1_PENDAHULUAN FI365 SISTEM INSTRUMENTASI. Program Studi Fisika. Waslaluddin, dkk

(1)

1_PENDAHULUAN

Program Studi Fisika

FI365

FI365 –

–

– SISTEM INSTRUMENTASI

–

SISTEM INSTRUMENTASI

(2)

S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I ISI KULIAH

Definisi dan Terminologi

Prinsip Transduksi Fisika dan Kimia

Klasifikasi Sensor

Perkembangan Sensor

F I 3 6 5 F I 3 6 5 F I 3 6 5 F I 3 6 5 S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I

1

(3)

S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I

DEFINISI DAN TERMINOLOGI

2

(4)

S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I DEFINISI

to sense : merasakan

Sensor

adalah suatu perangkat (device) atau

sistem (sensor system) yang dapat merasakan suatu besaran fisika, kimia atau biologi dan

merespon besaran tersebut dalam bentuk besaran fisika, kimia atau biologi lainnya atau

mengkonversi besaran yang dirasakan menjadi

3

mengkonversi besaran yang dirasakan menjadi besaran lainnya.

Sensor head

Transducer

adalah suatu perangkat (device)

dapat mengubah (to convert) suatu energi atau besaran fisika, kimia atau biologi ke bentuk energi atau besaran lainnya

(5)

S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I DEFINISI Mekanik Mekanik Radiasi Kimia Mekanik Mekanik Radiasi Kimia F I 3 6 5 F I 3 6 5 F I 3 6 5 F I 3 6 5 S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I

4

Magnetik Magnetik _Termal Elektrik Magnetik Magnetik _Termal Elektrik

(6)

Transduser: Sensor dan Aktuator

Sensor : Sebagai transduser input

misal : microphone, thermocouple, RTD, pitot tube dsb

Aktuator : Sebagai transduser output

misal : loud speaker, control valve, damper, motor listrik dsb

5

(7)

S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I DEFINISI Sistem

Kombinasi dua atau lebih elemen, subsistem atau bagian yang

diperlukan untuk menghasilkan suatu fungsi

Untuk berinteraksi dengan lingkungan (real world) suatu sistem

memerlukan

Sensor : perangkat input Aktuator : perangkat output

Pemroses : sinyal informasi dan pengetahuan

6

Sensor merespon dalam bentuk sinyal yang dapat diproses lebih lanjut seperti

(8)

S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I DEFINISI Sensor atau Sistem Sensor Sensor atau Sistem Sensor Variabel-variabel fisika, kimia atau

Sensor, sistem sensor atau transduser merupakan antar muka (interface) antara besaran-besaran fisika pada fenomena alam, proses, mesin, lingkungan dan sebagainya ke suatu sistem

pengukuran, monitoring dan pengontrolan

Variabel-variabel fisika, kimia atau F I 3 6 5 F I 3 6 5 F I 3 6 5 F I 3 6 5 S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I

7

kimia atau biologi kimia atau biologi

(umumnya besaran listrik seperti arus atau

(9)

S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I DEFINISI Measurement

The process of comparing an unknown quantity with a standard of

the same quantity or standard of two or more related quantities Measurement Science

the systematic study and organization of the methods by which

INFORMATION is gathered from the PHYSICAL world

8

(10)

S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I DEFINISI Instrument Engineering

the systematic design and manufacture of reliable, cost

effective measuring instrumentation that fulfills a given measurement specification F I 3 6 5 F I 3 6 5 F I 3 6 5 F I 3 6 5 S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I

9

(11)

S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I Intelligent Sensor Intelligent

Kemampuan untuk mengkombinasikan

A priori knowledge (available before experience) & Adaptive learning (from experience)

Intelligent sensor system

Suatu sistem sensor yang memiliki kemampuan menyimpan

informasi sebelumnya dan adaptasi menyesuaikan dengan keadaan yang saat ini dan akan datang

10

yang saat ini dan akan datang

Beberapa definisi yang ada

A sensor that is capable of modifying its internal behavior to optimize the collection of data from the external world [Whi97] Konsep adaptasi dan kompensasi adalah sentral filosofi sensor cerdas Suatu perangkat yang mengkombinasikan suatu elemen sensor dan

pemroses sinyal pada suatu IC tunggal [PY95a]

