Team Lifted: Critical Design Review

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

2. Overview / Revised GoalsDan Crowe

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

4. 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

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

6. 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

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

8. 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

9. Hardware/Schematics Ryan Yeash

10. Hardware Block Diagram

12. ADC Conversion Circuit

13. RS232 Connection

14. JTAG Connection

15. Power Circuitry

16. Electromagnet Control

17. Electromagnet SpecificsSujan Gautam

18. 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 • 100-200 turns depending on field output

19. 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

20. Firmware SpecificsAnthony Schubert

21. 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

22. FPGA Configuration

23. 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

24. 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

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

26. Logistics and Administration Andrew Cober

27. Cost

28. Division of Labor R – Responsible and CI – Consult and Inform Everyone is informed when a task is completed or needs further assistance

29. Timeline Estimate

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

31. FPGA PCB Layout Rev. 1

32. 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

33. Questions ?

34. Extra Slides

35. 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

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

37. 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

38. NiosII Softcore

39. 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