Brian Saghy (CE) Team Leader & Programming Lead Alejandro Lam (EE) Integration Lead

1. Multidisciplinary Engineering Senior Design Project 05400 Construction of 3-D Objects and Displays using Swarms of Intelligent Microsystems Preliminary Design ReviewMay 11, 2005 Brian Saghy (CE) Team Leader & Programming Lead Alejandro Lam (EE) Integration Lead Nathan Pendleton (EE) Electronics Lead Brian Payant (EE) E&M Lead Gaurav Patel (ME) Mechanical Lead

2. Presentation Overview • Introduction • Past Work • Detailed Description Gen1b • Problems with Gen1b • Critical Parameters • Requirements • Project Plan • Redesign Concepts, Ideas, and Feasibility Assessments • Future Considerations • Summary • Questions

3. Project Introduction and History Swarms of small, intelligent objects can form a large shape. Future MEMS technology could make for microscopic robot.

4. Market Rapid-prototyping & Simulating 3D displays Advertising

5. Previous Work Inertial Drive Does not work due to lack of static friction in fluid, and symmetric design.

6. Previous WorkMagnetic Field Propulsion • Tank has six high power magnetic coils on each side • Chunxil drives itself by turning on internal coils to attract it to the desired wall • Chunxil is able to determine location in tank by the strength of the EMF fields induced by the external coils • Control Problems

7. Timing Diagram North AC Signal Asserts Interrupt, Begin GETAC routine DELD2 used here DELAC used here DELDC used here Wake Up Signal Post Wake Up Delay Sleep Timer Running N S E W F B N S E W F B W 600ms 2000ms 1200ms 1000ms DELD2 used here N S E W F B N N S E W F B B N S E W F B E N S E W F B S N S E W F B F N S E W F B N N S E

8. Proteus 1BDemonstration Video

9. Considerations and Objectives • Our main goal during this term is the control of the Chunxil • Secondary goals include assembly ease, modularity, programmability and charging ease. • Start with small steps, rather than trying to tackle the whole project at once. Start with 1 Dimension. • Utilize improvements over the last few years in microcontrollers and batteries

10. Critical Parameters

11. Requirements High-level Objectives • An small intelligent robot, called a Chunxil, shall be designed to navigate to a predetermined position within somewhere in a constrained 3-D space, most likely ocupied by a fluid. • As a method of control, only 1-dimensional positioning will be required for the scope of this project. • If One-Dimension is attained, then multiple dimensions will be explored, given appropriate amount of time. • The Chunxil should be designed with nano-technology limits in mind. Extra hardware should be avoided if possible, considering the possibility of placing the entire chunxil in a system-on-chip configuration for future generations. The less things used in the Chunxil, the more feasible it would be to get them to a very small size at a low production cost. Size and Shape a.Tank • The Tank size shall remain the same as before, a cube, 6"x6"x6" +- 0.5". b.Chunxil • The Chunxil's weight, height, nor depth shall excede 1" in dimension. • The Chunxil shall be a regular shape such that it can nest, or at least sit plush with another Chunxil. • The Chunxil enclosure should be designed for relatively easy replication, allowing for multiple Chunxils to be built for testing.

12. Requirements Motion • The first revision of this project shall be designed to limit the Chunxil to 1-dimension of motion. Should this task be accomplished, then more dimensions of freedom will be granted. • The values should be able to be programmed statically, meaning that each Chunxil is pre-programed with a pre-determined numeric set of data corresponding to a location in the tank. • The Chunxil shall be able to move to and maintain a position in within 1/4th of the measured diameter of the Chunxil from any starting position within the given working dimension. • Discrete positions shall be defined within the tank,with corresponding values that should be programmed in the Chunxil to achieve such positions. • In one dimension, tilt of axis (spinning and rotation) is not of concern. However, in two or more dimensions the angle of the chunxil from any wall of the tank shall not excede 10 degrees. Weight a. Distribution The center of mass of the Chunxil shall be +- 10% of the measured physical center. b. Density The Chunxil shall be neutrally bouyant, +- 10% of the density of the medium (liquid) in the tank.

13. Requirements Power • The minimum battery shall be defined as supplying enough energy for the Chunxil • to make 10 round trip cycles from extreme opposite corners of the tank. • The battery shall be rechargeable. • The battery must conform to the Chunxil Size and Weight requirements. • Recharging time should be under 5 hours. • Charging nor tank operation shall excede the wall power, voltage or current • specifications defined by RGE and safety regulations. Visibility • The medium (liquid) in the tank shall be transparent. • The sides of the tank shall be at least 80% visible, defined by surface area of visible • portion to non-visible portion.

