Power Supply for a Remotely Operated Vehicle (May05-12) Team Members: Jonathan GettlerEE Tai OngEE Adam WhiteEE Wei YauEE Client:Scott Morgan Stealth ISR Engineering St. Paul, Minnesota Faculty Advisor: Dr. Venkataramana Ajjarapu Date:April 25 th, 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 5 th mechanical team was more successful than expected Loosens electrical design constraints Mechanical Design Electrical Design Start End Product

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 Alternative electronics onboard UAVs Increased power requirements stress the system Increased power requirements stress the system Onboard batteries are overcharged and overheated Onboard batteries are overcharged and overheated Options for power supplies are limited 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 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 100% (completed) Design100% (completed) Research100% (completed) Testing 80% (completed) May05-12

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 May05-12 Hobby Airplane Engine 3 Phase Generator 3 Phase Rectifier Boost Voltage Regulator Battery Charger Batteries Load 12V Buck Regulator 5V Buck Regulator 3.3V Buck Regulator 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 May05-12 Hobby Airplane Engine 3 Phase Generator 3 Phase Rectifier Boost Voltage Regulator Battery Charger Batteries Load 12V Buck Regulator 5V Buck Regulator 3.3V Buck Regulator Load

Approaches ConsideredMay05-12 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 Airplane Engine 3 Phase Generator 3 Phase Rectifier Boost Voltage Regulator Battery Charger Batteries Load 12V Buck Regulator 5V Buck Regulator 3.3V Buck Regulator 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 May05-12 Hobby Airplane Engine 3 Phase Generator 3 Phase Rectifier Boost Voltage Regulator Battery Charger Batteries Load 12V Buck Regulator 5V Buck Regulator 3.3V Buck Regulator Load

Project Definition Activities May05-12 Used for small airplane Power on-board electronics

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 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 May05-12 #3 #4 #5 #1 #2

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 May05-12

Resource Cost May05-12 ItemCost Poster$50.00 Rectifier/Booster parts$30.04 Battery charger$61.32 Batteries$91.80 DC/DC boost converter$ volt regulator$ Total$433.16

Total Project Cost $61.32 Battery charger $91.80 Batteries $ $433.16Totals $ $0.00Subtotal $ $0.00 Yau, Wei $ $0.00 White, Adam $ $0.00 Ong, Tai $ $0.00 Gettler, Jonathan Labor ($10.30 per hour): $ Subtotal $ DC/DC boost converter $30.04 Rectifier/Booster parts donated* (donated by client)Generator Project Parts: $50.00 Project Poster Parts and Materials:With LaborWithout Labor May volt regulator$100.00

Project Task ScheduleMay05-12 Specification changes Specification changes Additional lead time on parts Additional lead time on parts

Project Evaluation May05-12 #MilestoneCompletionRating 1Project definition100%14.28% 2Research and technology selection100%14.28% 3Design100%21.44% 4Implementation100%21.44% 5Testing80%14.28% 6Project reporting100%7.14% Overall97.14%

Commercialization May05-12 Potential market Potential market Remote control hobbyists Remote control hobbyists Production cost $350 Production cost $350 Retail price $700 Retail price $700

Recommendations for Future Work May05-12 Complete testing Complete testing of battery charger Increase load handling capability Increase load handling capability Size and weight reduction of prototype Size and weight reduction of prototype

Lessons Learned May05-12 Went well Team communication Team communication Vision of final product Vision of final product Desire to finish project Desire to finish project Did not go well Did not go well Difference between experimental and expected results of testing Difference between experimental and expected results of testing Lack of circuit fabrication experience Lack of circuit fabrication experience Often behind schedule Often behind schedule

Lessons Learned Technical knowledge gained Electrical characteristics of motors Electrical characteristics of motors Power electronics design and modeling Power electronics design and modeling Operation of a gas engine for UAV Operation of a gas engine for UAV Datasheet implementation Datasheet implementation Non-technical knowledge gained Non-technical knowledge gained Public speech Public speech Improved formal documentation and communication skills Improved formal documentation and communication skills May05-12

Lessons Learned What would be done differently Further define project specifications Further define project specifications More work in the beginning stages More work in the beginning stages Order parts sooner Order parts sooner Clearly divide tasks among members Clearly divide tasks among members May05-12

Risk and Risk Management May05-12 Potential/Encountered risks Lead time on ordered parts Lead time on ordered parts Loss of stored data Loss of stored data Voltage drop when load is connected Voltage drop when load is connected Management of risks Management of risks Backup data on engineering storage drive Backup data on engineering storage drive Increase generator output by changing gear ratio Increase generator output by changing gear ratio

Closing Summary May05-12 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? May05-12

Thanks for your time!