electromechanics: integrating 19 th century theory with 21 st century technology – applications to...

Electromechanics: Integrating 19th Century Theory with 21st Century Technology – Applications to Aerospace Systems

Gregory D. BucknerAssistant Professor

Department of Mechanical

and Aerospace Engineering

September 4, 2003

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PRESENTATION OVERVIEW

• Electromechanics– What is Electromechanics?– Bridging 19th Century Theory with 21st Century

Technology

• Electromechanics Research at NCSU– EM Research Laboratory

– Active Magnetic Bearings

– Automated Chatter Prediction on HSM Centers

– Semi-Active Vehicle Suspensions

– Other Projects

• Conclusions

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WHAT IS ELECTROMECHANICS?

• Electromechanics explores the interactions of electric and magnetic fields (electromagnetism) and how these interactions can be harnessed to produce mechanical work

– An inherently multi-disciplinary engineering field

– The design, analysis, and control of electric machines:

Electrica lSystem

M agneticF ie ld

M echanicalSystem

Electrica l Losses(Coil Resistance)

M echanical Losses(S lid ing Friction)RV BF

i,e v,f

Electrica lInput/O utput

i,V

M echanicalO utput/Input

v,F

Lossless

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• Electromechanics is a “mature” engineering discipline

– Principles unchanged since the 19th century (Maxwell’s equations)

– The design of many industrial machines (motors, generators) has changed little in the past 25 years

– Once a core component of the Electrical Engineering curriculum, now few engineering undergraduates are exposed


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• Electromechanics Mechatronics (though the two are highly related and complimentary)


Electro-Mechanics

Electrical andComputer

Engineering

Mechanical andAerospace

Engineering

Computer andInformation

Science

Mecha-Tronics

ElectricalComputing

MechanicalComputing

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• Recent advancements in technology have renewed interest and extended applications

– Materials• High-energy permanent magnets• “Smart materials” – SMAs, MR fluids, magnetostrictives, etc.• Superconductors, hi-mu alloys

– Manufacturing Processes• Precision machining – DTMs, ultramills• MEMS fabrication - silicon micromachining, LIGA, etc.

– Computational Advancements• Microcontrollers• Design software – FEA, BEM• Simulation software – MATLAB, Simulink • Control algorithms – adaptive and intelligent control

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ELECTROMECHANICS RESEARCH AT NCSU

• Electro-Mechanics Research Lab (EMRL)

– Research focus: development and transfer of enabling technologies (a bridge between 19th century theory and 21st century technology)

– Over $1.2M in research grants • $725K federal: NSF CISE, NSF DMII, NASA NIA, DOE NNP• $450K industrial: Ethicon (J&J), Gillette, Vulcancraft, Carrera, AO

Smith, Hyster/Yale• $35K non-profit: Doris Duke, NCIIA

– Supported 26 student researchers• 6 PhD (4 current)• 11 Masters (2 current)• 9 Undergraduate (2 current)

– Resulted in 21 papers, 5 patent disclosures

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• Intelligent Controllers for Active Magnetic Bearings

– Sponsor: NSF (CISE)

– Research Objective: Develop self-learning (“intelligent”) AMB controllers that will enable the development of practical flywheel battery systems for automotive and aerospace applications


NASA Graphics from website GDB 090403-8



– Motivation: Flywheels for space applications

• Motor when solar panels are active

• Generate when panels are inactive

• AMBs provide non-contacting support, reduce friction and wear, and eliminate lubrication concerns

• Have higher power and energy densities than batteries

• Longer life!

