Practical structural design and control for digital clay
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PhD Defense Presentation. Practical Structural Design and Control for Digital Clay. Haihong Zhu. Woodruff School of Mechanical Engineering Georgia Institute of Technology. www.imdl.gatech.edu/haihong. PhD Reading Committee Members. Dr. Wayne J. Book, Chair, Advisor, ME

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Practical structural design and control for digital clay

PhD Defense Presentation

Practical Structural Design and Control for Digital Clay

Haihong Zhu

Woodruff School of Mechanical Engineering

Georgia Institute of Technology

www.imdl.gatech.edu/haihong


Phd reading committee members

PhD Reading Committee Members

  • Dr. Wayne J. Book, Chair, Advisor, ME

  • Dr. Imme Ebert-Uphoff, ME

  • Dr. Mark Allen, ECE

  • Dr. David Rosen, ME

  • Dr. Jarek Rossignac, COC


Outline of this presentation

Outline of This Presentation

  • Introduction to Digital Clay

  • Cell of Digital Clay

  • Cell array of Digital Clay

  • Implementations of the multi-cell system

  • Conclusions and recommendations

  • Basic idea

  • Background & context

  • Hardware of Digital Clay

  • Control of Digital Clay

  • Advantages and potential applications

  • Overview & objectives

  • Cell level control

    • Control methods

    • Control states, switching logic and user gesture interpretation

    • Experimental system & results

  • Displacement measurement

    • PWM speed control and displacement estimation

    • Non-contacting resistance displacement sensor

    • Displacement sensor embedded micro actuator

  • 1x5 prototype

  • Summary

  • Overview & objectives

  • “N2 by 2N” fluidic matrix drive

  • Surface refresh methods for the fluidic matrix drive

  • Control architecture based on fluidic matrix drive

  • Summary

  • Overview & objectives

  • Mechanical structure design

    • Functional modules

    • Realization of “N2 by 2N” fluidic matrix drive

    • Displacement sensor embedded actuator array assembly

    • Pressure sensor array mounting base

  • Electronic system

    • Functional block diagram of the electronic system

    • Displacement sensor array multiplexing

  • 5x5 cell array prototype

  • Summary


Outline of current section

Outline of Current Section

  • Basic idea

  • Background & context

  • Hardware of Digital Clay

  • Control of Digital Clay

  • Advantages and potential applications

Introduction to Digital Clay


Basic idea

Introduction to Digital Clay

Basic Idea

  • 3D human-machine haptic interface

    • Input / output using tangible 3D shape/surface

    • Computer controlled

    • Haptic/semi-haptic style

    • Can be edited / transferred digitally

Video

Haptic?

Sense of touch


Background context

Introduction to Digital Clay

Background & Context

  • Haptic manipulators

  • Tactile array

  • Haptic display interfaces


Hardware of digital clay

Introduction to Digital Clay

Hardware of Digital Clay

  • General structure

    • Formable crust

    • Formable body

      • Planar pin-rod array

  • Composition

    • Actuator array

    • Sensors array

    • Fluidics system

    • Control system

Actuator Array

Video

Fluidics System

On-board

Controller


Control structure

Introduction to Digital Clay

Sensor

Sensor

Sensor

Actuator

Actuator

Actuator

Cell System

Cell System

Cell System

Control Structure

  • Cell Level Control

  • Surface Level Control

  • User API

User AP I

User API

Surface Level Control

API

Interface

Surface Level Controller

Feedback Processor

Command Bus

Feedback Bus

Cell Level Control

Cell-Level Controller

Cell-Level Controller

Cell-Level Controller


Advantages and applications

Introduction to Digital Clay

Advantages and Applications

  • Advantages

    • Natural, direct, fast and efficient communication

    • Unleash the mind power of creation, perception and intuition

  • Applications

    • Engineering design & science research

    • Medical diagnosis

    • Vision Impaired assistance

    • Military & civil map

    • Art

    • Communication

    • Education, Entertainment, etc.

