Review of Previous Work

Mars Rover

• By:

• Colin Shea

• Dan Dunn

• Eric Spiller

Outline

• Project Summary

• Review of Previous Work

• Patents

• Project Description

• Data Sheet

• Equipment and Parts

• Preliminary Research

• Schedule

• Division of Labor

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 PC104 to control the interface among the user and the Rover and high level software.

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

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

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

Patents

• The following patents were collected from the United States Patent and Trademark Office searchable on-line database using the keywords wireless, network, 802.11, web, camera, USB camera, PCMCIA, and hard disk

• 6,484,029 Apparatus and methods for adapting mobile unit to wireless LAN
• 6,453,159 Multi-level encryption system for wireless network
• 6,486,832 Direction-agile antenna system for wireless communications
• 6,434,132 Wireless LAN for reestablishing wireless links between hosts according to monitored

Patents

• 5,982,807 High data rate spread spectrum transceiver and associated methods
• 6,005,613 Multi-mode digital camera with computer interface using data packets
• 6,484,308 System and method for ensuring data integrity on a removable hard drive
• 6,292,863 PC card
• 6,336,142 Methods and apparatus for downloading data between an information processing device and an external device via a wireless communications technique
• 5,619,396 Modular PCMCIA card
• 5,231,693 Telerobotics

Standards

• Internet Standards

• Most internet standards are documented in Internet Request For Comments which are indexed at Ohio State University. Java is trademarked by Sun Computer Systems.

• RFC 791 - Internet Protocol (IP)
• RFC 793 - Transmission Control Protocol (TCP)
• RFC 826 - An Ethernet Address Resolution Protocol (ARP)
• RFC 893 - Internet Protocol on Ethernet Networks
• RFC 1866 - Hypertext Markup Language (HTML/2.0)
• RFC 1945 - Hypertext Transfer Protocol (HTTP/1.0)

• USB Standard is found from USB.org, the document is part of a zip file that also includes information on the newest standard USB 2.0.

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.

Functional Description

• Low battery mode –
• Battery drops below 10% of charge
• Email sent to Dr. Malinowski requesting a charge
• Rover shuts down all components.
• Charge mode –
• Rover continues to charge until power button is pressed
• Stays in this mode until battery level reaches 100%
• User mode –
• All Systems powered
• Distance and Direction Control
• Web Page accessible to user
• Image capture and display
• Battery Status is Monitored

Functional Description

System Block Diagram

Software Flow Chart

• High Level Software

• Rover Control

Software Flow Chart

• High Level Software

• Image Retrieval/Display

Software Flow Chart

• Low Level Software

• Motor Control

Software Flow Chart

• Low Level Software

• Object Detection

Software Flow Chart

• Low Level Software

• Battery Voltage Level

Preliminary Research

• Hard drives –

• Standard IDE

• Large power consumption

• Flash Card

• Very small power consumption

• Not large enough to run Linux

• PCMCIA

• Good power consumption

• Large enough to run Linux

Preliminary Research

• Wireless Cards –

• Dell Truemobile

• Lowest power consumption

• Not compatible with Linux

• Linksys

• Good power consumption

• Compatible with Linux

• Cisco

• Higher power consumption

• Compatible with Linux

Preliminary Research

• Computer Platform

• Format

• PC/104

• PC/104+

• SBC

• Processors

• Intel PIII ULV

• Transmeta Crusoe Processor

• National Semiconductor Geode Processor

• Boot Options

• Disk-on-Chip

• USB

• Floppy

• Expansion Options

• PCMCIA

• Serial

Preliminary Research

• Format Differences:

• PC/104 – Based on a ISA bus expansion – supports 8bit and 16bit devices

• PC/104+ Based on a PCI bus expansion – supports 16bit and 32bit devices

• SBC – has no bus expansion, usually

Preliminary Research

• Processors:

• Intel power

• highest power in sleep mode >1.0watts

• Transmeta Crusoe power

• lowest power in sleep mode <.05 Watts

• National Semiconductor power

• second lowest >.05Watts

• Speed:

• Intel – 450Mhz-1.0Ghz

• Transmeta 300Mhz – 700Mhz

• National Semiconductor 200Mhz – 333Mhz

Preliminary Research

• Battery Report:

• A battery with the highest amp hours and lowest weight must be selected
• After a meeting with the project advisors, the decision was made to use a 12V battery supply, primarily, the batteries used in the Robotic Platform Design.
• Trickle charge applies a continuous constant low current to maintain charge
• A deep discharge will shorten the life and partial discharges will extend life.