– CONs• AMBs are inherently unstable, highly nonlinear

• Gyroscopic and bending effects, model uncertainty

NASA Graphics from website

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– Approach:

• Artificial neural networks are used to characterize (“learn”) model uncertainty

• These intelligent uncertainty bounds are fused with robust control synthesis

• Resulting controller adapts for improved performance, responds to parameter variations

• This fusion of intelligent and robust control is both innovative and applicable to a wide range of problems

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• Intelligent Controllers for Active Magnetic Bearings– Results:

• This intelligent approach has been successfully applied to single-input, single-output magnetic bearings

• Application to a 5-axis, flexible rotor AMB test rig is underway

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• Integrated Chatter Prediction on High Speed Machining Centers– Sponsor: Vulcancraft, Inc.

– Research Objectives:

• Increase High Speed Machining (HSM) productivity by predicting the onset of regenerative chatter on milling centers

• Design non-contacting EM actuators, sensors, and algorithms for modal testing of HSM centers


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Boeing Graphics from website

• Integrated Chatter Prediction on High Speed Machining Centers

– Motivation:

• HSM advantages:– Very high material removal rates (MRR) in aluminum– Tooth passing frequency approaches or exceeds first natural

frequency – Parts simultaneously lighter, stronger, cheaper– Embraced by aircraft industry

• HSM disadvantages:– Limited by unstable self-induced vibration… ‘regenerative chatter’– Poor part surface finish– Tool wear/breakage


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– Approach:

• Develop non-contating EM actuator, tool, displacement sensor

• Use modal testing to identify the combined tool/toolholder/spindle dynamics

• Use RCSA to identify the toolholder/spindle dynamics

• Combined response for any tool can be computed


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– Results:

• Developed non-contacting EM actuator, displacement sensor, tool

• Currently validating RCSA to identify toolholder/spindle dynamics


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• Optimization and Control of MR Dampers for Semi-Active Vehicle Suspensions

– Sponsor: Carrera, Inc. (Atlanta)

– Research Objectives:

• optimize the electromechanics of a commercial semi-active shock absorber

• develop and demonstrate real-time actuation and control to improve ride quality and vehicle handling


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• Optimization and Control of MR Dampers for Semi-Active Vehicle Suspensions– Motivation:

• Ride quality and vehicle handling represent design tradeoffs

• Off-road suspensions require large displacements, peak forces

• Active vehicles suspensions are COMPLEX, expensive, durability is questionable

• Semi-active suspensions, particularly MR dampers, have fewer moving parts, are cheaper, more durable


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• Optimization and Control of MR Dampers for Semi-Active Vehicle Suspensions

– Results:• Carrera’s Magneshock was redesigned

using FEA for optimal EM performance

• Efficiency, damping characteristics were significantly improved

• FL controllers were developed and demonstrated on a vehicle equipped with Magneshocks

• Ride quality was significantly improved vs. passive shocks


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• Other Ongoing Research Projects

– AMBs for Tool Deflection Compensation in Precision Milling Operations

• Sponsor: NSF (DMII)

• Co-I: Dr. Tom Dow, NCSU Precision Engineering Center

– Development of a Low-Frequency MEMS Vibration Sensor

• Sponsor: DOE (NNP Fellowship)

• Collaborator: Dr. Angus Kingon, NCSU Thin Films Lab


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• Other Ongoing Research Projects

– Reliability Analysis and Life Prediction of Aircraft Structures

• Sponsor: NASA (NIA)

• Co-I: Dr. Mohammad Noori, NCSU MAE

– Technology Development for Robot-Assisted Cardiac Surgery

• Sponsor: CardioVations (J&J)

• Collaborator: Dr. Randolph Chitwood, ECU Brody School of Medicine


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• Conclusions

– Electromechanics research at NCSU focuses on the development and transfer of enabling technologies (a bridge between 19th century theory and 21st century technology)

– A broad range of research projects are underway, funded by federal agencies and industries and conducted at the EMRL

– Aerospace applications are obvious in many of these projects

– Ideas for specific NIA projects are being explored


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electromechanics: integrating 19 th century theory with 21 st century technology – applications to...

Documents

electromechanics mechatronics

research grants

intelligent control

th century theory

website gdb

aerospace engineering

nsf cise research objective

intelligent controllers