Video


Outline of current section1

Outline of Current Section

  • Overview & objectives

  • Cell level control

    • Control for solenoid valve based system

    • Control states, switching logic and user gesture interpretation

    • Experimental system & results

  • Displacement measurement

    • PWM speed control and displacement estimation

    • Non-contacting resistance displacement sensor

    • Displacement sensor embedded micro actuator

  • 1x5 prototype

  • Summary

Cell of Digital Clay


Overview and objectives

Cell of Digital Clay

Skin

K

x

F

b

Overview and Objectives

  • Overview

    • Elementary unit of Digital Clay

    • Mimics a point on a material surface

    • One dimensional actuation type

  • Challenges

    • Control:

      • Haptic effect compromised by on-off valves

      • User gesture interpretation without other help

      • Volume change using unidirectional force (push)

    • No suitable displacement sensor

    • Micro actuator suitable for massive production

  • Objectives

    • Control algorithm to mimic a point on a material surface

    • Sensing methods

    • Actuator


Cell level control i

Cell of Digital Clay

Ff (External force)

Pressure

12

Potentiometer

Pressure Source

Cylinder

10

Displacement

Pressure (PSI)

Solenoid Valves

8

Pressure Sensor

6

800

900

850

650

750

700

Time (milliseconds)

Drain Tank

Displacement

Pressure

Position Control

Pressure Sensor

Displacement

Pressure

Pressure Control

Cell Level Control (I)

  • Control for solenoid valve based hydraulic system

    • Testing system setup

    • Pressure surge caused by solenoid valve

    • Pressure signal filtering

    • Position control vs. pressure control


Cell level control ii

Cell of Digital Clay

External Force Ff

b

c

Fy

Edit mode

External Force Ff

Display mode

a

d

Ff > Fy

X0

X1

Actuator’s Displacement

Elastic state

Plastic state

Ff < Fy

a

Fp

b

e

Quickly remove finger or turn off the toggle switch

Holding finger for 2 second while the toggle switch is on

c

Fl

d

Shaping state

  • Ff -- External Force Acting on the Actuator

  • Fy -- The Virtual Yielding Force Limit

Feedback

Control state selection

Actuator’s Displacement

Control law generation

Control Law

Timer/ Trigger

PI control

Plant

Cell Level Control (II)

  • Control states, switching logic and user gesture interpretation


Cell level control iii

Cell of Digital Clay

Input Force (Pressure PSI)

12

Ff (External force)

11

10

9

j

f

k

b

c

Fy

g

i

Potentiometer

7

e

Pressure Source

Fl

d

Cylinder

h

5

4

Solenoid Valves

3

2

a

l

Pressure Sensor

1

0

5

10

15

20

25

30

-5

Actuation Displacement (mm)

Drain Tank

Cell Level Control (III)

  • Elastic state

  • Experimental system & results

  • Plastic state

  • Keep stationary

  • Shaping state

  • Exit shaping state


Where are we

Cell of Digital Clay

Where are we?

  • Overview & objectives

  • Cell level control

  • Displacement measurement

    • PWM speed control and displacement estimation

    • Non-contacting resistance displacement sensor

    • Displacement sensor embedded micro actuator

  • 1x5 prototype

  • Summary

  • Why is this topic important?

  • Sensor and actuator are critical

  • Huge number of sensors and actuators are needed

  • No suitable existing products are found


Displacement measurement i

Cell of Digital Clay

13 PSI

11 PSI

High Pressure Source

1 PSI

Solenoid Valves

Drain Tank

Pressure Sensors

Linear Actuator

Cylinder

Low Pressure Source

Measuring System

Potentiometer

Displacement Measurement (I)

  • PWM Speed Control and Displacement Estimation

    • Experimental system & preliminary test results

      • PWM Frequency <100 Hz:High Linearity; Bad haptic sense

      • PWM Frequency >150 Hz:Low linearity; Good haptic sense


Displacement measurement ii

Cell of Digital Clay

Displacement Measurement (II)

  • PWM Speed Control and Displacement Estimation

    • Analytic model used for curve fitting

  • Phase I

    Flow = 0

  • Phase II

  • Phase III

  • Phase IV

! Definitions of terms can be found in the thesis


Displacement measurement iii

Cell of Digital Clay

High Pressure Source

Solenoid Valves

Drain Tank

Pressure Sensors

External Force

Speed and Position Control Using PWM

70

14

Cylinder

Pressure across the Valve (Caused by Input Force)

60

12

50

10

Potentiometer

Low Pressure Source

40

8

Pressure across the Valve (PSI)

Cylinder Rod Displacement (mm)

30

6

20

4

Measured Displacement

Ideal Displacement (Dashed Line)

10

2

0

0

0

0

500

500

1000

1000

1500

1500

2000

2000

2500

2500

3000

3000

3500

3500

4000

4000

4500

4500

5000

5000

Time (millisecond)

Pressure

Sampling

Duty

Required

Speed

Duty Generation

One Step

Delay

PWM Generation

Driver

Position Estimation

Required

Position

Stop Signal

Position

Sampling

Recording

Plotting

Displacement Measurement (III)