Preliminary Research

• DC Motor Report:

• Researched a 5V motor, but later the decision was made to use a 12V motor .
• Pittman motors will be used for the Mars Rover.
• major factor in determining which motor that will be used is the value of the load current.

Power Calculations

• Power Consumption for Sleep Mode:

• PC104 computer .026A

• PC104 PCMCIA module .07A

• PCMCIA Hard drive .015A

• PCMCIA Wireless Card .009A

• EMAC .045A

• + _____

• Total .165A

• 24hrs * 7days = 168hrs

• 168hrs * .165A = 27.72 Ah @ 5V

• 27.72Ah * 5V = 138.6Wh

• Using 2 - 12 Volt, 7.2Ah batteries:

• 12V * 7.2Ah * 2 = 172.8Wh available

Power Calculations

• Power Consumption for User Mode:

• PC104 computer .8A

• PC104 PCMCIA module .07A

• PCMCIA Hard drive .4A

• PCMCIA Wireless Card .285A

• EMAC .045A

• Camera .1A

• 2 Polaroid Ultrasonic 6500 .2066A

• + ______

• Total 1.9066A

Power Calculations

• Pittman GM9236 motors:

• Total with motors 1.9066A + 16.9A * 2 = 35.7A

• User is connected 3% of the time (or 5 hrs out of a week), then power consumption is as follows:

• (1.9066A * 3% + .165A * 97%) * 168 * 5V= 182.48Wh without motors

• ((33.8A*12V+1.9066A*5V)*3% + .165A*97%*5V)*168hrs = 2226.7Wh

• With Pittman GM9X12 motors which pull 4.56A @ 12V:

• ((9.12A*12V+1.9066A*5V)*3%+.165A*97%*5V)*168hrs =726.8Wh

• To meet the requirements to run for 7 days without a recharge using 2 – 12V @ 7.2Ah batteries, the user would only be able to run the rover for 1.5hrs a week

• ((9.12A*12V+1.9066A*5V)*.9%+.165A*99.1%*5V)*168hrs =179.1Wh

Data Sheet

• Specifications

• Turning accuracy - ± 5° for an individual turn command

• Driving accuracy - ± 5cm and ± 2° for a 100cm command

• Camera capture speed – 5 frames/sec @ 324x288 resolution for a 10BaseT connection

• Weight – ~28lbs

• Battery life – 7 days without a recharge if user connects <= 1.5 hours a week

• Top speed – 10cm/s

• Speed range – 1 cm/s to 10 cm/s

• Acoustic sensors –

• Time between transmit signals – 10 seconds

• Farthest object detection – 200cm

• Closest object detection – 50cm

Data Sheet

• Motors –

• Model number – GM9X12

• Gearing – 1:65.5

• Max current – 4.56A

• Voltage – 12V

• Wheel Sensors –

• Output – TTL

• Pulses per revolution of shaft – 512

• Voltage required – 5V

• Battery charge level accuracy - ± 5%

• Wireless protocol – 802.11b

• Dimensions – 31.4cm x 46.4cm x 21cm (L x W x H)

• Battery – 2 - 12V @ 7.2Ah

• Wheels – 5cm x 16cm (Width x Diameter)

Parts and Price List

Division of Labor

• Dan Dunn Colin Shea Eric Spiller

• Assembly Code Java Hardware

• - Motor Speed - Image Capture - DC Motors

• - Wheel Sensors - Rover Controls - Platform Construction

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

• -Serial Connection

• -Acoustics Sensors

• Linux Linux Linux

Questions and Answers