Sensor cerdas adalah suatu sensor yang memiliki fungsi yang diperlukan untuk menghasilkan representasi yang benar besaran yang dideteksi atau besaran yang dikontrol [1451.2][Fnk00]

(12)

Prinsip Sub-sistem dalam suatu Sistem Sensor Cerdas [BW96]

Elemen primer (primary sensing elements) Kontrol eksitasi

Amplifikasi

Pemfilteran analog Konversi data

Kompensasi

Pemrosesan informasi digital Pemrosesan komunikasi digital

11

(13)

Prinsip Sub-sistem dalam suatu Sistem Sensor Cerdas [BW96]

12

(14)

S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I E-nose F I 3 6 5 F I 3 6 5 F I 3 6 5 F I 3 6 5 S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I

13

(15)

PRINSIP TRANSDUKSI FISIKA

DAN KIMIA

14

(16)

Transduksi: Pengubahan dari satu energi ke energi lain

energi termal energi elektrik energi mekanik energi elektrik energi radiasi energi elektrik energi magnetik energi elektrik energi kimia energi elektrik

D I R E C T Radiasi F I 3 6 5 F I 3 6 5 F I 3 6 5 F I 3 6 5 S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I

15

C O M P L E X X

energi kimia energi mekanik energi elektrik energi mekanik energi termal

energi elektrik Mekanik Kimia Magnetik _Termal Elektrik

(17)

S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S

I

SINYAL DOMAIN ENERGI

Mekanik : L, A, V, v, ωωωω, a, m, F, P, Torsi, aliran, viskositas

Termal : Temp (T), Cp, aliran kalor, keadaan materi Elektrik : V, I, Q, R, L, C, E, ε. F I 3 6 5 F I 3 6 5 F I 3 6 5 F I 3 6 5 S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I

16

Magnetik : H, B, ΦΦΦΦ, χχχχ, µµµµ, dipol momen (µµµµ_m).

Radiasi : Warna, Int., T, R, A, refraktif indeks (n), koef. ekst.(k) Kimia : Komposisi (x_A), C, kec. reaksi (R), pH, humiditas

(18)

I

TRANSDUKSI KE PENGLIHATAN (E. RADIASI)

thermometers: temperature (T) panjang (L) barometers: tekanan udara (P) panjang (L) scales: berat/massa (m) sudut (θθθθ)

kelembaban: puntiran rambut (τ) sudut (θθθθ)

17

kelembaban: puntiran rambut (τ) sudut (θθθθ)

indicator dyes: konsentrasi kimia (C) warna

photo film: intensitas radiasi (I) kepekatan Ag (ρρρρ) speedometers: kecepatan (v) sudut (θθθθ)

(19)

TRANSDUKSI KE ELEKTRIK

Thermistor : temperature resistance Electrochemical : chemistry voltage

Photocurrent : light intensity current

Pyroelectric : thermal radiation voltage

18

Pyroelectric : thermal radiation voltage Humidity : humidity capacitance

Length (LVDT) : displacement inductance Microphone : sound pressure ……???

(20)

Physical effect: signal energy conversion

19

(21)

I

SENSE – THINK - ACT

m e a s transduce perception to electrical signal measure in volts, amps, ohms, henrys, farads, etc.

convert from signal to symbol SENSOR ADC F I 3 6 5 F I 3 6 5 F I 3 6 5 F I 3 6 5 S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I

20

s u r a n d signal to symbol

compute control action transduce signal to heat, displacement, illumination, etc convert from symbol to signal SENSOR ACTUATOR ADC DAC Transducer

(22)

PRINSIP TRANSDUKSI

Capacitance

V

q

C

=

21

21 ( )

b

a

d

A

C

o o

/

ln

2 π

ε

l

ε

=

l

(23)

PRINSIP TRANSDUKSI

( )

b

a

H

C

_o o

/

ln

2 π

ε

=

Contoh : Level sensor (physical)

ε

o,r , b, a, H h V F I 3 6 5 F I 3 6 5 F I 3 6 5 F I 3 6 5 S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I

22

22 h

C

V

ε

o,r , b, a, H constant

( ) (

b

a

[

H

h

)

h

]

C

=

π

ε

_o

−

+

ε

_r

/

ln

2

(24)

PRINSIP TRANSDUKSI

Contoh : Occupancy sensor (physical) _x _V

x F I 3 6 5 F I 3 6 5 F I 3 6 5 F I 3 6 5 S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I

23

23 x

C

_so

V

C_sg, C_og: constant

(25)

PRINSIP TRANSDUKSI

Resistance

( )

_V

_i

_R

A

T

R

=

ρ

l

=

.