  • PWM speed control and position estimation test

    • Test setup

    • Control structure

    • Test result

Video


Displacement measurement iv

Cell of Digital Clay

Goodness of fit:

SSE: 1.297

R-square: 0.9999

Cylinder Bore

Resistance Film

Cylinder Rod

Signal Out

Piston (graphite)

Proposed Sensor

LVDT

Uout

C1

Uin

Sensor DATA (mm)

y vs. x

70

Fitted curve

65

60

55

REFERENCE DATA (LVDT) (mm)

50

45

40

35

30

25

20

25

30

35

40

45

50

55

60

65

70

75

Displacement Measurement (IV)

  • Displacement Sensor Embedded Micro Actuator

  • Non-contacting Resistance Sensor

    • Resistance to displacement signal

    • Capacitor picks up the signal

  • Structure

    • Micro glass tube + graphite piston

    • Uniform thin film deposited

  • Advantages

    • Ultra-compact size

    • Low cost

    • Interchangeable with LVDT

    • Nonlinearity < 0.5%

    • Resolution Theoretically Infinity


Where are we1

Cell of Digital Clay

Where are we?

  • Overview & objectives

  • Cell level control

  • Displacement measurement

  • 1x5 prototype

  • Summary


1 x 5 cell array prototype of digital clay

Cell of Digital Clay

Return Pressure

Pressure

Signal

Low

Pressure

Valves

High

Pressure

1 x 5 Cell Array Prototype of Digital Clay

  • A line on a material surface

  • Structure Features

    • Micro Solenoid Valve

    • No Displacement Sensor

    • SLA10120 Base

  • Control

    • Direct control on each cell using proposed PWM method

Video


Summary

Cell of Digital Clay

Summary

  • Position control method is suitable for solenoid valve based hydraulic system

  • Proposed control states, switching logic and user gesture interpretation are effective for hydraulic system to mimic material mechanics properties with haptic senses

  • Novel displacement measurement methods suitable for large number and micro size hydraulic system are presented

    • PWM speed control and displacement estimation

    • Non-contacting resistance displacement sensor

    • Displacement sensor embedded micro actuator (patent in application)

  • 1x5 prototype gives one solution to realize the Digital Clay

  • Good experimental system & results are shown


Outline of current section2

Outline of Current Section

  • Overview & objectives

  • “N2 by 2N” fluidic matrix drive

  • Surface refresh methods for fluidic matrix drive

  • Control architecture based on fluidic matrix drive

  • Summary

Cell Array of Digital Clay


Overview and objectives1

Cell Array of Digital Clay

Overview and objectives

  • Overview

    • Forms the human-machine interactive tangible surface

    • Planar pin-rod array (bed of nails)

    • Huge number of identical components involved

    • Challenges and solutions

  • Objectives

    • Conceptual design of practical structure suitable to realize cell array that has huge number of cells

    • Control architecture suitable for large scale subsystem array

  • Practical structure at current stage of technology

  • One dimensional actuation

  • 2.5 D

  • Hardware

    • Raw material cost

    • Manufacturing

    • Structural simplicity

    • Fluidic Matrix Drive

  • Control

    • Control resource

    • Dynamic control resource allocation


N 2 by 2n fluidic matrix drive fmd i

Cell Array of Digital Clay

Hydraulic Actuator

Row Control Valve Array

Actuator

Control Adaptor

Row Control Valve Array

Column Control Valve Array

Low Pressure

High Pressure

High Pressure

Low Pressure

Column Valve Array

Pressure Source Selection Valve

High Pressure

Low Pressure

Pressure Source Selection Valve

High Pressure

Low Pressure

“N2 by 2N” Fluidic Matrix Drive (FMD) (I)

  • 2N (+ 1 or 2) control valves control an N by N actuator array (needs 2N2 valves usually )

  • Column and row matching style

  • Independently addresses every actuator

  • Greatly reduced the amount of valves and control resourse

    example. N=100, 2*1002 =20,000 >> 201

  • Relatively slow


N 2 by 2n fluidic matrix drive fmd ii

Cell Array of Digital Clay

“N2 by 2N” Fluidic Matrix Drive (FMD) (II)

  • Working principle of the control adapter

Control Adapter

Column Control Valve

Pressure Selection Valve

Row Control Valve

High Low

Control Pressure


Surface refresh methods for fmd i

Cell Array of Digital Clay

Control Adapter

Column Control Valve

Row Control Valve

Surface Refresh Methods for FMD (I)