14. Requirements Safety • All external wires on the tank shall be insulated. • Electrical components shall be isolated from the liquid medium. • Coil current should be within reasonable specifications for the given amount of time that they are powered. • No component shall excede temperature capable of burning human skin or starting fire. If such a component can occur, it shall be properly cooled and shielded. Modularity and Sustainability • The Chunxil shall be reprogrammible without replacing any physical parts. • The Chunxil should not have to be opened for programming, recharging the batteries, or connecting to a debugger. • Each Chunxil shall have a standard, compatible method to program, recharge, and debug so that the same programming and charging device can be used for all Chunxils.

15. Project Timeline SD1

16. Project Timeline Summer

17. Project Timeline SD2

18. Our Proposal Analysis, Improvements, & Ideas to Control The Chunxil

19. Force Equations Z Y X Internal coil External coil With: R1 = radius of the external coil R2 = radius of internal coil N1 = Number of turns of the external coil N2 = Number of turns of the internal coil And the distance X, Y and Z: -3/2 m0 N1 N2 I1 I2 R12 A2 z Force = --------------------------------- (R12 + z2)5/2

20. Stabilization of Chunxil Axes • Widen Tank Coils • Advantages: • Straighten Field Lines Inside Tank. • Increase Visibility • Disadvantages: • Physical Modification of Tank • Invalidate Past EMF Values

21. Stabilization of Chunxil Axes 2) Simultaneous Activation of Opposite Coils Inside Chunxil Advantages: Greater Resistance to Spin Opposing Field Directions on Opposite Chunxil Faces Disadvantages: Greater Power Consumption in Chunxil More Complex Circuitry More Complex Mathematical Model

22. 1 Coil Chunxil Model

23. 2 Coil Chunxil Model

24. Stabilization of Chunxil Axes 2) Simultaneous Activation of Opposite Coils Inside Chunxil Advantages: Greater Resistance to Spin Opposing Field Directions on Opposite Chunxil Faces Disadvantages: Greater Power Consumption in Chunxil More Complex Circuitry More Complex Mathematical Model

25. Stabilization of Chunxil Axes 3) Simultaneous Activation of Opposite Coils On Tank Advantages: Straightens Field Lines Inside Tank Disadvantages: Needs Two Coils Inside Coil Activated Greater Chance of Chunxil Spinning on “Pushing” Half of the Tank More Complex Tank Circuitry More Complex Mathematical Model

26. Stabilization of Chunxil AxesFeasibility Assessment

27. Stabilization of Chunxil AxesHybrid Model + = “Pulls Toward” - = “ Pushes Away”

28. Velocity Control • Increase Tank Coil Diameters • Decrease Current • Lessen # of Turns on Coil • Pulse Coils

29. Electronics Requirements • The electronics should not take up more than 50% of the volume of a 1” cube Chunxil.(Leaving 50% volume for the coils.) • Chunxils will be pre-programmed to a specific route, but must be easily reprogrammed. • The battery must be rechargeable, & able to recharge in less than 5 hours. • A Chunxil shall be recharged, reprogrammed & debugged without being disassembled. • All Chunxils must conform to a common interface standard, such that a universal reprogramming, recharging, and debugging method can easily be used for all Chunxils. • A Chunxil must be able to make 10 round trip cycles across the diagonal of the tank.

30. Battery Feasibility Assessment

31. Battery Specifications • LiR2032 Rechargeable Li-Ion coin cell • 3.7 V nominal voltage • 35mAh nominal capacity • 70mA Max. drain current • Dimensions: 20mm dia. * 3.2mm thick • Mass: 3.0 grams • Unit price: $1.26

32. Overall re-designed circuit

33. Re-Designed Op-Amp circuit

34. Other Improvements

35. Coil Control Circuit

36. PIC Choices • Desired Traits: • Reprogrammable • Low Power • Backward compatible with current code • High Resolution A-D Converter • Programmable in-circuit

37. PIC Feasibility Assessment

38. Chunxil Tank

39. Chunxil Axis Limiter

40. Chunxil Cube (Encasing)

41. Cube Feasibility Assessment*

42. Chunxil Cube Inner Assembly

43. Coil Winding

44. Future Implementations & Ideas • Recharging and Programming using only inductors (No physical Connection) • Wireless control of the Chunxil • Use of multicolor LED’s inside, for color replications. Will add realism to the shape formed • Making it smaller and smaller.. nanotechnology • “Freeze Mode” after Chunxils are all nested together.

45. Brief Summary

46. Questions?

47. Sneaker Slides

48. Spiral Development Model*

49. Wiki • Online Collaboration • Easy to edit • Accessible from Anywhere

50. 2 Coil Chunxil Model