Magnetic Manipulator

Team 125

Chad Perkins (Spring Team Lead)John Olennikov(Web Master)

Ben YounceMarley Rutkowski(Fall Team Lead)

Professor Robert J. Albright (Faculty Advisor)Andy McConnell (Industry Advisor)

Meet Team 125!

What We Did...• Magnetic Levitation!

o Has been implemented with control interface that allows a user to raise and lower a neodymium magnet suspended below a solenoid

o The magnet can be suspended indefinitely

How We Did It...• Electromagnet controlled by a

microcomputer• 2 Hall sensors sense magnetic fields• Adjust electromagnetic strength

o Pulse width modulation (PWM) defines strength

o Power transistor turn power on/off at high frequency

• PID algorithm for control

State Machine (Arduino code)• This runs on the Arduino• Start at System Initialize• Calibrate Mode gets

necessary values• Idle Mode means the

solenoid is waiting for a magnet to come within range of the Hall sensors

State Machine (Arduino code)• PID Control Mode means

that the system is executing algorithm to levitate object in range• Off Mode means that the

magnet is too close and the solenoid shuts off• The lights on the top of

the Mag-Lev tell us what state it is in

Hardware Overview • Arduino

o Computer(GUI)

o Transistor Circuit

o System state LEDS

Hardware Overview • Electromagne

to Levitating

Objecto Bottom Hall

sensoro Top Hall

sensor

Hardware Overview • Hall

Processing Circuit o data to

Arduino• Enable switch

Computer/Graphical User Interface• Why a GUI?• Arduino can

levitate magnet without computer• Processing Code

o User Interfaceo Debugo Data Display

Computer/GUI – Functional vs OOP

Computer/GUI - Prototype• Text Fields• Buttons

Computer/GUI - Layout• Text Fields• Text

Input/Console• Buttons• Graph

Computer/GUI – Final Layout

Software Challenges • Analog to Digital Converter (ADC)

o Problems Unstable values analogRead() not fast enough

o Solution; average over space & time Moving Mean 8 timer triggered synchronous ADCs

• No support for Arduino Due, required reading CPU manual

Software Challenges• Pulse Width Modulation (PWM)

o Problems analogWrite()

• uncustomizable low frequency• not precise (only 256 values)

Software interrupt PWM• too much CPU load

o Solution Utilize Atmel PWM module

Challenges - Noise• Power Sources

o Filter Capacitors• Signal Wires

o Grounded Shield Wireso Lead Lengths

• Power Transistor Circuit Isolationo Separate, more Robust board

Challenges - Field Calculations• The magnetic field of the coil

o Educated “guesses”• Real Time measurements

o Second Hall Effect Sensoro New op amp circuit addition

ConclusionSuccess!• “Eyes were bigger than our

stomachs”• A few setbacks• Digital feedback control system

o PIDo PWM

• Interesting and Interactive GUISuccess!!!

That’s All, Folks!Questions?Questions?Questions?Questions?Questions?Questions?Questions?Questions?Questions?Questions?Questions?Questions?Questions?Questions?Questions?Questions?Questions?Questions?Questions?Questions?Questions? Questions? Questions?