  • Model of the FMD Node

Flow rate:

Actuator displacement:

  • δ1 and δ2 are the PWM duty cycles applied to the valves

  • k is a constant

  • PWM waves are of the same phase


Surface refresh methods for fmd ii

Cell Array of Digital Clay

Surface Refresh Methods for FMD (II)

  • Reducing the FMD node model

    • Keep row control valve only on or off (PWM duty cycle = 0% or 100%)


Surface refresh methods for fmd iii

Cell Array of Digital Clay

1st RRC

2nd RRC

1st RRC

2nd RRC

Surface Refresh Methods for FMD (III)

  • Matrix representation of surface refresh

    • Working surface matrix representation

    • Surface refresh

  • α and β are the PWM duty cycle vectors applied on the column and row control valve arrays


Surface refresh methods for fmd iv

Cell Array of Digital Clay

Surface Refresh Methods for FMD (IV)

  • One-time refresh method

    • Process

      • Fully open one row valve;

      • Control the column valve array until the actuators in that row reach the desired final position;

      • Close that row valve;

      • Open the next row valve and repeat step 2.

    • Advantage and disadvantages

      • Simple

      • Slow

      • Bad visual effect and haptic effect

In this example, actual total time taken is around 3.5 seconds


Surface refresh methods for fmd v

Cell Array of Digital Clay

Surface Refresh Methods for FMD (V)

  • Gradual refresh method

    • Process

      • Divide the desired final surface into several intermediate surfaces;

      • Use one-time refresh method to achieve each intermediate surfaces.

    • Advantage and disadvantages

      • Good visual effect and haptic effect

      • Relatively complicated

      • Slower

In this example, actual total time taken is around 5.5 seconds


Surface refresh methods for fmd vi

Cell Array of Digital Clay

Surface Refresh Methods for FMD (VI)

  • Gradual approximation refresh method

    • Process

      • Divide the desired final surface into several intermediate surfaces;

      • Decompose and translate intermediate surfaces into certain sub-surfaces;

      • Realize each sub-surface once a time;

      • When realizing each sub surface all the valves are activated at certain PWM duty cycle.

    • Advantage and disadvantages

      • Good visual effect and haptic effect

      • Most complicated

      • Very fast

      • Need further research

In this example, total time taken is around 1 second


Control architecture based on fmd i

Cell Array of Digital Clay

Cell Level Control

Surface Refresh Coordinator

Hot Area Processor

Memory

PWM Vector

PWM Vector

Cell Level Control

Valve Controller

Valve Controller

ID1+ PWM Duty1; ID2+ PWM Duty2; …

Control Valves

Actuator & Sensor

Valve Controller

Multiplexers & Feedback Processor

Valve Controller

ID Recognition

PWM Wave Generation

Valve Driver

Valve Driver

Valve Controller

Valve Array

Control Architecture Based on FMD (I)

  • Cell level control

    • Surface refresh coordinator

    • Dynamic control resource allocation

    • Hot area processor


Control architecture based on fmd

Cell Array of Digital Clay

Desired material property for each cell to simulate

Control Architecture Based on FMD

Desired actuator array’s displacement matrix and the speed to achieve the displacement

The matrix contains the information of user actions and intentions for each cell in the hot area

GUI

Desired [MP]

User API

CAD Model

Other User Inputs

[User Motion]

Desired [X] &[V]

Current [ X ], [ P ]

To compensate the surface discrepancy caused by the delayed refresh on the surface other than the hot area

  • Surface Level Control

    • Position matrix decomposition

    • Contact detection

    • Control source allocation

    • Aftermath compensation

Signal to tell surface refresh coordinator lower down its priority, and tell Hot area processor to work

Desired actuator array’s displacement matrix in the next surface refresh cycle

Current [ X ] & [ P ]

Hot areas’ locations, sizes, etc.

Desired [ X ]

Compensation matrix

[User Motion]

Contact Process information

Contact Process Signal

Multiplexers & Feedback Processor

  • Surface Refresh Coordinator

    • PWM vector generation

    • Compensate structural variation

Current [ X ]

Current actuator array’s displacement matrix and pressure matrix

PWM Vector

Valve Controllers

  • Hot Area Processor

    • Haptic reaction

    • PWM vector generation

    • Aftermath compensation

Current [ X ] & [ P ]

PWM Vector

Valve Controllers


Summary1

Cell Array of Digital Clay

Summary

  • “N2 by 2N” fluidic matrix drive is novel and has great benefits for large scale fluidic subsystem array. (Patent application)

    • Greatly reduces the control valves and control channels needed

    • Makes the cell array (with huge number of units) practical

    • Relatively slow speed maybe compensated using proper surface refresh method

  • Suitable surface refresh methods for fluidic matrix drive make it possible for the system using FMD to achieve smooth and fast surface refresh.

