Team Lifted: Critical Design Review Andrew Cober Dan Crowe Sujan Gautam Anthony Schubert Ryan Yeash

Overview / Revised Goals Dan Crowe

Overview Project Problems and Design Modifications Hardware/Schematics Electromagnet Construction Firmware/Software Logistics and Administration Questions

Project: Magnetic Control Use electromagnets to control the position of a magnetic object  Control x and y position Control object through a user interface  First approach: buttons  Second approach: touchscreen

Problems Encountered Power limitations Prefabricated Electromagnets have undesired design Iron core laminates disappointing Buck converters unable to source sufficient current

Design Modifications Control object on 2D surface Construct electromagnets powerful enough to meet specifications Use ferrite cores for lower core loss Implement H-bridge to divert current Control position of a magnetic object Apparatus made of plexiglass

Revised Goals Effectively control the object with 1cm accuracy in 2-D plane Touchscreen sensing  Touchscreen interface Object follows a user defined path

Revised Design Four electromagnets mounted on a platform Cyclone II FPGA used to control the current to the electromagnets through H- bridge Control based on position of the object  Touchscreen

Hardware/Schematics Ryan Yeash

Hardware Block Diagram

ADC Conversion Circuit

RS232 Connection

JTAG Connection

Power Circuitry

Electromagnet Control

Electromagnet Specifics Sujan Gautam

Electromagnets I-Core solenoid 3.5”x1”x1” Ferrite core for low power loss and high magnetic flux density 18 AWG wire to handle sufficient current and lower resistivity turns depending on field output

Some Calculations Length  3.5” Number of turns  100 DC current  5 A Relative permeability  200 B  0.5 Tesla This does not take into account the core and wire loss

Firmware Specifics Anthony Schubert

Some Altera Details HAL  Hardware Abstraction Layer  An API (Application Programming Interface) for use with Altera’s Nios II modules  Allows easy C programming Parallel I/O  General purpose interface for peripherals  Allows for many possible configurations

FPGA Configuration

Current Tasks Interrupt-driven user interface  Have been using HAL API to write interrupt handlers for button inputs  Will eventually use for user input SRAM  Configured Cyclone II on development board to use off-chip SDRAM  Would prefer to use off-chip SRAM Smaller but faster  Need off chip memory to use HAL Start processing ADC input

Controller Firmware Proportional Controller  Implemented through control of electromagnets with PWM Derivative Controller  Implemented by calculating the rate at which the object is moving Hence PD control

Software Flow Diagram Power on Initialize Hardware Activate Magnets Object Detected? Center Object Yes No Object Shifted? Yes No Start User Input User shift? Yes No Shutdown Sequence

Logistics and Administration Andrew Cober

Cost

Division of Labor Andrew Cober Dan Crowe Anthony Schubert Ryan Yeash Sujan Gautam MechanicalRCIRR PCBCIR Power Control RCIR System Modeling RCIRR Control Algorithm RRRCI FirmwareRRR R – Responsible and CI – Consult and Inform Everyone is informed when a task is completed or needs further assistance

Timeline Estimate

Milestones Completed  CDR: Obtained most parts, started development of software framework, FPGA PCB design completed

FPGA PCB Layout Rev. 1

Milestones Continued Still to come  M1: Simple one dimensional control and movement of object  M2: Control x and y coordinates of the object  Expo: Path control and completion of project

Questions ?

Extra Slides

Risks Power limitations into the magnets may limit object size Control complexity may be too difficult to implement May have to rescale from FPGA to MSP

Contingency Plans Use photo diodes rather than touchscreen for object position control

Possible Extensions Addition of LCD to display object data  Touchscreen for user control  Trackball control Wireless communication between apparatus and user interface Implement multi-core processing on Cyclone II

NiosII Softcore

FPGA Configuration Cyclone II FPGA  Nios II softcore processor  LCD controlled using FSM Receives commands and data from NIOS II via parallel I/O May switch to built-in LCD module  Parallel I/O for button inputs  JTAG module for programming/debug  SRAM/SDRAM controller