Level Software
• Rover Control

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Software Flow Chart

• High Level Software
• Image Retrieval/Display

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Software Flow Chart

• Low Level Software
• Motor Control

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Software Flow Chart

• Low Level Software
• Object Detection

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Software Flow Chart

• Low Level Software
• Battery Voltage Level

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Data Sheet

• Specifications
• Turning accuracy - 5 for an individual turn
  command
• Turning resolution - 15
• Driving accuracy - 5cm and 2 for a 100cm
  command
• Camera capture speed 5 frames/sec _at_ 324x288
  resolution for a 10BaseT connection
• Weight 33lbs
• Battery life 7 days without a recharge
• Top speed 10cm/s
• Battery charge level accuracy - 5
• Acoustic sensors
• Time between transmit signals 1 second
• Farthest object detection 200cm
• Closest object detection 5cm

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Data Sheet

• PC104
• Max Current, during boot 1.5A
• Normal operating current .8A
• Sleep mode current .026A
• Processor National Semiconductor Geode
  Processor _at_ 300MHz
• RAM 128MB
• Video Onboard Video card
• PCMCIA module
• Current - .07A
• Wireless Card
• Linksys WPC11
• Max Current - .3A
• Current in Sleep mode - .02A
• Hard Drive
• IBM Travelstar 2.5 inch IDE hard drive, 10GB
• Max Current - .94A (Spin-up Current)
• Current in Sleep Mode - .02A
• Camera
• Logitech USB Webcam

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Power Calculations

• Power Consumption for Sleep Mode
• PC104 computer .026A
• PC104 PCMCIA module .07A
• IDE Laptop Hard drive .015A
• PCMCIA Wireless Card .009A
• EMAC .045A
• _____
• Total .165A
• 24hrs 7days 168hrs
• 168hrs .165A 27.72 Ah _at_ 5V
• 27.72Ah 5V 138.6Wh
• Using 3 - 12 Volt, 7.2Ah batteries
• 12V 7.2Ah 3 259.2 Wh available

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Power Calculations

• Power Consumption for User Mode
• PC104 computer .800A
• PC104 PCMCIA module .070A
• IDE Laptop Hard drive .400A
• PCMCIA Wireless Card .285A
• EMAC .045A
• Camera .100A
• 2 DevanTech SRF04 .060A
• ______
• Total 1.760A

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Power 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, then
• 168 hrs 4.1 6.88hrs of battery life
  dedicated to User Mode

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Parts and Price List
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Design 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

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Design 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)

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Schedule
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Progress Flow Chart
Green Developed
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Results

• H-bridges introduced noise to the system

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Future Revisions

• Replace H-Bridge with Power Amp / Switching
  Circuit

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Mars Rover
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Mars Rover
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Questions and Answers