  • Carefully designed control architecture for FMD can both reduced hardware cost and computing resource.


Outline of current section3

Outline of Current Section

  • Overview & objectives

  • Mechanical structure design

    • Functional modules

    • Realization of “N2 by 2N” fluidic matrix drive

    • Displacement sensor embedded actuator array assembly

    • Pressure sensor array mounting base

  • Electronic system

    • Functional block diagram of the electronic system

    • Displacement sensor array multiplexing

  • 5x5 cell array prototype

  • Summary

Implementations of the Multi-cell System


Overview objectives

Implementations of the Multi-cell System

Overview & objectives

  • Practical structural implementation

  • Aims at N by N cell array

  • Challenges

  • Objectives

    • Design for manufacturing

      • Modular design

      • Structural simplicity

      • Design for mass production

    • Design for scalability

      • Structural expandable

      • Size and resolution scalable

    • Vertically modular

  • Large number of identical components

    • Material cost, fabrication cost, assemble cost

    • Manufacture and assemble difficulty

  • Large number of feedback measurements

    • Hardware cost

    • DAQ resource limitation


Mechanical structure design i

Implementations of the Multi-cell System

Mechanical Structure Design (I)

  • Functional Modules

    • Row control hydraulic board

    • Column control hydraulic board

    • Pressure sensor array assembly

    • Fluidic channel concentrating block

    • Actuator-sensor array assembly

Actuator-sensor Array Assembly

Row Control Valves

Column Control Valves

Fluidic Channel Concentrating Block

Pressure Sensor Array Assembly

Column Control Hydraulic Board

Row Control Hydraulic Board


Mechanical structure design ii

Implementations of the Multi-cell System

Input channel

Output channel

Input channel

Output channel

Working chamber

Column control valve

Membrane

Residue volume

Control chamber

Row control valve

Mechanical Structure Design (II)

  • Realization of “N2 by 2N” fluidic matrix drive

    • Design of the control adapter


Mechanical structure design iii

Implementations of the Multi-cell System

Retracting Pressure

Displacement Sensor

To Control Valves

Digital Switch

Multiplexer

Sealing Board

Return Pressure

Top Pressure Chamber

Conductive Epoxy

Sensor Embedded Cylinder

Conductive Epoxy

Bottom Plate

Tube Racks

Glass Tubes

Plugs prevent graphite paste from getting into the tubes

Graphite Paste

Mechanical Structure Design (III)

  • Displacement sensor embedded actuator array assembly


Mechanical structure design iv

Implementations of the Multi-cell System

Pressure Sensor

Leads

Top Metal Plate

Printed Circuit Board

Bottom Metal Plate

Branch Channel

Main Channel

Pressure Sensor

Leads

SLA Base

Printed Circuit Board

Branch Channel

Main Channel

Mechanical Structure Design (IV)

  • Pressure sensor array mounting base


Electronic system i

Implementations of the Multi-cell System

To Cell Level Control

Filter Array

Interfaces

Pressure Sensor Array

Multiplexer

Multiplexer Driving Circuit

Signal Conditioners

Multiplexer

Position Sensor Array

Multiplexer Driving Circuit

Valve Driver Array

Control Valve Array

Electronic System (I)

  • Functional block diagram of the electronic system


Electronic system ii

Implementations of the Multi-cell System

Cs

To A/D Converter

U

Excitation Voltage

Signal Conditioner

Vi

V’

Ii

R

Cgi

Ci

Vk

Ik

Resistive Film

Electronic System (II)

  • Displacement sensor array multiplexing

    • Simple multiplexing scheme


Electronic system iii

Implementations of the Multi-cell System

4

1000 Sensors

3.5

||U|| (V)

3

2.5

100 Sensors

2

10 Sensors

1.5

1

Without Crosstalk

0.5

0

0

1

2

3

4

5

6

7

8

9

||Vk|| (V)

C1 = 18pf, C2 = 30pf, Cs = 0.3 pf, R = 1M

Active sensor output: 0 - 10 volt

Inactive channels’ outputs: 10 volt

Electronic System (III)

