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 strengtho Pulse width modulation (PWM)

defines strengtho 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

• Arduinoo Computer(GUI

)o Transistor

Circuito System state

LEDS

Hardware Overview

• Electromagneto 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 Codeo User Interfaceo Debugo Data Display

Computer/GUI - Functional vs OOP

• Why OOP over functional programming?o Contained

variables (avoid conflicts)

o Blueprintso Hierarchy

Computer/GUI – Functional vs OOP

Computer/GUI – Humble Beginnings

• 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 Sourceso Filter Capacitors

• Signal Wireso Grounded Shield Wireso Lead Lengths

• Power Transistor Circuit Isolationo Separate, more Robust board

Challenges - Field Calculations

• The magnetic field of the coilo Educated “guesses”

• Real Time measurementso Second Hall Effect Sensoro New op amp circuit addition

Conclusion

Success!

• “Eyes were bigger than our stomachs”

• A few setbacks

• Digital feedback control systemo PIDo PWM

• Interesting and Interactive GUI

Success!!!

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?