Power Supply for a Remotely Operated Vehicle (May05-12) Team Members: Jonathan GettlerEE Tai OngEE Adam WhiteEE Wei YauEE Client:Scott Morgan Stealth ISR.

Power Supply for a Remotely Power Supply for a Remotely Operated Vehicle (May05-Operated Vehicle (May05-

12)12)Team Members: Team Members: Jonathan GettlerJonathan Gettler EEEE

Tai OngTai Ong EEEEAdam WhiteAdam White EEEEWei YauWei Yau EEEE

Client:Client: Scott MorganScott MorganStealth ISR EngineeringStealth ISR EngineeringSt. Paul, MinnesotaSt. Paul, Minnesota

Faculty Advisor: Faculty Advisor: Dr. Venkataramana AjjarapuDr. Venkataramana Ajjarapu

Date:Date: April 25April 25thth, 2005, 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

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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 DesignMechanical Design

Electrical DesignElectrical DesignStartStart End ProductEnd Product

List of Definitions

• AGM – Absorbed Glass Mat

• PWM – Pulse Width Modulation

• UAV – Unmanned Aerial Vehicle

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Acknowledgements

• Thanks to Dr. Ajjarapu for investing research dollars into SimPower.

• Thanks to Scott Morgan for the personal contributions to the project.

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Problem StatementProblem Statement• Alternative electronics onboard UAVsAlternative electronics onboard UAVs

• Increased power requirements stress the Increased power requirements stress the systemsystem

• Onboard batteries are overcharged and Onboard batteries are overcharged and overheatedoverheated

• Options for power supplies are limitedOptions for power supplies are limited

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Approach Statement

• Design a power supply for large electrical loads

• Power supply must be versatile

• Increase reliability and life of the batteries

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Operating EnvironmentOperating Environment

• Extreme temperatures• -37°F to 125°F

• Extreme vibration

• Shock

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Intended UsersIntended Users

• Remote control hobbyists

• Any person who wants to generate electricity

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IntendedIntended Uses Uses

• Provide electric power to remotely operated vehicles

• Transform rotating mechanical energy into electrical energy

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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

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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

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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

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End Product and Other Deliverables

• Prototype mobile power supply

• Test results

• Specifications manual

• Final design report

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Present Accomplishments

• Order Parts 100% (completed)

• Design 100% (completed)

• Research 100% (completed)

• Testing 80% (completed)

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Approaches Considered

• Three-phase generator • Provided by the client

• AC to DC rectifier• Two choices

• Construct from scratch– Six diodes

– Circuit board

– Labor cost

• Purchase off the shelf– Less cost

May05-12May05-12

Hobby AirplaneEngine

3 PhaseGenerator

3 PhaseRectifier

Boost VoltageRegulator

Battery Charger

BatteriesLoad12V Buck Regulator

5V Buck Regulator

3.3V Buck RegulatorLoad

Load

Approaches Considered

• DC to DC step-up converter• Switching voltage regulator

• Light

• Efficient

• Transformer• Heavy

• Frequency issues

• DC to DC step-up converter• Switching voltage regulator

• Light

• Efficient

• Transformer• Heavy

• Frequency issues

May05-12May05-12

Hobby AirplaneEngine

3 PhaseGenerator

3 PhaseRectifier

Boost VoltageRegulator

Battery Charger

BatteriesLoad12V Buck Regulator

5V Buck Regulator

3.3V Buck RegulatorLoad

Load

Approaches Considered

May05-12May05-12

• 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

Hobby AirplaneEngine

3 PhaseGenerator

3 PhaseRectifier

Boost VoltageRegulator

Battery Charger

BatteriesLoad12V Buck Regulator

5V Buck Regulator

3.3V Buck RegulatorLoad

Load

Approaches Considered

• Batteries• AGM lead acid

• 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

May05-12May05-12

Hobby AirplaneEngine

3 PhaseGenerator

3 PhaseRectifier

Boost VoltageRegulator

Battery Charger

BatteriesLoad12V Buck Regulator

5V Buck Regulator

3.3V Buck RegulatorLoad

Load

Project Definition ActivitiesProject Definition Activities

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• Used for small airplane

• Power on-board electronics

Research Activities• Project components

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Research Activities: Generator• Experimental setup