  • Displacement sensor array multiplexing

    • Simple multiplexing scheme results


Electronic system iv

Implementations of the Multi-cell System

Excitation Voltage

Rg

To A/D Converter

Cs

U

Signal Conditioner

Vi

V’

Ii

R

Cgi

Ci

Vk

Ik

Resistive Film

Electronic System (IV)

  • Displacement sensor array multiplexing

    • Multiplexing scheme using grounding resistor


Electronic system v

Implementations of the Multi-cell System

40

35

Working Range

||U|| (millivolt)

30

25

20

1000 Sensors

100 Sensors

15

10 Sensors

Without Crosstalk

Rg = 20K 

Active sensor output: 0 - 10 volt

Inactive channels’ outputs: 10 volt

10

10

||Vk|| (Volt)

5

0

0

1

2

3

4

5

6

7

8

9

Electronic System (V)

  • Displacement sensor array multiplexing

    • Results of multiplexing scheme using grounding resistor


Electronic system vi

Implementations of the Multi-cell System

To A/D Converter

Signal Conditioner

Electronic System (VI)

  • Displacement sensor array multiplexing

    • Other multiplexing schemes

      • Numerically compensate

      • Two Digital Switches


5x5 cell array prototype

Implementations of the Multi-cell System

Column Control

Row Control

To ADC

Signal Conditioner

Signal Conditioner

Signal Conditioner

5x5 Cell Array Prototype

  • Designed and controlled using proposed solutions

  • Key Features

    • Stereolithography Technology

    • 5 x 5 actuators in a linear pattern

    • Grid size (center to center) is 5mm

    • Hydraulic Matrix Drive

    • Non contacting resistive sensors and modified pressure sensors

    • Reduced control signals for multiplexers

    • Controlled by RT Linux on a host PC


Summary2

Implementations of the Multi-cell System

Summary

  • Vertically modular design reduces the complexity of fabrication and assembly, improves the reliability and convenience for maintain, and suitable for mass production.

  • Successfully Designed FMD control adapter realized the concept of FMD

  • Displacement sensor embedded actuator array assembly makes fabrication of large number actuator-sensor array become simple and fast.

  • Pressure sensor array mounting technology reduces the cost and makes the multi-cell system expandable.

  • Carefully design electronic system can reduce the complexity of the control hardware, amount of components and improve the feasibility of realizing the Digital Clay.

  • Displacement sensor array multiplexing using grounding resistor is a simple but effective way to realize the large scale multiplexing.

  • 5x5 cell array prototype is designed under the guidelines suitable for N by N cell array, and can be expanded to larger size array. Test results preliminarily validated the design and control methods presented.


Conclusions i

Conclusions (I)

  • System development

    • Cell level control architecture and realization

      • Haptic control for solenoid valve based hydraulic system (Position control, shaping state, user gesture interpretation)

    • Surface refresh methods for FMD

    • Surface level control architecture based on the FMD

    • Vertical modular design for multi-cell system

  • Key components design

    • Displacement sensor embedded micro actuator

    • Fluidic matrix drive for multi-cell system with huge number of cells

    • Pressure sensor array assembly


Conclusions ii

Conclusions (II)

  • Measurement technology

    • PWM displacement estimation

    • Non-contacting displacement sensing

    • Multiplexing technology for huge amount AC signals

    • Control signal reducing for sensor arrays


Conclusions iii

Conclusions (III)

  • Prototype development and manufacturing process

    • Single cell system prototype validates the cell level control for single cell system

    • 1x5 cell array prototype validates the PWM control method and the horizontal modular design

    • 10x10 cell array prototype validates the concept of FMD

    • 5x5 cell array prototype validates the N x N planar pin-rod Digital Clay structure and control

    • Micro displacement sensor – actuator array mass production process Key step to the success of Digital Clay realization

    • Pressure sensor array assemble process Key step to the success of Digital Clay realization

    • FMD realization using SLA technology Key step to the success of Digital Clay realization


Recommendations on future work

Recommendations on Future Work

  • Actuator and sensors

    • Current displacement sensor needs further comprehensive test

    • Further investigations on the assembly of the pressure sensors array

  • Micro valve for the Fluidic Matrix Drive

    • Embed MEMS valve into the cell array system using fluidic matrix drive

  • Refresh method for Fluidic Matrix Drive

    • Gradual approximation refresh method shows promising merits, but the matrix decomposition needs to be solved before implementation

  • Other general topics

    • Control architecture for “2 valves per cell” driving scheme

    • The manufacturing process to realize multi-cell array system


Questions answers

Questions & Answers


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