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

Multidisciplinary Engineering Senior Design

Project 05400 Construction of 3-D Objects and Displays

using Swarms of Intelligent Microsystems

Preliminary Design ReviewMay 11, 2005

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

Project Introduction and History

Swarms of small, intelligent objects can form a large shape.

Future MEMS technology could make for microscopic robot.

Market

• Rapid-prototyping & Simulating

• 3D displays

• Advertising

Previous Work Inertial Drive

Does not work due to lack of static friction in fluid, and symmetric design.

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

Timing Diagram

N S E W F B N S E W F B W

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

Wake Up Signal Post Wake Up Delay Sleep Timer Running

North AC Signal Asserts Interrupt,

Begin GETAC routineDELD2 used here

DELAC used hereDELDC used here

600ms 2000ms 1200ms 1000ms

DELD2 used here

Proteus 1BDemonstration Video

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

Critical Parameters-----------------ENGINEERING CHARACTERISTICS-------------------

Chunxil Redesign Rev1C RE

LA

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MP

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NC

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Bat

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Siz

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Bat

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Life

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Tim

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Max

imum

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Cur

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Dim

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CUSTOMER REQUIREMENTS mm mAhV hr mA mm mA V Hz bits mm GaugemA turns mm GaugemA turnsin in degrees1 Run Time 6 10 6 4 6 6 102 Speed 4 3 8 8 8 3 8 8 8 7 73 Reliability and Control 10 3 3 4 8 5 5 7 9 8 2 104 Small Chunxil Size ( < 1") 8 7 7 8 8 105 Large Tank Size 4 8 106 Chunxil can move in three dimensions2 8 9 107 System Operation Power Usage 3 2 2 108 Safe to operate 4 3 8 9 79 Chunxil is easily visible 8 10 7 7 5 4

10 Nesting of Multiple Chunxils 2 10 511 Sustainability/Upgradability 10 8 8 10 5 9

ABSOLUTE IMPORTANCE 56 170 42 86 54 56 36 36 56 98 100 62 146 12 92 96 82 234 88 98 32 124 100 178 170 150RELATIVE IMPORTANCE 0.2 0.7 0.2 0.4 0.2 0.2 0.2 0.2 0.2 0.4 0.4 0.3 0.6 0.1 0.4 0.4 0.4 1 0.4 0.4 0.1 0.5 0.4 0.8 0.7 0.6

* 10 = ABSOLUTELY ESSENTIAL, 7 = VERY IMPORTANT, 5 = MODERATLY IMPORTANT, 3 = NOT VERY IMPORTANT, 1 = UNIMPORTANT

** 10 = CR DRIVEN BY THIS PARAMETER, 5 = CR MODERATELY INFLUENCED BY THIS PARAMETER, 1 = CR NOT SIGNIFICANTLY INFLUENCED BY THIS PARAMETER

RequirementsHigh-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.

RequirementsMotion •        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. DistributionThe 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.

RequirementsPower • 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.

RequirementsSafety • 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.

Project Timeline SD1

Project Timeline Summer

Project Timeline SD2

Our Proposal

Analysis, Improvements, & Ideas to Control The Chunxil

-3/2 0 N1 N2 I1 I2 R12 A2 z

Force = --------------------------------- (R1

2 + z2)5/2

X

Y

Z

External coil

Internal coil

  With: R1 = radius of the external coilR2 = radius of internal coilN1 = Number of turns of the external coilN2 = Number of turns of the internal coil

And the distance X, Y and Z:             

dt

di

XRZYX

XRRNN

emf *)(2

)(******

2/3221

222

22

22

1210

 

Force Equations

Stabilization of Chunxil Axes

1) Widen Tank CoilsAdvantages:

Straighten Field Lines Inside Tank.

Increase Visibility

Disadvantages:

Physical Modification of Tank

Invalidate Past EMF Values

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

1 Coil Chunxil Model

2 Coil Chunxil Model

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

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

Stabilization of Chunxil AxesFeasibility Assessment

Stabilization of Chunxil AxesHybrid Model

Movement Cycle External InternalE W E W

West to East - West Side of Tank 1a + On On1b + - Off Off

West to East - East Side of Tank 1a + On On1b + - On On

+ = “Pulls Toward”

- = “ Pushes Away”

Velocity Control

• Increase Tank Coil Diameters

• Decrease Current

• Lessen # of Turns on Coil

• Pulse Coils

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.

Battery Feasibility AssessmentEvaluate each additional concept

againstthe baseline, score each attribute as:

1 = much worse than baseline concept2 = worse than baseline3 = same as baseline4 = better than baseline5 = much better than baseline

[Presumed][Presumed]SanyoSanyo

CR-1/3NCR-1/3N LIR2032LIR2032 LIR2430LIR2430 LIR2450LIR2450 LIR2477LIR2477   

Rela

tive W

eig

ht

Rela

tive W

eig

ht

Weight / Mass (grams)Weight / Mass (grams) 3.0 3 2 1 1   14%

Size (mm)Size (mm) 3.0 5 4 3 1   25%

Voltage (v)Voltage (v) 3.0 4 4 4 4   11%

Normal Capacity (mAh)Normal Capacity (mAh) 3.0 1 1 2 3   18%

Max. Discharge rate [continuous] (mA)Max. Discharge rate [continuous] (mA) 3.0 4 4 5 5   21%

