Transcript May 01 02 - Senior Design

Power Supply for a Remotely
Operated Vehicle (May05-12)
Team Members:
Jonathan Gettler
Tai Ong
Adam White
Wei Yau
EE
EE
EE
EE
Client:
Scott Morgan
Stealth ISR Engineering
St. Paul, Minnesota
Faculty Advisor:
Dr. Venkataramana Ajjarapu
Date:
April 25th, 2005
Presentation Outline
• Jonathan
• Introduction
• Assumptions and
Limitations
• End-Product
• Tai
• Team
Accomplishments
• Approaches and
Considerations
• Adam
• Research, Design
and Implementation
• Other Project
Activities
• Yau
• Resources &
Schedules
• Closing Materials
• Questions
May05-12
Project Introduction
• Remote control plane
hobbyists want on-board
electronics
• Existing power systems do not
meet the power requirements
• Design a power supply that
meets the new needs of
hobbyists
Project History Summary
• Mechanical and electrical projects in
parallel
• April 5th mechanical team was more
successful than expected
• Loosens electrical design constraints
Mechanical Design
Start
End Product
Electrical Design
List of Definitions
• AGM – Absorbed Glass Mat
• PWM – Pulse Width Modulation
• UAV – Unmanned Aerial Vehicle
May05-12
Acknowledgements
• Thanks to Dr. Ajjarapu for investing
research dollars into SimPower.
• Thanks to Scott Morgan for the personal
contributions to the project.
May05-12
Problem Statement
• Alternative electronics onboard UAVs
• Increased power requirements stress the
system
• Onboard batteries are overcharged and
overheated
• Options for power supplies are limited
May05-12
Approach Statement
• Design a power supply for large electrical
loads
• Power supply must be versatile
• Increase reliability and life of the batteries
May05-12
Operating Environment
• Extreme temperatures
• -37°F to 125°F
• Extreme vibration
• Shock
May05-12
Intended Users
• Remote control hobbyists
• Any person who wants to generate
electricity
May05-12
Intended Uses
• Provide electric power to remotely
operated vehicles
• Transform rotating mechanical energy
into electrical energy
May05-12
Assumptions
• The gasoline motor will
operate between 2,500 RPM
and 13,000 RPM
• Total load will not draw more
than 100 Watts
• Rectified generator output
voltage will be 3.5-13 Volts
DC
May05-12
Power Limitations
• Output
• 3.3 Volts (+.1/-.05V)
• 5 Volts (+.2/-.1V)
• 12 Volts (+.4/-.2V)
• Less than .05 Vrms noise in the output
• Batteries must supply the full load for 15
minutes without generator power
May05-12
Physical Limitations
•
•
•
•
The power supply shall be less than 2 pounds
Physical size shall be less than 6”x4”x1”
Emissions shall conform to MIL-STD-704C
Costs shall not exceed $500
May05-12
End Product and Other
Deliverables
•
•
•
•
Prototype mobile power supply
Test results
Specifications manual
Final design report
May05-12
Present Accomplishments
•
•
•
•
Order Parts
Design
Research
Testing
100% (completed)
100% (completed)
100% (completed)
80% (completed)
May05-12
Approaches Considered
Hobby Airplane
Engine
• Three-phase generator
• Provided by the client
3 Phase
Generator
Load
12V Buck
Regulator
3 Phase
Rectifier
Boost Voltage
Regulator
Battery
Charger
Load
5V Buck
Regulator
Batteries
Load
3.3V Buck
Regulator
• AC to DC rectifier
• Two choices
• Construct from scratch
– Six diodes
– Circuit board
– Labor cost
• Purchase off the shelf
– Less cost
May05-12
Approaches Considered
Hobby Airplane
Engine
3 Phase
Generator
Load
12V Buck
Regulator
3 Phase
Rectifier
Boost Voltage
Regulator
Battery
Charger
Load
5V Buck
Regulator
Batteries
Load
3.3V Buck
Regulator
• DC to DC step-up converter
• Switching voltage regulator
• Light
• Efficient
• Transformer
• Heavy
• Frequency issues
May05-12
Approaches Considered
Hobby Airplane
Engine
3 Phase
Generator
Load
12V Buck
Regulator
3 Phase
Rectifier
Boost Voltage
Regulator
Battery
Charger
Load
5V Buck
Regulator
Batteries
Load
3.3V Buck
Regulator
• Battery charger
• MAX1873TEE evaluation kit
• Meets all project requirements with an
upgrade
• Other
• No other chargers were capable of
handling current requirements within
design limitations
May05-12
Approaches Considered
Hobby Airplane
Engine
3 Phase
Generator
Load
• Batteries
12V Buck
Regulator
• AGM lead acid
3 Phase
Rectifier
Boost Voltage
Regulator
Battery
Charger
Load
5V Buck
Regulator
Batteries
Load
3.3V Buck
Regulator
• Heavy, not available in small sizes
• Nickel Cadmium/Nickel Metal Hydride
• Lower capacity than Lithium Ion
• Lithium Ion
• High capacity
• Used for high power applications
May05-12
Project Definition Activities
• Used for small airplane
• Power on-board electronics
May05-12
Research Activities
• Project components
May05-12
Research Activities: Generator
• Experimental setup