A

l

24

24 (

)

A

R

A

R

∆

−

∆

+

∆

=

∆

=

l

ρ

,

(26)

PRINSIP TRANSDUKSI

Contoh : Level sensor (physical)

( )

R

i

V

A

T

R

=

ρ

l

=

.

h V F I 3 6 5 F I 3 6 5 F I 3 6 5 F I 3 6 5 S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I

25

25 h

d

R

V

h

(27)

PRINSIP TRANSDUKSI

Contoh : Force sensor (physical)

( )

_V

_i

_R

A

T

R

=

ρ

l

=

.

l

_F

E

σ

=

∆

=

F V F I 3 6 5 F I 3 6 5 F I 3 6 5 F I 3 6 5 S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I

26

26 l

l

V

R

V

a

R

a

E

ρ

σ

2

=

∆

=

l

F

σ

l

R

V

(28)

PRINSIP TRANSDUKSI

Contoh : Temperature sensor (physical)

( )

_V

_i

_R

A

T

R

=

ρ

l

=

.

T V bimetal F I 3 6 5 F I 3 6 5 F I 3 6 5 F I 3 6 5 S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I

27

27 (

)

[

]

V

a

R

T

2 1 2 1 2

1 l

l

ρ

α

=

−

+

=

T

α

l

R

V

2

l

1

l

bimetal

(29)

PRINSIP TRANSDUKSI

Contoh : Gas sensor (chem.) C R

C_CO F I 3 6 5 F I 3 6 5 F I 3 6 5 F I 3 6 5 S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I

28

28 t

w

A

R

qn

_e

.

1 l

l

σ

ρ

µ

σ

=

C

_CO

q

σ

R

t w

(30)

PRINSIP TRANSDUKSI

Contoh : Humidity sensor (chem.) %H2O Z

%H₂O _C 2, R2, C3, R3 constant F I 3 6 5 F I 3 6 5 F I 3 6 5 F I 3 6 5 S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I

29

29 %H

2

O

pore

C1, R1

Z

C

j

R

Z

=

₁

+

ω

(31)

KLASIFIKASI SENSOR

30

(32)

KLASIFIKASI SENSOR

Proprioception (Internal state) v.s. Exteroceptive (external state)

measure values internally to the system (robot), e.g.

battery level, wheel position, joint angle, etc,

observation of environments, objects

Active v.s. Passive F I 3 6 5 F I 3 6 5 F I 3 6 5 F I 3 6 5 S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I

31

Active v.s. Passive

emitting energy into the environment, e.g., radar, sonar passively receive energy to make observation, e.g.,

camera

Contact v.s. non-contact Visual v.s. non-visual

(33)

S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I Encoders, Potentiometers

measure angle of turn via change in resistance or by

counting optical pulses

Gyroscopes

measure rate of change of angles

Proprioceptive Sensors

32

measure rate of change of angles

fiber-optic (newer, better), magnetic (older)

Compass

measure which way is north

GPS

(34)

I

Classification of Sensors

• Stimulus : physical, chemical & biological measurand (energy)

• Transduction effects : Active (self-generating) vs Pasive (modulation) • Scale of measured properties : scale of measurands

• Sensing constraints : ways of measurement

33

• Field of applications : e.g. automotive, industrial, robotic, etc.

(35)

I

Stimulus

Mekanik Radiasi Kimia Magnetik Magnetik _Termal F I 3 6 5 F I 3 6 5 F I 3 6 5 F I 3 6 5 S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I S IS T E M I N S T R U M E N T A S I

34

Elektrik Sensor Sensor output signal measurand Sensor Sensor output signal measurand power supply