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Research Activities: Generator• Voltage vs. generator RPM curve with three phase

rectifier

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0

2

4

6

8

10

12

14

16

0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000

Source RPM

Vd

c

Research Activities: Step-up Converter

• Research components to use in building a step-up switching converter

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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

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Design Activities: Step-up Converter

• Initially selected components to use in a step-up switching converter

• TI, TL5001 PWM control circuit

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Design Activities: Step-up Converter

• Later purchased a step-up converter

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Design Activities: Battery Charger

• An evaluation kit in the prototype– Evaluation board needed special tweaking

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#3#4

#5

#1

#1

#2

Design Activities: Step-down Converter

• Client decided that only the 12V output was needed

• A 12V step-down regulator was purchased

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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

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Other Significant Project Activities

• Met with client in Eagan, MN

• Phone calls

• Sampled parts

• PSpice simulations of circuit components

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Personal EffortPersonal Effort

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Personnel Hours (Total of 934 Hours)

Gettler 240 25.7%

Ong 192 20.5%White 278 29.8%

Yau 224 24%

Gettler Ong White Yau

Resource Cost

May05-12May05-12

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

Total Project Cost

$61.32$61.32Battery charger

$91.80$91.80Batteries

$10053.36$433.16Totals

$9620.20$0.00Subtotal

$2307.20$0.00 Yau, Wei

$2863.40$0.00 White, Adam

$1977.60$0.00 Ong, Tai

$2472.00$0.00 Gettler, Jonathan

Labor ($10.30 per hour):

$433.16$433.16Subtotal

$100.00$100.00DC/DC boost converter

$30.04$30.04Rectifier/Booster parts

donated* (donated by client)Generator

Project Parts:

$50.00$50.00 Project Poster

Parts and Materials: With LaborWithout Labor

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12 volt regulator $100.00 $100.00

Project Task Schedule

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• Specification changesSpecification changes

• Additional lead time on partsAdditional lead time on parts

Project Evaluation

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# 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%

CommercializationCommercialization

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• Potential marketPotential market

• Remote control hobbyistsRemote control hobbyists

• Production cost $350Production cost $350

• Retail price $700Retail price $700

Recommendations for Future WorkRecommendations for Future Work

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• Complete testing Complete testing of battery charger

• Increase load handling capabilityIncrease load handling capability

• Size and weight reduction of prototypeSize and weight reduction of prototype

Lessons LearnedLessons Learned

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• Went wellWent well

• Team communicationTeam communication

• Vision of final productVision of final product

• Desire to finish projectDesire to finish project

• Did not go wellDid not go well

• Difference between experimental and Difference between experimental and expected results of testingexpected results of testing

• Lack of circuit fabrication experienceLack of circuit fabrication experience

• Often behind scheduleOften behind schedule

Lessons Learned• Technical knowledge gainedTechnical knowledge gained

• Electrical characteristics of motorsElectrical characteristics of motors

• Power electronics design and modelingPower electronics design and modeling

• Operation of a gas engine for UAVOperation of a gas engine for UAV

• Datasheet implementationDatasheet implementation

• Non-technical knowledge gainedNon-technical knowledge gained

• Public speechPublic speech

• Improved formal documentation and communication Improved formal documentation and communication skillsskills

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Lessons Learned

• What would be done differently

• Further define project specificationsFurther define project specifications

• More work in the beginning stagesMore work in the beginning stages

• Order parts soonerOrder parts sooner

• Clearly divide tasks among membersClearly divide tasks among members

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Risk and Risk ManagementRisk and Risk Management

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• Potential/Encountered risksPotential/Encountered risks

• Lead time on ordered partsLead time on ordered parts

• Loss of stored dataLoss of stored data

• Voltage drop when load is connectedVoltage drop when load is connected

• Management of risksManagement of risks

• Backup data on engineering storage driveBackup data on engineering storage drive

• Increase generator output by changing gear Increase generator output by changing gear ratio ratio

Closing SummaryClosing Summary

May05-12May05-12

• 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

Questions/Feedback?Questions/Feedback?

May05-12May05-12

Thanks for your time!