May05-12
Research Activities: Generator
• Voltage vs. generator RPM curve with three
phase rectifier
16
14
12
Vdc
10
8
6
4
2
0
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
20000
Source RPM
May05-12
Research Activities: Step-up
Converter
• Research components to use in building a
step-up switching converter
May05-12
Research Activities: Step-up
Converter
• Research commercially available step-up
switching converter
– After initially finding none that met the
project’s demands, one was stumbled upon
DCDC12/24/160 from Zahn Electronics
Research Activities: Batteries
and Charger
• Lithium Ion batteries to meet weight
and capacity requirements
• Maxim charger evaluation kit
Research Activities: Step-down
Converter
• Linear regulator
• Switching regulator
May05-12
Design Activities: Step-up
Converter
• Initially selected components to use in a step-up
switching converter
• TI, TL5001 PWM control circuit
May05-12
Design Activities: Step-up
Converter
• Later purchased a step-up converter
May05-12
Design Activities: Battery
Charger
• An evaluation kit in the prototype
– Evaluation board needed special tweaking
#1
#2
#5
#4
#1
#3
May05-12
Design Activities: Step-down
Converter
• Client decided that only the 12V output was
needed
• A 12V step-down regulator was purchased
May05-12
Testing and Modification Activities
• Tested Vout vs. RPM using a high-speed rotary tool
• Tested step-up voltage converter
• Unable to test battery charger due to shipping and
other supplier issues
• Tested ability of batteries to supply rated load
• Tested the step-down converter’s ability to power
12V load
May05-12
Other Significant Project Activities
•
•
•
•
Met with client in Eagan, MN
Phone calls
Sampled parts
PSpice simulations of circuit components
May05-12
Personal Effort
Personnel Hours (Total of 934 Hours)
Yau 224 24%
Gettler 240 25.7%
White 278 29.8%
Ong 192 20.5%
Gettler
Ong
White
Yau
May05-12
Resource Cost
Item
Cost
Poster
$50.00
Rectifier/Booster parts
$30.04
Battery charger
$61.32
Batteries
$91.80
DC/DC boost converter
$100.00
12 volt regulator
$100.00
Total
$433.16
May05-12
Total Project Cost
Parts and Materials:
Without Labor
With Labor
$50.00
$50.00
* (donated by client)
donated
Rectifier/Booster parts
$30.04
$30.04
Battery charger
$61.32
$61.32
Batteries
$91.80
$91.80
DC/DC boost converter
$100.00
$100.00
12 volt regulator
$100.00
$100.00
Subtotal
$433.16
$433.16
Gettler, Jonathan
$0.00
$2472.00
Ong, Tai
$0.00
$1977.60
White, Adam
$0.00
$2863.40
Yau, Wei
$0.00
$2307.20
$0.00
$9620.20
$433.16
$10053.36
Project Poster
Project Parts:
Generator
Labor ($10.30 per hour):
Subtotal
Totals
May05-12
Project Task Schedule
• Specification changes
• Additional lead time on parts
May05-12
Project Evaluation
#
Milestone
Completion
Rating
1
Project definition
100%
14.28%
2
Research and technology selection
100%
14.28%
3
Design
100%
21.44%
4
Implementation
100%
21.44%
5
Testing
80%
14.28%
6
Project reporting
100%
7.14%
Overall
97.14%
May05-12
Commercialization
• Potential market
• Remote control hobbyists
• Production cost $350
• Retail price $700
May05-12
Recommendations for Future Work
• Complete testing of battery charger
• Increase load handling capability
• Size and weight reduction of prototype
May05-12
Lessons Learned
• Went well
• Team communication
• Vision of final product
• Desire to finish project
• Did not go well
• Difference between experimental and
expected results of testing
• Lack of circuit fabrication experience
• Often behind schedule
May05-12
Lessons Learned
• Technical knowledge gained
• Electrical characteristics of motors
• Power electronics design and modeling
• Operation of a gas engine for UAV
• Datasheet implementation
• Non-technical knowledge gained
• Public speech
• Improved formal documentation and communication
skills
May05-12
Lessons Learned
• What would be done differently
• Further define project specifications
• More work in the beginning stages
• Order parts sooner
• Clearly divide tasks among members
May05-12
Risk and Risk Management
• Potential/Encountered risks
• Lead time on ordered parts
• Loss of stored data
• Voltage drop when load is connected
• Management of risks
• Backup data on engineering storage drive
• Increase generator output by changing gear
ratio
May05-12
Closing Summary
• Cascading system: generator, rectifier, booster,
charger, batteries, and regulator.
• Provide required 12 volts and 75 watts at output
• An easy to install and use add-on for remotely
operated vehicles that require on-board power
electronics
• Upgrade UAV’s power capabilities, ground/air
constant power source
May05-12
Questions/Feedback?
May05-12
Thanks for your time!