Internal Impedance (ohms)Internal Impedance (ohms) 3.0 4 4 5 5   0%

Average Lifespan (cycles)Average Lifespan (cycles) 3.0 3 3 3 3   4%

Price ($)Price ($) 3.0 5 5 5 4   7%

             

Weighted ScoreWeighted Score 3.0 3.6 3.2 3.2 2.8

Normalized ScoreNormalized Score 83.2% 100.0% 89.1% 89.1% 78.2%

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

Overall re-designed circuit

Re-Designed Op-Amp circuit

Other Improvements

Coil Control Circuit

PIC Choices

Desired Traits:

•Reprogrammable

•Low Power

•Backward compatible with current code

•High Resolution A-D Converter

•Programmable in-circuit

PIC Feasibility AssessmentEvaluate each additional concept against

the baseline, score each attribute as: 1

= much worse than baseline concept 2 =

worse than baseline 3 = same as

baseline 4 = better than baseline 5=

much better than baseline

Cur

rent

( P

IC16

C17

6)

PIC 1

6F819

Pic

16F88

Pic

18F13

20

TI

MS

P430F11

3

Rel

ativ

e W

eigh

t

Suffi cient Student Skills? 3.0 3.0 3.0 3.0 1.0 2%

Size/ Weight/ Nano-Feasibility 3.0 3.0 3.0 2.0 1.0 13%

Cost of Chips 3.0 3.0 3.0 2.0 3.0 8%

Cost of Programmer,Burner, and Sof tware 3.0 3.0 3.0 3.0 1.0 3%

Compatible I SA 3.0 2.0 2.0 1.0 1.0 10%

Compatible Pin Layout/ Voltages 3.0 2.0 2.0 2.0 1.0 5%

Memory (Flash, Ram) 3.0 4.0 5.0 5.0 5.0 13%

Program in-circuit 3.0 5.0 5.0 5.0 5.0 12%

Suffi cient bit-ADC 3.0 4.0 4.0 4.0 4.0 18%

Power Usage 3.0 5.0 5.0 4.0 1.0 15%

Hardware Multiplier 3.0 3.0 3.0 5.0 5.0 3%

Low-Power Programming 3.0 5.0 5.0 3.0 5.0 5%

Weighted Score 3.3 4.1 4.2 3.7 3.1

Normalized Score 77.7% 96.8% 100.0% 88.0% 74.9%

Chunxil Tank

Chunxil Axis Limiter

Chunxil Cube (Encasing)

Cube Feasibility Assessment*Evaluate each additional concept against

the baseline, score each attribute as: 1

= much worse than baseline concept 2 =

worse than baseline 3 = same as baseline

4 = better than baseline 5= much better

than baseline

Cur

rent

Chu

nxel

Cub

e (6

Sep

arat

e

Sid

es)

Prot

otyp

e 1:

Tw

o

shel

ls p

ut t

ogue

ther

Prot

otyp

e 2: U

se o

f

Exi

stin

g

Com

mer

cial

ly

Ava

ilable

1*1

*1 inc

h

Rel

ativ

e W

eigh

t

Chunxil Cube Size 3.0 1 5 25%

I nner Space for other components 3.0 2 4 21%

Waterproofi ng Capabilities 3.0 3 3 18%

Cost of Purchased Components? 3.0 4 2 4%

Ease of Assembly of a Full Chunxil

Everything I nside 3.0 2 4 7%

Modularity of Physical Parameter 3.0 3 3 7%

Nesting Ability 3.0 4 2 4%

Charging and Programming I nterface 3.0 5 1 14%

Weighted Score 3.0 2.6 3.4

Normalized Score 87.5% 75.0% 100.0%

Chunxil Cube Inner Assembly

Coil Winding

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.

Brief Summary

Questions?

Sneaker Slides

Spiral Development Model*

Wiki

•Online Collaboration

•Easy to edit

•Accessible from Anywhere

2 Coil Chunxil Model

INIT

RUN

calculate target differences

reset sleep timer

record NOIZ

wait for int, check flags

Power On

None

go flagsleep flag

interruptturn off a-d, etc

clear flagsenable ints,a-d,etcreset sleep timer

SLEEP

disable interrupts

wait for port b sig

meas VX,VY,VZcheck alignment

calc positon diffs

set move flagsif unaligned, set all move flags

set drive flags

stall .5 ac cycle

stall dc time

clear outputs++DCCNT

stall down time 2

re-enable interruptsclear flags

reset sleep timer

DCCNT==6?

drive flag,DCCNT==1?

stall down time

drive a coilyes

no

clr DCCNT

no

set SLP flag

save state

check source of interrupt

set GO flagdisable port b int

reset sleep timer

disable sleep timer

restore state

port b intothersleep timeout

interrupt GO FLGSLP FLG

Proteus Gen 1B Control Flow Chart

Proteus Gen 1B Communications Cycle

N S E W F B N S E W F B W

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

Wake Up Signal Post Wake Up Delay Sleep Timer Running

North AC Signal Asserts Interrupt,

Begin GETAC routineDELD2 used here

DELAC used hereDELDC used here

600ms 2000ms 1200ms 1000ms

DELD2 used here

Proteus Gen 1B Navigation ControlDifference = North Voltage – South Voltage

NO

RT

H C

OIL

SO

UT

H C

OIL

X Position

50mV

40mV

30mV

20mV

10mV

Target: Difference=30mV

D=20mV

D=0mV

D=40mV

D=30mV

Initial Battery saver circuit